diff options
| author | Michael Paquier | 2020-02-03 05:48:42 +0000 |
|---|---|---|
| committer | Michael Paquier | 2020-02-03 05:48:42 +0000 |
| commit | f1f10a1ba9e17e606a7b217ccccdd3cc4d8cb771 (patch) | |
| tree | 2ad0e6861232bcef32bc0924469de3958b86cdb4 /src/include/c.h | |
| parent | 6148e2b9a6399b77e10e277c32d701b84703820f (diff) | |
Add declaration-level assertions for compile-time checks
Those new assertions can be used at file scope, outside of any function
for compilation checks. This commit provides implementations for C and
C++, and fallback implementations.
Author: Peter Smith
Reviewed-by: Andres Freund, Kyotaro Horiguchi, Dagfinn Ilmari Mannsåker,
Michael Paquier
Discussion: https://postgr.es/m/201DD0641B056142AC8C6645EC1B5F62014B8E8030@SYD1217
Diffstat (limited to 'src/include/c.h')
| -rw-r--r-- | src/include/c.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/include/c.h b/src/include/c.h index 6898229b43e..d10b9812fbe 100644 --- a/src/include/c.h +++ b/src/include/c.h @@ -832,8 +832,10 @@ extern void ExceptionalCondition(const char *conditionName, * throw a compile error using the "errmessage" (a string literal). * * gcc 4.6 and up supports _Static_assert(), but there are bizarre syntactic - * placement restrictions. These macros make it safe to use as a statement - * or in an expression, respectively. + * placement restrictions. Macros StaticAssertStmt() and StaticAssertExpr() + * make it safe to use as a statement or in an expression, respectively. + * The macro StaticAssertDecl() is suitable for use at file scope (outside of + * any function). * * Otherwise we fall back on a kluge that assumes the compiler will complain * about a negative width for a struct bit-field. This will not include a @@ -845,11 +847,15 @@ extern void ExceptionalCondition(const char *conditionName, do { _Static_assert(condition, errmessage); } while(0) #define StaticAssertExpr(condition, errmessage) \ ((void) ({ StaticAssertStmt(condition, errmessage); true; })) +#define StaticAssertDecl(condition, errmessage) \ + _Static_assert(condition, errmessage) #else /* !HAVE__STATIC_ASSERT */ #define StaticAssertStmt(condition, errmessage) \ ((void) sizeof(struct { int static_assert_failure : (condition) ? 1 : -1; })) #define StaticAssertExpr(condition, errmessage) \ StaticAssertStmt(condition, errmessage) +#define StaticAssertDecl(condition, errmessage) \ + extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1]) #endif /* HAVE__STATIC_ASSERT */ #else /* C++ */ #if defined(__cpp_static_assert) && __cpp_static_assert >= 200410 @@ -857,12 +863,16 @@ extern void ExceptionalCondition(const char *conditionName, static_assert(condition, errmessage) #define StaticAssertExpr(condition, errmessage) \ ({ static_assert(condition, errmessage); }) -#else +#define StaticAssertDecl(condition, errmessage) \ + static_assert(condition, errmessage) +#else /* !__cpp_static_assert */ #define StaticAssertStmt(condition, errmessage) \ do { struct static_assert_struct { int static_assert_failure : (condition) ? 1 : -1; }; } while(0) #define StaticAssertExpr(condition, errmessage) \ ((void) ({ StaticAssertStmt(condition, errmessage); })) -#endif +#define StaticAssertDecl(condition, errmessage) \ + extern void static_assert_func(int static_assert_failure[(condition) ? 1 : -1]) +#endif /* __cpp_static_assert */ #endif /* C++ */ |