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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-06-08 03:38:29 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-06-08 18:55:02 +0200 |
| commit | a6e80f36afca7b7f6eeaf557cdbd1effca5cc810 (patch) | |
| tree | e272207624986109e767bd2790c921adcf240f16 /validation | |
| parent | 35b50cdb51b6c32262103672277135cb0b5311e6 (diff) | |
| download | sparse-dev-a6e80f36afca7b7f6eeaf557cdbd1effca5cc810.tar.gz | |
builtin: add support for __has_builtin()
Sparse has support for a subset of GCC's large collection of builtin
functions. As for GCC, it's not easy to know which builtins are
supported in which versions.
clang has a good solution to this problem: it adds the checking macro
__has_builtin(<name>) which evaluates to 1 if <name> is a builtin
function supported by the compiler and 0 otherwise.
It can be used like:
#if __has_builtin(__builtin_clz)
#define clz(x) __builtin_clz(x)
#else
...
#endif
It's possible or probable that GCC will have this soon too:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66970
Add support for this __has_builtin() macro by extending
the evaluation of preprocessor expressions very much like
it is done to support defined().
Note: Some function-like builtin features, like __builtin_offset(), are
considered as a kind of keyword/operator and processed as such.
These are *not* considered as builtins by __has_builtin().
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Diffstat (limited to 'validation')
| -rw-r--r-- | validation/preprocessor/has-builtin.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/validation/preprocessor/has-builtin.c b/validation/preprocessor/has-builtin.c new file mode 100644 index 00000000..03272fc9 --- /dev/null +++ b/validation/preprocessor/has-builtin.c @@ -0,0 +1,43 @@ +#ifndef __has_builtin +__has_builtin()??? Quesako? +#define __has_builtin(x) 0 +#else +"has __has_builtin(), yeah!" +#endif + +#if __has_builtin(nothing) +#error "not a builtin!" +#endif + +#if __has_builtin(__builtin_offsetof) \ + || __has_builtin(__builtin_types_compatible_p) +#error "builtin ops are not builtin functions!" +#endif + +#if __has_builtin(__builtin_va_list) \ + || __has_builtin(__builtin_ms_va_list) +#error "builtin types are not builtin functions!" +#endif + +#if __has_builtin(__builtin_abs) +abs +#endif + +#if __has_builtin(__builtin_constant_p) +constant_p +#endif + +123 __has_builtin(abc) def + +/* + * check-name: has-builtin + * check-command: sparse -E $file + * + * check-output-start + +"has __has_builtin(), yeah!" +abs +constant_p +123 0 def + * check-output-end + */ |