| /* 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_IDENTIFIER(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 */ |
