From 8beeb199d7e741776e659e120e1d84d98c3de996 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Thu, 4 Feb 2010 13:13:44 +0100 Subject: [PATCH] import recent include/linux/compiler*.h Signed-off-by: Marc Kleine-Budde --- include/linux/compiler-gcc.h | 30 +++++++- include/linux/compiler-gcc3.h | 11 ++- include/linux/compiler-gcc4.h | 32 ++++++++- include/linux/compiler.h | 124 +++++++++++++++++++++++++++++++--- 4 files changed, 180 insertions(+), 17 deletions(-) diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index 5c8351b85..73dcf804b 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -11,9 +11,19 @@ /* The "volatile" is due to gcc bugs */ #define barrier() __asm__ __volatile__("": : :"memory") -/* This macro obfuscates arithmetic on a variable address so that gcc - shouldn't recognize the original var, and make assumptions about it */ /* + * 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 @@ -42,7 +52,15 @@ #define __deprecated __attribute__((deprecated)) #define __packed __attribute__((packed)) #define __weak __attribute__((weak)) -#define __naked __attribute__((naked)) + +/* + * 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. + */ +#define __naked __attribute__((naked)) notrace + #define __noreturn __attribute__((noreturn)) /* @@ -61,3 +79,9 @@ #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__) diff --git a/include/linux/compiler-gcc3.h b/include/linux/compiler-gcc3.h index e5eb795f7..b721129e0 100644 --- a/include/linux/compiler-gcc3.h +++ b/include/linux/compiler-gcc3.h @@ -2,8 +2,9 @@ #error "Please don't include directly, include instead." #endif -/* These definitions are for GCC v3.x. */ -#include +#if __GNUC_MINOR__ < 2 +# error Sorry, your compiler is too old - please upgrade it. +#endif #if __GNUC_MINOR__ >= 3 # define __used __attribute__((__used__)) @@ -15,6 +16,12 @@ #define __must_check __attribute__((warn_unused_result)) #endif +#ifdef CONFIG_GCOV_KERNEL +# if __GNUC_MINOR__ < 4 +# error "GCOV profiling support for gcc versions below 3.4 not included" +# endif /* __GNUC_MINOR__ */ +#endif /* CONFIG_GCOV_KERNEL */ + /* * A trick to suppress uninitialized variable warning without generating any * code diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h index 974f5b7bb..94dea3ffb 100644 --- a/include/linux/compiler-gcc4.h +++ b/include/linux/compiler-gcc4.h @@ -2,8 +2,12 @@ #error "Please don't include directly, include instead." #endif -/* These definitions are for GCC v4.x. */ -#include +/* GCC 4.1.[01] miscompiles __weak */ +#ifdef __KERNEL__ +# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1 +# error Your version of gcc miscompiles the __weak directive +# endif +#endif #define __used __attribute__((__used__)) #define __must_check __attribute__((warn_unused_result)) @@ -16,7 +20,7 @@ */ #define uninitialized_var(x) x = x -#if !(__GNUC__ == 4 && __GNUC_MINOR__ < 3) +#if __GNUC_MINOR__ >= 3 /* 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 @@ -32,4 +36,26 @@ the kernel context */ #define __cold __attribute__((__cold__)) + +#if __GNUC_MINOR__ >= 5 +/* + * 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() +#endif + +#endif + +#if __GNUC_MINOR__ > 0 +#define __compiletime_object_size(obj) __builtin_object_size(obj, 0) +#endif +#if __GNUC_MINOR__ >= 4 +#define __compiletime_warning(message) __attribute__((warning(message))) +#define __compiletime_error(message) __attribute__((error(message))) #endif diff --git a/include/linux/compiler.h b/include/linux/compiler.h index c8bd2daf9..5be3dab4a 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -36,14 +36,12 @@ extern void __chk_io_ptr(const volatile void __iomem *); #ifdef __KERNEL__ -#if __GNUC__ >= 4 -# include -#elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2 -# include -#else -# error Sorry, your compiler is too old/not recognized. +#ifdef __GNUC__ +#include #endif +#define notrace __attribute__((no_instrument_function)) + /* Intel compiler defines __GNUC__. So we will overwrite implementations * coming from above header files here */ @@ -57,14 +55,100 @@ extern void __chk_io_ptr(const volatile void __iomem *); * specific implementations come from the above header files */ -#define likely(x) __builtin_expect(!!