diff options
Diffstat (limited to 'include/qemu/compiler.h')
| -rw-r--r-- | include/qemu/compiler.h | 206 |
1 files changed, 121 insertions, 85 deletions
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h index 261842beae..c797f0d457 100644 --- a/include/qemu/compiler.h +++ b/include/qemu/compiler.h @@ -7,28 +7,22 @@ #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 -/*---------------------------------------------------------------------------- -| The macro QEMU_GNUC_PREREQ tests for minimum version of the GNU C compiler. -| The code is a copy of SOFTFLOAT_GNUC_PREREQ, see softfloat-macros.h. -*----------------------------------------------------------------------------*/ -#if defined(__GNUC__) && defined(__GNUC_MINOR__) -# define QEMU_GNUC_PREREQ(maj, min) \ - ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min)) +#ifdef __cplusplus +#define QEMU_EXTERN_C extern "C" #else -# define QEMU_GNUC_PREREQ(maj, min) 0 +#define QEMU_EXTERN_C extern #endif -#define QEMU_NORETURN __attribute__ ((__noreturn__)) - -#define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) - -#define QEMU_SENTINEL __attribute__((sentinel)) - -#if defined(_WIN32) +#if defined(_WIN32) && (defined(__x86_64__) || defined(__i386__)) # define QEMU_PACKED __attribute__((gcc_struct, packed)) #else # define QEMU_PACKED __attribute__((packed)) @@ -39,15 +33,14 @@ #ifndef glue #define xglue(x, y) x ## y #define glue(x, y) xglue(x, y) -#define stringify(s) tostring(s) -#define tostring(s) #s +#define stringify(s) tostring(s) +#define tostring(s) #s #endif -#ifndef likely -#if __GNUC__ < 3 -#define __builtin_expect(x, n) (x) -#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 @@ -60,15 +53,18 @@ #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. */ -#ifdef __GNUC__ #define DO_UPCAST(type, field, dev) ( __extension__ ( { \ char __attribute__((unused)) offset_must_be_zero[ \ -offsetof(type, field)]; \ container_of(dev, type, field);})) -#else -#define DO_UPCAST(type, field, dev) container_of(dev, type, field) -#endif #define typeof_field(type, field) typeof(((type *)0)->field) #define type_check(t1,t2) ((t1*)0 - (t2*)0) @@ -78,39 +74,23 @@ int:(x) ? -1 : 1; \ } -/* QEMU_BUILD_BUG_MSG() emits the message given if _Static_assert is - * supported; otherwise, it will be omitted from the compiler error - * message (but as it remains present in the source code, it can still - * be useful when debugging). */ -#if defined(CONFIG_STATIC_ASSERT) #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg) -#elif defined(__COUNTER__) -#define QEMU_BUILD_BUG_MSG(x, msg) typedef QEMU_BUILD_BUG_ON_STRUCT(x) \ - glue(qemu_build_bug_on__, __COUNTER__) __attribute__((unused)) -#else -#define QEMU_BUILD_BUG_MSG(x, msg) -#endif #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 __GNUC__ -# if !QEMU_GNUC_PREREQ(4, 4) - /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */ -# define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m))) -# else - /* Use gnu_printf when supported (qemu uses standard format strings). */ -# define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m))) -# if 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 -# endif -#else -#define GCC_FMT_ATTR(n, m) +#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 @@ -129,6 +109,14 @@ #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 @@ -151,44 +139,92 @@ # define QEMU_ERROR(X) #endif -/* Implement C11 _Generic via GCC builtins. Example: - * - * QEMU_GENERIC(x, (float, sinf), (long double, sinl), sin) (x) - * - * The first argument is the discriminator. The last is the default value. - * The middle ones are tuples in "(type, expansion)" format. +/* + * 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 -/* First, find out the number of generic cases. */ -#define QEMU_GENERIC(x, ...) \ - QEMU_GENERIC_(typeof(x), __VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0) +/* + * 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 -/* There will be extra arguments, but they are not used. */ -#define QEMU_GENERIC_(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, count, ...) \ - QEMU_GENERIC##count(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9) +/** + * 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 -/* Two more helper macros, this time to extract items from a parenthesized - * list. +#ifdef CONFIG_CFI +/* + * If CFI is enabled, use an attribute to disable cfi-icall on the following + * function */ -#define QEMU_FIRST_(a, b) a -#define QEMU_SECOND_(a, b) b - -/* ... and a final one for the common part of the "recursion". */ -#define QEMU_GENERIC_IF(x, type_then, else_) \ - __builtin_choose_expr(__builtin_types_compatible_p(x, \ - QEMU_FIRST_ type_then), \ - QEMU_SECOND_ type_then, else_) - -/* CPP poor man's "recursion". */ -#define QEMU_GENERIC1(x, a0, ...) (a0) -#define QEMU_GENERIC2(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC1(x, __VA_ARGS__)) -#define QEMU_GENERIC3(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC2(x, __VA_ARGS__)) -#define QEMU_GENERIC4(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC3(x, __VA_ARGS__)) -#define QEMU_GENERIC5(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC4(x, __VA_ARGS__)) -#define QEMU_GENERIC6(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC5(x, __VA_ARGS__)) -#define QEMU_GENERIC7(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC6(x, __VA_ARGS__)) -#define QEMU_GENERIC8(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC7(x, __VA_ARGS__)) -#define QEMU_GENERIC9(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC8(x, __VA_ARGS__)) -#define QEMU_GENERIC10(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC9(x, __VA_ARGS__)) +#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) #endif /* COMPILER_H */ |