trap SIGSEGV, SIGBUS and SIGFPE by default, in addition to SIGILL (#58 )

motivation: print crash trace on segmentation faults and other common failures beyond illegal instructions changes: * include SIGSEGV, SIGBUS and SIGFPE in the default signals trapped * update and improve tests
Merge pull request #57 from Fabio1988/patch-1
2022-06-08 09:06:33 -07:00 · 2022-04-06 10:45:57 +09:00 · 2022-03-17 12:17:02 +01:00 · 2022-03-16 21:15:06 -07:00 · 2021-09-23 06:03:22 +09:00 · 2021-09-22 12:02:54 -07:00
51 changed files with 9955 additions and 79 deletions
@@ -2,3 +2,5 @@
 /.build
 /Packages
 /*.xcodeproj
+.swiftpm
+.*.sw[nop]
@@ -0,0 +1,3 @@
+Tomer Doron <tomer@apple.com> <tomer@apple.com>
+Tomer Doron <tomer@apple.com> <tomerd@apple.com>
+Tomer Doron <tomer@apple.com> <tomer.doron@gmail.com>
@@ -0,0 +1,13 @@
+# file options
+
+--swiftversion 5.0
+--exclude .build
+
+# format options
+
+--self insert
+--patternlet inline
+--stripunusedargs unnamed-only
+--ifdef no-indent
+
+# rules
@@ -0,0 +1,21 @@
+For the purpose of tracking copyright, this is the list of individuals and
+organizations who have contributed source code to SwiftLinuxBacktrace.
+
+For employees of an organization/company where the copyright of work done
+by employees of that company is held by the company itself, only the company
+needs to be listed here.
+
+## COPYRIGHT HOLDERS
+
+- Apple Inc. (all contributors with '@apple.com')
+
+### Contributors
+
+- Ian Partridge <i.partridge@uk.ibm.com>
+- Tanner <me@tanner.xyz>
+- Tomer Doron <tomer@apple.com>
+- Zsolt Váradi <vzsg@users.noreply.github.com>
+
+**Updating this list**
+
+Please do not edit this file manually. It is generated using `./scripts/generate_contributors_list.sh`. If a name is misspelled or appearing multiple times: add an entry in `./.mailmap`
@@ -0,0 +1,6 @@
+This product contains a derivation of "libbacktrace" from Ian Lance Taylor.
+
+ * LICENSE (BSD-3-Clause):
+   * https://github.com/ianlancetaylor/libbacktrace/blob/master/LICENSE
+ * HOMEPAGE:
+   * https://github.com/ianlancetaylor/libbacktrace
@@ -7,16 +7,18 @@ let package = Package(
    products: [
        .library(
            name: "Backtrace",
-            targets: ["Backtrace"]),
+            targets: ["Backtrace"]
+        ),
    ],
    dependencies: [],
    targets: [
-        .systemLibrary(name: "CBacktrace"),
-        .target(
-            name: "Backtrace",
-            dependencies: [.target(name: "CBacktrace")]),
-        .testTarget(
-            name: "BacktraceTests",
-            dependencies: ["Backtrace"])
+        .target(name: "Backtrace",
+                dependencies: ["CBacktrace"]),
+        .target(name: "CBacktrace",
+                dependencies: []),
+        .target(name: "Sample",
+                dependencies: ["Backtrace"]),
+        .testTarget(name: "BacktraceTests",
+                    dependencies: ["Backtrace"]),
    ]
 )
@@ -1,22 +0,0 @@
-// swift-tools-version:4.2
-
-import PackageDescription
-
-let package = Package(
-    name: "swift-backtrace",
-    products: [
-        .library(
-            name: "Backtrace",
-            targets: ["Backtrace"]),
-    ],
-    dependencies: [],
-    targets: [
-        .systemLibrary(name: "CBacktrace"),
-        .target(
-            name: "Backtrace",
-            dependencies: [.target(name: "CBacktrace")]),
-        .testTarget(
-            name: "BacktraceTests",
-            dependencies: ["Backtrace"])
-    ]
-)
@@ -2,11 +2,19 @@

 This Swift package provides support for automatically printing crash backtraces of Swift programs.

+The library is designed to fill a gap in backtraces support for Swift on non-Darwin platforms. 
+When this gap is closed at the language runtime level, this library will become redundant and be deprecated.
+
 ## Usage

-Add `https://github.com/ianpartridge/swift-backtrace.git` as a dependency in your `Package.swift`.
+When building web-services and daemons, direct usage of this library is discouraged. 
+Instead, use [swift-service-lifecycle](https://github.com/swift-server/swift-service-lifecycle) which helps manage the application lifecycle including setting up backtraces hooks when needed. 

-Then, in your `main.swift`, do:
+Add `https://github.com/swift-server/swift-backtrace.git` as a dependency in your `Package.swift`.
+
+### Crash backtraces
+
+In your `main.swift`, do:

 ```swift
 import Backtrace
@@ -15,12 +23,22 @@ import Backtrace
 Backtrace.install()
 ```

-Finally, make sure you build your application with debug symbols enabled:
+Finally, for Swift < 5.2, make sure you build your application with debug symbols enabled. Debug symbols are automatically included for Swift 5.2 and above.

 ```
 $ swift build -c release -Xswiftc -g
 ```

+When your app crashes, a stacktrace will be printed to `stderr`.
+
+## Security
+
+Please see [SECURITY.md](SECURITY.md) for details on the security process.
+
 ## Acknowledgements

-@weissi, for the code!
+Ian Partridge ([GitHub](https://github.com/ianpartridge/), [Twitter](https://twitter.com/alfa)) the original author of this package.
+
+Johannes Weiss ([GitHub](https://github.com/weissi), [Twitter](https://twitter.com/johannesweiss)) for the signal handling code.
+
+Saleem Abdulrasool ([GitHub](https://github.com/compnerd), [Twitter](https://twitter.com/compnerd)) for the Windows port.
@@ -0,0 +1,43 @@
+# Security
+
+This document specifies the security process for the Backtrace project.
+
+## Disclosures
+
+### Private Disclosure Process
+
+The Backtrace maintainers ask that known and suspected vulnerabilities be
+privately and responsibly disclosed by emailing
+[sswg-security-reports@forums.swift.org](mailto:sswg-security-reports@forums.swift.org)
+with the all the required detail.
+**Do not file a public issue.**
+
+#### When to report a vulnerability
+
+* You think you have discovered a potential security vulnerability in Backtrace.
+* You are unsure how a vulnerability affects Backtrace.
+
+#### What happens next?
+
+* A member of the team will acknowledge receipt of the report within 3
+  working days (United States). This may include a request for additional
+  information about reproducing the vulnerability.
+* We will privately inform the Swift Server Work Group ([SSWG][sswg]) of the
+  vulnerability within 10 days of the report as per their [security
+  guidelines][sswg-security].
+* Once we have identified a fix we may ask you to validate it. We aim to do this
+  within 30 days. In some cases this may not be possible, for example when the
+  vulnerability exists at the protocol level and the industry must coordinate on
+  the disclosure process.
+* If a CVE number is required, one will be requested from [MITRE][mitre]
+  providing you with full credit for the discovery.
+* We will decide on a planned release date and let you know when it is.
+* Prior to release, we will inform major dependents that a security-related
+  patch is impending.
+* Once the fix has been released we will publish a security advisory on GitHub
+  and in the Server → Security Updates category on the [Swift forums][swift-forums-sec].
+
+[sswg]: https://github.com/swift-server/sswg
+[sswg-security]: https://github.com/swift-server/sswg/blob/main/security/README.md
+[swift-forums-sec]: https://forums.swift.org/c/server/security-updates/
+[mitre]: https://cveform.mitre.org/
@@ -1,23 +1,92 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
 #if os(Linux)
-import Glibc
 import CBacktrace
+import Glibc
+
+typealias CBacktraceErrorCallback = @convention(c) (_ data: UnsafeMutableRawPointer?, _ msg: UnsafePointer<CChar>?, _ errnum: CInt) -> Void
+typealias CBacktraceFullCallback = @convention(c) (_ data: UnsafeMutableRawPointer?, _ pc: UInt, _ filename: UnsafePointer<CChar>?, _ lineno: CInt, _ function: UnsafePointer<CChar>?) -> CInt
+typealias CBacktraceSimpleCallback = @convention(c) (_ data: UnsafeMutableRawPointer?, _ pc: UInt) -> CInt
+typealias CBacktraceSyminfoCallback = @convention(c) (_ data: UnsafeMutableRawPointer?, _ pc: UInt, _ filename: UnsafePointer<CChar>?, _ symval: UInt, _ symsize: UInt) -> Void
+
+private let state = backtrace_create_state(nil, /* BACKTRACE_SUPPORTS_THREADS */ 1, nil, nil)
+
+private let fullCallback: CBacktraceFullCallback? = {
+    _, pc, filename, lineno, function in
+
+    var str = "0x"
+    str.append(String(pc, radix: 16))
+    if let function = function {
+        str.append(", ")
+        var fn = String(cString: function)
+        if fn.hasPrefix("$s") || fn.hasPrefix("$S") {
+            fn = _stdlib_demangleName(fn)
+        }
+        str.append(fn)
+    }
+    if let filename = filename {
+        str.append(" at ")
+        str.append(String(cString: filename))
+        str.append(":")
+        str.append(String(lineno))
+    }
+    str.append("\n")
+
+    str.withCString { ptr in
+        _ = withVaList([ptr]) { vaList in
+            vfprintf(stderr, "%s", vaList)
+        }
+    }
+    return 0
+}
+
+private let errorCallback: CBacktraceErrorCallback? = {
+    _, msg, errNo in
+    if let msg = msg {
+        _ = withVaList([msg, errNo]) { vaList in
+            vfprintf(stderr, "SwiftBacktrace ERROR: %s (errno: %d)\n", vaList)
+        }
+    }
+}
+
+private func printBacktrace(signal: CInt) {
+    _ = fputs("Received signal \(signal). Backtrace:\n", stderr)
+    backtrace_full(state, /* skip */ 0, fullCallback, errorCallback, nil)
+}

 public enum Backtrace {
+    /// Install the backtrace handler on default signals: `SIGILL`, `SIGSEGV`, `SIGBUS`, `SIGFPE`.
    public static func install() {
-        setupHandler(signal: SIGILL) { _ in
-            // this is all undefined behaviour, not allowed to malloc or call backtrace here...
-            let maxFrames = 50
-            let stackSymbols: UnsafeMutableBufferPointer<UnsafeMutableRawPointer?> = .allocate(capacity: maxFrames)
-            stackSymbols.initialize(repeating: nil)
-            let howMany = backtrace(stackSymbols.baseAddress!, CInt(maxFrames))
-            let ptr = backtrace_symbols(stackSymbols.baseAddress!, howMany)
-            let realAddresses = Array(UnsafeBufferPointer(start: ptr, count: Int(howMany))).compactMap { $0 }
-            realAddresses.forEach {
-                print(String(cString: $0))
+        Backtrace.install(signals: [SIGILL, SIGSEGV, SIGBUS, SIGFPE])
+    }
+
+    /// Install the backtrace handler when any of `signals` happen.
+    public static func install(signals: [CInt]) {
+        for signal in signals {
+            self.setupHandler(signal: signal) { signal in
+                printBacktrace(signal: signal)
+                raise(signal)
            }
        }
    }

+    @available(*, deprecated, message: "This method will be removed in the next major version.")
+    public static func print() {
+        backtrace_full(state, /* skip */ 0, fullCallback, errorCallback, nil)
+    }
+
    private static func setupHandler(signal: Int32, handler: @escaping @convention(c) (CInt) -> Void) {
        typealias sigaction_t = sigaction
        let sa_flags = CInt(SA_NODEFER) | CInt(bitPattern: CUnsignedInt(SA_RESETHAND))
@@ -30,9 +99,175 @@ public enum Backtrace {
        }
    }
 }
+
+#elseif os(Windows)
+#if swift(<5.4)
+#error("unsupported Swift version")
 #else
+@_implementationOnly import CRT
+@_implementationOnly import WinSDK
+#endif
+
 public enum Backtrace {
-    public static func install() { 
+    private static var MachineType: DWORD {
+        #if arch(arm)
+        DWORD(IMAGE_FILE_MACHINE_ARMNT)
+        #elseif arch(arm64)
+        DWORD(IMAGE_FILE_MACHINE_ARM64)
+        #elseif arch(i386)
+        DWORD(IMAGE_FILE_MACHINE_I386)
+        #elseif arch(x86_64)
+        DWORD(IMAGE_FILE_MACHINE_AMD64)
+        #else
+        #error("unsupported architecture")
+        #endif
+    }
+
+    @available(*, deprecated, message: "signal selection unavailable on Windows")
+    public static func install(signals: [CInt]) {
+        Backtrace.install()
+    }
+
+    public static func install() {
+        // Install a last-chance vectored exception handler to capture the error
+        // before the termination and report the stack trace.  It is unlikely
+        // that this will be recovered at this point by a SEH handler.