(x), 1) -#define unlikely(x) __builtin_expect(!!(x), 0) +struct ftrace_branch_data { + const char *func; + const char *file; + unsigned line; + union { + struct { + unsigned long correct; + unsigned long incorrect; + }; + struct { + unsigned long miss; + unsigned long hit; + }; + unsigned long miss_hit[2]; + }; +}; + +/* + * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code + * to disable branch tracing on a per file basis. + */ +#if defined(CONFIG_TRACE_BRANCH_PROFILING) \ + && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) +void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); + +#define likely_notrace(x) __builtin_expect(!!(x), 1) +#define unlikely_notrace(x) __builtin_expect(!!(x), 0) + +#define __branch_check__(x, expect) ({ \ + int ______r; \ + static struct ftrace_branch_data \ + __attribute__((__aligned__(4))) \ + __attribute__((section("_ftrace_annotated_branch"))) \ + ______f = { \ + .func = __func__, \ + .file = __FILE__, \ + .line = __LINE__, \ + }; \ + ______r = likely_notrace(x); \ + ftrace_likely_update(&______f, ______r, expect); \ + ______r; \ + }) + +/* + * Using __builtin_constant_p(x) to ignore cases where the return + * value is always the same. This idea is taken from a similar patch + * written by Daniel Walker. + */ +# ifndef likely +# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) +# endif +# ifndef unlikely +# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) +# endif + +#ifdef CONFIG_PROFILE_ALL_BRANCHES +/* + * "Define 'is'", Bill Clinton + * "Define 'if'", Steven Rostedt + */ +#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) +#define __trace_if(cond) \ + if (__builtin_constant_p((cond)) ? !!(cond) : \ + ({ \ + int ______r; \ + static struct ftrace_branch_data \ + __attribute__((__aligned__(4))) \ + __attribute__((section("_ftrace_branch"))) \ + ______f = { \ + .func = __func__, \ + .file = __FILE__, \ + .line = __LINE__, \ + }; \ + ______r = !!(cond); \ + ______f.miss_hit[______r]++; \ + ______r; \ + })) +#endif /* CONFIG_PROFILE_ALL_BRANCHES */ + +#else +# define likely(x) __builtin_expect(!!(x), 1) +# define unlikely(x) __builtin_expect(!!(x), 0) +#endif /* Optimization barrier */ #ifndef barrier # define barrier() __memory_barrier() #endif +/* Unreachable code */ +#ifndef unreachable +# define unreachable() do { } while (1) +#endif + #ifndef RELOC_HIDE # define RELOC_HIDE(ptr, off) \ ({ unsigned long __ptr; \ @@ -134,6 +218,10 @@ extern void __chk_io_ptr(const volatile void __iomem *); # define __maybe_unused /* unimplemented */ #endif +#ifndef __always_unused +# define __always_unused /* unimplemented */ +#endif + #ifndef noinline #define noinline #endif @@ -182,6 +270,22 @@ extern void __chk_io_ptr(const volatile void __iomem *); # define __section(S) __attribute__ ((__section__(#S))) #endif +/* Are two types/vars the same type (ignoring qualifiers)? */ +#ifndef __same_type +# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) +#endif + +/* Compile time object size, -1 for unknown */ +#ifndef __compiletime_object_size +# define __compiletime_object_size(obj) -1 +#endif +#ifndef __compiletime_warning +# define __compiletime_warning(message) +#endif +#ifndef __compiletime_error +# define __compiletime_error(message) +#endif + /* * Prevent the compiler from merging or refetching accesses. The compiler * is also forbidden from reordering successive instances of ACCESS_ONCE(), @@ -190,7 +294,9 @@ extern void __chk_io_ptr(const volatile void __iomem *); * ACCESS_ONCE() in different C statements. * * This macro does absolutely -nothing- to prevent the CPU from reordering, - * merging, or refetching absolutely anything at any time. + * merging, or refetching absolutely anything at any time. Its main intended + * use is to mediate communication between process-level code and irq/NMI + * handlers, all running on the same CPU. */ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))