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