+        _ = AddVectoredExceptionHandler(0) { _ in
+            // NOTE: GetCurrentProcess does not increment the reference count on
+            // the process.  This handle should _not_ be closed upon completion.
+            let hProcess: HANDLE = GetCurrentProcess()
+
+            var cxr: CONTEXT = CONTEXT()
+            cxr.ContextFlags =
+                DWORD(CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_FLOATING_POINT)
+            RtlCaptureContext(&cxr)
+
+            _ = SymInitializeW(hProcess, nil, true)
+            _ = SymSetOptions(DWORD(SYMOPT_DEFERRED_LOADS | SYMOPT_LOAD_LINES | SYMOPT_UNDNAME))
+
+            var Frame: STACKFRAME64 = STACKFRAME64()
+            #if arch(arm)
+            Frame.AddrPC.Offset = cxr.Pc
+            Frame.AddrFrame.Offset = cxr.R11
+            Frame.AddrStack.Offset = cxr.Sp
+            #elseif arch(arm64)
+            Frame.AddrPC.Offset = cxr.Pc
+            Frame.AddrFrame.Offset = cxr.Fp
+            Frame.AddrStack.Offset = cxr.Sp
+            #elseif arch(i386)
+            Frame.AddrPC.Offset = cxr.Eip
+            Frame.AddrFrame.Offset = cxr.Ebp
+            Frame.AddrStack.Offset = cxr.Esp
+            #elseif arch(x86_64)
+            Frame.AddrPC.Offset = cxr.Rip
+            Frame.AddrFrame.Offset = cxr.Rbp
+            Frame.AddrStack.Offset = cxr.Rsp
+            #else
+            #error("unsupported architecture")
+            #endif
+            Frame.AddrPC.Mode = AddrModeFlat
+            Frame.AddrFrame.Mode = AddrModeFlat
+            Frame.AddrStack.Mode = AddrModeFlat
+
+            // Constant indicating the maximum symbol length that we expect
+            // during symbolication of the stack trace.
+            let kMaxSymbolLength: Int = 255
+
+            // Heap allocate the buffer as we need to account for the trailing
+            // storage that we need to provide.
+            let pSymbolBuffer: UnsafeMutableRawPointer =
+                UnsafeMutableRawPointer.allocate(byteCount: MemoryLayout<IMAGEHLP_SYMBOL64>.size + kMaxSymbolLength,
+                                                 alignment: 1)
+            defer { pSymbolBuffer.deallocate() }
+
+            let pSymbol: UnsafeMutablePointer<IMAGEHLP_SYMBOL64> =
+                pSymbolBuffer.bindMemory(to: IMAGEHLP_SYMBOL64.self,
+                                         capacity: 1)
+
+            let hThread: HANDLE = GetCurrentThread()
+            while StackWalk64(Backtrace.MachineType, hProcess, hThread,
+                              &Frame, &cxr, nil, SymFunctionTableAccess64,
+                              SymGetModuleBase64, nil) {
+                var qwModuleBase: DWORD64 =
+                    SymGetModuleBase64(hProcess, Frame.AddrPC.Offset)
+
+                let module: String = withUnsafeMutablePointer(to: &qwModuleBase) {
+                    $0.withMemoryRebound(to: HINSTANCE.self, capacity: 1) { hInstance in
+                        String(decoding: [WCHAR](unsafeUninitializedCapacity: Int(MAX_PATH + 1)) {
+                            $1 = Int(GetModuleFileNameW(hInstance.pointee,
+                                                        $0.baseAddress,
+                                                        DWORD($0.count)))
+                        }, as: UTF16.self)
+                    }
+                }
+
+                pSymbol.pointee.SizeOfStruct =
+                    DWORD(MemoryLayout<IMAGEHLP_SYMBOL64>.size)
+                pSymbol.pointee.MaxNameLength = DWORD(kMaxSymbolLength)
+                _ = SymGetSymFromAddr64(hProcess, Frame.AddrPC.Offset, nil,
+                                        pSymbol)
+
+                var symbol: String =
+                    withUnsafePointer(to: &pSymbol.pointee.Name) {
+                        String(cString: $0)
+                    }
+
+                // Undecorate Swift 3+ names only.  Earlier Swift decorations
+                // are unsupported.  Any MSVC name decoration has been
+                // unperformed during the DbgHelp operation through the use of
+                // the `SYMOPT_UNDNAME` option.
+                if symbol.hasPrefix("$s") || symbol.hasPrefix("$S") {
+                    symbol = _stdlib_demangleName(symbol)
+                }
+
+                var Displacement: DWORD = 0
+                var Line: IMAGEHLP_LINE64 = IMAGEHLP_LINE64()
+                Line.SizeOfStruct = DWORD(MemoryLayout<IMAGEHLP_LINE64>.size)
+                _ = SymGetLineFromAddr64(hProcess, Frame.AddrPC.Offset,
+                                         &Displacement, &Line)
+
+                var details: String = ""
+
+                if !symbol.isEmpty {
+                    // Truncate the module path to the filename.  The
+                    // `PathFindFileNameW` call will return the beginning of the
+                    // string if a path separator character is not found.
+                    if let pszModule = module.withCString(encodedAs: UTF16.self,
+                                                          PathFindFileNameW) {
+                        details.append(", \(String(decodingCString: pszModule, as: UTF16.self))!\(symbol)")
+                    }
+                }
+
+                if let szFileName = Line.FileName {
+                    details.append(" at \(String(cString: szFileName)):\(Line.LineNumber)")
+                }
+
+                _ = details.withCString { pszDetails in
+                    withVaList([Frame.AddrPC.Offset, pszDetails]) {
+                        #if arch(arm64) || arch(x86_64)
+                        vfprintf(stderr, "%#016x%s\n", $0)
+                        #else
+                        vfprintf(stderr, "%#08x%s\n", $0)
+                        #endif
+                    }
+                }
+            }
+
+            _ = SymCleanup(hProcess)
+
+            // We have not handled the exception, continue the search.
+            return EXCEPTION_CONTINUE_SEARCH
+        }
    }
 }
+
+#else
+public enum Backtrace {
+    public static func install() {}
+
+    public static func install(signals: [CInt]) {}
+
+    @available(*, deprecated, message: "This method will be removed in the next major version.")
+    public static func print() {}
+}
 #endif
@@ -0,0 +1,57 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+#if os(Linux)
+import Glibc
+#elseif os(Windows)
+#if swift(<5.4)
+#error("unsupported Swift version")
+#else
+@_implementationOnly
+import ucrt
+#endif
+#endif
+
+#if os(Linux) || os(Windows)
+@_silgen_name("swift_demangle")
+public
+func _stdlib_demangleImpl(
+    mangledName: UnsafePointer<CChar>?,
+    mangledNameLength: UInt,
+    outputBuffer: UnsafeMutablePointer<CChar>?,
+    outputBufferSize: UnsafeMutablePointer<UInt>?,
+    flags: UInt32
+) -> UnsafeMutablePointer<CChar>?
+
+internal func _stdlib_demangleName(_ mangledName: String) -> String {
+    return mangledName.utf8CString.withUnsafeBufferPointer {
+        mangledNameUTF8CStr in
+
+        let demangledNamePtr = _stdlib_demangleImpl(
+            mangledName: mangledNameUTF8CStr.baseAddress,
+            mangledNameLength: UInt(mangledNameUTF8CStr.count - 1),
+            outputBuffer: nil,
+            outputBufferSize: nil,
+            flags: 0
+        )
+
+        if let demangledNamePtr = demangledNamePtr {
+            let demangledName = String(cString: demangledNamePtr)
+            free(demangledNamePtr)
+            return demangledName
+        }
+        return mangledName
+    }
+}
+#endif
@@ -0,0 +1,29 @@
+# Copyright (C) 2012-2016 Free Software Foundation, Inc.
+
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+
+#     (1) Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer. 
+
+#     (2) Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in
+#     the documentation and/or other materials provided with the
+#     distribution.  
+    
+#     (3) The name of the author may not be used to
+#     endorse or promote products derived from this software without
+#     specific prior written permission.
+
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
@@ -0,0 +1,115 @@
+#ifdef __linux__
+/* atomic.c -- Support for atomic functions if not present.
+   Copyright (C) 2013-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <sys/types.h>
+
+#include "include/backtrace.h"
+#include "backtrace-supported.h"
+#include "internal.h"
+
+/* This file holds implementations of the atomic functions that are
+   used if the host compiler has the sync functions but not the atomic
+   functions, as is true of versions of GCC before 4.7.  */
+
+#if !defined (HAVE_ATOMIC_FUNCTIONS) && defined (HAVE_SYNC_FUNCTIONS)
+
+/* Do an atomic load of a pointer.  */
+
+void *
+backtrace_atomic_load_pointer (void *arg)
+{
+  void **pp;
+  void *p;
+
+  pp = (void **) arg;
+  p = *pp;
+  while (!__sync_bool_compare_and_swap (pp, p, p))
+    p = *pp;
+  return p;
+}
+
+/* Do an atomic load of an int.  */
+
+int
+backtrace_atomic_load_int (int *p)
+{
+  int i;
+
+  i = *p;
+  while (!__sync_bool_compare_and_swap (p, i, i))
+    i = *p;
+  return i;
+}
+
+/* Do an atomic store of a pointer.  */
+
+void
+backtrace_atomic_store_pointer (void *arg, void *p)
+{
+  void **pp;
+  void *old;
+
+  pp = (void **) arg;
+  old = *pp;
+  while (!__sync_bool_compare_and_swap (pp, old, p))
+    old = *pp;
+}
+
+/* Do an atomic store of a size_t value.  */
+
+void
+backtrace_atomic_store_size_t (size_t *p, size_t v)
+{
+  size_t old;
+
+  old = *p;
+  while (!__sync_bool_compare_and_swap (p, old, v))
+    old = *p;
+}
+
+/* Do an atomic store of a int value.  */
+
+void
+backtrace_atomic_store_int (int *p, int v)
+{
+  size_t old;
+
+  old = *p;
+  while (!__sync_bool_compare_and_swap (p, old, v))
+    old = *p;
+}
+
+#endif
+#endif
@@ -0,0 +1,68 @@
+#ifdef __linux__
+/* backtrace-supported.h.in -- Whether stack backtrace is supported.
