blob: 925322ff441af3761a4e9d1495ed08890fa4d12d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
// This code is compiled directly on many platforms, including client
// platforms like Windows, Mac, and embedded systems. Before making
// any changes here, make sure that you're not breaking any platforms.
//
#ifndef DYNAMIC_DEPTH_INTERNAL_BASE_MACROS_H_ // NOLINT
#define DYNAMIC_DEPTH_INTERNAL_BASE_MACROS_H_ // NOLINT
#include <stddef.h> // For size_t
#include "base/port.h"
// The FALLTHROUGH_INTENDED macro can be used to annotate implicit fall-through
// between switch labels:
// switch (x) {
// case 40:
// case 41:
// if (truth_is_out_there) {
// ++x;
// FALLTHROUGH_INTENDED; // Use instead of/along with annotations in
// // comments.
// } else {
// return x;
// }
// case 42:
// ...
//
// As shown in the example above, the FALLTHROUGH_INTENDED macro should be
// followed by a semicolon. It is designed to mimic control-flow statements
// like 'break;', so it can be placed in most places where 'break;' can, but
// only if there are no statements on the execution path between it and the
// next switch label.
//
// When compiled with clang in C++11 mode, the FALLTHROUGH_INTENDED macro is
// expanded to [[clang::fallthrough]] attribute, which is analysed when
// performing switch labels fall-through diagnostic ('-Wimplicit-fallthrough').
// See clang documentation on language extensions for details:
// http://clang.llvm.org/docs/AttributeReference.html#fallthrough-clang-fallthrough
//
// When used with unsupported compilers, the FALLTHROUGH_INTENDED macro has no
// effect on diagnostics.
//
// In either case this macro has no effect on runtime behavior and performance
// of code.
#if defined(__clang__) && defined(LANG_CXX11) && defined(__has_warning)
#if __has_feature(cxx_attributes) && __has_warning("-Wimplicit-fallthrough")
#define FALLTHROUGH_INTENDED [[clang::fallthrough]] // NOLINT
#endif
#endif
#ifndef FALLTHROUGH_INTENDED // NOLINT
#define FALLTHROUGH_INTENDED \
do { \
} while (0)
#endif
#endif // DYNAMIC_DEPTH_INTERNAL_BASE_MACROS_H_ // NOLINT
|
