diff options
Diffstat (limited to 'include/qemu/compiler.h')
| -rw-r--r-- | include/qemu/compiler.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index c797f0d457..554c5ce7df 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -227,4 +227,50 @@ #define SECOND_ARG(first, second, ...) second #define IS_EMPTY_(junk_maybecomma) SECOND_ARG(junk_maybecomma 1, 0) +#ifndef __cplusplus +/* + * Useful in macros that need to declare temporary variables. For example, + * the variable that receives the old value of an atomically-accessed + * variable must be non-qualified, because atomic builtins return values + * through a pointer-type argument as in __atomic_load(&var, &old, MODEL). + * + * This macro has to handle types smaller than int manually, because of + * implicit promotion. int and larger types, as well as pointers, can be + * converted to a non-qualified type just by applying a binary operator. + */ +#define typeof_strip_qual(expr) \ + typeof( \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(expr), bool) || \ + __builtin_types_compatible_p(typeof(expr), const bool) || \ + __builtin_types_compatible_p(typeof(expr), volatile bool) || \ + __builtin_types_compatible_p(typeof(expr), const volatile bool), \ + (bool)1, \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(expr), signed char) || \ + __builtin_types_compatible_p(typeof(expr), const signed char) || \ + __builtin_types_compatible_p(typeof(expr), volatile signed char) || \ + __builtin_types_compatible_p(typeof(expr), const volatile signed char), \ + (signed char)1, \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(expr), unsigned char) || \ + __builtin_types_compatible_p(typeof(expr), const unsigned char) || \ + __builtin_types_compatible_p(typeof(expr), volatile unsigned char) || \ + __builtin_types_compatible_p(typeof(expr), const volatile unsigned char), \ + (unsigned char)1, \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(expr), signed short) || \ + __builtin_types_compatible_p(typeof(expr), const signed short) || \ + __builtin_types_compatible_p(typeof(expr), volatile signed short) || \ + __builtin_types_compatible_p(typeof(expr), const volatile signed short), \ + (signed short)1, \ + __builtin_choose_expr( \ + __builtin_types_compatible_p(typeof(expr), unsigned short) || \ + __builtin_types_compatible_p(typeof(expr), const unsigned short) || \ + __builtin_types_compatible_p(typeof(expr), volatile unsigned short) || \ + __builtin_types_compatible_p(typeof(expr), const volatile unsigned short), \ + (unsigned short)1, \ + (expr)+0)))))) +#endif + #endif /* COMPILER_H */ |