+   Copyright (C) 2012-2016 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+/* The file backtrace-supported.h.in is used by configure to generate
+   the file backtrace-supported.h.  The file backtrace-supported.h may
+   be #include'd to see whether the backtrace library will be able to
+   get a backtrace and produce symbolic information.  */
+
+
+/* BACKTRACE_SUPPORTED will be #define'd as 1 if the backtrace library
+   should work, 0 if it will not.  Libraries may #include this to make
+   other arrangements.  */
+
+#define BACKTRACE_SUPPORTED 1
+
+/* BACKTRACE_USES_MALLOC will be #define'd as 1 if the backtrace
+   library will call malloc as it works, 0 if it will call mmap
+   instead.  This may be used to determine whether it is safe to call
+   the backtrace functions from a signal handler.  In general this
+   only applies to calls like backtrace and backtrace_pcinfo.  It does
+   not apply to backtrace_simple, which never calls malloc.  It does
+   not apply to backtrace_print, which always calls fprintf and
+   therefore malloc.  */
+
+#define BACKTRACE_USES_MALLOC 0
+
+/* BACKTRACE_SUPPORTS_THREADS will be #define'd as 1 if the backtrace
+   library is configured with threading support, 0 if not.  If this is
+   0, the threaded parameter to backtrace_create_state must be passed
+   as 0.  */
+
+#define BACKTRACE_SUPPORTS_THREADS 1
+
+/* BACKTRACE_SUPPORTS_DATA will be #defined'd as 1 if the backtrace_syminfo
+   will work for variables.  It will always work for functions.  */
+
+#define BACKTRACE_SUPPORTS_DATA 1
+#endif
@@ -0,0 +1,131 @@
+#ifdef __linux__
+/* backtrace.c -- Entry point for stack backtrace library.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <sys/types.h>
+
+#include "unwind.h"
+#include "include/backtrace.h"
+#include "internal.h"
+
+/* The main backtrace_full routine.  */
+
+/* Data passed through _Unwind_Backtrace.  */
+
+struct backtrace_data
+{
+  /* Number of frames to skip.  */
+  int skip;
+  /* Library state.  */
+  struct backtrace_state *state;
+  /* Callback routine.  */
+  backtrace_full_callback callback;
+  /* Error callback routine.  */
+  backtrace_error_callback error_callback;
+  /* Data to pass to callback routines.  */
+  void *data;
+  /* Value to return from backtrace_full.  */
+  int ret;
+  /* Whether there is any memory available.  */
+  int can_alloc;
+};
+
+/* Unwind library callback routine.  This is passed to
+   _Unwind_Backtrace.  */
+
+static _Unwind_Reason_Code
+unwind (struct _Unwind_Context *context, void *vdata)
+{
+  struct backtrace_data *bdata = (struct backtrace_data *) vdata;
+  uintptr_t pc;
+  int ip_before_insn = 0;
+
+#ifdef HAVE_GETIPINFO
+  pc = _Unwind_GetIPInfo (context, &ip_before_insn);
+#else
+  pc = _Unwind_GetIP (context);
+#endif
+
+  if (bdata->skip > 0)
+    {
+      --bdata->skip;
+      return _URC_NO_REASON;
+    }
+
+  if (!ip_before_insn)
+    --pc;
+
+  if (!bdata->can_alloc)
+    bdata->ret = bdata->callback (bdata->data, pc, NULL, 0, NULL);
+  else
+    bdata->ret = backtrace_pcinfo (bdata->state, pc, bdata->callback,
+				   bdata->error_callback, bdata->data);
+  if (bdata->ret != 0)
+    return _URC_END_OF_STACK;
+
+  return _URC_NO_REASON;
+}
+
+/* Get a stack backtrace.  */
+
+int
+backtrace_full (struct backtrace_state *state, int skip,
+		backtrace_full_callback callback,
+		backtrace_error_callback error_callback, void *data)
+{
+  struct backtrace_data bdata;
+  void *p;
+
+  bdata.skip = skip + 1;
+  bdata.state = state;
+  bdata.callback = callback;
+  bdata.error_callback = error_callback;
+  bdata.data = data;
+  bdata.ret = 0;
+
+  /* If we can't allocate any memory at all, don't try to produce
+     file/line information.  */
+  p = backtrace_alloc (state, 4096, NULL, NULL);
+  if (p == NULL)
+    bdata.can_alloc = 0;
+  else
+    {
+      backtrace_free (state, p, 4096, NULL, NULL);
+      bdata.can_alloc = 1;
+    }
+
+  _Unwind_Backtrace (unwind, &bdata);
+  return bdata.ret;
+}
+#endif
@@ -0,0 +1,152 @@
+#ifdef __linux__
+/* config.h.  Generated from config.h.in by configure.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* ELF size: 32 or 64 */
+#define BACKTRACE_ELF_SIZE 64
+
+/* XCOFF size: 32 or 64 */
+#define BACKTRACE_XCOFF_SIZE unused
+
+/* Define to 1 if you have the __atomic functions */
+#define HAVE_ATOMIC_FUNCTIONS 1
+
+/* Define to 1 if you have the `clock_gettime' function. */
+#define HAVE_CLOCK_GETTIME 1
+
+/* Define to 1 if you have the declaration of `strnlen', and to 0 if you
+   don't. */
+#define HAVE_DECL_STRNLEN 1
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define if dl_iterate_phdr is available. */
+#define HAVE_DL_ITERATE_PHDR 1
+
+/* Define to 1 if you have the fcntl function */
+#define HAVE_FCNTL 1
+
+/* Define if getexecname is available. */
+/* #undef HAVE_GETEXECNAME */
+
+/* Define if _Unwind_GetIPInfo is available. */
+#define HAVE_GETIPINFO 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the `z' library (-lz). */
+/* #undef HAVE_LIBZ */
+
+/* Define to 1 if you have the <link.h> header file. */
+#define HAVE_LINK_H 1
+
+/* Define if AIX loadquery is available. */
+/* #undef HAVE_LOADQUERY */
+
+/* Define to 1 if you have the `lstat' function. */
+#define HAVE_LSTAT 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if you have the `readlink' function. */
+#define HAVE_READLINK 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if you have the __sync functions */
+#define HAVE_SYNC_FUNCTIONS 1
+
+/* Define to 1 if you have the <sys/ldr.h> header file. */
+/* #undef HAVE_SYS_LDR_H */
+
+/* Define to 1 if you have the <sys/mman.h> header file. */
+#define HAVE_SYS_MMAN_H 1
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define if -lz is available. */
+/* #undef HAVE_ZLIB */
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#define LT_OBJDIR ".libs/"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT ""
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "package-unused"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "package-unused version-unused"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "libbacktrace"
+
+/* Define to the home page for this package. */
+#define PACKAGE_URL ""
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "version-unused"
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Enable extensions on AIX 3, Interix.  */
+#ifndef _ALL_SOURCE
+# define _ALL_SOURCE 1
+#endif
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE 1
+#endif
+/* Enable threading extensions on Solaris.  */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# define _POSIX_PTHREAD_SEMANTICS 1
+#endif
+/* Enable extensions on HP NonStop.  */
+#ifndef _TANDEM_SOURCE
+# define _TANDEM_SOURCE 1
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# define __EXTENSIONS__ 1
+#endif
+
+
+/* Number of bits in a file offset, on hosts where this is settable. */
+/* #undef _FILE_OFFSET_BITS */
+
+/* Define for large files, on AIX-style hosts. */
+/* #undef _LARGE_FILES */
+
+/* Define to 1 if on MINIX. */
+/* #undef _MINIX */
+
+/* Define to 2 if the system does not provide POSIX.1 features except with
+   this defined. */
+/* #undef _POSIX_1_SOURCE */
+
+/* Define to 1 if you need to in order for `stat' and other things to work. */
+/* #undef _POSIX_SOURCE */
+#endif
@@ -0,0 +1,203 @@
+#ifdef __linux__
+/* fileline.c -- Get file and line number information in a backtrace.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+#ifndef HAVE_GETEXECNAME
+#define getexecname() NULL
+#endif
+
+/* Initialize the fileline information from the executable.  Returns 1
+   on success, 0 on failure.  */
+
+static int
+fileline_initialize (struct backtrace_state *state,
+		     backtrace_error_callback error_callback, void *data)
+{
+  int failed;
+  fileline fileline_fn;
+  int pass;
+  int called_error_callback;
+  int descriptor;
+  const char *filename;
+  char buf[64];
+
+  if (!state->threaded)
+    failed = state->fileline_initialization_failed;
+  else
+    failed = backtrace_atomic_load_int (&state->fileline_initialization_failed);
+
+  if (failed)
+    {
+      error_callback (data, "failed to read executable information", -1);
+      return 0;
+    }
+
+  if (!state->threaded)
+    fileline_fn = state->fileline_fn;
+  else
+    fileline_fn = backtrace_atomic_load_pointer (&state->fileline_fn);
+  if (fileline_fn != NULL)
+    return 1;
+
+  /* We have not initialized the information.  Do it now.  */
+
+  descriptor = -1;
+  called_error_callback = 0;
+  for (pass = 0; pass < 5; ++pass)
+    {
+      int does_not_exist;
+
+      switch (pass)
+	{
+	case 0:
+	  filename = state->filename;
+	  break;
+	case 1:
+	  filename = "/proc/self/exe";
+	  break;
+	case 2:
+	  filename = "/proc/curproc/file";
+	  break;
+	case 3:
+	  filename = getexecname ();
+	  break;
+	case 4:
+	  snprintf (buf, sizeof (buf), "/proc/%ld/object/a.out",
+		    (long) getpid ());
+	  filename = buf;
+	  break;
+	default:
+	  abort ();
+	}
+
+      if (filename == NULL)
+	continue;
+
+      descriptor = backtrace_open (filename, error_callback, data,
+				   &does_not_exist);
+      if (descriptor < 0 && !does_not_exist)
+	{
+	  called_error_callback = 1;
+	  break;
+	}
+      if (descriptor >= 0)
+	break;
+    }
+
+  if (descriptor < 0)
+    {
+      if (!called_error_callback)
+	{
+	  if (state->filename != NULL)
+	    error_callback (data, state->filename, ENOENT);
+	  else
+	    error_callback (data,
+			    "libbacktrace could not find executable to open",
+			    0);
+	}
+      failed = 1;
+    }
+
+  if (!failed)
+    {
+      if (!backtrace_initialize (state, filename, descriptor, error_callback,
+				 data, &fileline_fn))
+	failed = 1;
+    }
+
+  if (failed)
+    {
+      if (!state->threaded)
+	state->fileline_initialization_failed = 1;
+      else
+	backtrace_atomic_store_int (&state->fileline_initialization_failed, 1);
+      return 0;
+    }
+
+  if (!state->threaded)
+    state->fileline_fn = fileline_fn;
+  else
+    {
+      backtrace_atomic_store_pointer (&state->fileline_fn, fileline_fn);
+
+      /* Note that if two threads initialize at once, one of the data
+	 sets may be leaked.  */
+    }
+
+  return 1;
+}
+
+/* Given a PC, find the file name, line number, and function name.  */
+
+int
+backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
+		  backtrace_full_callback callback,
+		  backtrace_error_callback error_callback, void *data)
+{
+  if (!fileline_initialize (state, error_callback, data))
+    return 0;
+
+  if (state->fileline_initialization_failed)
+    return 0;
+
+  return state->fileline_fn (state, pc, callback, error_callback, data);
+}
+
+/* Given a PC, find the symbol for it, and its value.  */
+
+int
+backtrace_syminfo (struct backtrace_state *state, uintptr_t pc,
+		   backtrace_syminfo_callback callback,
+		   backtrace_error_callback error_callback, void *data)
+{
+  if (!fileline_initialize (state, error_callback, data))
+    return 0;
+
+  if (state->fileline_initialization_failed)
+    return 0;
+
+  state->syminfo_fn (state, pc, callback, error_callback, data);
+  return 1;
+}
+#endif
@@ -0,0 +1,51 @@
+#ifdef __linux__
+/* btest.c -- Filename header for libbacktrace library
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#ifndef GCC_VERSION
+# define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
+#endif
+
+#if (GCC_VERSION < 2007)
+# define __attribute__(x)
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+#if defined(__MSDOS__) || defined(_WIN32) || defined(__OS2__) || defined (__CYGWIN__)
+# define IS_DIR_SEPARATOR(c) ((c) == '/' || (c) == '\\')
+#else
+# define IS_DIR_SEPARATOR(c) ((c) == '/')
+#endif
+#endif
@@ -0,0 +1,184 @@
+#ifdef __linux__
+/* backtrace.h -- Public header file for stack backtrace library.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#ifndef BACKTRACE_H
+#define BACKTRACE_H
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The backtrace state.  This struct is intentionally not defined in
+   the public interface.  */
+
+struct backtrace_state;
+
+/* The type of the error callback argument to backtrace functions.
+   This function, if not NULL, will be called for certain error cases.
+   The DATA argument is passed to the function that calls this one.
+   The MSG argument is an error message.  The ERRNUM argument, if
+   greater than 0, holds an errno value.  The MSG buffer may become
+   invalid after this function returns.
+
+   As a special case, the ERRNUM argument will be passed as -1 if no
+   debug info can be found for the executable, but the function
+   requires debug info (e.g., backtrace_full, backtrace_pcinfo).  The
+   MSG in this case will be something along the lines of "no debug
+   info".  Similarly, ERRNUM will be passed as -1 if there is no
+   symbol table, but the function requires a symbol table (e.g.,
+   backtrace_syminfo).  This may be used as a signal that some other
+   approach should be tried.  */
+
+typedef void (*backtrace_error_callback) (void *data, const char *msg,
+					  int errnum);
+
+/* Create state information for the backtrace routines.  This must be
+   called before any of the other routines, and its return value must
+   be passed to all of the other routines.  FILENAME is the path name
+   of the executable file; if it is NULL the library will try
+   system-specific path names.  If not NULL, FILENAME must point to a
+   permanent buffer.  If THREADED is non-zero the state may be
+   accessed by multiple threads simultaneously, and the library will
+   use appropriate atomic operations.  If THREADED is zero the state
+   may only be accessed by one thread at a time.  This returns a state
+   pointer on success, NULL on error.  If an error occurs, this will
+   call the ERROR_CALLBACK routine.  */
+
+extern struct backtrace_state *backtrace_create_state (
+    const char *filename, int threaded,
+    backtrace_error_callback error_callback, void *data);
+
+/* The type of the callback argument to the backtrace_full function.
+   DATA is the argument passed to backtrace_full.  PC is the program
+   counter.  FILENAME is the name of the file containing PC, or NULL
+   if not available.  LINENO is the line number in FILENAME containing
+   PC, or 0 if not available.  FUNCTION is the name of the function
+   containing PC, or NULL if not available.  This should return 0 to
+   continuing tracing.  The FILENAME and FUNCTION buffers may become
+   invalid after this function returns.  */
+
+typedef int (*backtrace_full_callback) (void *data, uintptr_t pc,
+					const char *filename, int lineno,
+					const char *function);
+
+/* Get a full stack backtrace.  SKIP is the number of frames to skip;
+   passing 0 will start the trace with the function calling
+   backtrace_full.  DATA is passed to the callback routine.  If any
+   call to CALLBACK returns a non-zero value, the stack backtrace
+   stops, and backtrace returns that value; this may be used to limit
+   the number of stack frames desired.  If all calls to CALLBACK
+   return 0, backtrace returns 0.  The backtrace_full function will
+   make at least one call to either CALLBACK or ERROR_CALLBACK.  This
+   function requires debug info for the executable.  */
+
+extern int backtrace_full (struct backtrace_state *state, int skip,
+			   backtrace_full_callback callback,
+			   backtrace_error_callback error_callback,
+			   void *data);
+
+/* The type of the callback argument to the backtrace_simple function.
