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| author | Cyrill Gorcunov <gorcunov@gmail.com> | 2018-02-25 17:09:11 +0300 |
|---|---|---|
| committer | Cyrill Gorcunov <gorcunov@gmail.com> | 2018-02-25 17:09:11 +0300 |
| commit | 8ba28e13ea4453a587d08e5533e60f4ff2b4781a (patch) | |
| tree | 87650f9d9cc2e77579e6cafff8ece738d4cae72b | |
| parent | fb9e00a1c3c3ec89d385175baa6e66b15318bda8 (diff) | |
| download | nasm-8ba28e13ea4453a587d08e5533e60f4ff2b4781a.tar.gz | |
compiler: Add fallthrough() helper
https://bugzilla.nasm.us/show_bug.cgi?id=3392465
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
| -rw-r--r-- | aclocal.m4 | 26 | ||||
| -rw-r--r-- | configure.ac | 5 | ||||
| -rw-r--r-- | include/compiler.h | 9 |
3 files changed, 40 insertions, 0 deletions
@@ -199,3 +199,29 @@ inline int foo(int x) [Define to 1 if your compiler supports C99 extern inline])], [AC_MSG_RESULT([no]) PA_ADD_CFLAGS([-fgnu89-inline])])]) + +dnl -------------------------------------------------------------------------- +dnl PA_CHECK_FALLTHROUGH_ATTRIBUTE +dnl -------------------------------------------------------------------------- +AC_DEFUN(PA_CHECK_FALLTHROUGH_ATTRIBUTE, +[AC_MSG_CHECKING([if $CC supports fallthrough attribute]) + AC_COMPILE_IFELSE([AC_LANG_SOURCE([ +AC_INCLUDES_DEFAULT +int main(int argc, char **argv) +{ + switch (argc) { + case 1: + (void)argc; + __attribute__((fallthrough)); + default: + (void)argv; + break; + } + return argc; +} + ])], + [AC_MSG_RESULT([yes]) + AC_DEFINE([HAVE_FALLTHROUGH_ATTRIBUTE], 1, + [Define to 1 if your compiler supports __attribute__((fallthrough))])], + [AC_MSG_RESULT([no])]) +]) diff --git a/configure.ac b/configure.ac index 44c9e179..2f4d26fa 100644 --- a/configure.ac +++ b/configure.ac @@ -294,6 +294,11 @@ dnl options. dnl PA_CHECK_BAD_STDC_INLINE +dnl Figure out if we can use fallthrough attribute or +dnl should provide simple comment instead. +dnl +PA_CHECK_FALLTHROUGH_ATTRIBUTE + dnl dnl support ccache dnl diff --git a/include/compiler.h b/include/compiler.h index fb146af4..f4393518 100644 --- a/include/compiler.h +++ b/include/compiler.h @@ -241,6 +241,15 @@ size_t strnlen(const char *s, size_t maxlen); #endif /* + * Fallthrough handling. + */ +#ifdef HAVE_FALLTHROUGH_ATTRIBUTE +# define fallthrough() __attribute__((fallthrough)) +#else +# define fallthrough() /* fall through */ +#endif + +/* * Hints to the compiler that a particular branch of code is more or * less likely to be taken. */ |