mirror of
https://github.com/mozilla/gecko-dev.git
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d8f7c11471
Differential Revision: https://phabricator.services.mozilla.com/D125000
624 lines
24 KiB
C++
624 lines
24 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/* Implementations of runtime and static assertion macros for C and C++. */
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#ifndef mozilla_Assertions_h
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#define mozilla_Assertions_h
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#if (defined(MOZ_HAS_MOZGLUE) || defined(MOZILLA_INTERNAL_API)) && \
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!defined(__wasi__)
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# define MOZ_DUMP_ASSERTION_STACK
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#endif
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#include "mozilla/Attributes.h"
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#include "mozilla/Compiler.h"
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#include "mozilla/Likely.h"
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#include "mozilla/MacroArgs.h"
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#include "mozilla/StaticAnalysisFunctions.h"
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#include "mozilla/Types.h"
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#ifdef MOZ_DUMP_ASSERTION_STACK
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# include "mozilla/StackWalk.h"
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#endif
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/*
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* The crash reason set by MOZ_CRASH_ANNOTATE is consumed by the crash reporter
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* if present. It is declared here (and defined in Assertions.cpp) to make it
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* available to all code, even libraries that don't link with the crash reporter
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* directly.
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*/
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MOZ_BEGIN_EXTERN_C
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extern MFBT_DATA const char* gMozCrashReason;
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MOZ_END_EXTERN_C
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#if defined(MOZ_HAS_MOZGLUE) || defined(MOZILLA_INTERNAL_API)
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static inline void AnnotateMozCrashReason(const char* reason) {
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gMozCrashReason = reason;
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}
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# define MOZ_CRASH_ANNOTATE(...) AnnotateMozCrashReason(__VA_ARGS__)
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#else
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# define MOZ_CRASH_ANNOTATE(...) \
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do { /* nothing */ \
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} while (false)
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#endif
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#ifdef _MSC_VER
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/*
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* TerminateProcess and GetCurrentProcess are defined in <winbase.h>, which
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* further depends on <windef.h>. We hardcode these few definitions manually
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* because those headers clutter the global namespace with a significant
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* number of undesired macros and symbols.
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*/
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MOZ_BEGIN_EXTERN_C
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__declspec(dllimport) int __stdcall TerminateProcess(void* hProcess,
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unsigned int uExitCode);
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__declspec(dllimport) void* __stdcall GetCurrentProcess(void);
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MOZ_END_EXTERN_C
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#elif defined(__wasi__)
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/*
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* On Wasm/WASI platforms, we just call __builtin_trap().
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*/
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#else
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# include <signal.h>
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#endif
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#ifdef ANDROID
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# include <android/log.h>
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#endif
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MOZ_BEGIN_EXTERN_C
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#if defined(ANDROID) && defined(MOZ_DUMP_ASSERTION_STACK)
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MOZ_MAYBE_UNUSED static void MOZ_ReportAssertionFailurePrintFrame(
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const char* aBuf) {
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__android_log_print(ANDROID_LOG_FATAL, "MOZ_Assert", "%s\n", aBuf);
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}
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#endif
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/*
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* Prints |aStr| as an assertion failure (using aFilename and aLine as the
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* location of the assertion) to the standard debug-output channel.
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*
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* Usually you should use MOZ_ASSERT or MOZ_CRASH instead of this method. This
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* method is primarily for internal use in this header, and only secondarily
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* for use in implementing release-build assertions.