+   DATA is the argument passed to simple_backtrace.  PC is the program
+   counter.  This should return 0 to continue tracing.  */
+
+typedef int (*backtrace_simple_callback) (void *data, uintptr_t pc);
+
+/* Get a simple backtrace.  SKIP is the number of frames to skip, as
+   in backtrace.  DATA is passed to the callback routine.  If any call
+   to CALLBACK returns a non-zero value, the stack backtrace stops,
+   and backtrace_simple returns that value.  Otherwise
+   backtrace_simple returns 0.  The backtrace_simple function will
+   make at least one call to either CALLBACK or ERROR_CALLBACK.  This
+   function does not require any debug info for the executable.  */
+
+extern int backtrace_simple (struct backtrace_state *state, int skip,
+			     backtrace_simple_callback callback,
+			     backtrace_error_callback error_callback,
+			     void *data);
+
+/* Print the current backtrace in a user readable format to a FILE.
+   SKIP is the number of frames to skip, as in backtrace_full.  Any
+   error messages are printed to stderr.  This function requires debug
+   info for the executable.  */
+
+extern void backtrace_print (struct backtrace_state *state, int skip, FILE *);
+
+/* Given PC, a program counter in the current program, call the
+   callback function with filename, line number, and function name
+   information.  This will normally call the callback function exactly
+   once.  However, if the PC happens to describe an inlined call, and
+   the debugging information contains the necessary information, then
+   this may call the callback function multiple times.  This will make
+   at least one call to either CALLBACK or ERROR_CALLBACK.  This
+   returns the first non-zero value returned by CALLBACK, or 0.  */
+
+extern int backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
+			     backtrace_full_callback callback,
+			     backtrace_error_callback error_callback,
+			     void *data);
+
+/* The type of the callback argument to backtrace_syminfo.  DATA and
+   PC are the arguments passed to backtrace_syminfo.  SYMNAME is the
+   name of the symbol for the corresponding code.  SYMVAL is the
+   value and SYMSIZE is the size of the symbol.  SYMNAME will be NULL
+   if no error occurred but the symbol could not be found.  */
+
+typedef void (*backtrace_syminfo_callback) (void *data, uintptr_t pc,
+					    const char *symname,
+					    uintptr_t symval,
+					    uintptr_t symsize);
+
+/* Given ADDR, an address or program counter in the current program,
+   call the callback information with the symbol name and value
+   describing the function or variable in which ADDR may be found.
+   This will call either CALLBACK or ERROR_CALLBACK exactly once.
+   This returns 1 on success, 0 on failure.  This function requires
+   the symbol table but does not require the debug info.  Note that if
+   the symbol table is present but ADDR could not be found in the
+   table, CALLBACK will be called with a NULL SYMNAME argument.
+   Returns 1 on success, 0 on error.  */
+
+extern int backtrace_syminfo (struct backtrace_state *state, uintptr_t addr,
+			      backtrace_syminfo_callback callback,
+			      backtrace_error_callback error_callback,
+			      void *data);
+
+#ifdef __cplusplus
+} /* End extern "C".  */
+#endif
+
+#endif
+#endif
@@ -0,0 +1,306 @@
+#ifdef __linux__
+/* internal.h -- Internal header file for stack backtrace library.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#ifndef BACKTRACE_INTERNAL_H
+#define BACKTRACE_INTERNAL_H
+
+/* We assume that <sys/types.h> and "include/backtrace.h" have already been
+   included.  */
+
+#ifndef GCC_VERSION
+# define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
+#endif
+
+#if (GCC_VERSION < 2007)
+# define __attribute__(x)
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+#ifndef ATTRIBUTE_MALLOC
+# if (GCC_VERSION >= 2096)
+#  define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+# else
+#  define ATTRIBUTE_MALLOC
+# endif
+#endif
+
+#ifndef HAVE_SYNC_FUNCTIONS
+
+/* Define out the sync functions.  These should never be called if
+   they are not available.  */
+
+#define __sync_bool_compare_and_swap(A, B, C) (abort(), 1)
+#define __sync_lock_test_and_set(A, B) (abort(), 0)
+#define __sync_lock_release(A) abort()
+
+#endif /* !defined (HAVE_SYNC_FUNCTIONS) */
+
+#ifdef HAVE_ATOMIC_FUNCTIONS
+
+/* We have the atomic builtin functions.  */
+
+#define backtrace_atomic_load_pointer(p) \
+    __atomic_load_n ((p), __ATOMIC_ACQUIRE)
+#define backtrace_atomic_load_int(p) \
+    __atomic_load_n ((p), __ATOMIC_ACQUIRE)
+#define backtrace_atomic_store_pointer(p, v) \
+    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
+#define backtrace_atomic_store_size_t(p, v) \
+    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
+#define backtrace_atomic_store_int(p, v) \
+    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
+
+#else /* !defined (HAVE_ATOMIC_FUNCTIONS) */
+#ifdef HAVE_SYNC_FUNCTIONS
+
+/* We have the sync functions but not the atomic functions.  Define
+   the atomic ones in terms of the sync ones.  */
+
+extern void *backtrace_atomic_load_pointer (void *);
+extern int backtrace_atomic_load_int (int *);
+extern void backtrace_atomic_store_pointer (void *, void *);
+extern void backtrace_atomic_store_size_t (size_t *, size_t);
+extern void backtrace_atomic_store_int (int *, int);
+
+#else /* !defined (HAVE_SYNC_FUNCTIONS) */
+
+/* We have neither the sync nor the atomic functions.  These will
+   never be called.  */
+
+#define backtrace_atomic_load_pointer(p) (abort(), (void *) NULL)
+#define backtrace_atomic_load_int(p) (abort(), 0)
+#define backtrace_atomic_store_pointer(p, v) abort()
+#define backtrace_atomic_store_size_t(p, v) abort()
+#define backtrace_atomic_store_int(p, v) abort()
+
+#endif /* !defined (HAVE_SYNC_FUNCTIONS) */
+#endif /* !defined (HAVE_ATOMIC_FUNCTIONS) */
+
+/* The type of the function that collects file/line information.  This
+   is like backtrace_pcinfo.  */
+
+typedef int (*fileline) (struct backtrace_state *state, uintptr_t pc,
+			 backtrace_full_callback callback,
+			 backtrace_error_callback error_callback, void *data);
+
+/* The type of the function that collects symbol information.  This is
+   like backtrace_syminfo.  */
+
+typedef void (*syminfo) (struct backtrace_state *state, uintptr_t pc,
+			 backtrace_syminfo_callback callback,
+			 backtrace_error_callback error_callback, void *data);
+
+/* What the backtrace state pointer points to.  */
+
+struct backtrace_state
+{
+  /* The name of the executable.  */
+  const char *filename;
+  /* Non-zero if threaded.  */
+  int threaded;
+  /* The master lock for fileline_fn, fileline_data, syminfo_fn,
+     syminfo_data, fileline_initialization_failed and everything the
+     data pointers point to.  */
+  void *lock;
+  /* The function that returns file/line information.  */
+  fileline fileline_fn;
+  /* The data to pass to FILELINE_FN.  */
+  void *fileline_data;
+  /* The function that returns symbol information.  */
+  syminfo syminfo_fn;
+  /* The data to pass to SYMINFO_FN.  */
+  void *syminfo_data;
+  /* Whether initializing the file/line information failed.  */
+  int fileline_initialization_failed;
+  /* The lock for the freelist.  */
+  int lock_alloc;
+  /* The freelist when using mmap.  */
+  struct backtrace_freelist_struct *freelist;
+};
+
+/* Open a file for reading.  Returns -1 on error.  If DOES_NOT_EXIST
+   is not NULL, *DOES_NOT_EXIST will be set to 0 normally and set to 1
+   if the file does not exist.  If the file does not exist and
+   DOES_NOT_EXIST is not NULL, the function will return -1 and will
+   not call ERROR_CALLBACK.  On other errors, or if DOES_NOT_EXIST is
+   NULL, the function will call ERROR_CALLBACK before returning.  */
+extern int backtrace_open (const char *filename,
+			   backtrace_error_callback error_callback,
+			   void *data,
+			   int *does_not_exist);
+
+/* A view of the contents of a file.  This supports mmap when
+   available.  A view will remain in memory even after backtrace_close
+   is called on the file descriptor from which the view was
+   obtained.  */
+
+struct backtrace_view
+{
+  /* The data that the caller requested.  */
+  const void *data;
+  /* The base of the view.  */
+  void *base;
+  /* The total length of the view.  */
+  size_t len;
+};
+
+/* Create a view of SIZE bytes from DESCRIPTOR at OFFSET.  Store the
+   result in *VIEW.  Returns 1 on success, 0 on error.  */
+extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
+			       off_t offset, size_t size,
+			       backtrace_error_callback error_callback,
+			       void *data, struct backtrace_view *view);
+
+/* Release a view created by backtrace_get_view.  */
+extern void backtrace_release_view (struct backtrace_state *state,
+				    struct backtrace_view *view,
+				    backtrace_error_callback error_callback,
+				    void *data);
+
+/* Close a file opened by backtrace_open.  Returns 1 on success, 0 on
+   error.  */
+
+extern int backtrace_close (int descriptor,
+			    backtrace_error_callback error_callback,
+			    void *data);
+
+/* Sort without using memory.  */
+
+extern void backtrace_qsort (void *base, size_t count, size_t size,
+			     int (*compar) (const void *, const void *));
+
+/* Allocate memory.  This is like malloc.  If ERROR_CALLBACK is NULL,
+   this does not report an error, it just returns NULL.  */
+
+extern void *backtrace_alloc (struct backtrace_state *state, size_t size,
+			      backtrace_error_callback error_callback,
+			      void *data) ATTRIBUTE_MALLOC;
+
+/* Free memory allocated by backtrace_alloc.  If ERROR_CALLBACK is
+   NULL, this does not report an error.  */
+
+extern void backtrace_free (struct backtrace_state *state, void *mem,
+			    size_t size,
+			    backtrace_error_callback error_callback,
+			    void *data);
+
+/* A growable vector of some struct.  This is used for more efficient
+   allocation when we don't know the final size of some group of data
+   that we want to represent as an array.  */
+
+struct backtrace_vector
+{
+  /* The base of the vector.  */
+  void *base;
+  /* The number of bytes in the vector.  */
+  size_t size;
+  /* The number of bytes available at the current allocation.  */
+  size_t alc;
+};
+
+/* Grow VEC by SIZE bytes.  Return a pointer to the newly allocated
+   bytes.  Note that this may move the entire vector to a new memory
+   location.  Returns NULL on failure.  */
+
+extern void *backtrace_vector_grow (struct backtrace_state *state, size_t size,
+				    backtrace_error_callback error_callback,
+				    void *data,
+				    struct backtrace_vector *vec);
+
+/* Finish the current allocation on VEC.  Prepare to start a new
+   allocation.  The finished allocation will never be freed.  Returns
+   a pointer to the base of the finished entries, or NULL on
+   failure.  */
+
+extern void* backtrace_vector_finish (struct backtrace_state *state,
+				      struct backtrace_vector *vec,
+				      backtrace_error_callback error_callback,
+				      void *data);
+
+/* Release any extra space allocated for VEC.  This may change
+   VEC->base.  Returns 1 on success, 0 on failure.  */
+
+extern int backtrace_vector_release (struct backtrace_state *state,
+				     struct backtrace_vector *vec,
+				     backtrace_error_callback error_callback,
+				     void *data);
+
+/* Read initial debug data from a descriptor, and set the
+   fileline_data, syminfo_fn, and syminfo_data fields of STATE.
