zephyr/include/toolchain/gcc.h

305 lines
8.2 KiB
C

/*
* Copyright (c) 2010-2014,2017 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief GCC toolchain abstraction
*
* Macros to abstract compiler capabilities for GCC toolchain.
*/
/*
* GCC 4.6 and higher have _Static_assert built in, and its output is
* easier to understand than the common BUILD_ASSERT macros.
*/
#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
#define BUILD_ASSERT(EXPR) _Static_assert(EXPR, "")
#define BUILD_ASSERT_MSG(EXPR, MSG) _Static_assert(EXPR, MSG)
#endif
#include <toolchain/common.h>
#define ALIAS_OF(of) __attribute__((alias(#of)))
#define FUNC_ALIAS(real_func, new_alias, return_type) \
return_type new_alias() ALIAS_OF(real_func)
#define CODE_UNREACHABLE __builtin_unreachable()
#define FUNC_NORETURN __attribute__((__noreturn__))
/* The GNU assembler for Cortex-M3 uses # for immediate values, not
* comments, so the @nobits# trick does not work.
*/
#if defined(CONFIG_ARM)
#define _NODATA_SECTION(segment) __attribute__((section(#segment)))
#else
#define _NODATA_SECTION(segment) \
__attribute__((section(#segment ",\"wa\",@nobits#")))
#endif
/* Unaligned access */
#define UNALIGNED_GET(p) \
__extension__ ({ \
struct __attribute__((__packed__)) { \
__typeof__(*(p)) __v; \
} *__p = (__typeof__(__p)) (p); \
__p->__v; \
})
#define UNALIGNED_PUT(v, p) \
do { \
struct __attribute__((__packed__)) { \
__typeof__(*p) __v; \
} *__p = (__typeof__(__p)) (p); \
__p->__v = (v); \
} while (0)
/* Double indirection to ensure section names are expanded before
* stringification
*/
#define __GENERIC_SECTION(segment) __attribute__((section(STRINGIFY(segment))))
#define _GENERIC_SECTION(segment) __GENERIC_SECTION(segment)
#define ___in_section(a, b, c) \
__attribute__((section("." _STRINGIFY(a) \
"." _STRINGIFY(b) \
"." _STRINGIFY(c))))
#define __in_section(a, b, c) ___in_section(a, b, c)
#define __in_section_unique(seg) ___in_section(seg, _FILE_PATH_HASH, \
__COUNTER__)
#ifndef __packed
#define __packed __attribute__((__packed__))
#endif
#ifndef __aligned
#define __aligned(x) __attribute__((__aligned__(x)))
#endif
#define __may_alias __attribute__((__may_alias__))
#ifndef __printf_like
#define __printf_like(f, a) __attribute__((format (printf, f, a)))
#endif
#define __used __attribute__((__used__))
#define __deprecated __attribute__((deprecated))
#define ARG_UNUSED(x) (void)(x)
#define likely(x) __builtin_expect((long)!!(x), 1L)
#define unlikely(x) __builtin_expect((long)!!(x), 0L)
#define popcount(x) __builtin_popcount(x)
#define __weak __attribute__((__weak__))
#define __unused __attribute__((__unused__))
/* These macros allow having ARM asm functions callable from thumb */
#if defined(_ASMLANGUAGE) && !defined(_LINKER)
#ifdef CONFIG_ARM
#if defined(CONFIG_ISA_THUMB)
#define FUNC_CODE() \
.code 16; \
.thumb_func;
#define FUNC_INSTR(a) \
BX pc; \
NOP; \
.code 32; \
A##a:
#elif defined(CONFIG_ISA_THUMB2)
#define FUNC_CODE() .thumb;
#define FUNC_INSTR(a)
#elif defined(CONFIG_ISA_ARM)
#define FUNC_CODE() .code 32;
#define FUNC_INSTR(a)
#else
#error unknown instruction set
#endif /* ISA */
#else
#define FUNC_CODE()
#define FUNC_INSTR(a)
#endif /* !CONFIG_ARM */
#endif /* _ASMLANGUAGE && !_LINKER */
/*
* These macros are used to declare assembly language symbols that need
* to be typed properly(func or data) to be visible to the OMF tool.
* So that the build tool could mark them as an entry point to be linked
* correctly. This is an elfism. Use #if 0 for a.out.
*/
#if defined(_ASMLANGUAGE) && !defined(_LINKER)
#if defined(CONFIG_ARM) || defined(CONFIG_NIOS2) || defined(CONFIG_RISCV32) \
|| defined(CONFIG_XTENSA)
#define GTEXT(sym) .global sym; .type sym, %function
#define GDATA(sym) .global sym; .type sym, %object
#define WTEXT(sym) .weak sym; .type sym, %function
#define WDATA(sym) .weak sym; .type sym, %object
#elif defined(CONFIG_ARC)
/*
* Need to use assembly macros because ';' is interpreted as the start of
* a single line comment in the ARC assembler.