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*/
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MOZ_MAYBE_UNUSED static MOZ_COLD MOZ_NEVER_INLINE void
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MOZ_ReportAssertionFailure(const char* aStr, const char* aFilename,
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int aLine) MOZ_PRETEND_NORETURN_FOR_STATIC_ANALYSIS {
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#ifdef ANDROID
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__android_log_print(ANDROID_LOG_FATAL, "MOZ_Assert",
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"Assertion failure: %s, at %s:%d\n", aStr, aFilename,
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aLine);
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# if defined(MOZ_DUMP_ASSERTION_STACK)
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MozWalkTheStackWithWriter(MOZ_ReportAssertionFailurePrintFrame, CallerPC(),
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/* aMaxFrames */ 0);
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# endif
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#else
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fprintf(stderr, "Assertion failure: %s, at %s:%d\n", aStr, aFilename, aLine);
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# if defined(MOZ_DUMP_ASSERTION_STACK)
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MozWalkTheStack(stderr, CallerPC(), /* aMaxFrames */ 0);
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# endif
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fflush(stderr);
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#endif
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}
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MOZ_MAYBE_UNUSED static MOZ_COLD MOZ_NEVER_INLINE void MOZ_ReportCrash(
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const char* aStr, const char* aFilename,
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int aLine) MOZ_PRETEND_NORETURN_FOR_STATIC_ANALYSIS {
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#ifdef ANDROID
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__android_log_print(ANDROID_LOG_FATAL, "MOZ_CRASH",
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"Hit MOZ_CRASH(%s) at %s:%d\n", aStr, aFilename, aLine);
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#else
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fprintf(stderr, "Hit MOZ_CRASH(%s) at %s:%d\n", aStr, aFilename, aLine);
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# if defined(MOZ_DUMP_ASSERTION_STACK)
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MozWalkTheStack(stderr, CallerPC(), /* aMaxFrames */ 0);
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# endif
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fflush(stderr);
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#endif
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}
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/**
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* MOZ_REALLY_CRASH is used in the implementation of MOZ_CRASH(). You should
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* call MOZ_CRASH instead.
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*/
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#if defined(_MSC_VER)
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/*
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* On MSVC use the __debugbreak compiler intrinsic, which produces an inline
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* (not nested in a system function) breakpoint. This distinctively invokes
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* Breakpad without requiring system library symbols on all stack-processing
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* machines, as a nested breakpoint would require.
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*
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* We use __LINE__ to prevent the compiler from folding multiple crash sites
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* together, which would make crash reports hard to understand.
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*
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* We use TerminateProcess with the exit code aborting would generate
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* because we don't want to invoke atexit handlers, destructors, library
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* unload handlers, and so on when our process might be in a compromised
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* state.
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*
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* We don't use abort() because it'd cause Windows to annoyingly pop up the
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* process error dialog multiple times. See bug 345118 and bug 426163.
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*
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* (Technically these are Windows requirements, not MSVC requirements. But
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* practically you need MSVC for debugging, and we only ship builds created
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* by MSVC, so doing it this way reduces complexity.)
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*/
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MOZ_MAYBE_UNUSED static MOZ_COLD MOZ_NORETURN MOZ_NEVER_INLINE void
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MOZ_NoReturn(int aLine) {
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*((volatile int*)NULL) = aLine;
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TerminateProcess(GetCurrentProcess(), 3);
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}
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# define MOZ_REALLY_CRASH(line) \
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do { \
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__debugbreak(); \
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MOZ_NoReturn(line); \
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} while (false)
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#elif __wasi__
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# define MOZ_REALLY_CRASH(line) __builtin_trap()
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#else
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/*
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* MOZ_CRASH_WRITE_ADDR is the address to be used when performing a forced
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* crash. NULL is preferred however if for some reason NULL cannot be used
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* this makes choosing another value possible.
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*
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* In the case of UBSan certain checks, bounds specifically, cause the compiler
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* to emit the 'ud2' instruction when storing to 0x0. This causes forced
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* crashes to manifest as ILL (at an arbitrary address) instead of the expected
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* SEGV at 0x0.
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*/
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# ifdef MOZ_UBSAN
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# define MOZ_CRASH_WRITE_ADDR 0x1
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# else
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# define MOZ_CRASH_WRITE_ADDR NULL
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# endif
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# ifdef __cplusplus
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# define MOZ_REALLY_CRASH(line) \
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do { \
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*((volatile int*)MOZ_CRASH_WRITE_ADDR) = line; /* NOLINT */ \
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::abort(); \
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} while (false)
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# else
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# define MOZ_REALLY_CRASH(line) \
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do { \
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*((volatile int*)MOZ_CRASH_WRITE_ADDR) = line; /* NOLINT */ \
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abort(); \
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} while (false)
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# endif
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#endif
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/*
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* MOZ_CRASH([explanation-string]) crashes the program, plain and simple, in a
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* Breakpad-compatible way, in both debug and release builds.