+   Return the fileln_fn field in *FILELN_FN--this is done this way so
+   that the synchronization code is only implemented once.  This is
+   called after the descriptor has first been opened.  It will close
+   the descriptor if it is no longer needed.  Returns 1 on success, 0
+   on error.  There will be multiple implementations of this function,
+   for different file formats.  Each system will compile the
+   appropriate one.  */
+
+extern int backtrace_initialize (struct backtrace_state *state,
+				 const char *filename,
+				 int descriptor,
+				 backtrace_error_callback error_callback,
+				 void *data,
+				 fileline *fileline_fn);
+
+/* Add file/line information for a DWARF module.  */
+
+extern int backtrace_dwarf_add (struct backtrace_state *state,
+				uintptr_t base_address,
+				const unsigned char* dwarf_info,
+				size_t dwarf_info_size,
+				const unsigned char *dwarf_line,
+				size_t dwarf_line_size,
+				const unsigned char *dwarf_abbrev,
+				size_t dwarf_abbrev_size,
+				const unsigned char *dwarf_ranges,
+				size_t dwarf_range_size,
+				const unsigned char *dwarf_str,
+				size_t dwarf_str_size,
+				int is_bigendian,
+				backtrace_error_callback error_callback,
+				void *data, fileline *fileline_fn);
+
+/* A test-only hook for elf_uncompress_zdebug.  */
+
+extern int backtrace_uncompress_zdebug (struct backtrace_state *,
+					const unsigned char *compressed,
+					size_t compressed_size,
+					backtrace_error_callback, void *data,
+					unsigned char **uncompressed,
+					size_t *uncompressed_size);
+
+#endif
+#endif
@@ -0,0 +1,327 @@
+#ifdef __linux__
+/* mmap.c -- Memory allocation with mmap.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+/* Memory allocation on systems that provide anonymous mmap.  This
+   permits the backtrace functions to be invoked from a signal
+   handler, assuming that mmap is async-signal safe.  */
+
+#ifndef MAP_ANONYMOUS
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+/* A list of free memory blocks.  */
+
+struct backtrace_freelist_struct
+{
+  /* Next on list.  */
+  struct backtrace_freelist_struct *next;
+  /* Size of this block, including this structure.  */
+  size_t size;
+};
+
+/* Free memory allocated by backtrace_alloc.  */
+
+static void
+backtrace_free_locked (struct backtrace_state *state, void *addr, size_t size)
+{
+  /* Just leak small blocks.  We don't have to be perfect.  Don't put
+     more than 16 entries on the free list, to avoid wasting time
+     searching when allocating a block.  If we have more than 16
+     entries, leak the smallest entry.  */
+
+  if (size >= sizeof (struct backtrace_freelist_struct))
+    {
+      size_t c;
+      struct backtrace_freelist_struct **ppsmall;
+      struct backtrace_freelist_struct **pp;
+      struct backtrace_freelist_struct *p;
+
+      c = 0;
+      ppsmall = NULL;
+      for (pp = &state->freelist; *pp != NULL; pp = &(*pp)->next)
+	{
+	  if (ppsmall == NULL || (*pp)->size < (*ppsmall)->size)
+	    ppsmall = pp;
+	  ++c;
+	}
+      if (c >= 16)
+	{
+	  if (size <= (*ppsmall)->size)
+	    return;
+	  *ppsmall = (*ppsmall)->next;
+	}
+
+      p = (struct backtrace_freelist_struct *) addr;
+      p->next = state->freelist;
+      p->size = size;
+      state->freelist = p;
+    }
+}
+
+/* Allocate memory like malloc.  If ERROR_CALLBACK is NULL, don't
+   report an error.  */
+
+void *
+backtrace_alloc (struct backtrace_state *state,
+		 size_t size, backtrace_error_callback error_callback,
+		 void *data)
+{
+  void *ret;
+  int locked;
+  struct backtrace_freelist_struct **pp;
+  size_t pagesize;
+  size_t asksize;
+  void *page;
+
+  ret = NULL;
+
+  /* If we can acquire the lock, then see if there is space on the
+     free list.  If we can't acquire the lock, drop straight into
+     using mmap.  __sync_lock_test_and_set returns the old state of
+     the lock, so we have acquired it if it returns 0.  */
+
+  if (!state->threaded)
+    locked = 1;
+  else
+    locked = __sync_lock_test_and_set (&state->lock_alloc, 1) == 0;
+
+  if (locked)
+    {
+      for (pp = &state->freelist; *pp != NULL; pp = &(*pp)->next)
+	{
+	  if ((*pp)->size >= size)
+	    {
+	      struct backtrace_freelist_struct *p;
+
+	      p = *pp;
+	      *pp = p->next;
+
+	      /* Round for alignment; we assume that no type we care about
+		 is more than 8 bytes.  */
+	      size = (size + 7) & ~ (size_t) 7;
+	      if (size < p->size)
+		backtrace_free_locked (state, (char *) p + size,
+				       p->size - size);
+
+	      ret = (void *) p;
+
+	      break;
+	    }
+	}
+
+      if (state->threaded)
+	__sync_lock_release (&state->lock_alloc);
+    }
+
+  if (ret == NULL)
+    {
+      /* Allocate a new page.  */
+
+      pagesize = getpagesize ();
+      asksize = (size + pagesize - 1) & ~ (pagesize - 1);
+      page = mmap (NULL, asksize, PROT_READ | PROT_WRITE,
+		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+      if (page == MAP_FAILED)
+	{
+	  if (error_callback)
+	    error_callback (data, "mmap for alloc", errno);
+	}
+      else
+	{
+	  size = (size + 7) & ~ (size_t) 7;
+	  if (size < asksize)
+	    backtrace_free (state, (char *) page + size, asksize - size,
+			    error_callback, data);
+
+	  ret = page;
+	}
+    }
+
+  return ret;
+}
+
+/* Free memory allocated by backtrace_alloc.  */
+
+void
+backtrace_free (struct backtrace_state *state, void *addr, size_t size,
+		backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
+		void *data ATTRIBUTE_UNUSED)
+{
+  int locked;
+
+  /* If we are freeing a large aligned block, just release it back to
+     the system.  This case arises when growing a vector for a large
+     binary with lots of debug info.  Calling munmap here may cause us
+     to call mmap again if there is also a large shared library; we
+     just live with that.  */
+  if (size >= 16 * 4096)
+    {
+      size_t pagesize;
+
+      pagesize = getpagesize ();
+      if (((uintptr_t) addr & (pagesize - 1)) == 0
+	  && (size & (pagesize - 1)) == 0)
+	{
+	  /* If munmap fails for some reason, just add the block to
+	     the freelist.  */
+	  if (munmap (addr, size) == 0)
+	    return;
+	}
+    }
+
+  /* If we can acquire the lock, add the new space to the free list.
+     If we can't acquire the lock, just leak the memory.
+     __sync_lock_test_and_set returns the old state of the lock, so we
+     have acquired it if it returns 0.  */
+
+  if (!state->threaded)
+    locked = 1;
+  else
+    locked = __sync_lock_test_and_set (&state->lock_alloc, 1) == 0;
+
+  if (locked)
+    {
+      backtrace_free_locked (state, addr, size);
+
+      if (state->threaded)
+	__sync_lock_release (&state->lock_alloc);
+    }
+}
+
+/* Grow VEC by SIZE bytes.  */
+
+void *
+backtrace_vector_grow (struct backtrace_state *state,size_t size,
+		       backtrace_error_callback error_callback,
+		       void *data, struct backtrace_vector *vec)
+{
+  void *ret;
+
+  if (size > vec->alc)
+    {
+      size_t pagesize;
+      size_t alc;
+      void *base;
+
+      pagesize = getpagesize ();
+      alc = vec->size + size;
+      if (vec->size == 0)
+	alc = 16 * size;
+      else if (alc < pagesize)
+	{
+	  alc *= 2;
+	  if (alc > pagesize)
+	    alc = pagesize;
+	}
+      else
+	{
+	  alc *= 2;
+	  alc = (alc + pagesize - 1) & ~ (pagesize - 1);
+	}
+      base = backtrace_alloc (state, alc, error_callback, data);
+      if (base == NULL)
+	return NULL;
+      if (vec->base != NULL)
+	{
+	  memcpy (base, vec->base, vec->size);
+	  backtrace_free (state, vec->base, vec->size + vec->alc,
+			  error_callback, data);
+	}
+      vec->base = base;
+      vec->alc = alc - vec->size;
+    }
+
+  ret = (char *) vec->base + vec->size;
+  vec->size += size;
+  vec->alc -= size;
+  return ret;
+}
+
+/* Finish the current allocation on VEC.  */
+
+void *
+backtrace_vector_finish (
+  struct backtrace_state *state ATTRIBUTE_UNUSED,
+  struct backtrace_vector *vec,
+  backtrace_error_callback error_callback ATTRIBUTE_UNUSED,
+  void *data ATTRIBUTE_UNUSED)
+{
+  void *ret;
+
+  ret = vec->base;
+  vec->base = (char *) vec->base + vec->size;
+  vec->size = 0;
+  return ret;
+}
+
+/* Release any extra space allocated for VEC.  */
+
+int
+backtrace_vector_release (struct backtrace_state *state,
+			  struct backtrace_vector *vec,
+			  backtrace_error_callback error_callback,
+			  void *data)
+{
+  size_t size;
+  size_t alc;
+  size_t aligned;
+
+  /* Make sure that the block that we free is aligned on an 8-byte
+     boundary.  */
+  size = vec->size;
+  alc = vec->alc;
+  aligned = (size + 7) & ~ (size_t) 7;
+  alc -= aligned - size;
+
+  backtrace_free (state, (char *) vec->base + aligned, alc,
+		  error_callback, data);
+  vec->alc = 0;
+  return 1;
+}
+#endif
@@ -0,0 +1,102 @@
+#ifdef __linux__
+/* mmapio.c -- File views using mmap.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+/* This file implements file views and memory allocation when mmap is
+   available.  */
+
+/* Create a view of SIZE bytes from DESCRIPTOR at OFFSET.  */
+
+int
+backtrace_get_view (struct backtrace_state *state ATTRIBUTE_UNUSED,
+		    int descriptor, off_t offset, size_t size,
+		    backtrace_error_callback error_callback,
+		    void *data, struct backtrace_view *view)
+{
+  size_t pagesize;
+  unsigned int inpage;
+  off_t pageoff;
+  void *map;
+
+  pagesize = getpagesize ();
+  inpage = offset % pagesize;
+  pageoff = offset - inpage;
+
+  size += inpage;
+  size = (size + (pagesize - 1)) & ~ (pagesize - 1);
+
+  map = mmap (NULL, size, PROT_READ, MAP_PRIVATE, descriptor, pageoff);
+  if (map == MAP_FAILED)
+    {
+      error_callback (data, "mmap file i/o", errno);
+      return 0;
+    }
+
+  view->data = (char *) map + inpage;
+  view->base = map;
+  view->len = size;
+
+  return 1;
+}
+
+/* Release a view read by backtrace_get_view.  */
+
+void
+backtrace_release_view (struct backtrace_state *state ATTRIBUTE_UNUSED,
+			struct backtrace_view *view,
+			backtrace_error_callback error_callback,
+			void *data)
+{
+  union {
+    const void *cv;
+    void *v;
+  } const_cast;
+
+  const_cast.cv = view->base;
+  if (munmap (const_cast.v, view->len) < 0)
+    error_callback (data, "munmap", errno);
+}
+#endif
@@ -1,4 +0,0 @@
-module CBacktrace {
-    header "shim.h"
-    export *
-}
@@ -0,0 +1,102 @@
+#ifdef __linux__
+/* posix.c -- POSIX file I/O routines for the backtrace library.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+#ifndef O_BINARY
+#define O_BINARY 0
+#endif
+
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+
+#ifndef FD_CLOEXEC
+#define FD_CLOEXEC 1
+#endif
+
+/* Open a file for reading.  */
+
+int
+backtrace_open (const char *filename, backtrace_error_callback error_callback,
+		void *data, int *does_not_exist)
+{
+  int descriptor;
+
+  if (does_not_exist != NULL)
+    *does_not_exist = 0;
+
+  descriptor = open (filename, (int) (O_RDONLY | O_BINARY | O_CLOEXEC));
+  if (descriptor < 0)
+    {
+      if (does_not_exist != NULL && errno == ENOENT)
+	*does_not_exist = 1;
+      else
+	error_callback (data, filename, errno);
+      return -1;
+    }
+
+#ifdef HAVE_FCNTL
+  /* Set FD_CLOEXEC just in case the kernel does not support
+     O_CLOEXEC. It doesn't matter if this fails for some reason.
