[linux-2.6-block.git] / include / linux / compiler-gcc.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#error "Please do not include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
#endif

/*
 * Common definitions for all gcc versions go here.
 */
#define GCC_VERSION (__GNUC__ * 10000		\
		     + __GNUC_MINOR__ * 100	\
		     + __GNUC_PATCHLEVEL__)

/*
 * This macro obfuscates arithmetic on a variable address so that gcc
 * shouldn't recognize the original var, and make assumptions about it.
 *
 * This is needed because the C standard makes it undefined to do
 * pointer arithmetic on "objects" outside their boundaries and the
 * gcc optimizers assume this is the case. In particular they
 * assume such arithmetic does not wrap.
 *
 * A miscompilation has been observed because of this on PPC.
 * To work around it we hide the relationship of the pointer and the object
 * using this macro.
 *
 * Versions of the ppc64 compiler before 4.1 had a bug where use of
 * RELOC_HIDE could trash r30. The bug can be worked around by changing
 * the inline assembly constraint from =g to =r, in this particular
 * case either is valid.
 */
#define RELOC_HIDE(ptr, off)						\
({									\
	unsigned long __ptr;						\
	__asm__ ("" : "=r"(__ptr) : "0"(ptr));				\
	(typeof(ptr)) (__ptr + (off));					\
})

#ifdef CONFIG_MITIGATION_RETPOLINE
#define __noretpoline __attribute__((__indirect_branch__("keep")))
#endif

#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
#define __latent_entropy __attribute__((latent_entropy))
#endif

/*
 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
 * confuse the stack allocation in gcc, leading to overly large stack
 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
 *
 * Adding an empty inline assembly before it works around the problem
 */
#define barrier_before_unreachable() asm volatile("")

#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#define __HAVE_BUILTIN_BSWAP16__
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */

#if GCC_VERSION >= 70000
#define KASAN_ABI_VERSION 5
#else
#define KASAN_ABI_VERSION 4
#endif

#ifdef CONFIG_SHADOW_CALL_STACK
#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
#endif

#ifdef __SANITIZE_HWADDRESS__
#define __no_sanitize_address __attribute__((__no_sanitize__("hwaddress")))
#else
#define __no_sanitize_address __attribute__((__no_sanitize_address__))
#endif

#if defined(__SANITIZE_THREAD__)
#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
#else
#define __no_sanitize_thread
#endif

#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))

/*
 * Only supported since gcc >= 12
 */
#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
#else
#define __no_sanitize_coverage
#endif

/*
 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
 * matching the defines used by Clang.
 */
#ifdef __SANITIZE_HWADDRESS__
#define __SANITIZE_ADDRESS__
#endif

/*
 * GCC does not support KMSAN.
 */
#define __no_sanitize_memory
#define __no_kmsan_checks

/*
 * Turn individual warnings and errors on and off locally, depending
 * on version.
 */
#define __diag_GCC(version, severity, s) \
	__diag_GCC_ ## version(__diag_GCC_ ## severity s)

/* Severity used in pragma directives */
#define __diag_GCC_ignore	ignored
#define __diag_GCC_warn		warning
#define __diag_GCC_error	error

#define __diag_str1(s)		#s
#define __diag_str(s)		__diag_str1(s)
#define __diag(s)		_Pragma(__diag_str(GCC diagnostic s))

#if GCC_VERSION >= 80000
#define __diag_GCC_8(s)		__diag(s)
#else
#define __diag_GCC_8(s)
#endif

#define __diag_ignore_all(option, comment) \
	__diag(__diag_GCC_ignore option)

/*
 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
 * attribute) do not work, and must be disabled.
 */
#if GCC_VERSION < 90100
#undef __alloc_size__
#endif