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*
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* MOZ_CRASH is a good solution for "handling" failure cases when you're
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* unwilling or unable to handle them more cleanly -- for OOM, for likely memory
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* corruption, and so on. It's also a good solution if you need safe behavior
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* in release builds as well as debug builds. But if the failure is one that
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* should be debugged and fixed, MOZ_ASSERT is generally preferable.
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*
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* The optional explanation-string, if provided, must be a string literal
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* explaining why we're crashing. This argument is intended for use with
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* MOZ_CRASH() calls whose rationale is non-obvious; don't use it if it's
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* obvious why we're crashing.
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*
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* If we're a DEBUG build and we crash at a MOZ_CRASH which provides an
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* explanation-string, we print the string to stderr. Otherwise, we don't
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* print anything; this is because we want MOZ_CRASH to be 100% safe in release
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* builds, and it's hard to print to stderr safely when memory might have been
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* corrupted.
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*/
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#if !(defined(DEBUG) || defined(FUZZING))
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# define MOZ_CRASH(...) \
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do { \
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MOZ_CRASH_ANNOTATE("MOZ_CRASH(" __VA_ARGS__ ")"); \
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MOZ_REALLY_CRASH(__LINE__); \
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} while (false)
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#else
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# define MOZ_CRASH(...) \
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do { \
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MOZ_ReportCrash("" __VA_ARGS__, __FILE__, __LINE__); \
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MOZ_CRASH_ANNOTATE("MOZ_CRASH(" __VA_ARGS__ ")"); \
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MOZ_REALLY_CRASH(__LINE__); \
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} while (false)
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#endif
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/*
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* MOZ_CRASH_UNSAFE(explanation-string) can be used if the explanation string
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* cannot be a string literal (but no other processing needs to be done on it).
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* A regular MOZ_CRASH() is preferred wherever possible, as passing arbitrary
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* strings from a potentially compromised process is not without risk. If the
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* string being passed is the result of a printf-style function, consider using
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* MOZ_CRASH_UNSAFE_PRINTF instead.
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*
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* @note This macro causes data collection because crash strings are annotated
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* to crash-stats and are publicly visible. Firefox data stewards must do data
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* review on usages of this macro.
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*/
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static MOZ_ALWAYS_INLINE_EVEN_DEBUG MOZ_COLD MOZ_NORETURN void MOZ_Crash(
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const char* aFilename, int aLine, const char* aReason) {
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#if defined(DEBUG) || defined(FUZZING)
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MOZ_ReportCrash(aReason, aFilename, aLine);
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#endif
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MOZ_CRASH_ANNOTATE(aReason);
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MOZ_REALLY_CRASH(aLine);
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}
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#define MOZ_CRASH_UNSAFE(reason) MOZ_Crash(__FILE__, __LINE__, reason)
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static const size_t sPrintfMaxArgs = 4;
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static const size_t sPrintfCrashReasonSize = 1024;
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MFBT_API MOZ_COLD MOZ_NEVER_INLINE MOZ_FORMAT_PRINTF(1, 2) const
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char* MOZ_CrashPrintf(const char* aFormat, ...);
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/*
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* MOZ_CRASH_UNSAFE_PRINTF(format, arg1 [, args]) can be used when more
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* information is desired than a string literal can supply. The caller provides
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* a printf-style format string, which must be a string literal and between
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* 1 and 4 additional arguments. A regular MOZ_CRASH() is preferred wherever
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* possible, as passing arbitrary strings to printf from a potentially
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* compromised process is not without risk.
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*
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* @note This macro causes data collection because crash strings are annotated
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* to crash-stats and are publicly visible. Firefox data stewards must do data
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* review on usages of this macro.
