Source/WTF/wtf/Assertions.cpp

/*
 * Copyright (C) 2003, 2006, 2007, 2013 Apple Inc.  All rights reserved.
 * Copyright (C) 2007-2009 Torch Mobile, Inc.
 * Copyright (C) 2011 University of Szeged. All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. OR
 * CONTRIBUTORS 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 vprintf_stderr_common function triggers this error in the Mac build.
// Feel free to remove this pragma if this file builds on Mac.
// According to http://gcc.gnu.org/onlinedocs/gcc-4.2.1/gcc/Diagnostic-Pragmas.html#Diagnostic-Pragmas
// we need to place this directive before any data or functions are defined.
#pragma GCC diagnostic ignored "-Wmissing-format-attribute"

#include "config.h"
#include "Assertions.h"

#include "Compiler.h"
#include <wtf/StdLibExtras.h>
#include <wtf/StringExtras.h>
#include <wtf/text/CString.h>
#include <wtf/text/WTFString.h>

#include <stdio.h>
#include <string.h>

#if HAVE(SIGNAL_H)
#include <signal.h>
#endif

#if USE(CF)
#include <CoreFoundation/CFString.h>
#if PLATFORM(COCOA)
#define USE_APPLE_SYSTEM_LOG 1
#include <asl.h>
#endif
#endif // USE(CF)

#if COMPILER(MSVC)
#include <crtdbg.h>
#endif

#if OS(WINDOWS)
#include <windows.h>
#endif

#if OS(DARWIN)
#include <sys/sysctl.h>
#include <unistd.h>
#endif

#if OS(DARWIN) || (OS(LINUX) && !defined(__UCLIBC__))
#include <cxxabi.h>
#include <dlfcn.h>
#include <execinfo.h>
#endif

extern "C" {

WTF_ATTRIBUTE_PRINTF(1, 0)
static void vprintf_stderr_common(const char* format, va_list args)
{
#if USE(CF) && !OS(WINDOWS)
    if (strstr(format, "%@")) {
        CFStringRef cfFormat = CFStringCreateWithCString(NULL, format, kCFStringEncodingUTF8);

#if COMPILER(CLANG)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wformat-nonliteral"
#endif
        CFStringRef str = CFStringCreateWithFormatAndArguments(NULL, NULL, cfFormat, args);
#if COMPILER(CLANG)
#pragma clang diagnostic pop
#endif
        CFIndex length = CFStringGetMaximumSizeForEncoding(CFStringGetLength(str), kCFStringEncodingUTF8);
        char* buffer = (char*)malloc(length + 1);

        CFStringGetCString(str, buffer, length, kCFStringEncodingUTF8);

#if USE(APPLE_SYSTEM_LOG)
        asl_log(0, 0, ASL_LEVEL_NOTICE, "%s", buffer);
#endif
        fputs(buffer, stderr);

        free(buffer);
        CFRelease(str);
        CFRelease(cfFormat);
        return;
    }

#if USE(APPLE_SYSTEM_LOG)
    va_list copyOfArgs;
    va_copy(copyOfArgs, args);
    asl_vlog(0, 0, ASL_LEVEL_NOTICE, format, copyOfArgs);
    va_end(copyOfArgs);
#endif

    // Fall through to write to stderr in the same manner as other platforms.

#elif HAVE(ISDEBUGGERPRESENT)
    if (IsDebuggerPresent()) {
        size_t size = 1024;

        do {
            char* buffer = (char*)malloc(size);

            if (buffer == NULL)
                break;

            if (vsnprintf(buffer, size, format, args) != -1) {
                OutputDebugStringA(buffer);
                free(buffer);
                break;
            }

            free(buffer);
            size *= 2;
        } while (size > 1024);
    }
#endif
    vfprintf(stderr, format, args);
}