+     FIXME: At some point it should be safe to only do this if
+     O_CLOEXEC == 0.  */
+  fcntl (descriptor, F_SETFD, FD_CLOEXEC);
+#endif
+
+  return descriptor;
+}
+
+/* Close DESCRIPTOR.  */
+
+int
+backtrace_close (int descriptor, backtrace_error_callback error_callback,
+		 void *data)
+{
+  if (close (descriptor) < 0)
+    {
+      error_callback (data, "close", errno);
+      return 0;
+    }
+  return 1;
+}
+#endif
@@ -0,0 +1,94 @@
+#ifdef __linux__
+/* print.c -- Print the current backtrace.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+/* Passed to callbacks.  */
+
+struct print_data
+{
+  struct backtrace_state *state;
+  FILE *f;
+};
+
+/* Print one level of a backtrace.  */
+
+static int
+print_callback (void *data, uintptr_t pc, const char *filename, int lineno,
+		const char *function)
+{
+  struct print_data *pdata = (struct print_data *) data;
+
+  fprintf (pdata->f, "0x%lx %s\n\t%s:%d\n",
+	   (unsigned long) pc,
+	   function == NULL ? "???" : function,
+	   filename == NULL ? "???" : filename,
+	   lineno);
+  return 0;
+}
+
+/* Print errors to stderr.  */
+
+static void
+error_callback (void *data, const char *msg, int errnum)
+{
+  struct print_data *pdata = (struct print_data *) data;
+
+  if (pdata->state->filename != NULL)
+    fprintf (stderr, "%s: ", pdata->state->filename);
+  fprintf (stderr, "libbacktrace: %s", msg);
+  if (errnum > 0)
+    fprintf (stderr, ": %s", strerror (errnum));
+  fputc ('\n', stderr);
+}
+
+/* Print a backtrace.  */
+
+void
+backtrace_print (struct backtrace_state *state, int skip, FILE *f)
+{
+  struct print_data data;
+
+  data.state = state;
+  data.f = f;
+  backtrace_full (state, skip + 1, print_callback, error_callback,
+		  (void *) &data);
+}
+#endif
@@ -1,6 +0,0 @@
-#ifndef shim_h
-#define shim_h
-
-#include <execinfo.h>
-
-#endif /* shim_h */
@@ -0,0 +1,110 @@
+#ifdef __linux__
+/* simple.c -- The backtrace_simple function.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include "unwind.h"
+#include "include/backtrace.h"
+
+/* The simple_backtrace routine.  */
+
+/* Data passed through _Unwind_Backtrace.  */
+
+struct backtrace_simple_data
+{
+  /* Number of frames to skip.  */
+  int skip;
+  /* Library state.  */
+  struct backtrace_state *state;
+  /* Callback routine.  */
+  backtrace_simple_callback callback;
+  /* Error callback routine.  */
+  backtrace_error_callback error_callback;
+  /* Data to pass to callback routine.  */
+  void *data;
+  /* Value to return from backtrace.  */
+  int ret;
+};
+
+/* Unwind library callback routine.  This is passd to
+   _Unwind_Backtrace.  */
+
+static _Unwind_Reason_Code
+simple_unwind (struct _Unwind_Context *context, void *vdata)
+{
+  struct backtrace_simple_data *bdata = (struct backtrace_simple_data *) vdata;
+  uintptr_t pc;
+  int ip_before_insn = 0;
+
+#ifdef HAVE_GETIPINFO
+  pc = _Unwind_GetIPInfo (context, &ip_before_insn);
+#else
+  pc = _Unwind_GetIP (context);
+#endif
+
+  if (bdata->skip > 0)
+    {
+      --bdata->skip;
+      return _URC_NO_REASON;
+    }
+
+  if (!ip_before_insn)
+    --pc;
+
+  bdata->ret = bdata->callback (bdata->data, pc);
+
+  if (bdata->ret != 0)
+    return _URC_END_OF_STACK;
+
+  return _URC_NO_REASON;
+}
+
+/* Get a simple stack backtrace.  */
+
+int
+backtrace_simple (struct backtrace_state *state, int skip,
+		  backtrace_simple_callback callback,
+		  backtrace_error_callback error_callback, void *data)
+{
+  struct backtrace_simple_data bdata;
+
+  bdata.skip = skip + 1;
+  bdata.state = state;
+  bdata.callback = callback;
+  bdata.error_callback = error_callback;
+  bdata.data = data;
+  bdata.ret = 0;
+  _Unwind_Backtrace (simple_unwind, &bdata);
+  return bdata.ret;
+}
+#endif
@@ -0,0 +1,110 @@
+#ifdef __linux__
+/* sort.c -- Sort without allocating memory
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <stddef.h>
+#include <sys/types.h>
+
+#include "include/backtrace.h"
+#include "internal.h"
+
+/* The GNU glibc version of qsort allocates memory, which we must not
+   do if we are invoked by a signal handler.  So provide our own
+   sort.  */
+
+static void
+swap (char *a, char *b, size_t size)
+{
+  size_t i;
+
+  for (i = 0; i < size; i++, a++, b++)
+    {
+      char t;
+
+      t = *a;
+      *a = *b;
+      *b = t;
+    }
+}
+
+void
+backtrace_qsort (void *basearg, size_t count, size_t size,
+		 int (*compar) (const void *, const void *))
+{
+  char *base = (char *) basearg;
+  size_t i;
+  size_t mid;
+
+ tail_recurse:
+  if (count < 2)
+    return;
+
+  /* The symbol table and DWARF tables, which is all we use this
+     routine for, tend to be roughly sorted.  Pick the middle element
+     in the array as our pivot point, so that we are more likely to
+     cut the array in half for each recursion step.  */
+  swap (base, base + (count / 2) * size, size);
+
+  mid = 0;
+  for (i = 1; i < count; i++)
+    {
+      if ((*compar) (base, base + i * size) > 0)
+	{
+	  ++mid;
+	  if (i != mid)
+	    swap (base + mid * size, base + i * size, size);
+	}
+    }
+
+  if (mid > 0)
+    swap (base, base + mid * size, size);
+
+  /* Recurse with the smaller array, loop with the larger one.  That
+     ensures that our maximum stack depth is log count.  */
+  if (2 * mid < count)
+    {
+      backtrace_qsort (base, mid, size, compar);
+      base += (mid + 1) * size;
+      count -= mid + 1;
+      goto tail_recurse;
+    }
+  else
+    {
+      backtrace_qsort (base + (mid + 1) * size, count - (mid + 1),
+		       size, compar);
+      count = mid;
+      goto tail_recurse;
+    }
+}
+#endif
@@ -0,0 +1,74 @@
+#ifdef __linux__
+/* state.c -- Create the backtrace state.
+   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <string.h>
+#include <sys/types.h>
+
+#include "include/backtrace.h"
+#include "backtrace-supported.h"
+#include "internal.h"
+
+/* Create the backtrace state.  This will then be passed to all the
+   other routines.  */
+
+struct backtrace_state *
+backtrace_create_state (const char *filename, int threaded,
+			backtrace_error_callback error_callback,
+			void *data)
+{
+  struct backtrace_state init_state;
+  struct backtrace_state *state;
+
+#ifndef HAVE_SYNC_FUNCTIONS
+  if (threaded)
+    {
+      error_callback (data, "backtrace library does not support threads", 0);
+      return NULL;
+    }
+#endif
+
+  memset (&init_state, 0, sizeof init_state);
+  init_state.filename = filename;
+  init_state.threaded = threaded;
+
+  state = ((struct backtrace_state *)
+	   backtrace_alloc (&init_state, sizeof *state, error_callback, data));
+  if (state == NULL)
+    return NULL;
+  *state = init_state;
+
+  return state;
+}
+#endif
@@ -0,0 +1,40 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+import Backtrace
+#if canImport(Darwin)
+import Darwin
+#elseif os(Linux)
+import Glibc
+#endif
+
+Backtrace.install()
+
+func raiseSignal(_ signal: Int32) {
+    raise(signal)
+}
+
+let reason = CommandLine.arguments.count == 2 ? CommandLine.arguments[1] : "unknown"
+switch reason.uppercased() {
+case "SIGILL":
+    raiseSignal(SIGILL)
+case "SIGSEGV":
+    raiseSignal(SIGSEGV)
+case "SIGBUS":
+    raiseSignal(SIGBUS)
+case "SIGFPE":
+    raiseSignal(SIGFPE)
+default:
+    fatalError(reason)
+}
@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+//
+// BacktraceTests+XCTest.swift
+//
+import XCTest
+
+///
+/// NOTE: This file was generated by generate_linux_tests.rb
+///
+/// Do NOT edit this file directly as it will be regenerated automatically when needed.
+///
+
+extension BacktraceTests {
+    public static var allTests: [(String, (BacktraceTests) -> () throws -> Void)] {
+        return [
+            ("testFatalError", testFatalError),
+            ("testSIGILL", testSIGILL),
+            ("testSIGSEGV", testSIGSEGV),
+            ("testSIGBUS", testSIGBUS),
+            ("testSIGFPE", testSIGFPE),
+        ]
+    }
+}
@@ -1,15 +1,90 @@
-import XCTest
-@testable import Backtrace
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//

-final class BacktraceTests: XCTestCase {
-    func testExample() {
-        // This is an example of a functional test case.
-        // Use XCTAssert and related functions to verify your tests produce the correct
-        // results.
-        XCTAssert(true)
+import XCTest
+
+public final class BacktraceTests: XCTestCase {
+    func testFatalError() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let expectedError = UUID().uuidString
+        let stderr = try runSample(reason: expectedError)
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal 4. Backtrace:"))
+        XCTAssert(stderr.contains("Current stack trace:"), "expected stanard error to include backtrace")
+        XCTAssert(stderr.contains("Fatal error: \(expectedError)"), "expected stanard error to include error information")
    }

-    static var allTests = [
-        ("testExample", testExample),
-    ]
+    func testSIGILL() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGILL")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGILL). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGSEGV() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGSEGV")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGSEGV). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGBUS() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGBUS")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGBUS). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func testSIGFPE() throws {
+        #if !os(Linux)
+        try XCTSkipIf(true, "test is only supported on Linux")
+        #endif
+
+        let stderr = try runSample(reason: "SIGFPE")
+        print(stderr)
+
+        XCTAssert(stderr.contains("Received signal \(SIGFPE). Backtrace:"))
+        XCTAssert(stderr.contains("Sample.raiseSignal"))
+    }
+
+    func runSample(reason: String) throws -> String {
+        let pipe = Pipe()
+        let process = Process()
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/swift")
+        process.arguments = ["run", "Sample", reason]
+        process.standardError = pipe
+        try process.run()
+        process.waitUntilExit()
+        return String(data: pipe.fileHandleForReading.readDataToEndOfFile(), encoding: .utf8) ?? ""
+    }
 }
@@ -1,9 +0,0 @@
-import XCTest
-
-#if !canImport(ObjectiveC)
-public func allTests() -> [XCTestCaseEntry] {
-    return [
-        testCase(BacktraceTests.allTests),
-    ]
-}
-#endif
@@ -1,7 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+//
+// LinuxMain.swift
+//
 import XCTest

+///
+/// NOTE: This file was generated by generate_linux_tests.rb
+///
+/// Do NOT edit this file directly as it will be regenerated automatically when needed.
+///
+
+#if os(Linux) || os(FreeBSD)
 import BacktraceTests

-var tests = [XCTestCaseEntry]()
-tests += BacktraceTests.allTests()
-XCTMain(tests)
+XCTMain([
+    testCase(BacktraceTests.allTests),
+])
+#endif
@@ -0,0 +1,34 @@
+ARG swift_version=5.0
+ARG ubuntu_version=bionic
+ARG base_image=swift:$swift_version-$ubuntu_version
+FROM $base_image
+# needed to do again after FROM due to docker limitation
+ARG swift_version
+ARG ubuntu_version
+
+# set as UTF-8
+RUN apt-get update && apt-get install -y locales locales-all
+ENV LC_ALL en_US.UTF-8
+ENV LANG en_US.UTF-8
+ENV LANGUAGE en_US.UTF-8
+
+# dependencies
+RUN apt-get update && apt-get install -y wget
+RUN apt-get update && apt-get install -y lsof dnsutils netcat-openbsd net-tools curl jq # used by integration tests
+
+# ruby and jazzy for docs generation
+RUN apt-get update && apt-get install -y ruby ruby-dev libsqlite3-dev build-essential
+# jazzy no longer works on older version of ubuntu as ruby is too old.
+RUN if [ "${ubuntu_version}" = "focal" ] ; then echo "gem: --no-document" > ~/.gemrc ; fi
+RUN if [ "${ubuntu_version}" = "focal" ] ; then gem install jazzy ; fi
+
+# tools
+RUN mkdir -p $HOME/.tools
+RUN echo 'export PATH="$HOME/.tools:$PATH"' >> $HOME/.profile
+
+# swiftformat (until part of the toolchain)
+
+ARG swiftformat_version=0.44.6
+RUN git clone --branch $swiftformat_version --depth 1 https://github.com/nicklockwood/SwiftFormat $HOME/.tools/swift-format
+RUN cd $HOME/.tools/swift-format && swift build -c release
+RUN ln -s $HOME/.tools/swift-format/.build/release/swiftformat $HOME/.tools/swiftformat
@@ -0,0 +1,18 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:16.04-5.1
+    build:
+      args:
+        ubuntu_version: "xenial"
+        swift_version: "5.1"
+
+  test:
+    image: swift-linux-backtrace:16.04-5.1
+    environment:
+      - SANITIZER_ARG=--sanitize=thread
+
+  shell:
+    image: swift-linux-backtrace:16.04-5.1
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:18.04-5.0
+    build:
+      args:
+        ubuntu_version: "bionic"
+        swift_version: "5.0"
+
+  test:
+    image: swift-linux-backtrace:18.04-5.0
+
+  shell:
+    image: swift-linux-backtrace:18.04-5.0
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:18.04-5.2
+    build:
+      args:
+        ubuntu_version: "bionic"
+        swift_version: "5.2"
+
+  test:
+    image: swift-linux-backtrace:18.04-5.2
+
+  shell:
+    image: swift-linux-backtrace:18.04-5.2
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:18.04-5.3
+    build:
+      args:
+        ubuntu_version: "bionic"
+        swift_version: "5.3"
+
+  test:
+    image: swift-linux-backtrace:18.04-5.3
+
+  shell:
+    image: swift-linux-backtrace:18.04-5.3
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.4
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.4"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.4
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.4
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.5
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.5"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.5
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.5
@@ -0,0 +1,16 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.6
+    build:
+      args:
+        ubuntu_version: "focal"
+        swift_version: "5.6"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.6
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.6
@@ -0,0 +1,15 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-5.7
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-main-focal"
+
+  test:
+    image: swift-linux-backtrace:20.04-5.7
+
+  shell:
+    image: swift-linux-backtrace:20.04-5.7
@@ -0,0 +1,15 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:20.04-main
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-main-focal"
+
+  test:
+    image: swift-linux-backtrace:20.04-main
+
+  shell:
+    image: swift-linux-backtrace:20.04-main
@@ -0,0 +1,37 @@
+# this file is not designed to be run directly
+# instead, use the docker-compose.<os>.<swift> files
+# eg docker-compose -f docker/docker-compose.yaml -f docker/docker-compose.1804.50.yaml run test
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: swift-linux-backtrace:default
+    build:
+      context: .