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*/
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#define MOZ_CRASH_UNSAFE_PRINTF(format, ...) \
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do { \
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static_assert(MOZ_ARG_COUNT(__VA_ARGS__) > 0, \
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"Did you forget arguments to MOZ_CRASH_UNSAFE_PRINTF? " \
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"Or maybe you want MOZ_CRASH instead?"); \
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static_assert(MOZ_ARG_COUNT(__VA_ARGS__) <= sPrintfMaxArgs, \
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"Only up to 4 additional arguments are allowed!"); \
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static_assert(sizeof(format) <= sPrintfCrashReasonSize, \
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"The supplied format string is too long!"); \
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MOZ_Crash(__FILE__, __LINE__, MOZ_CrashPrintf("" format, __VA_ARGS__)); \
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} while (false)
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MOZ_END_EXTERN_C
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/*
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* MOZ_ASSERT(expr [, explanation-string]) asserts that |expr| must be truthy in
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* debug builds. If it is, execution continues. Otherwise, an error message
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* including the expression and the explanation-string (if provided) is printed,
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* an attempt is made to invoke any existing debugger, and execution halts.
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* MOZ_ASSERT is fatal: no recovery is possible. Do not assert a condition
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* which can correctly be falsy.
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*
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* The optional explanation-string, if provided, must be a string literal
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* explaining the assertion. It is intended for use with assertions whose
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* correctness or rationale is non-obvious, and for assertions where the "real"
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* condition being tested is best described prosaically. Don't provide an
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* explanation if it's not actually helpful.
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*
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* // No explanation needed: pointer arguments often must not be NULL.
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* MOZ_ASSERT(arg);
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*
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* // An explanation can be helpful to explain exactly how we know an
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* // assertion is valid.
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* MOZ_ASSERT(state == WAITING_FOR_RESPONSE,
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* "given that <thingA> and <thingB>, we must have...");
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*
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* // Or it might disambiguate multiple identical (save for their location)
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* // assertions of the same expression.
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* MOZ_ASSERT(getSlot(PRIMITIVE_THIS_SLOT).isUndefined(),
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* "we already set [[PrimitiveThis]] for this Boolean object");
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* MOZ_ASSERT(getSlot(PRIMITIVE_THIS_SLOT).isUndefined(),
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* "we already set [[PrimitiveThis]] for this String object");
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*
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* MOZ_ASSERT has no effect in non-debug builds. It is designed to catch bugs
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* *only* during debugging, not "in the field". If you want the latter, use
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* MOZ_RELEASE_ASSERT, which applies to non-debug builds as well.
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*
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* MOZ_DIAGNOSTIC_ASSERT works like MOZ_RELEASE_ASSERT in Nightly/Aurora and
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* MOZ_ASSERT in Beta/Release - use this when a condition is potentially rare
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* enough to require real user testing to hit, but is not security-sensitive.
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* This can cause user pain, so use it sparingly. If a MOZ_DIAGNOSTIC_ASSERT
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* is firing, it should promptly be converted to a MOZ_ASSERT while the failure
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* is being investigated, rather than letting users suffer.
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*
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* MOZ_DIAGNOSTIC_ASSERT_ENABLED is defined when MOZ_DIAGNOSTIC_ASSERT is like
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* MOZ_RELEASE_ASSERT rather than MOZ_ASSERT.
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*/
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/*
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* Implement MOZ_VALIDATE_ASSERT_CONDITION_TYPE, which is used to guard against
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* accidentally passing something unintended in lieu of an assertion condition.