#if COMPILER(GCC_OR_CLANG)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-nonliteral"
#endif

static void vprintf_stderr_with_prefix(const char* prefix, const char* format, va_list args)
{
    size_t prefixLength = strlen(prefix);
    size_t formatLength = strlen(format);
    auto formatWithPrefix = std::make_unique<char[]>(prefixLength + formatLength + 1);
    memcpy(formatWithPrefix.get(), prefix, prefixLength);
    memcpy(formatWithPrefix.get() + prefixLength, format, formatLength);
    formatWithPrefix[prefixLength + formatLength] = 0;

    vprintf_stderr_common(formatWithPrefix.get(), args);
}

static void vprintf_stderr_with_trailing_newline(const char* format, va_list args)
{
    size_t formatLength = strlen(format);
    if (formatLength && format[formatLength - 1] == '\n') {
        vprintf_stderr_common(format, args);
        return;
    }

    auto formatWithNewline = std::make_unique<char[]>(formatLength + 2);
    memcpy(formatWithNewline.get(), format, formatLength);
    formatWithNewline[formatLength] = '\n';
    formatWithNewline[formatLength + 1] = 0;

    vprintf_stderr_common(formatWithNewline.get(), args);
}

#if COMPILER(GCC_OR_CLANG)
#pragma GCC diagnostic pop
#endif

WTF_ATTRIBUTE_PRINTF(1, 2)
static void printf_stderr_common(const char* format, ...)
{
    va_list args;
    va_start(args, format);
    vprintf_stderr_common(format, args);
    va_end(args);
}

static void printCallSite(const char* file, int line, const char* function)
{
#if OS(WINDOWS) && defined(_DEBUG)
    _CrtDbgReport(_CRT_WARN, file, line, NULL, "%s\n", function);
#else
    // By using this format, which matches the format used by MSVC for compiler errors, developers
    // using Visual Studio can double-click the file/line number in the Output Window to have the
    // editor navigate to that line of code. It seems fine for other developers, too.
    printf_stderr_common("%s(%d) : %s\n", file, line, function);
#endif
}

void WTFReportAssertionFailure(const char* file, int line, const char* function, const char* assertion)
{
    if (assertion)
        printf_stderr_common("ASSERTION FAILED: %s\n", assertion);
    else
        printf_stderr_common("SHOULD NEVER BE REACHED\n");
    printCallSite(file, line, function);
}

void WTFReportAssertionFailureWithMessage(const char* file, int line, const char* function, const char* assertion, const char* format, ...)
{
    va_list args;
    va_start(args, format);
    vprintf_stderr_with_prefix("ASSERTION FAILED: ", format, args);
    va_end(args);
    printf_stderr_common("\n%s\n", assertion);
    printCallSite(file, line, function);
}

void WTFReportArgumentAssertionFailure(const char* file, int line, const char* function, const char* argName, const char* assertion)
{
    printf_stderr_common("ARGUMENT BAD: %s, %s\n", argName, assertion);
    printCallSite(file, line, function);
}

void WTFGetBacktrace(void** stack, int* size)
{
#if OS(DARWIN) || (OS(LINUX) && !defined(__UCLIBC__))
    *size = backtrace(stack, *size);
#elif OS(WINDOWS)
    // The CaptureStackBackTrace function is available in XP, but it is not defined
    // in the Windows Server 2003 R2 Platform SDK. So, we'll grab the function
    // through GetProcAddress.
    typedef WORD (NTAPI* RtlCaptureStackBackTraceFunc)(DWORD, DWORD, PVOID*, PDWORD);
    HMODULE kernel32 = ::GetModuleHandleW(L"Kernel32.dll");
    if (!kernel32) {
        *size = 0;
        return;
    }
    RtlCaptureStackBackTraceFunc captureStackBackTraceFunc = reinterpret_cast<RtlCaptureStackBackTraceFunc>(
        ::GetProcAddress(kernel32, "RtlCaptureStackBackTrace"));
    if (captureStackBackTraceFunc)
        *size = captureStackBackTraceFunc(0, *size, stack, 0);
    else
        *size = 0;
#else
    *size = 0;
#endif
}

void WTFReportBacktrace()
{
    static const int framesToShow = 31;
    static const int framesToSkip = 2;
    void* samples[framesToShow + framesToSkip];
    int frames = framesToShow + framesToSkip;

