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compiler*.h: sync include/linux/compiler*.h with Linux 4.5-rc6
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Copy these from Linux v4.5-rc6 tag.

This is needed so that we can keep up with newer gcc versions.  Note
that we don't have the uapi/ hierarchy from the kernel so continue to
use <linux/types.h>

Signed-off-by: Tom Rini <[email protected]>
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@trini @abhimanyuv1
trini authored and abhimanyuv1 committed Oct 1, 2017
1 parent 28dd6b7 commit 72f1817
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259 changes: 207 additions & 52 deletions include/linux/compiler-gcc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,14 +5,28 @@
/*
* Common definitions for all gcc versions go here.
*/
#define GCC_VERSION (__GNUC__ * 10000 \
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)

#define GCC_VERSION (__GNUC__ * 10000 \
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)

/* Optimization barrier */

/* The "volatile" is due to gcc bugs */
#define barrier() __asm__ __volatile__("": : :"memory")
/*
* This version is i.e. to prevent dead stores elimination on @ptr
* where gcc and llvm may behave differently when otherwise using
* normal barrier(): while gcc behavior gets along with a normal
* barrier(), llvm needs an explicit input variable to be assumed
* clobbered. The issue is as follows: while the inline asm might
* access any memory it wants, the compiler could have fit all of
* @ptr into memory registers instead, and since @ptr never escaped
* from that, it proofed that the inline asm wasn't touching any of
* it. This version works well with both compilers, i.e. we're telling
* the compiler that the inline asm absolutely may see the contents
* of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
*/
#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")

/*
* This macro obfuscates arithmetic on a variable address so that gcc
Expand All @@ -32,58 +46,63 @@
* 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)); })
#define RELOC_HIDE(ptr, off) \
({ \
unsigned long __ptr; \
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
(typeof(ptr)) (__ptr + (off)); \
})

/* Make the optimizer believe the variable can be manipulated arbitrarily. */
#define OPTIMIZER_HIDE_VAR(var) __asm__ ("" : "=r" (var) : "0" (var))
#define OPTIMIZER_HIDE_VAR(var) \
__asm__ ("" : "=r" (var) : "0" (var))

#ifdef __CHECKER__
#define __must_be_array(arr) 0
#define __must_be_array(a) 0
#else
/* &a[0] degrades to a pointer: a different type from an array */
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#endif

/*
* Force always-inline if the user requests it so via the .config,
* or if gcc is too old:
*/
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
!defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
# define inline inline __attribute__((always_inline)) notrace
# define __inline__ __inline__ __attribute__((always_inline)) notrace
# define __inline __inline __attribute__((always_inline)) notrace
#define inline inline __attribute__((always_inline)) notrace
#define __inline__ __inline__ __attribute__((always_inline)) notrace
#define __inline __inline __attribute__((always_inline)) notrace
#else
/* A lot of inline functions can cause havoc with function tracing */
# define inline inline notrace
# define __inline__ __inline__ notrace
# define __inline __inline notrace
#define inline inline notrace
#define __inline__ __inline__ notrace
#define __inline __inline notrace
#endif

#define __deprecated __attribute__((deprecated))
#ifndef __packed
#define __packed __attribute__((packed))
#endif
#ifndef __weak
#define __weak __attribute__((weak))
#endif
#define __always_inline inline __attribute__((always_inline))
#define noinline __attribute__((noinline))

#define __deprecated __attribute__((deprecated))
#define __packed __attribute__((packed))
#define __weak __attribute__((weak))
#define __alias(symbol) __attribute__((alias(#symbol)))

/*
* it doesn't make sense on ARM (currently the only user of __naked) to trace
* naked functions because then mcount is called without stack and frame pointer
* being set up and there is no chance to restore the lr register to the value
* before mcount was called.
* it doesn't make sense on ARM (currently the only user of __naked)
* to trace naked functions because then mcount is called without
* stack and frame pointer being set up and there is no chance to
* restore the lr register to the value before mcount was called.
*
* The asm() bodies of naked functions often depend on standard calling
* conventions, therefore they must be noinline and noclone.
*
* The asm() bodies of naked functions often depend on standard calling conventions,
* therefore they must be noinline and noclone. GCC 4.[56] currently fail to enforce
* this, so we must do so ourselves. See GCC PR44290.
* GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
* See GCC PR44290.
*/
#define __naked __attribute__((naked)) noinline __noclone notrace
#define __naked __attribute__((naked)) noinline __noclone notrace

#define __noreturn __attribute__((noreturn))
#define __noreturn __attribute__((noreturn))

/*
* From the GCC manual:
Expand All @@ -95,34 +114,170 @@
* would be.
* [...]
*/
#ifndef __pure
#define __pure __attribute__((pure))
#define __pure __attribute__((pure))
#define __aligned(x) __attribute__((aligned(x)))
#define __printf(a, b) __attribute__((format(printf, a, b)))
#define __scanf(a, b) __attribute__((format(scanf, a, b)))
#define __attribute_const__ __attribute__((__const__))
#define __maybe_unused __attribute__((unused))
#define __always_unused __attribute__((unused))

/* gcc version specific checks */

#if GCC_VERSION < 30200
# error Sorry, your compiler is too old - please upgrade it.
#endif