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*/
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#ifdef __cplusplus
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# include <type_traits>
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namespace mozilla {
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namespace detail {
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template <typename T>
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struct AssertionConditionType {
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using ValueT = std::remove_reference_t<T>;
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static_assert(!std::is_array_v<ValueT>,
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"Expected boolean assertion condition, got an array or a "
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"string!");
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static_assert(!std::is_function_v<ValueT>,
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"Expected boolean assertion condition, got a function! Did "
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"you intend to call that function?");
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static_assert(!std::is_floating_point_v<ValueT>,
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"It's often a bad idea to assert that a floating-point number "
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"is nonzero, because such assertions tend to intermittently "
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"fail. Shouldn't your code gracefully handle this case instead "
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"of asserting? Anyway, if you really want to do that, write an "
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"explicit boolean condition, like !!x or x!=0.");
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static const bool isValid = true;
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};
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} // namespace detail
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} // namespace mozilla
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# define MOZ_VALIDATE_ASSERT_CONDITION_TYPE(x) \
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static_assert( \
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mozilla::detail::AssertionConditionType<decltype(x)>::isValid, \
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"invalid assertion condition")
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#else
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# define MOZ_VALIDATE_ASSERT_CONDITION_TYPE(x)
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#endif
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#if defined(DEBUG) || defined(MOZ_ASAN)
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# define MOZ_REPORT_ASSERTION_FAILURE(...) \
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MOZ_ReportAssertionFailure(__VA_ARGS__)
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#else
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# define MOZ_REPORT_ASSERTION_FAILURE(...) \
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do { /* nothing */ \
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} while (false)
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#endif
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/* First the single-argument form. */
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#define MOZ_ASSERT_HELPER1(kind, expr) \
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do { \
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MOZ_VALIDATE_ASSERT_CONDITION_TYPE(expr); \
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if (MOZ_UNLIKELY(!MOZ_CHECK_ASSERT_ASSIGNMENT(expr))) { \
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MOZ_REPORT_ASSERTION_FAILURE(#expr, __FILE__, __LINE__); \
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MOZ_CRASH_ANNOTATE(kind "(" #expr ")"); \
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MOZ_REALLY_CRASH(__LINE__); \
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} \
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} while (false)
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/* Now the two-argument form. */
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#define MOZ_ASSERT_HELPER2(kind, expr, explain) \
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do { \
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MOZ_VALIDATE_ASSERT_CONDITION_TYPE(expr); \
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if (MOZ_UNLIKELY(!MOZ_CHECK_ASSERT_ASSIGNMENT(expr))) { \
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MOZ_REPORT_ASSERTION_FAILURE(#expr " (" explain ")", __FILE__, \
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__LINE__); \
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MOZ_CRASH_ANNOTATE(kind "(" #expr ") (" explain ")"); \
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MOZ_REALLY_CRASH(__LINE__); \
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} \
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} while (false)
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#define MOZ_ASSERT_GLUE(a, b) a b
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#define MOZ_RELEASE_ASSERT(...) \
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MOZ_ASSERT_GLUE( \
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MOZ_PASTE_PREFIX_AND_ARG_COUNT(MOZ_ASSERT_HELPER, __VA_ARGS__), \
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("MOZ_RELEASE_ASSERT", __VA_ARGS__))
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#ifdef DEBUG
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# define MOZ_ASSERT(...) \
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MOZ_ASSERT_GLUE( \
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MOZ_PASTE_PREFIX_AND_ARG_COUNT(MOZ_ASSERT_HELPER, __VA_ARGS__), \
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("MOZ_ASSERT", __VA_ARGS__))
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#else
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# define MOZ_ASSERT(...) \
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do { \
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} while (false)
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#endif /* DEBUG */
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#if defined(NIGHTLY_BUILD) || defined(MOZ_DEV_EDITION) || defined(DEBUG)
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# define MOZ_DIAGNOSTIC_ASSERT(...) \
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MOZ_ASSERT_GLUE( \
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MOZ_PASTE_PREFIX_AND_ARG_COUNT(MOZ_ASSERT_HELPER, __VA_ARGS__), \
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("MOZ_DIAGNOSTIC_ASSERT", __VA_ARGS__))
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# define MOZ_DIAGNOSTIC_ASSERT_ENABLED 1
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#else
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# define MOZ_DIAGNOSTIC_ASSERT(...) \
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do { \
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} while (false)
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#endif
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/*
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* MOZ_ASSERT_IF(cond1, cond2) is equivalent to MOZ_ASSERT(cond2) if cond1 is
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* true.