    WTFGetBacktrace(samples, &frames);
    WTFPrintBacktrace(samples + framesToSkip, frames - framesToSkip);
}

#if OS(DARWIN) || OS(LINUX)
#  if PLATFORM(GTK)
#    if defined(__GLIBC__) && !defined(__UCLIBC__)
#      define USE_BACKTRACE_SYMBOLS 1
#    endif
#  else
#    define USE_DLADDR 1
#  endif
#endif

void WTFPrintBacktrace(void** stack, int size)
{
#if USE(BACKTRACE_SYMBOLS)
    char** symbols = backtrace_symbols(stack, size);
    if (!symbols)
        return;
#endif

    for (int i = 0; i < size; ++i) {
        const char* mangledName = 0;
        char* cxaDemangled = 0;
#if USE(BACKTRACE_SYMBOLS)
        mangledName = symbols[i];
#elif USE(DLADDR)
        Dl_info info;
        if (dladdr(stack[i], &info) && info.dli_sname)
            mangledName = info.dli_sname;
        if (mangledName)
            cxaDemangled = abi::__cxa_demangle(mangledName, 0, 0, 0);
#endif
        const int frameNumber = i + 1;
        if (mangledName || cxaDemangled)
            printf_stderr_common("%-3d %p %s\n", frameNumber, stack[i], cxaDemangled ? cxaDemangled : mangledName);
        else
            printf_stderr_common("%-3d %p\n", frameNumber, stack[i]);
        free(cxaDemangled);
    }

#if USE(BACKTRACE_SYMBOLS)
    free(symbols);
#endif
}

#undef USE_BACKTRACE_SYMBOLS
#undef USE_DLADDR

static WTFCrashHookFunction globalHook = 0;

void WTFSetCrashHook(WTFCrashHookFunction function)
{
    globalHook = function;
}

void WTFCrash()
{
    if (globalHook)
        globalHook();

    WTFReportBacktrace();
    *(int *)(uintptr_t)0xbbadbeef = 0;
    // More reliable, but doesn't say BBADBEEF.
#if COMPILER(GCC_OR_CLANG)
    __builtin_trap();
#else
    ((void(*)())0)();
#endif
}
    
void WTFCrashWithSecurityImplication()
{
    if (globalHook)
        globalHook();
    WTFReportBacktrace();
    *(int *)(uintptr_t)0xfbadbeef = 0;
    // More reliable, but doesn't say fbadbeef.
#if COMPILER(GCC_OR_CLANG)
    __builtin_trap();
#else
    ((void(*)())0)();
#endif
}

#if HAVE(SIGNAL_H)
static NO_RETURN void dumpBacktraceSignalHandler(int sig)
{
    WTFReportBacktrace();
    exit(128 + sig);
}

static void installSignalHandlersForFatalErrors(void (*handler)(int))
{
    signal(SIGILL, handler); //    4: illegal instruction (not reset when caught).
    signal(SIGTRAP, handler); //   5: trace trap (not reset when caught).
    signal(SIGFPE, handler); //    8: floating point exception.
    signal(SIGBUS, handler); //   10: bus error.
    signal(SIGSEGV, handler); //  11: segmentation violation.
    signal(SIGSYS, handler); //   12: bad argument to system call.
    signal(SIGPIPE, handler); //  13: write on a pipe with no reader.
    signal(SIGXCPU, handler); //  24: exceeded CPU time limit.
    signal(SIGXFSZ, handler); //  25: exceeded file size limit.
}

static void resetSignalHandlersForFatalErrors()
{
    installSignalHandlersForFatalErrors(SIG_DFL);
}
#endif

