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#if defined(LIBC_COPT_USE_C_ASSERT) || !defined(LIBC_FULL_BUILD)
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/exit.h"
24#include "src/__support/OSUtil/io.h"
25#include "src/__support/integer_to_string.h"
26#include "src/__support/macros/attributes.h" // For LIBC_INLINE
27#include "src/__support/macros/config.h"
28#include "src/__support/macros/optimization.h" // For LIBC_UNLIKELY
29
30namespace LIBC_NAMESPACE_DECL {
31
32// This is intended to be removed in a future patch to use a similar design to
33// below, but it's necessary for the external assert.
34LIBC_INLINE void report_assertion_failure(const char *assertion,
35 const char *filename, unsigned line,
36 const char *funcname) {
37 const IntegerToString<unsigned> line_buffer(line);
38 write_to_stderr(filename);
39 write_to_stderr(":");
40 write_to_stderr(line_buffer.view());
41 write_to_stderr(": Assertion failed: '");
42 write_to_stderr(assertion);
43 write_to_stderr("' in function: '");
44 write_to_stderr(funcname);
45 write_to_stderr("'\n");
46}
47
48} // namespace LIBC_NAMESPACE_DECL
49
50#ifdef LIBC_ASSERT
51#error "Unexpected: LIBC_ASSERT macro already defined"
52#endif
53
54// The public "assert" macro calls abort on failure. Should it be same here?
55// The libc internal assert can fire from anywhere inside the libc. So, to
56// avoid potential chicken-and-egg problems, it is simple to do an exit
57// on assertion failure instead of calling abort. We also don't want to use
58// __builtin_trap as it could potentially be implemented using illegal
59// instructions which can be very misleading when debugging.
60#ifdef NDEBUG
61#define LIBC_ASSERT(COND) \
62 do { \
63 } while (false)
64#else
65
66// Convert __LINE__ to a string using macros. The indirection is necessary
67// because otherwise it will turn "__LINE__" into a string, not its value. The
68// value is evaluated in the indirection step.
69#define __LIBC_MACRO_TO_STR(x) #x
70#define __LIBC_MACRO_TO_STR_INDIR(y) __LIBC_MACRO_TO_STR(y)
71#define __LIBC_LINE_STR__ __LIBC_MACRO_TO_STR_INDIR(__LINE__)
72
73#define LIBC_ASSERT(COND) \
74 do { \
75 if (LIBC_UNLIKELY(!(COND))) { \
76 LIBC_NAMESPACE::write_to_stderr(__FILE__ ":" __LIBC_LINE_STR__ \
77 ": Assertion failed: '" #COND \
78 "' in function: '"); \
79 LIBC_NAMESPACE::write_to_stderr(__PRETTY_FUNCTION__); \
80 LIBC_NAMESPACE::write_to_stderr("'\n"); \
81 LIBC_NAMESPACE::internal::exit(0xFF); \
82 } \
83 } while (false)
84#endif // NDEBUG
85
86#endif // LIBC_COPT_USE_C_ASSERT
87
88#endif // LLVM_LIBC_SRC___SUPPORT_LIBC_ASSERT_H
89