*/
.macro glbl_text symbol
.globl \symbol
.type \symbol, %function
.endm
.macro glbl_data symbol
.globl \symbol
.type \symbol, %object
.endm
.macro weak_data symbol
.weak \symbol
.type \symbol, %object
.endm
#define GTEXT(sym) glbl_text sym
#define GDATA(sym) glbl_data sym
#define WDATA(sym) weak_data sym
#else /* !CONFIG_ARM && !CONFIG_ARC */
#define GTEXT(sym) .globl sym; .type sym, @function
#define GDATA(sym) .globl sym; .type sym, @object
#endif
/*
* These macros specify the section in which a given function or variable
* resides.
*
* - SECTION_FUNC allows only one function to reside in a sub-section
* - SECTION_SUBSEC_FUNC allows multiple functions to reside in a sub-section
* This ensures that garbage collection only discards the section
* if all functions in the sub-section are not referenced.
*/
#if defined(CONFIG_ARC)
/*
* Need to use assembly macros because ';' is interpreted as the start of
* a single line comment in the ARC assembler.
*
* Also, '\()' is needed in the .section directive of these macros for
* correct substitution of the 'section' variable.
*/
.macro section_var section, symbol
.section .\section\().\symbol
\symbol :
.endm
.macro section_func section, symbol
.section .\section\().\symbol, "ax"
FUNC_CODE()
PERFOPT_ALIGN
\symbol :
FUNC_INSTR(\symbol)
.endm
.macro section_subsec_func section, subsection, symbol
.section .\section\().\subsection, "ax"
PERFOPT_ALIGN
\symbol :
.endm
#define SECTION_VAR(sect, sym) section_var sect, sym
#define SECTION_FUNC(sect, sym) section_func sect, sym
#define SECTION_SUBSEC_FUNC(sect, subsec, sym) \
section_subsec_func sect, subsec, sym
#else /* !CONFIG_ARC */
#define SECTION_VAR(sect, sym) .section .sect.##sym; sym :
#define SECTION_FUNC(sect, sym) \
.section .sect.sym, "ax"; \
FUNC_CODE() \
PERFOPT_ALIGN; sym : \
FUNC_INSTR(sym)
#define SECTION_SUBSEC_FUNC(sect, subsec, sym) \
.section .sect.subsec, "ax"; PERFOPT_ALIGN; sym :
#endif /* CONFIG_ARC */
#endif /* _ASMLANGUAGE && !_LINKER */
#if defined(CONFIG_ARM) && defined(_ASMLANGUAGE)
#if defined(CONFIG_ISA_THUMB2)
/* '.syntax unified' is a gcc-ism used in thumb-2 asm files */
#define _ASM_FILE_PROLOGUE .text; .syntax unified; .thumb
#elif defined(CONFIG_ISA_THUMB)
#define _ASM_FILE_PROLOGUE .text; .code 16
#else
#define _ASM_FILE_PROLOGUE .text; .code 32
#endif
#endif
/*
* These macros generate absolute symbols for GCC
*/
/* create an extern reference to the absolute symbol */
#define GEN_OFFSET_EXTERN(name) extern const char name[]
#define GEN_ABS_SYM_BEGIN(name) \
EXTERN_C void name(void); \
void name(void) \
{
#define GEN_ABS_SYM_END }
#if defined(CONFIG_ARM)
/*
* GNU/ARM backend does not have a proper operand modifier which does not
* produces prefix # followed by value, such as %0 for PowerPC, Intel, and
* MIPS. The workaround performed here is using %B0 which converts
* the value to ~(value). Thus "n"(~(value)) is set in operand constraint
* to output (value) in the ARM specific GEN_OFFSET macro.
*/
#define GEN_ABSOLUTE_SYM(name, value) \
__asm__(".globl\t" #name "\n\t.equ\t" #name \
",%B0" \
"\n\t.type\t" #name ",%%object" : : "n"(~(value)))
#elif defined(CONFIG_X86) || defined(CONFIG_ARC)
#define GEN_ABSOLUTE_SYM(name, value) \
__asm__(".globl\t" #name "\n\t.equ\t" #name \
",%c0" \
"\n\t.type\t" #name ",@object" : : "n"(value))
#elif defined(CONFIG_NIOS2) || defined(CONFIG_RISCV32) || defined(CONFIG_XTENSA)
/* No special prefixes necessary for constants in this arch AFAICT */
#define GEN_ABSOLUTE_SYM(name, value) \
__asm__(".globl\t" #name "\n\t.equ\t" #name \
",%0" \
"\n\t.type\t" #name ",%%object" : : "n"(value))
#else
#error processor architecture not supported
#endif
#define compiler_barrier() do { \
__asm__ __volatile__ ("" ::: "memory"); \
} while ((0))