libc/src/__support/libc_assert.h

   1 //===-- Definition of a libc internal assert macro --------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_LIBC_SRC_SUPPORT_LIBC_ASSERT_H
  10 #define LLVM_LIBC_SRC_SUPPORT_LIBC_ASSERT_H
  11
  12 #ifdef LIBC_COPT_USE_C_ASSERT
  13
  14 // The build is configured to just use the public <assert.h> API
  15 // for libc's internal assertions.
  16
  17 #include <assert.h>
  18
  19 #define LIBC_ASSERT(COND) assert(COND)
  20
  21 #else // Not LIBC_COPT_USE_C_ASSERT
  22
  23 #include "src/__support/OSUtil/io.h"
  24 #include "src/__support/OSUtil/quick_exit.h"
  25 #include "src/__support/integer_to_string.h"
  26 #include "src/__support/macros/attributes.h" // For LIBC_INLINE
  27
  28 namespace __llvm_libc {
  29
  30 LIBC_INLINE void report_assertion_failure(const char *assertion,
  31                                           const char *filename, unsigned line,
  32                                           const char *funcname) {
  33   char line_str[IntegerToString::dec_bufsize<unsigned>()];
  34   IntegerToString::dec(line, line_str);
  35   __llvm_libc::write_to_stderr(filename);
  36   __llvm_libc::write_to_stderr(":");
  37   __llvm_libc::write_to_stderr(line_str);
  38   __llvm_libc::write_to_stderr(": Assertion failed: '");
  39   __llvm_libc::write_to_stderr(assertion);
  40   __llvm_libc::write_to_stderr("' in function: '");
  41   __llvm_libc::write_to_stderr(funcname);
  42   __llvm_libc::write_to_stderr("'\n");
  43 }
  44
  45 } // namespace __llvm_libc
  46
  47 #ifdef LIBC_ASSERT
  48 #error "Unexpected: LIBC_ASSERT macro already defined"
  49 #endif
  50
  51 // The public "assert" macro calls abort on failure. Should it be same here?
  52 // The libc internal assert can fire from anywhere inside the libc. So, to
  53 // avoid potential chicken-and-egg problems, it is simple to do a quick_exit
  54 // on assertion failure instead of calling abort. We also don't want to use
  55 // __builtin_trap as it could potentially be implemented using illegal
  56 // instructions which can be very misleading when debugging.
  57 #ifdef NDEBUG
  58 #define LIBC_ASSERT(COND)                                                      \
  59   do {                                                                         \
  60   } while (false)
  61 #else
  62 #define LIBC_ASSERT(COND)                                                      \
  63   do {                                                                         \
  64     if (!(COND)) {                                                             \
  65       __llvm_libc::report_assertion_failure(#COND, __FILE__, __LINE__,         \
  66                                             __PRETTY_FUNCTION__);              \
  67       __llvm_libc::quick_exit(0xFF);                                           \
  68     }                                                                          \
  69   } while (false)
  70 #endif // NDEBUG
  71
  72 #endif // LIBC_COPT_USE_C_ASSERT
  73
  74 #endif // LLVM_LIBC_SRC_SUPPORT_LIBC_ASSERT_H