+      dockerfile: Dockerfile
+
+  common: &common
+    image: swift-linux-backtrace:default
+    depends_on: [runtime-setup]
+    volumes:
+      - ~/.ssh:/root/.ssh
+      - ..:/code:z
+    working_dir: /code
+    cap_drop:
+      - CAP_NET_RAW
+      - CAP_NET_BIND_SERVICE
+
+  sanity:
+    <<: *common
+    command: /bin/bash -cl "./scripts/sanity.sh"
+
+  test:
+    <<: *common
+    command: /bin/bash -cl "swift test -c release -Xswiftc -g -Xswiftc -warnings-as-errors $${SANITIZER_ARG-}"
+
+  # util
+
+  shell:
+    <<: *common
+    entrypoint: /bin/bash -l
@@ -0,0 +1,39 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftLinuxBacktrace open source project
+##
+## Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+
+set -eu
+here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+contributors=$( cd "$here"/.. && git shortlog -es | cut -f2 | sed 's/^/- /' )
+
+cat > "$here/../CONTRIBUTORS.txt" <<- EOF
+	For the purpose of tracking copyright, this is the list of individuals and
+	organizations who have contributed source code to SwiftLinuxBacktrace.
+
+	For employees of an organization/company where the copyright of work done
+	by employees of that company is held by the company itself, only the company
+	needs to be listed here.
+
+	## COPYRIGHT HOLDERS
+
+	- Apple Inc. (all contributors with '@apple.com')
+
+	### Contributors
+
+	$contributors
+
+	**Updating this list**
+
+	Please do not edit this file manually. It is generated using \`./scripts/generate_contributors_list.sh\`. If a name is misspelled or appearing multiple times: add an entry in \`./.mailmap\`
+EOF
@@ -0,0 +1,231 @@
+#!/usr/bin/env ruby
+
+#
+#   process_test_files.rb
+#
+#   Copyright 2016 Tony Stone
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+#   Created by Tony Stone on 5/4/16.
+#
+require 'getoptlong'
+require 'fileutils'
+require 'pathname'
+
+include FileUtils
+
+#
+# This ruby script will auto generate LinuxMain.swift and the +XCTest.swift extension files for Swift Package Manager on Linux platforms.
+#
+# See https://github.com/apple/swift-corelibs-xctest/blob/master/Documentation/Linux.md
+#
+def header(fileName)
+  string = <<-eos
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+//
+// <FileName>
+//
+import XCTest
+
+///
+/// NOTE: This file was generated by generate_linux_tests.rb
+///
+/// Do NOT edit this file directly as it will be regenerated automatically when needed.
+///
+    eos
+
+  string
+    .sub('<FileName>', File.basename(fileName))
+    .sub('<Date>', Time.now.to_s)
+end
+
+def createExtensionFile(fileName, classes)
+  extensionFile = fileName.sub! '.swift', '+XCTest.swift'
+  print 'Creating file: ' + extensionFile + "\n"
+
+  File.open(extensionFile, 'w') do |file|
+    file.write header(extensionFile)
+    file.write "\n"
+
+    for classArray in classes
+      file.write 'extension ' + classArray[0] + " {\n"
+      file.write '    public static var allTests: [(String, (' + classArray[0] + ") -> () throws -> Void)] {\n"
+      file.write "        return [\n"
+
+      for funcName in classArray[1]
+        file.write '            ("' + funcName + '", ' + funcName + "),\n"
+      end
+
+      file.write "        ]\n"
+      file.write "    }\n"
+      file.write "}\n"
+    end
+  end
+end
+
+def createLinuxMain(testsDirectory, allTestSubDirectories, files)
+  fileName = testsDirectory + '/LinuxMain.swift'
+  print 'Creating file: ' + fileName + "\n"
+
+  File.open(fileName, 'w') do |file|
+    file.write header(fileName)
+    file.write "\n"
+
+    file.write "#if os(Linux) || os(FreeBSD)\n"
+    for testSubDirectory in allTestSubDirectories.sort { |x, y| x <=> y }
+      file.write 'import ' + testSubDirectory + "\n"
+    end
+    file.write "\n"
+    file.write "XCTMain([\n"
+
+    testCases = []
+    for classes in files
+      for classArray in classes
+        testCases << classArray[0]
+      end
+    end
+
+    for testCase in testCases.sort { |x, y| x <=> y }
+      file.write '    testCase(' + testCase + ".allTests),\n"
+    end
+    file.write "])\n"
+    file.write "#endif\n"
+  end
+end
+
+def parseSourceFile(fileName)
+  puts 'Parsing file:  ' + fileName + "\n"
+
+  classes = []
+  currentClass = nil
+  inIfLinux = false
+  inElse    = false
+  ignore    = false
+
+  #
+  # Read the file line by line
+  # and parse to find the class
+  # names and func names
+  #
+  File.readlines(fileName).each do |line|
+    if inIfLinux
+      if /\#else/.match(line)
+        inElse = true
+        ignore = true
+      else
+        if /\#end/.match(line)
+          inElse = false
+          inIfLinux = false
+          ignore = false
+        end
+        end
+    else
+      if /\#if[ \t]+os\(Linux\)/.match(line)
+        inIfLinux = true
+        ignore = false
+        end
+    end
+
+    next if ignore
+    # Match class or func
+    match = line[/class[ \t]+[a-zA-Z0-9_]*(?=[ \t]*:[ \t]*XCTestCase)|func[ \t]+test[a-zA-Z0-9_]*(?=[ \t]*\(\))/, 0]
+    if match
+
+      if match[/class/, 0] == 'class'
+        className = match.sub(/^class[ \t]+/, '')
+        #
+        # Create a new class / func structure
+        # and add it to the classes array.
+        #
+        currentClass = [className, []]
+        classes << currentClass
+      else # Must be a func
+        funcName = match.sub(/^func[ \t]+/, '')
+        #
+        # Add each func name the the class / func
+        # structure created above.
+        #
+        currentClass[1] << funcName
+      end
+    end
+  end
+  classes
+end
+
+#
+# Main routine
+#
+#
+
+testsDirectory = 'Tests'
+
+options = GetoptLong.new(['--tests-dir', GetoptLong::OPTIONAL_ARGUMENT])
+options.quiet = true
+
+begin
+  options.each do |option, value|
+    case option
+    when '--tests-dir'
+      testsDirectory = value
+    end
+  end
+rescue GetoptLong::InvalidOption
+end
+
+allTestSubDirectories = []
+allFiles = []
+
+Dir[testsDirectory + '/*'].each do |subDirectory|
+  next unless File.directory?(subDirectory)
+  directoryHasClasses = false
+  Dir[subDirectory + '/*Test{s,}.swift'].each do |fileName|
+    next unless File.file? fileName
+    fileClasses = parseSourceFile(fileName)
+
+    #
+    # If there are classes in the
+    # test source file, create an extension
+    # file for it.
+    #
+    next unless fileClasses.count > 0
+    createExtensionFile(fileName, fileClasses)
+    directoryHasClasses = true
+    allFiles << fileClasses
+  end
+
+  if directoryHasClasses
+    allTestSubDirectories << Pathname.new(subDirectory).split.last.to_s
+  end
+end
+
+#
+# Last step is the create a LinuxMain.swift file that
+# references all the classes and funcs in the source files.
+#
+if allFiles.count > 0
+  createLinuxMain(testsDirectory, allTestSubDirectories, allFiles)
+end
+# eof
@@ -0,0 +1,140 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftLinuxBacktrace open source project
+##
+## Copyright (c) 2017-2018 Apple Inc. and the SwiftLinuxBacktrace project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+
+set -eu
+
+here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+function replace_acceptable_years() {
+    # this needs to replace all acceptable forms with 'YEARS'
+    sed -e 's/2017-2018/YEARS/' -e 's/2019-2020/YEARS/' -e 's/2019/YEARS/' -e 's/2020/YEARS/'
+}
+
+printf "=> Checking linux tests... "
+FIRST_OUT="$(git status --porcelain)"
+ruby "$here/../scripts/generate_linux_tests.rb" > /dev/null
+SECOND_OUT="$(git status --porcelain)"
+if [[ "$FIRST_OUT" != "$SECOND_OUT" ]]; then
+  printf "\033[0;31mmissing changes!\033[0m\n"
+  git --no-pager diff
+  exit 1
+else
+  printf "\033[0;32mokay.\033[0m\n"
+fi
+
+printf "=> Checking format... "
+FIRST_OUT="$(git status --porcelain)"
+swiftformat . > /dev/null 2>&1
+SECOND_OUT="$(git status --porcelain)"
+if [[ "$FIRST_OUT" != "$SECOND_OUT" ]]; then
+  printf "\033[0;31mformatting issues!\033[0m\n"
+  git --no-pager diff
+  exit 1
+else
+  printf "\033[0;32mokay.\033[0m\n"
+fi
+
+printf "=> Checking license headers\n"
+tmp=$(mktemp /tmp/.swift-aws-lambda-sanity_XXXXXX)
+
+for language in swift-or-c bash dtrace; do
+  printf "   * $language... "
+  declare -a matching_files
+  declare -a exceptions
+  expections=( )
+  matching_files=( -name '*' )
+  case "$language" in
+      swift-or-c)
+        exceptions=( -name Package.swift -o -path './Sources/CBacktrace/*' )
+        matching_files=( -name '*.swift' -o -name '*.c' -o -name '*.h' )
+        cat > "$tmp" <<"EOF"
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftLinuxBacktrace open source project
+//
+// Copyright (c) YEARS Apple Inc. and the SwiftLinuxBacktrace project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+EOF
+        ;;
+      bash)
+        matching_files=( -name '*.sh' )
+        cat > "$tmp" <<"EOF"
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftLinuxBacktrace open source project
+##
+## Copyright (c) YEARS Apple Inc. and the SwiftLinuxBacktrace project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+EOF
+      ;;
+      dtrace)
+        matching_files=( -name '*.d' )
+        cat > "$tmp" <<"EOF"
+#!/usr/sbin/dtrace -q -s
+/*===----------------------------------------------------------------------===*
+ *
+ *  This source file is part of the SwiftLinuxBacktrace open source project
+ *
+ *  Copyright (c) YEARS Apple Inc. and the SwiftLinuxBacktrace project authors
+ *  Licensed under Apache License v2.0
+ *
+ *  See LICENSE.txt for license information
+ *  See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *===----------------------------------------------------------------------===*/
+EOF
+      ;;
+    *)
+      echo >&2 "ERROR: unknown language '$language'"
+      ;;
+  esac
+
+  expected_lines=$(cat "$tmp" | wc -l)
+  expected_sha=$(cat "$tmp" | shasum)
+
+  (
+    cd "$here/.."
+    find . \
+      \( \! -path './.build/*' -a \
+      \( "${matching_files[@]}" \) -a \
+      \( \! \( "${exceptions[@]}" \) \) \) | while read line; do
+      if [[ "$(cat "$line" | replace_acceptable_years | head -n $expected_lines | shasum)" != "$expected_sha" ]]; then
+        printf "\033[0;31mmissing headers in file '$line'!\033[0m\n"
+        diff -u <(cat "$line" | replace_acceptable_years | head -n $expected_lines) "$tmp"
+        exit 1
+      fi
+    done
+    printf "\033[0;32mokay.\033[0m\n"
+  )
+done
+
+rm "$tmp"
@@ -0,0 +1,90 @@
+#!/bin/bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the SwiftLinuxBacktrace open source project
+##
+## Copyright (c) 2019-2020 Apple Inc. and the SwiftLinuxBacktrace project authors
+## Licensed under Apache License v2.0
+##
+## See LICENSE.txt for license information
+## See CONTRIBUTORS.txt for the list of SwiftLinuxBacktrace project authors
+##
+## SPDX-License-Identifier: Apache-2.0
+##
+##===----------------------------------------------------------------------===##
+
+#!/bin/bash
+
+# This script creates a vendored copy of libbacktrace that is
+# suitable for building with the Swift Package Manager.
+#
+# Usage:
+#   1. Run this script in the package root. It will place
+#      a local copy of the libbacktrace sources in Sources/CBacktrace.
+#      Any prior contents of Sources/CBacktrace will be deleted.
