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Diffstat (limited to 'include/zircon/compiler.h')
| -rw-r--r-- | include/zircon/compiler.h | 380 |
1 files changed, 0 insertions, 380 deletions
diff --git a/include/zircon/compiler.h b/include/zircon/compiler.h deleted file mode 100644 index 45ea8d6..0000000 --- a/include/zircon/compiler.h +++ /dev/null @@ -1,380 +0,0 @@ -// Copyright 2016 The Fuchsia Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -// This file provides macros for unifying differences in C/C++ compiler -// extensions, and providing backwards-compatibility for older C++ standards. -// -// May be included by C, C++, and assembly files. - -#ifndef ZIRCON_COMPILER_H_ -#define ZIRCON_COMPILER_H_ - -// Ensure we are using a known compiler. -#if !defined(__GNUC__) && !defined(__clang__) -#error "Unrecognized compiler!" -#endif - -// Feature checking macros. -// -// If feature checking macros are not provided by the compiler, we assume that the -// checked features are unavailable. - -// C++11 attribute checking. -#ifndef __has_cpp_attribute -#define __has_cpp_attribute(x) 0 -#endif - -// clang feature checking. -#ifndef __has_feature -#define __has_feature(x) 0 -#endif - -#if !defined(__ASSEMBLER__) - -// C++ header guards. -#ifdef __cplusplus -#define __BEGIN_CDECLS extern "C" { -#define __END_CDECLS } -#else -#define __BEGIN_CDECLS -#define __END_CDECLS -#endif - -// -// Function and data attributes. -// - -// Function inlining directives. -#define __NO_INLINE __attribute__((__noinline__)) -#define __ALWAYS_INLINE __attribute__((__always_inline__)) - -// Avoid issuing a warning if the given variable/function is unused. -#ifndef __cplusplus -#define __UNUSED __attribute__((__unused__)) -#endif - -// Pack the given structure or class, omitting padding between fields. -#define __PACKED __attribute__((packed)) - -// Place the variable in thread-local storage. -#define __THREAD __thread - -// Align the variable or type to at least `x` bytes. `x` must be a power of two. -#define __ALIGNED(x) __attribute__((aligned(x))) - -// Declare the given function will never return. (such as `exit`, `abort`, etc). -#define __NO_RETURN __attribute__((__noreturn__)) - -// Warn if the result of this function is ignored by the caller. -#define __WARN_UNUSED_RESULT __attribute__((__warn_unused_result__)) - -// Declare that the given stack variable may be left uninitialized if it does -// not have a specified initial value. -#if defined(__clang__) -#define __UNINITIALIZED __attribute__((uninitialized)) -#else -#define __UNINITIALIZED -#endif - -// Warn if a constructed objected is not used by the caller. -// -// Generates a warning on code like this: -// -// { -// AutoLock(&mutex); // error: the AutoLock goes out of scope immediately. -// locked_variable = 42; -// } -// -// C++17 defines [[nodiscard]] to do this, but some older but supported -// versions of GCC support [[nodiscard]] on functions but not constructors. -// Having a separate __WARN_UNUSED_CONSTRUCTOR allows us to hide the attribute -// only on constructors on old versions of GCC. -#if defined(__cplusplus) -#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 10)) -#define __WARN_UNUSED_CONSTRUCTOR [[nodiscard]] -#else -#define __WARN_UNUSED_CONSTRUCTOR -#endif -#endif - -// Mark a function or variable as deprecated, warning about any callers. -#if !defined(__DEPRECATE) -#define __DEPRECATE __attribute__((__deprecated__)) -#endif - -// Mark a function as having no visible side-effects: It may read memory, but -// will not modify it. -// -// Multiple calls to the function may be optimized away by the compiler. -#define __PURE __attribute__((__pure__)) - -// Mark a function has having an output determined solely on its input -// parameters (but not memory). -// -// Multiple calls to the function may be optimized away by the compiler, even -// if memory is modified between calls. -#define __CONST __attribute__((__const__)) - -// The given function is malloc-like, returning a pointer to new, unused -// memory. -// -// The compiler can assume that the returned pointer does not alias any other -// pointer, which may help the compiler optimize the program. -#define __MALLOC __attribute__((__malloc__)) - -// The given function allocates memory of size argument |x| or |x| * |y| and returns -// a pointer to that memory. Argument indexes are one-based. The compiler can use this -// information to support compile-time __builtin_object_size checks. -#if defined(__clang__) -#define __ALLOC_SIZE(x, ...) __attribute__((__alloc_size__(x, ##__VA_ARGS__))) -#else -// TODO(fxrev.dev/571541): GCC warns incorrectly on constructs that could result in -// large allocations for type reasons but cannot for other (checked) reasons. Disable -// the attribute there. -#define __ALLOC_SIZE(x, ...) -#endif - -// Indicate that the given function takes a printf/scanf-style format string. -// -// "__fmt" is the argument number of the format string, indexed from 1. -// "__varargs" is the argument number of the variable args "..." argument -// counting from 1. -// -// If applied to a class method, the implicit "this" parameter counts as the -// first argument. -#define __PRINTFLIKE(__fmt, __varargs) __attribute__((__format__(__printf__, __fmt, __varargs))) -#define __SCANFLIKE(__fmt, __varargs) __attribute__((__format__(__scanf__, __fmt, __varargs))) - -// Indicate that the `n`th argument to a function is non-null. -// -// The compiler will emit warnings if it can prove an argument is null, and -// may optimise assuming that the values are non-null. -#define __NONNULL(n) __attribute__((__nonnull__ n)) - -// The given function is a "leaf", and won't call further functions. -// -// Leaf functions must only return directly, and not call back into the -// current compilation unit (either via direct calls, or function pointers). -// -// May help the compiler optimize calls to the function in some cases. -#define __LEAF_FN __attribute__((__leaf__)) - -// Mark the given function or variable as `constexpr`. -// -// Used in code included by both C and C++. Code that is pure C++ should use -// `constexpr` directly. -#ifdef __cplusplus -#define __CONSTEXPR constexpr -#else -#define __CONSTEXPR -#endif - -// Optimize the given function using custom flags. -// -// For example, -// -// __OPTIMIZE("O3") int myfunction() { ... } -// -// will cause GCC to optimize the function at the O3 level, independent -// of what the compiler optimization flags are. -#if !defined(__clang__) -#define __OPTIMIZE(x) __attribute__((__optimize__(x))) -#else -#define __OPTIMIZE(x) -#endif - -// Indicate the given function should not use LLVM's stack hardening features, -// but instead put all local variables on the standard stack. -// -// c.f. https://clang.llvm.org/docs/SafeStack.html -#if defined(__clang__) -#define __NO_SAFESTACK __attribute__((__no_sanitize__("safe-stack", "shadow-call-stack"))) -#else -#define __NO_SAFESTACK -#endif - -// The given C++ class or struct need not have a unique address when part of -// a larger struct or class, but can be safely collapsed into a zero-byte -// object by the compiler. -#if __has_cpp_attribute(no_unique_address) -#define __NO_UNIQUE_ADDRESS [[no_unique_address]] -#elif __has_cpp_attribute(msvc::no_unique_address) -// msvc targets, as used by efi, have a different attribute name, even when -// targeting C++20. -#define __NO_UNIQUE_ADDRESS [[msvc::no_unique_address]] -#else -#define __NO_UNIQUE_ADDRESS -#endif - -// Indicate that the given function should be treated by the Clang static -// analyzer as if it doesn't return. -// -// A workaround to help static analyzer identify assertion failures -#if defined(__clang__) -#define __ANALYZER_CREATE_SINK __attribute__((analyzer_noreturn)) -#else -#define __ANALYZER_CREATE_SINK -#endif - -// Mark the given function as externally visible, and shouldn't be optimized -// away by link-time optimizations or whole-program optimizations. -#if !defined(__clang__) -#define __EXTERNALLY_VISIBLE __attribute__((__externally_visible__)) -#else -#define __EXTERNALLY_VISIBLE -#endif - -// Declare that this function declaration should be emitted as an alias for -// another function. -#define __ALIAS(x) __attribute__((__alias__(x))) - -// Place the given global into a particular linker section. -#define __SECTION(x) __attribute__((__section__(x))) - -// The given function or global should be given a weak symbol, or a weak -// alias to another symbol. -#define __WEAK __attribute__((__weak__)) -#define __WEAK_ALIAS(x) __attribute__((__weak__, __alias__(x))) - -// The given static variable should still be emitted by the compiler, even if it -// appears unused to the compiler. -// -// Rarely needed. Not to be confused with "__UNUSED", which avoids the -// compiler warning if a variable appears unused. -#define __ALWAYS_EMIT __attribute__((__used__)) - -// Declare this object's ELF symbol visibility. -#define __EXPORT __attribute__((__visibility__("default"))) -#define __LOCAL __attribute__((__visibility__("hidden"))) - -// -// Builtin functions. -// - -// Provide a hint to the compiler that the given expression is likely/unlikely -// to be true. -// -// if (unlikely(status != ZX_OK)) { -// error(...); -// } -// -#ifndef likely -#define likely(x) __builtin_expect(!!(x), 1) -#endif - -#ifndef unlikely -#define unlikely(x) __builtin_expect(!!