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*
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* MOZ_ASSERT_IF(isPrime(num), num == 2 || isOdd(num));
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*
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* As with MOZ_ASSERT, MOZ_ASSERT_IF has effect only in debug builds. It is
|
|
* designed to catch bugs during debugging, not "in the field".
|
|
*/
|
|
#ifdef DEBUG
|
|
# define MOZ_ASSERT_IF(cond, expr) \
|
|
do { \
|
|
if (cond) { \
|
|
MOZ_ASSERT(expr); \
|
|
} \
|
|
} while (false)
|
|
#else
|
|
# define MOZ_ASSERT_IF(cond, expr) \
|
|
do { \
|
|
} while (false)
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_DIAGNOSTIC_ASSERT_IF is like MOZ_ASSERT_IF, but using
|
|
* MOZ_DIAGNOSTIC_ASSERT as the underlying assert.
|
|
*
|
|
* See the block comment for MOZ_DIAGNOSTIC_ASSERT above for more details on how
|
|
* diagnostic assertions work and how to use them.
|
|
*/
|
|
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
|
|
# define MOZ_DIAGNOSTIC_ASSERT_IF(cond, expr) \
|
|
do { \
|
|
if (cond) { \
|
|
MOZ_DIAGNOSTIC_ASSERT(expr); \
|
|
} \
|
|
} while (false)
|
|
#else
|
|
# define MOZ_DIAGNOSTIC_ASSERT_IF(cond, expr) \
|
|
do { \
|
|
} while (false)
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ASSUME_UNREACHABLE_MARKER() expands to an expression which states that
|
|
* it is undefined behavior for execution to reach this point. No guarantees
|
|
* are made about what will happen if this is reached at runtime. Most code
|
|
* should use MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE because it has extra
|
|
* asserts.
|
|
*/
|
|
#if defined(__clang__) || defined(__GNUC__)
|
|
# define MOZ_ASSUME_UNREACHABLE_MARKER() __builtin_unreachable()
|
|
#elif defined(_MSC_VER)
|
|
# define MOZ_ASSUME_UNREACHABLE_MARKER() __assume(0)
|
|
#else
|
|
# ifdef __cplusplus
|
|
# define MOZ_ASSUME_UNREACHABLE_MARKER() ::abort()
|
|
# else
|
|
# define MOZ_ASSUME_UNREACHABLE_MARKER() abort()
|
|
# endif
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE([reason]) tells the compiler that it
|
|
* can assume that the macro call cannot be reached during execution. This lets
|
|
* the compiler generate better-optimized code under some circumstances, at the
|
|
* expense of the program's behavior being undefined if control reaches the
|
|
* MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE.
|
|
*
|
|
* In Gecko, you probably should not use this macro outside of performance- or
|
|
* size-critical code, because it's unsafe. If you don't care about code size
|
|
* or performance, you should probably use MOZ_ASSERT or MOZ_CRASH.
|
|
*
|
|
* SpiderMonkey is a different beast, and there it's acceptable to use
|
|
* MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE more widely.
|
|
*
|
|
* Note that MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE is noreturn, so it's valid
|
|
* not to return a value following a MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE
|
|
* call.
|
|
*
|
|
* Example usage:
|
|
*
|
|
* enum ValueType {
|
|
* VALUE_STRING,
|
|
* VALUE_INT,
|
|
* VALUE_FLOAT
|
|
* };
|
|
*
|
|
* int ptrToInt(ValueType type, void* value) {
|
|
* {
|
|
* // We know for sure that type is either INT or FLOAT, and we want this
|
|
* // code to run as quickly as possible.
|
|
* switch (type) {
|
|
* case VALUE_INT:
|
|
* return *(int*) value;
|
|
* case VALUE_FLOAT:
|
|
* return (int) *(float*) value;
|
|
* default:
|
|
* MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE("Unexpected ValueType");
|
|
* }
|
|
* }
|
|
*/
|
|
|
|
/*
|
|
* Unconditional assert in debug builds for (assumed) unreachable code paths
|
|
* that have a safe return without crashing in release builds.
