sysdeps/i386/sysdep.h

   1 /* Assembler macros for i386.
   2    Copyright (C) 1991,92,93,95,96,98,2002,2003 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <sysdeps/generic/sysdep.h>
  21
  22 #ifdef  __ASSEMBLER__
  23
  24 /* Syntactic details of assembler.  */
  25
  26 #ifdef HAVE_ELF
  27
  28 /* ELF uses byte-counts for .align, most others use log2 of count of bytes.  */
  29 #define ALIGNARG(log2) 1<<log2
  30 /* For ELF we need the `.type' directive to make shared libs work right.  */
  31 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
  32 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
  33
  34 /* In ELF C symbols are asm symbols.  */
  35 #undef  NO_UNDERSCORES
  36 #define NO_UNDERSCORES
  37
  38 #else
  39
  40 #define ALIGNARG(log2) log2
  41 #define ASM_TYPE_DIRECTIVE(name,type)   /* Nothing is specified.  */
  42 #define ASM_SIZE_DIRECTIVE(name)        /* Nothing is specified.  */
  43
  44 #endif
  45
  46
  47 /* Define an entry point visible from C.
  48
  49    There is currently a bug in gdb which prevents us from specifying
  50    incomplete stabs information.  Fake some entries here which specify
  51    the current source file.  */
  52 #define ENTRY(name)                                                           \
  53   STABS_CURRENT_FILE1("")                                                     \
  54   STABS_CURRENT_FILE(name)                                                    \
  55   ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name);                                   \
  56   ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function)                          \
  57   .align ALIGNARG(4);                                                         \
  58   STABS_FUN(name)                                                             \
  59   C_LABEL(name)                                                               \
  60   CALL_MCOUNT
  61
  62 #undef  END
  63 #define END(name)                                                             \
  64   ASM_SIZE_DIRECTIVE(name)                                                    \
  65   STABS_FUN_END(name)
  66
  67 #ifdef HAVE_CPP_ASM_DEBUGINFO
  68 /* Disable that goop, because we just pass -g through to the assembler
  69    and it generates proper line number information directly.  */
  70 # define STABS_CURRENT_FILE1(name)
  71 # define STABS_CURRENT_FILE(name)
  72 # define STABS_FUN(name)
  73 # define STABS_FUN_END(name)
  74 #else
  75 /* Remove the following two lines once the gdb bug is fixed.  */
  76 #define STABS_CURRENT_FILE(name)                                              \
  77   STABS_CURRENT_FILE1 (#name)
  78 #define STABS_CURRENT_FILE1(name)                                             \
  79   1: .stabs name,100,0,0,1b;
  80 /* Emit stabs definition lines.  We use F(0,1) and define t(0,1) as `int',
  81    the same way gcc does it.  */
  82 #define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
  83 #define STABS_FUN2(name, namestr)                                             \
  84   .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0;               \
  85   .stabs #namestr,36,0,0,name;
  86 #define STABS_FUN_END(name)                                                   \
  87   1: .stabs "",36,0,0,1b-name;
  88 #endif
  89
  90 /* If compiled for profiling, call `mcount' at the start of each function.  */
  91 #ifdef  PROF
  92 /* The mcount code relies on a normal frame pointer being on the stack
  93    to locate our caller, so push one just for its benefit.  */
  94 #define CALL_MCOUNT \
  95   pushl %ebp; movl %esp, %ebp; call JUMPTARGET(mcount); popl %ebp;
  96 #else
  97 #define CALL_MCOUNT             /* Do nothing.  */
  98 #endif
  99
 100 #ifdef  NO_UNDERSCORES
 101 /* Since C identifiers are not normally prefixed with an underscore
 102    on this system, the asm identifier `syscall_error' intrudes on the
 103    C name space.  Make sure we use an innocuous name.  */
 104 #define syscall_error   __syscall_error
 105 #define mcount          _mcount
 106 #endif
 107
 108 #define PSEUDO(name, syscall_name, args)                                      \
 109   .globl syscall_error;                                                       \
 110 lose: SYSCALL_PIC_SETUP                                                       \
 111   jmp JUMPTARGET(syscall_error);                                              \
 112   ENTRY (name)                                                                \
 113   DO_CALL (syscall_name, args);                                               \
 114   jb lose
 115
 116 #undef  PSEUDO_END
 117 #define PSEUDO_END(name)                                                      \
 118   END (name)
 119
 120 #undef JUMPTARGET
 121 #ifdef PIC
 122 #define JUMPTARGET(name)        name##@PLT
 123 #define SYSCALL_PIC_SETUP \
 124     pushl %ebx;                                                               \
 125     call 0f;                                                                  \
 126 0:  popl %ebx;                                                                \
 127     addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
 128 #else
 129 #define JUMPTARGET(name)        name
 130 #define SYSCALL_PIC_SETUP       /* Nothing.  */
 131 #endif
 132
 133 /* Local label name for asm code. */
 134 #ifndef L
 135 #ifdef HAVE_ELF
 136 #define L(name)         .L##name
 137 #else
 138 #define L(name)         name
 139 #endif
 140 #endif
 141
 142 #endif  /* __ASSEMBLER__ */