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 #include "src/__support/OSUtil/io.h"
  13 #include "src/__support/OSUtil/quick_exit.h"
  14 #include "src/__support/integer_to_string.h"
  15 #include "src/__support/macros/attributes.h" // For LIBC_INLINE
  16
  17 namespace __llvm_libc {
  18
  19 LIBC_INLINE void report_assertion_failure(const char *assertion,
  20                                           const char *filename, unsigned line,
  21                                           const char *funcname) {
  22   char line_str[IntegerToString::dec_bufsize<unsigned>()];
  23   IntegerToString::dec(line, line_str);
  24   __llvm_libc::write_to_stderr(filename);
  25   __llvm_libc::write_to_stderr(":");
  26   __llvm_libc::write_to_stderr(line_str);
  27   __llvm_libc::write_to_stderr(": Assertion failed: '");
  28   __llvm_libc::write_to_stderr(assertion);
  29   __llvm_libc::write_to_stderr("' in function: '");
  30   __llvm_libc::write_to_stderr(funcname);
  31   __llvm_libc::write_to_stderr("'\n");
  32 }
  33
  34 } // namespace __llvm_libc
  35
  36 #ifdef LIBC_ASSERT
  37 #error "Unexpected: LIBC_ASSERT macro already defined"
  38 #endif
  39
  40 // The public "assert" macro calls abort on failure. Should it be same here?
  41 // The libc intenral assert can fire from anywhere inside the libc. So, to
  42 // avoid potential chicken-and-egg problems, it is simple to do a quick_exit
  43 // on assertion failure instead of calling abort. We also don't want to use
  44 // __builtin_trap as it could potentially be implemented using illegal
  45 // instructions which can be very misleading when debugging.
  46 #ifdef NDEBUG
  47 #define LIBC_ASSERT(COND)                                                      \
  48   do {                                                                         \
  49   } while (false)
  50 #else
  51 #define LIBC_ASSERT(COND)                                                      \
  52   do {                                                                         \
  53     if (!(COND)) {                                                             \
  54       __llvm_libc::report_assertion_failure(#COND, __FILE__, __LINE__,         \
  55                                             __PRETTY_FUNCTION__);              \
  56       __llvm_libc::quick_exit(0xFF);                                           \
  57     }                                                                          \
  58   } while (false)
  59 #endif // NDEBUG
  60
  61 #endif // LLVM_LIBC_SRC_SUPPORT_LIBC_ASSERT_H