#if GCC_VERSION < 30300
# define __used __attribute__((__unused__))
#else
# define __used __attribute__((__used__))
#endif

#ifdef CONFIG_GCOV_KERNEL
# if GCC_VERSION < 30400
# error "GCOV profiling support for gcc versions below 3.4 not included"
# endif /* __GNUC_MINOR__ */
#endif /* CONFIG_GCOV_KERNEL */

#if GCC_VERSION >= 30400
#define __must_check __attribute__((warn_unused_result))
#endif

#if GCC_VERSION >= 40000

/* GCC 4.1.[01] miscompiles __weak */
#ifdef __KERNEL__
# if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
# error Your version of gcc miscompiles the __weak directive
# endif
#endif

#define __used __attribute__((__used__))
#define __compiler_offsetof(a, b) \
__builtin_offsetof(a, b)

#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
#endif

#if GCC_VERSION >= 40300
/* Mark functions as cold. gcc will assume any path leading to a call
* to them will be unlikely. This means a lot of manual unlikely()s
* are unnecessary now for any paths leading to the usual suspects
* like BUG(), printk(), panic() etc. [but let's keep them for now for
* older compilers]
*
* Early snapshots of gcc 4.3 don't support this and we can't detect this
* in the preprocessor, but we can live with this because they're unreleased.
* Maketime probing would be overkill here.
*
* gcc also has a __attribute__((__hot__)) to move hot functions into
* a special section, but I don't see any sense in this right now in
* the kernel context
*/
#define __cold __attribute__((__cold__))

#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)

#ifndef __CHECKER__
# define __compiletime_warning(message) __attribute__((warning(message)))
# define __compiletime_error(message) __attribute__((error(message)))
#endif /* __CHECKER__ */
#endif /* GCC_VERSION >= 40300 */

#if GCC_VERSION >= 40500
/*
* Mark a position in code as unreachable. This can be used to
* suppress control flow warnings after asm blocks that transfer
* control elsewhere.
*
* Early snapshots of gcc 4.5 don't support this and we can't detect
* this in the preprocessor, but we can live with this because they're
* unreleased. Really, we need to have autoconf for the kernel.
*/
#define unreachable() __builtin_unreachable()

/* Mark a function definition as prohibited from being cloned. */
#define __noclone __attribute__((__noclone__))

#endif /* GCC_VERSION >= 40500 */

#if GCC_VERSION >= 40600
/*
* When used with Link Time Optimization, gcc can optimize away C functions or
* variables which are referenced only from assembly code. __visible tells the
* optimizer that something else uses this function or variable, thus preventing
* this.
*/
#define __visible __attribute__((externally_visible))
#endif
#ifndef __aligned
#define __aligned(x) __attribute__((aligned(x)))


#if GCC_VERSION >= 40900 && !defined(__CHECKER__)
/*
* __assume_aligned(n, k): Tell the optimizer that the returned
* pointer can be assumed to be k modulo n. The second argument is
* optional (default 0), so we use a variadic macro to make the
* shorthand.
*
* Beware: Do not apply this to functions which may return
* ERR_PTRs. Also, it is probably unwise to apply it to functions
* returning extra information in the low bits (but in that case the
* compiler should see some alignment anyway, when the return value is
* massaged by 'flags = ptr & 3; ptr &= ~3;').
*/
#define __assume_aligned(a, ...) __attribute__((__assume_aligned__(a, ## __VA_ARGS__)))
#endif
#define __printf(a, b) __attribute__((format(printf, a, b)))
#define __scanf(a, b) __attribute__((format(scanf, a, b)))
#define noinline __attribute__((noinline))
#define __attribute_const__ __attribute__((__const__))
#define __maybe_unused __attribute__((unused))
#define __always_unused __attribute__((unused))

#define __gcc_header(x) #x
#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
#define gcc_header(x) _gcc_header(x)
#include gcc_header(__GNUC__)
/*
* GCC 'asm goto' miscompiles certain code sequences:
*
* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
*
* Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
*
* (asm goto is automatically volatile - the naming reflects this.)
*/
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)

#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
#if GCC_VERSION >= 40400
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#endif
#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
#define __HAVE_BUILTIN_BSWAP16__
#endif
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */

#if GCC_VERSION >= 50000
#define KASAN_ABI_VERSION 4
#elif GCC_VERSION >= 40902
#define KASAN_ABI_VERSION 3
#endif

#if GCC_VERSION >= 40902
/*
* Tell the compiler that address safety instrumentation (KASAN)
* should not be applied to that function.
* Conflicts with inlining: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
*/
#define __no_sanitize_address __attribute__((no_sanitize_address))
#endif

#endif /* gcc version >= 40000 specific checks */

#if !defined(__noclone)
#define __noclone /* not needed */
#endif

#if !defined(__no_sanitize_address)
#define __no_sanitize_address
#endif

/*
* A trick to suppress uninitialized variable warning without generating any
* code
*/
#define uninitialized_var(x) x = x

#ifndef __always_inline
#define __always_inline inline __attribute__((always_inline))
#endif
23 changes: 0 additions & 23 deletions include/linux/compiler-gcc3.h
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