glibc/sysdeps/i386/sysdep.h

168 lines
5.4 KiB
C

/* Assembler macros for i386.
Copyright (C) 1991-93,95,96,98,2002,2003,2005,2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdeps/generic/sysdep.h>
#ifdef __ASSEMBLER__
/* Syntactic details of assembler. */
#ifdef HAVE_ELF
/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
#define ALIGNARG(log2) 1<<log2
/* For ELF we need the `.type' directive to make shared libs work right. */
#define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
/* In ELF C symbols are asm symbols. */
#undef NO_UNDERSCORES
#define NO_UNDERSCORES
#else
#define ALIGNARG(log2) log2
#define ASM_TYPE_DIRECTIVE(name,type) /* Nothing is specified. */
#define ASM_SIZE_DIRECTIVE(name) /* Nothing is specified. */
#endif
/* Define an entry point visible from C.
There is currently a bug in gdb which prevents us from specifying
incomplete stabs information. Fake some entries here which specify
the current source file. */
#define ENTRY(name) \
STABS_CURRENT_FILE1("") \
STABS_CURRENT_FILE(name) \
ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
.align ALIGNARG(4); \
STABS_FUN(name) \
C_LABEL(name) \
cfi_startproc; \
CALL_MCOUNT
#undef END
#define END(name) \
cfi_endproc; \
ASM_SIZE_DIRECTIVE(name) \
STABS_FUN_END(name)
#ifdef HAVE_CPP_ASM_DEBUGINFO
/* Disable that goop, because we just pass -g through to the assembler
and it generates proper line number information directly. */
# define STABS_CURRENT_FILE1(name)
# define STABS_CURRENT_FILE(name)
# define STABS_FUN(name)
# define STABS_FUN_END(name)
#else
/* Remove the following two lines once the gdb bug is fixed. */
#define STABS_CURRENT_FILE(name) \
STABS_CURRENT_FILE1 (#name)
#define STABS_CURRENT_FILE1(name) \
1: .stabs name,100,0,0,1b;
/* Emit stabs definition lines. We use F(0,1) and define t(0,1) as `int',
the same way gcc does it. */
#define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
#define STABS_FUN2(name, namestr) \
.stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0; \
.stabs #namestr,36,0,0,name;
#define STABS_FUN_END(name) \
1: .stabs "",36,0,0,1b-name;
#endif
/* If compiled for profiling, call `mcount' at the start of each function. */
#ifdef PROF
/* The mcount code relies on a normal frame pointer being on the stack
to locate our caller, so push one just for its benefit. */
#define CALL_MCOUNT \
pushl %ebp; cfi_adjust_cfa_offset (4); movl %esp, %ebp; \
cfi_def_cfa_register (ebp); call JUMPTARGET(mcount); \
popl %ebp; cfi_def_cfa (esp, 4);
#else
#define CALL_MCOUNT /* Do nothing. */
#endif
#ifdef NO_UNDERSCORES
/* Since C identifiers are not normally prefixed with an underscore
on this system, the asm identifier `syscall_error' intrudes on the
C name space. Make sure we use an innocuous name. */
#define syscall_error __syscall_error
#define mcount _mcount
#endif
#define PSEUDO(name, syscall_name, args) \
.globl syscall_error; \
lose: SYSCALL_PIC_SETUP \
jmp JUMPTARGET(syscall_error); \
ENTRY (name) \
DO_CALL (syscall_name, args); \
jb lose
#undef PSEUDO_END
#define PSEUDO_END(name) \
END (name)
#undef JUMPTARGET
#ifdef PIC
#define JUMPTARGET(name) name##@PLT
#define SYSCALL_PIC_SETUP \
pushl %ebx; \
cfi_adjust_cfa_offset (4); \
call 0f; \
0: popl %ebx; \
cfi_adjust_cfa_offset (-4); \
addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
# define SETUP_PIC_REG(reg) \
.ifndef __i686.get_pc_thunk.reg; \
.section .gnu.linkonce.t.__i686.get_pc_thunk.reg,"ax",@progbits; \
.globl __i686.get_pc_thunk.reg; \
.hidden __i686.get_pc_thunk.reg; \
.type __i686.get_pc_thunk.reg,@function; \
__i686.get_pc_thunk.reg: \
movl (%esp), %e##reg; \
ret; \
.size __i686.get_pc_thunk.reg, . - __i686.get_pc_thunk.reg; \
.previous; \
.endif; \
call __i686.get_pc_thunk.reg
# define LOAD_PIC_REG(reg) \
SETUP_PIC_REG(reg); addl $_GLOBAL_OFFSET_TABLE_, %e##reg
#else
#define JUMPTARGET(name) name
#define SYSCALL_PIC_SETUP /* Nothing. */
#endif
/* Local label name for asm code. */
#ifndef L
#ifdef HAVE_ELF
#define L(name) .L##name
#else
#define L(name) name
#endif
#endif
#endif /* __ASSEMBLER__ */