(x), 0) -#endif - -// Return the program counter of the calling function. -#define __GET_CALLER(x) __builtin_return_address(0) - -// Return the address of the current stack frame. -#define __GET_FRAME(x) __builtin_frame_address(0) - -// Return true if the given expression is a known compile-time constant. -#define __ISCONSTANT(x) __builtin_constant_p(x) - -// Assume this branch of code cannot be reached. -#define __UNREACHABLE __builtin_unreachable() - -// Get the offset of `field` from the beginning of the struct or class `type`. -#define __offsetof(type, field) __builtin_offsetof(type, field) - -// Perform an arithmetic operation, returning "true" if the operation overflowed. -// -// Equivalent to: { *result = a + b; return _overflow_occurred; } -#define add_overflow(a, b, result) __builtin_add_overflow(a, b, result) -#define sub_overflow(a, b, result) __builtin_sub_overflow(a, b, result) -#define mul_overflow(a, b, result) __builtin_mul_overflow(a, b, result) - -// Indicate the given case of a switch statement is intended to fall through -// to the next case, and avoid generating a compiler warning. -// -// switch (n) { -// case 0: -// case 1: -// handle_zero_and_one_case(); -// __FALLTHROUGH; -// default: -// handle_all_cases(); -// break; -// } -// -#if defined(__cplusplus) -#define __FALLTHROUGH [[fallthrough]] -#elif defined(__cplusplus) && defined(__clang__) -#define __FALLTHROUGH [[clang::fallthrough]] -// The GNU style attribute is supported by Clang for C code, but __GNUC__ for -// clang right now is 4. -#elif __GNUC__ >= 7 || (!defined(__cplusplus) && defined(__clang__)) -#define __FALLTHROUGH __attribute__((__fallthrough__)) -#else -#define __FALLTHROUGH \ - do { \ - } while (0) -#endif - -// Locking annotations. -// -// The following annotations allow compile-time checking that annotated data -// is only accessed while holding the correct locks. -// -// The annotations are only supported by Clang, and frequently used with C++ -// standard library types in userspace, so only enable in Clang when we know -// that the C++ standard library types are annotated or if we're in kernel -// code. -#if defined(__clang__) && (defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS) || defined(_KERNEL)) -#define __THREAD_ANNOTATION(x) __attribute__((x)) -#else -#define __THREAD_ANNOTATION(x) -#endif -#define __TA_CAPABILITY(x) __THREAD_ANNOTATION(__capability__(x)) -#define __TA_GUARDED(x) __THREAD_ANNOTATION(__guarded_by__(x)) -#define __TA_ACQUIRE(...) __THREAD_ANNOTATION(__acquire_capability__(__VA_ARGS__)) -#define __TA_ACQUIRE_SHARED(...) __THREAD_ANNOTATION(__acquire_shared_capability__(__VA_ARGS__)) -#define __TA_TRY_ACQUIRE(...) __THREAD_ANNOTATION(__try_acquire_capability__(__VA_ARGS__)) -#define __TA_TRY_ACQUIRE_SHARED(...) \ - __THREAD_ANNOTATION(__try_acquire_shared_capability__(__VA_ARGS__)) -// Neither ACQUIRED_BEFORE nor ACQUIRED_AFTER are implemented in clang. Users of these macros must -// not rely upon them to catch lock ordering bugs, and must treat them as documentation only. -// See: -// https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#acquired-before-and-acquired-after-are-currently-unimplemented -#define __TA_ACQUIRED_BEFORE(...) __THREAD_ANNOTATION(__acquired_before__(__VA_ARGS__)) -#define __TA_ACQUIRED_AFTER(...) __THREAD_ANNOTATION(__acquired_after__(__VA_ARGS__)) -#define __TA_RELEASE(...) __THREAD_ANNOTATION(__release_capability__(__VA_ARGS__)) -#define __TA_RELEASE_SHARED(...) __THREAD_ANNOTATION(__release_shared_capability__(__VA_ARGS__)) -#define __TA_REQUIRES(...) __THREAD_ANNOTATION(__requires_capability__(__VA_ARGS__)) -#define __TA_REQUIRES_SHARED(...) __THREAD_ANNOTATION(__requires_shared_capability__(__VA_ARGS__)) -#define __TA_EXCLUDES(...) __THREAD_ANNOTATION(__locks_excluded__(__VA_ARGS__)) -#define __TA_ASSERT(...) __THREAD_ANNOTATION(__assert_capability__(__VA_ARGS__)) -#define __TA_ASSERT_SHARED(...) __THREAD_ANNOTATION(__assert_shared_capability__(__VA_ARGS__)) -#define __TA_RETURN_CAPABILITY(x) __THREAD_ANNOTATION(__lock_returned__(x)) -#define __TA_SCOPED_CAPABILITY __THREAD_ANNOTATION(__scoped_lockable__) -#define __TA_NO_THREAD_SAFETY_ANALYSIS __THREAD_ANNOTATION(__no_thread_safety_analysis__) - -// Experimental lifetime analysis annotations. -#ifndef __OWNER -#ifdef __clang__ -#define __OWNER(x) [[gsl::Owner(x)]] -#define __POINTER(x) [[gsl::Pointer(x)]] -#else -#define __OWNER(x) -#define __POINTER(x) -#endif -#endif - -#if defined(__cpp_constinit) && __cpp_constinit >= 201907L -#define __CONSTINIT constinit -#elif defined(__clang__) -#define __CONSTINIT [[clang::require_constant_initialization]] -#elif defined(__GNUC__) && __GNUC__ >= 13 -#define __CONSTINIT __constinit -#else -#define __CONSTINIT -#endif - -#endif // !defined(__ASSEMBLER__) - -#endif // ZIRCON_COMPILER_H_ |