void WTFInstallReportBacktraceOnCrashHook()
{
#if HAVE(SIGNAL_H)
    // Needed otherwise we are going to dump the stack trace twice
    // in case we hit an assertion.
    WTFSetCrashHook(&resetSignalHandlersForFatalErrors);
    installSignalHandlersForFatalErrors(&dumpBacktraceSignalHandler);
#endif
}

bool WTFIsDebuggerAttached()
{
#if OS(DARWIN)
    struct kinfo_proc info;
    int mib[] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, getpid() };
    size_t size = sizeof(info);
    if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), &info, &size, nullptr, 0) == -1)
        return false;
    return info.kp_proc.p_flag & P_TRACED;
#else
    return false;
#endif
}

void WTFReportFatalError(const char* file, int line, const char* function, const char* format, ...)
{
    va_list args;
    va_start(args, format);
    vprintf_stderr_with_prefix("FATAL ERROR: ", format, args);
    va_end(args);
    printf_stderr_common("\n");
    printCallSite(file, line, function);
}

void WTFReportError(const char* file, int line, const char* function, const char* format, ...)
{
    va_list args;
    va_start(args, format);
    vprintf_stderr_with_prefix("ERROR: ", format, args);
    va_end(args);
    printf_stderr_common("\n");
    printCallSite(file, line, function);
}

void WTFLog(WTFLogChannel* channel, const char* format, ...)
{
    if (channel->state != WTFLogChannelOn)
        return;

    va_list args;
    va_start(args, format);
    vprintf_stderr_with_trailing_newline(format, args);
    va_end(args);
}

void WTFLogVerbose(const char* file, int line, const char* function, WTFLogChannel* channel, const char* format, ...)
{
    if (channel->state != WTFLogChannelOn)
        return;

    va_list args;
    va_start(args, format);
    vprintf_stderr_with_trailing_newline(format, args);
    va_end(args);

    printCallSite(file, line, function);
}

void WTFLogAlwaysV(const char* format, va_list args)
{
    vprintf_stderr_with_trailing_newline(format, args);
}

void WTFLogAlways(const char* format, ...)
{
    va_list args;
    va_start(args, format);
    WTFLogAlwaysV(format, args);
    va_end(args);
}

void WTFLogAlwaysAndCrash(const char* format, ...)
{
    va_list args;
    va_start(args, format);
    WTFLogAlwaysV(format, args);
    va_end(args);
    WTFCrash();
}

WTFLogChannel* WTFLogChannelByName(WTFLogChannel* channels[], size_t count, const char* name)
{
    for (size_t i = 0; i < count; ++i) {
        WTFLogChannel* channel = channels[i];
        if (!strcasecmp(name, channel->name))
            return channel;
    }

    return 0;
}

static void setStateOfAllChannels(WTFLogChannel* channels[], size_t channelCount, WTFLogChannelState state)
{
    for (size_t i = 0; i < channelCount; ++i)
        channels[i]->state = state;
}

void WTFInitializeLogChannelStatesFromString(WTFLogChannel* channels[], size_t count, const char* logLevel)
{
    String logLevelString = logLevel;
    Vector<String> components;
    logLevelString.split(',', components);

    for (size_t i = 0; i < components.size(); ++i) {
        String component = components[i];

        WTFLogChannelState logChannelState = WTFLogChannelOn;
        if (component.startsWith('-')) {
            logChannelState = WTFLogChannelOff;
            component = component.substring(1);
        }

        if (equalIgnoringCase(component, "all")) {
            setStateOfAllChannels(channels, count, logChannelState);
            continue;
        }

        if (WTFLogChannel* channel = WTFLogChannelByName(channels, count, component.utf8().data()))
            channel->state = logChannelState;
        else
            WTFLogAlways("Unknown logging channel: %s", component.utf8().data());
    }
}

} // extern "C"