diff options
| -rw-r--r-- | third_party/base/logging.h | 93 |
1 files changed, 81 insertions, 12 deletions
diff --git a/third_party/base/logging.h b/third_party/base/logging.h index 76555f563e..d4a0734a50 100644 --- a/third_party/base/logging.h +++ b/third_party/base/logging.h @@ -8,16 +8,90 @@ #include <assert.h> #include <stdlib.h> -#ifndef _WIN32 -#define NULL_DEREF_IF_POSSIBLE __builtin_unreachable() +#include "build/build_config.h" +#include "third_party/base/compiler_specific.h" + +#if defined(COMPILER_GCC) + +#if defined(ARCH_CPU_X86_FAMILY) +// int 3 will generate a SIGTRAP. +#define TRAP_SEQUENCE() \ + asm volatile( \ + "int3; ud2; push %0;" ::"i"(static_cast<unsigned char>(__COUNTER__))) + +#elif defined(ARCH_CPU_ARMEL) +// bkpt will generate a SIGBUS when running on armv7 and a SIGTRAP when running +// as a 32 bit userspace app on arm64. There doesn't seem to be any way to +// cause a SIGTRAP from userspace without using a syscall (which would be a +// problem for sandboxing). +#define TRAP_SEQUENCE() \ + asm volatile("bkpt #0; udf %0;" ::"i"(__COUNTER__ % 256)) + +#elif defined(ARCH_CPU_ARM64) +// This will always generate a SIGTRAP on arm64. +#define TRAP_SEQUENCE() \ + asm volatile("brk #0; hlt %0;" ::"i"(__COUNTER__ % 65536)) + +#else +// Crash report accuracy will not be guaranteed on other architectures, but at +// least this will crash as expected. +#define TRAP_SEQUENCE() __builtin_trap() +#endif // ARCH_CPU_* + +// CHECK() and the trap sequence can be invoked from a constexpr function. +// This could make compilation fail on GCC, as it forbids directly using inline +// asm inside a constexpr function. However, it allows calling a lambda +// expression including the same asm. +// The side effect is that the top of the stacktrace will not point to the +// calling function, but to this anonymous lambda. This is still useful as the +// full name of the lambda will typically include the name of the function that +// calls CHECK() and the debugger will still break at the right line of code. +#if !defined(__clang__) +#define WRAPPED_TRAP_SEQUENCE() \ + do { \ + [] { TRAP_SEQUENCE(); }(); \ + } while (false) #else -#define NULL_DEREF_IF_POSSIBLE __assume(0) +#define WRAPPED_TRAP_SEQUENCE() TRAP_SEQUENCE() #endif -#define CHECK(condition) \ - if (!(condition)) { \ - abort(); \ - NULL_DEREF_IF_POSSIBLE;\ +#define IMMEDIATE_CRASH() \ + ({ \ + WRAPPED_TRAP_SEQUENCE(); \ + __builtin_unreachable(); \ + }) + +#elif defined(COMPILER_MSVC) + +// Clang is cleverer about coalescing int3s, so we need to add a unique-ish +// instruction following the __debugbreak() to have it emit distinct locations +// for CHECKs rather than collapsing them all together. It would be nice to use +// a short intrinsic to do this (and perhaps have only one implementation for +// both clang and MSVC), however clang-cl currently does not support intrinsics. +// On the flip side, MSVC x64 doesn't support inline asm. So, we have to have +// two implementations. Normally clang-cl's version will be 5 bytes (1 for +// `int3`, 2 for `ud2`, 2 for `push byte imm`, however, TODO(scottmg): +// https://crbug.com/694670 clang-cl doesn't currently support %'ing +// __COUNTER__, so eventually it will emit the dword form of push. +// TODO(scottmg): Reinvestigate a short sequence that will work on both +// compilers once clang supports more intrinsics. See https://crbug.com/693713. +#if defined(__clang__) +#define IMMEDIATE_CRASH() \ + ({ \ + {__asm int 3 __asm ud2 __asm push __COUNTER__}; \ + __builtin_unreachable(); \ + }) +#else +#define IMMEDIATE_CRASH() __debugbreak() +#endif // __clang__ + +#else +#error Port +#endif + +#define CHECK(condition) \ + if (UNLIKELY(!(condition))) { \ + IMMEDIATE_CRASH(); \ } // TODO(palmer): These are quick hacks to import PartitionAlloc with minimum @@ -28,11 +102,6 @@ #define DCHECK_EQ(x, y) CHECK((x) == (y)) #define DCHECK_IS_ON() true -// TODO(palmer): Also a quick hack. IMMEDIATE_CRASH used to be simple in -// Chromium base/, but it got way more complicated and has lots of base/ -// dependencies now. Sad! -#define IMMEDIATE_CRASH() abort(); - #define NOTREACHED() assert(false) #endif // THIRD_PARTY_BASE_LOGGING_H_ |