/* compiler.h: macros to abstract away compiler specifics * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. */ #ifndef COMPILER_H #define COMPILER_H #define HOST_BIG_ENDIAN (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) /* HOST_LONG_BITS is the size of a native pointer in bits. */ #define HOST_LONG_BITS (__SIZEOF_POINTER__ * 8) #if defined __clang_analyzer__ || defined __COVERITY__ #define QEMU_STATIC_ANALYSIS 1 #endif #ifdef __cplusplus #define QEMU_EXTERN_C extern "C" #else #define QEMU_EXTERN_C extern #endif #if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__)) # define QEMU_PACKED __attribute__((gcc_struct, packed)) #else # define QEMU_PACKED __attribute__((packed)) #endif #define QEMU_ALIGNED(X) __attribute__((aligned(X))) #ifndef glue #define xglue(x, y) x ## y #define glue(x, y) xglue(x, y) #define stringify(s) tostring(s) #define tostring(s) #s #endif /* Expands into an identifier stemN, where N is another number each time */ #define MAKE_IDENTFIER(stem) glue(stem, __COUNTER__) #ifndef likely #define likely(x) __builtin_expect(!!(x), 1) #define unlikely(x) __builtin_expect(!!(x), 0) #endif #ifndef container_of #define container_of(ptr, type, member) ({ \ const typeof(((type *) 0)->member) *__mptr = (ptr); \ (type *) ((char *) __mptr - offsetof(type, member));}) #endif #define sizeof_field(type, field) sizeof(((type *)0)->field) /* * Calculate the number of bytes up to and including the given 'field' of * 'container'. */ #define endof(container, field) \ (offsetof(container, field) + sizeof_field(container, field)) /* Convert from a base type to a parent type, with compile time checking. */ #define DO_UPCAST(type, field, dev) ( __extension__ ( { \ char __attribute__((unused)) offset_must_be_zero[ \ -offsetof(type, field)]; \ container_of(dev, type, field);})) #define typeof_field(type, field) typeof(((type *)0)->field) #define type_check(t1,t2) ((t1*)0 - (t2*)0) #define QEMU_BUILD_BUG_ON_STRUCT(x) \ struct { \ int:(x) ? -1 : 1; \ } #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg) #define QEMU_BUILD_BUG_ON(x) QEMU_BUILD_BUG_MSG(x, "not expecting: " #x) #define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \ sizeof(QEMU_BUILD_BUG_ON_STRUCT(x))) #if !defined(__clang__) && defined(_WIN32) /* * Map __printf__ to __gnu_printf__ because we want standard format strings even * when MinGW or GLib include files use __printf__. */ # define __printf__ __gnu_printf__ #endif #ifndef __has_warning #define __has_warning(x) 0 /* compatibility with non-clang compilers */ #endif #ifndef __has_feature #define __has_feature(x) 0 /* compatibility with non-clang compilers */ #endif #ifndef __has_builtin #define __has_builtin(x) 0 /* compatibility with non-clang compilers */ #endif #if __has_builtin(__builtin_assume_aligned) || !defined(__clang__) #define HAS_ASSUME_ALIGNED #endif #ifndef __has_attribute #define __has_attribute(x) 0 /* compatibility with older GCC */ #endif #if defined(__SANITIZE_ADDRESS__) || __has_feature(address_sanitizer) # define QEMU_SANITIZE_ADDRESS 1 #endif #if defined(__SANITIZE_THREAD__) || __has_feature(thread_sanitizer) # define QEMU_SANITIZE_THREAD 1 #endif /* * GCC doesn't provide __has_attribute() until GCC 5, but we know all the GCC * versions we support have the "flatten" attribute. Clang may not have the * "flatten" attribute but always has __has_attribute() to check for it. */ #if __has_attribute(flatten) || !defined(__clang__) # define QEMU_FLATTEN __attribute__((flatten)) #else # define QEMU_FLATTEN #endif /* * If __attribute__((error)) is present, use it to produce an error at * compile time. Otherwise, one must wait for the linker to diagnose * the missing symbol. */ #if __has_attribute(error) # define QEMU_ERROR(X) __attribute__((error(X))) #else # define QEMU_ERROR(X) #endif /* * The nonstring variable attribute specifies that an object or member * declaration with type array of char or pointer to char is intended * to store character arrays that do not necessarily contain a terminating * NUL character. This is useful in detecting uses of such arrays or pointers * with functions that expect NUL-terminated strings, and to avoid warnings * when such an array or pointer is used as an argument to a bounded string * manipulation function such as strncpy. */ #if __has_attribute(nonstring) # define QEMU_NONSTRING __attribute__((nonstring)) #else # define QEMU_NONSTRING #endif /* * Forced inlining may be desired to encourage constant propagation * of function parameters. However, it can also make debugging harder, * so disable it for a non-optimizing build. */ #if defined(__OPTIMIZE__) #define QEMU_ALWAYS_INLINE __attribute__((always_inline)) #else #define QEMU_ALWAYS_INLINE #endif /** * In most cases, normal "fallthrough" comments are good enough for * switch-case statements, but sometimes the compiler has problems * with those. In that case you can use QEMU_FALLTHROUGH instead. */ #if __has_attribute(fallthrough) # define QEMU_FALLTHROUGH __attribute__((fallthrough)) #else # define QEMU_FALLTHROUGH do {} while (0) /* fallthrough */ #endif #ifdef CONFIG_CFI /* * If CFI is enabled, use an attribute to disable cfi-icall on the following * function */ #define QEMU_DISABLE_CFI __attribute__((no_sanitize("cfi-icall"))) #else /* If CFI is not enabled, use an empty define to not change the behavior */ #define QEMU_DISABLE_CFI #endif /* * Apple clang version 14 has a bug in its __builtin_subcll(); define * BUILTIN_SUBCLL_BROKEN for the offending versions so we can avoid it. * When a version of Apple clang which has this bug fixed is released * we can add an upper bound to this check. * See https://gitlab.com/qemu-project/qemu/-/issues/1631 * and https://gitlab.com/qemu-project/qemu/-/issues/1659 for details. * The bug never made it into any upstream LLVM releases, only Apple ones. */ #if defined(__apple_build_version__) && __clang_major__ >= 14 #define BUILTIN_SUBCLL_BROKEN #endif #if __has_attribute(annotate) #define QEMU_ANNOTATE(x) __attribute__((annotate(x))) #else #define QEMU_ANNOTATE(x) #endif #if __has_attribute(used) # define QEMU_USED __attribute__((used)) #else # define QEMU_USED #endif /* * Ugly CPP trick that is like "defined FOO", but also works in C * code. Useful to replace #ifdef with "if" statements; assumes * the symbol was defined with Meson's "config.set()", so it is empty * if defined. */ #define IS_ENABLED(x) IS_EMPTY(x) #define IS_EMPTY_JUNK_ junk, #define IS_EMPTY(value) IS_EMPTY_(IS_EMPTY_JUNK_##value) /* Expands to either SECOND_ARG(junk, 1, 0) or SECOND_ARG(IS_EMPTY_JUNK_CONFIG_FOO 1, 0) */ #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 */