|
|
*/
|
|
#define MOZ_ASSERT_UNREACHABLE(reason) \
|
|
MOZ_ASSERT(false, "MOZ_ASSERT_UNREACHABLE: " reason)
|
|
|
|
#define MOZ_MAKE_COMPILER_ASSUME_IS_UNREACHABLE(reason) \
|
|
do { \
|
|
MOZ_ASSERT_UNREACHABLE(reason); \
|
|
MOZ_ASSUME_UNREACHABLE_MARKER(); \
|
|
} while (false)
|
|
|
|
/**
|
|
* MOZ_FALLTHROUGH_ASSERT is an annotation to suppress compiler warnings about
|
|
* switch cases that MOZ_ASSERT(false) (or its alias MOZ_ASSERT_UNREACHABLE) in
|
|
* debug builds, but intentionally fall through in release builds to handle
|
|
* unexpected values.
|
|
*
|
|
* Why do we need MOZ_FALLTHROUGH_ASSERT in addition to [[fallthrough]]? In
|
|
* release builds, the MOZ_ASSERT(false) will expand to `do { } while (false)`,
|
|
* requiring a [[fallthrough]] annotation to suppress a -Wimplicit-fallthrough
|
|
* warning. In debug builds, the MOZ_ASSERT(false) will expand to something like
|
|
* `if (true) { MOZ_CRASH(); }` and the [[fallthrough]] annotation will cause
|
|
* a -Wunreachable-code warning. The MOZ_FALLTHROUGH_ASSERT macro breaks this
|
|
* warning stalemate.
|
|
*
|
|
* // Example before MOZ_FALLTHROUGH_ASSERT:
|
|
* switch (foo) {
|
|
* default:
|
|
* // This case wants to assert in debug builds, fall through in release.
|
|
* MOZ_ASSERT(false); // -Wimplicit-fallthrough warning in release builds!
|
|
* [[fallthrough]]; // but -Wunreachable-code warning in debug builds!
|
|
* case 5:
|
|
* return 5;
|
|
* }
|
|
*
|
|
* // Example with MOZ_FALLTHROUGH_ASSERT:
|
|
* switch (foo) {
|
|
* default:
|
|
* // This case asserts in debug builds, falls through in release.
|
|
* MOZ_FALLTHROUGH_ASSERT("Unexpected foo value?!");
|
|
* case 5:
|
|
* return 5;
|
|
* }
|
|
*/
|
|
#ifdef DEBUG
|
|
# define MOZ_FALLTHROUGH_ASSERT(...) \
|
|
MOZ_CRASH("MOZ_FALLTHROUGH_ASSERT: " __VA_ARGS__)
|
|
#else
|
|
# define MOZ_FALLTHROUGH_ASSERT(...) [[fallthrough]]
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ALWAYS_TRUE(expr) and friends always evaluate the provided expression,
|
|
* in debug builds and in release builds both. Then, in debug builds and
|
|
* Nightly and DevEdition release builds, the value of the expression is
|
|
* asserted either true or false using MOZ_DIAGNOSTIC_ASSERT.
|
|
*/
|
|
#define MOZ_ALWAYS_TRUE(expr) \
|
|
do { \
|
|
if (MOZ_LIKELY(expr)) { \
|
|
/* Silence [[nodiscard]]. */ \
|
|
} else { \
|
|
MOZ_DIAGNOSTIC_ASSERT(false, #expr); \
|
|
} \
|
|
} while (false)
|
|
|
|
#define MOZ_ALWAYS_FALSE(expr) MOZ_ALWAYS_TRUE(!(expr))
|
|
#define MOZ_ALWAYS_OK(expr) MOZ_ALWAYS_TRUE((expr).isOk())
|
|
#define MOZ_ALWAYS_ERR(expr) MOZ_ALWAYS_TRUE((expr).isErr())
|
|
|
|
#undef MOZ_DUMP_ASSERTION_STACK
|
|
#undef MOZ_CRASH_CRASHREPORT
|
|
|
|
/*
|
|
* This is only used by Array and nsTArray classes, therefore it is not
|
|
* required when included from C code.
|
|
*/
|
|
#ifdef __cplusplus
|
|
namespace mozilla::detail {
|
|
MFBT_API MOZ_NORETURN MOZ_COLD void InvalidArrayIndex_CRASH(size_t aIndex,
|
|
size_t aLength);
|
|
} // namespace mozilla::detail
|
|
#endif // __cplusplus
|
|
|
|
#endif /* mozilla_Assertions_h */
|