/*
 * Declare compiler support for __typeof_unqual__() operator.
 *
 * Bindgen uses LLVM even if our C compiler is GCC, so we cannot
 * rely on the auto-detected CONFIG_CC_HAS_TYPEOF_UNQUAL.
 */
#define CC_HAS_TYPEOF_UNQUAL (__GNUC__ >= 14)
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef __LINUX_COMPILER_TYPES_H
	3	#error "Please do not include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
	4	#endif
	5
	6	/*
	7	* Common definitions for all gcc versions go here.
	8	*/
	9	#define GCC_VERSION (__GNUC__ * 10000 \
	10	+ __GNUC_MINOR__ * 100 \
	11	+ __GNUC_PATCHLEVEL__)
	12
	13	/*
	14	* This macro obfuscates arithmetic on a variable address so that gcc
	15	* shouldn't recognize the original var, and make assumptions about it.
	16	*
	17	* This is needed because the C standard makes it undefined to do
	18	* pointer arithmetic on "objects" outside their boundaries and the
	19	* gcc optimizers assume this is the case. In particular they
	20	* assume such arithmetic does not wrap.
	21	*
	22	* A miscompilation has been observed because of this on PPC.
	23	* To work around it we hide the relationship of the pointer and the object
	24	* using this macro.
	25	*
	26	* Versions of the ppc64 compiler before 4.1 had a bug where use of
	27	* RELOC_HIDE could trash r30. The bug can be worked around by changing
	28	* the inline assembly constraint from =g to =r, in this particular
	29	* case either is valid.
	30	*/
	31	#define RELOC_HIDE(ptr, off) \
	32	({ \
	33	unsigned long __ptr; \
	34	__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
	35	(typeof(ptr)) (__ptr + (off)); \
	36	})
	37
	38	#ifdef CONFIG_MITIGATION_RETPOLINE
	39	#define __noretpoline __attribute__((__indirect_branch__("keep")))
	40	#endif
	41
	42	#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
	43	#define __latent_entropy __attribute__((latent_entropy))
	44	#endif
	45
	46	/*
	47	* calling noreturn functions, __builtin_unreachable() and __builtin_trap()
	48	* confuse the stack allocation in gcc, leading to overly large stack
	49	* frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
	50	*
	51	* Adding an empty inline assembly before it works around the problem
	52	*/
	53	#define barrier_before_unreachable() asm volatile("")
	54
	55	#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
	56	#define __HAVE_BUILTIN_BSWAP32__
	57	#define __HAVE_BUILTIN_BSWAP64__
	58	#define __HAVE_BUILTIN_BSWAP16__
	59	#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
	60
	61	#if GCC_VERSION >= 70000
	62	#define KASAN_ABI_VERSION 5
	63	#else
	64	#define KASAN_ABI_VERSION 4
	65	#endif
	66
	67	#ifdef CONFIG_SHADOW_CALL_STACK
	68	#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
	69	#endif
	70
	71	#ifdef __SANITIZE_HWADDRESS__
	72	#define __no_sanitize_address __attribute__((__no_sanitize__("hwaddress")))
	73	#else
	74	#define __no_sanitize_address __attribute__((__no_sanitize_address__))
	75	#endif
	76
	77	#if defined(__SANITIZE_THREAD__)
	78	#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
	79	#else
	80	#define __no_sanitize_thread
	81	#endif
	82
	83	#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
	84
	85	/*
	86	* Only supported since gcc >= 12
	87	*/
	88	#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
	89	#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
	90	#else
	91	#define __no_sanitize_coverage
	92	#endif
	93
	94	/*
	95	* Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
	96	* matching the defines used by Clang.
	97	*/
	98	#ifdef __SANITIZE_HWADDRESS__
	99	#define __SANITIZE_ADDRESS__
	100	#endif
	101
	102	/*
	103	* GCC does not support KMSAN.
	104	*/
	105	#define __no_sanitize_memory
	106	#define __no_kmsan_checks
	107
	108	/*
	109	* Turn individual warnings and errors on and off locally, depending
	110	* on version.
	111	*/
	112	#define __diag_GCC(version, severity, s) \
	113	__diag_GCC_ ## version(__diag_GCC_ ## severity s)
	114
	115	/* Severity used in pragma directives */
	116	#define __diag_GCC_ignore ignored
	117	#define __diag_GCC_warn warning
	118	#define __diag_GCC_error error
	119
	120	#define __diag_str1(s) #s
	121	#define __diag_str(s) __diag_str1(s)
	122	#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
	123
	124	#if GCC_VERSION >= 80000
	125	#define __diag_GCC_8(s) __diag(s)
	126	#else
	127	#define __diag_GCC_8(s)
	128	#endif
	129
	130	#define __diag_ignore_all(option, comment) \
	131	__diag(__diag_GCC_ignore option)
	132
	133	/*
	134	* Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
	135	* attribute) do not work, and must be disabled.
	136	*/
	137	#if GCC_VERSION < 90100
	138	#undef __alloc_size__
	139	#endif
	140
	141	/*
	142	* Declare compiler support for __typeof_unqual__() operator.
	143	*
	144	* Bindgen uses LLVM even if our C compiler is GCC, so we cannot
	145	* rely on the auto-detected CONFIG_CC_HAS_TYPEOF_UNQUAL.
	146	*/
	147	#define CC_HAS_TYPEOF_UNQUAL (__GNUC__ >= 14)