+
+set -eou pipefail
+
+if [ "$(uname -s)" != "Linux" ]
+then
+    echo "This script may only be run on Linux"
+    exit 1
+fi
+
+HERE=$(pwd)
+DSTROOT=Sources/CBacktrace
+TMPDIR=$(mktemp -d /tmp/.workingXXXXXX)
+SRCROOT="${TMPDIR}/src/libbacktrace"
+
+echo "REMOVING any previously-vendored libbacktrace code"
+rm -rf "${DSTROOT:?}/"*
+
+echo "CLONING libbacktrace"
+mkdir -p "$SRCROOT"
+git clone https://github.com/ianlancetaylor/libbacktrace.git "$SRCROOT"
+echo "CLONED libbacktrace"
+
+echo "CONFIGURING libbacktrace"
+cd "$SRCROOT"
+./configure > configure_log.txt 2>&1
+cd "$HERE"
+
+PATTERNS=(
+'*.c'
+'*.h'
+'LICENSE'
+)
+
+for pattern in "${PATTERNS[@]}"
+do
+  echo "COPYING $pattern"
+  cp "$SRCROOT"/$pattern "$DSTROOT"
+done
+
+EXCLUDES=(
+'*test*'
+'alloc.c'
+'nounwind.c'
+'pecoff.c'
+'read.c'
+'unknown.c'
+'xcoff.c'
+)
+
+for exclude in "${EXCLUDES[@]}"
+do
+  echo "EXCLUDING $exclude"
+  find $DSTROOT -name "$exclude" -exec rm -rf {} \;
+done
+
+echo "MOVING backtrace.h"
+mkdir -p "$DSTROOT/include"
+mv "$DSTROOT/backtrace.h" "$DSTROOT/include"
+
+echo "REPLACING references to \"backtrace.h\" with \"include/backtrace.h\""
+find $DSTROOT -name "*.[ch]" -print0 | xargs -0 sed -i -e 's#"backtrace.h"#"include/backtrace.h"#g'
+
+echo "ADDING preprocessor conditionals"
+find $DSTROOT -name "*.[ch]" -print0 | xargs -0 sed -i -e '1i#ifdef __linux__' -e '$a#endif'
+
+echo "DONE"
Author	SHA1	Message	Date
tomer doron	baf9597d12	trap SIGSEGV, SIGBUS and SIGFPE by default, in addition to SIGILL (#58 ) motivation: print crash trace on segmentation faults and other common failures beyond illegal instructions changes: * include SIGSEGV, SIGBUS and SIGFPE in the default signals trapped * update and improve tests	2022-06-08 09:06:33 -07:00
Konrad `ktoso` Malawski	7ba397e50d	Merge pull request #57 from Fabio1988/patch-1 exit after printing stacktrace #51	2022-04-06 10:45:57 +09:00
Fabio1988	ad485ae151	exit after printing stacktrace #51	2022-03-17 12:17:02 +01:00
tomer doron	662e436989	ci update (#56 ) motivation: 5.6 is out changes: * use release version of 5.6 * add docker setup for 5.7 (using nightly for now)	2022-03-16 21:15:06 -07:00
Konrad `ktoso` Malawski	923624a26e	Merge pull request #53 from swift-server/tomerd-patch-2 update CI setup with new versions of swift	2021-09-23 06:03:22 +09:00
tomer doron	e2621e2fa1	Create docker-compose.2004.main.yaml * add ci setup for nightly toolchain	2021-09-22 12:02:54 -07:00
tomer doron	ea4824d488	Update Dockerfile address jazzy install issues on older ubuntu versions	2021-09-22 12:00:46 -07:00
tomer doron	f1db8bf93d	update CI setup with new versions of swift motivation: 5.5 release is available changes: * add docker CI setup to for 5.5	2021-09-22 11:56:43 -07:00
tomer doron	99a6c79fc5	Update README.md (#50 ) motivation: highlight the background for this library and incourage use via service-lifecycle changes: update readme to reflect these ideas	2021-07-28 16:13:56 -07:00
Johannes Weiss	d3e04a9d4b	Merge pull request #49 from weissi/jw-other-platforms forgot other platforms	2021-07-16 19:50:16 +01:00
Johannes Weiss	b3b195e0e6	forgot other platforms	2021-07-16 19:34:47 +01:00
Johannes Weiss	e434780428	Merge pull request #48 from weissi/jw-signals allow other signals	2021-07-15 21:24:11 +01:00
Johannes Weiss	ceaaf36f0f	allow other signals	2021-07-15 19:40:14 +01:00
Konrad `ktoso` Malawski	bb3bd2357e	Merge pull request #45 from swift-server/tomerd-patch-1 adopt SSWG security guidelines	2021-06-21 11:24:12 +09:00
tomer doron	5f7686a18b	Merge branch 'main' into tomerd-patch-1	2021-06-11 09:13:34 -07:00
tomer doron	d9655c7867	add 5.4 CI (#46 ) motivation: 5.4 was released, add 5.4 CI changes: add docker-compose setup for 5.4	2021-06-11 09:13:24 -07:00
tomer doron	84bcaad52f	Update README.md	2021-06-08 10:38:03 -07:00
tomer doron	7152ac0033	adopt SSWG security guidelines add SECURITY.md detailing the security process	2021-06-08 10:37:16 -07:00
tomer doron	54a65d6391	recent changes to support windows broke macos (#44 ) motivation: unbreak macos changes: make _stdlib_demangleName only available on macOS and Windows where it is fully supported	2021-04-20 11:04:11 -07:00
Saleem Abdulrasool	1ca1dbd9ff	README: add acknowledgement for Windows port (#43 )	2021-04-20 10:10:33 -07:00
Johannes Weiss	182caea1a4	Merge pull request #42 from compnerd/windows Backtrace: enable support for Windows	2021-04-20 14:04:13 +01:00
Saleem Abdulrasool	5b47490c74	Backtrace: adjust style (NFC) Adjust the style for the linter.	2021-04-19 13:13:09 -07:00
Saleem Abdulrasool	b097912943	Backtrace: enable support for Windows Add an implementation across all architectures supported by Windows: - x86 - x86_64 - ARM - ARM64 This relies on DbgHlp32.dll which makes this unfriendly to store applications. We can investigate improvements to that in the future. This sketches out an implementation which allows building and using the interface for providing backtraces. This requires that the programs be built with debug information in CodeView format. Without the additional debug information, the stack traces will be limited to symbolication and resolution to export only symbols. Resolves: #34	2021-04-18 11:16:45 -07:00
Saleem Abdulrasool	a4f7b4204e	Backtrace: make `_stdlib_demangleName` part of all platforms (#41 )	2021-04-17 21:45:37 -07:00
Saleem Abdulrasool	9a2ef536ee	git: ignore vim swap files (#39 )	2021-04-17 19:54:24 -07:00
Johannes Weiss	c859218177	Merge pull request #37 from mpdifran/patch-1 Update build flags with Swift version info	2021-03-03 10:24:02 +00:00
Mark DiFranco	1d5fbd8c42	Update build flags with Swift version info As of Swift 5.2, this build flag is no longer necessary.	2021-03-01 09:11:11 -05:00
Johannes Weiss	93b3d9a764	Merge pull request #35 from weissi/jw-error better distinguish mmap errors & print errno	2021-02-22 11:10:40 +00:00
Johannes Weiss	4353fd38d5	Merge branch 'main' into jw-error	2021-02-22 11:09:50 +00:00
Johannes Weiss	97a034c8a4	Merge pull request #36 from weissi/jw-exe-name determine the executable path automatically	2021-02-22 11:09:38 +00:00
Johannes Weiss	566d2454b2	determine the executable path automatically Motivation: Previously, we would use `CommandLine.arguments[0]`/`argv[0]`/`getexecname()` as the preferred ways to find the main binary. That sounds sensible, especially given the fact that we'd fall back onto other methods (such as `/proc/self/exe`) when the previous ones don't work. There is however an unfortunate edge case. If you for example have your app binary at `/app/app` and you start it with a relative path `./app` from within `/app`, then `CommandLine.arguments[0]` will only contain `./app`. If now the app changes its working directory to `/`, `./app` would mean `/app` which is the directory. This would mean we will find the target but instead of the binary we'd find the directory `/app`. From then on, everything else fails. A similar problem is if `argv[0]` was actually set incorrectly when `exec*`ing the process. This has happened at least in one instance. Modification: Given that we only target Linux here, we can actually here, we can change the order in which we try to find the main binary. We can start by using `/proc/self/exe` which is a very high quality and almost guaranteed to work way to find the main binary, nevermind the information in `argv`. Result: More robust symbolications, especially in environments like Heroku/Dokku where we've seen `argv` not being set correctly.	2021-02-21 18:28:38 +00:00
Johannes Weiss	c8d8ddd88b	better distinguish mmap errors & print errno Motivation: In case SwiftBacktrace fails, we get only very little output. Unfortunately, some crucial information (like the errno) is missing and in case `mmap` fails, we don't know if the problem is file I/O or allocating memory. Modification: - print errnos - distinguish the two mmaps Result: Easier debugging	2021-02-20 23:12:33 +00:00
tomer doron	4915cdd24e	remove symbolicate-linux-fatal from Docker (#33 ) motivation: we are not actually using symbolicate-linux-fatal in any meaningful way in CI and it's pinned to the master branch which has been removed changes: remove symbolicate-linux-fatal fetching from Docker	2020-10-07 17:29:02 -07:00
tomer doron	7a48ec7baa	Swift 5.3 was released, use if for CI (#32 ) motivation: Swift 5.3 was released, use if for CI changes: update docker setup to use the release version of 5.3	2020-09-18 12:59:21 -07:00
tomer doron	c6559c866c	stabilize ci (#31 ) motivation: update swift-server ci changes: * remove travis ci definition * dont install jazzy on 16.04 - its broken on that version and not in use (stabilize ci) * using 5.3 nightlies (stabilize ci)	2020-08-19 11:33:07 -07:00
tomer doron	232bd5bdbc	update ci setup (#27 ) motivation: 5.2 adoption, prepare for 5.3 changes: * add 5.2 docker-compose setup * add 5.3 docker-compose setup (placeholder)	2020-04-04 00:20:09 -07:00
tomer doron	f2fd8c4845	add testing (#26 ) motivation: make sure library works as expected changes: * add a Sample target we can use for testing * add a test to make sure backtraces are printed as expected * make docker tests use a release version for a more realistic tests * update linux test generation script to work with release builds	2020-03-25 12:29:57 -07:00
tomer doron	7faa1c401b	remove print from public API (#25 ) motivation: reduce public API surface area given the plan is to abosrb this library in the language runtime eventually changes: * make print function private * remove explicit swift-server file	2020-03-25 12:06:04 -07:00
tomer doron	1afd60a0bb	ci setup (#23 ) motivation: setup ci for the project changes: * add docker setup for testing 5.0, 5.1 and 5.2 * fix license headers * add sanity script * format * regenerate tests to match convention	2020-03-20 16:20:00 -07:00
Ian Partridge	5074f997bf	Fix package url in README.md (#21 )	2020-03-05 12:48:10 +00:00
Tanner	f5462810b8	Update README.md	2020-02-18 10:48:35 -05:00
Tanner	e735696872	Update README.md	2020-02-18 10:48:24 -05:00
Ian Partridge	383950b36a	ci: Swift 5.1 testing (#20 )	2019-11-01 13:54:05 +01:00
Ian Partridge	feaee74aa6	Update README.md	2019-09-11 08:59:31 -04:00
Ian Partridge	eaf2cef011	feat: cross-compilation (#17 )	2019-09-03 14:28:12 +01:00
Ian Partridge	f244ad1074	feat: add Backtrace.print() function (#15 )	2019-07-22 08:19:56 +01:00
Ian Partridge	39bf306f55	chore: add Xcode 11 testing (#12 )	2019-07-18 14:05:15 +01:00
Ian Partridge	a28e8f99bb	doc: update README as post-mortem symbolication is no longer needed	2019-07-18 13:11:25 +01:00
Ian Partridge	4f9b59d324	fix: use backtrace_full() to get better stacks in release mode (#11 )	2019-07-18 13:02:37 +01:00
Ian Partridge	932f170ce0	feat: add demangling (#10 )	2019-07-18 09:35:45 +01:00
Ian Partridge	ce7ff11ed7	chore: add NOTICE.txt	2019-07-09 15:46:22 +01:00
Ian Partridge	fabd575ba5	feat: use libbacktrace (#8 )	2019-07-09 15:30:38 +01:00
Ian Partridge	df959cd60d	Update README.md	2019-07-01 15:37:46 +01:00
Zsolt Váradi	c5b4501408	Fix backtrace prints on Heroku by using stderr (#7 ) * Use backtrace_symbols_fd to write the stacktrace to stderr	2019-06-26 13:00:22 +01:00
Ian Partridge	4e9985ae9e	feat: Travis CI testing (#4 ) * feat: Travis CI testing	2019-04-24 11:02:53 +01:00