sysdeps/i386/sysdep.h

   1 /* Assembler macros for i386.
   2    Copyright (C) 1991, 92, 93, 95, 96, 98 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 /* Remove the following two lines once the gdb bug is fixed.  */
  68 #define STABS_CURRENT_FILE(name)                                              \
  69   STABS_CURRENT_FILE1 (#name)
  70 #define STABS_CURRENT_FILE1(name)                                             \
  71   1: .stabs name,100,0,0,1b;
  72 /* Emit stabs definition lines.  We use F(0,1) and define t(0,1) as `int',
  73    the same way gcc does it.  */
  74 #define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1))
  75 #define STABS_FUN2(name, namestr)                                             \
  76   .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0;               \
  77   .stabs #namestr,36,0,0,name;
  78 #define STABS_FUN_END(name)                                                   \
  79   1: .stabs "",36,0,0,1b-name;
  80
  81 /* If compiled for profiling, call `mcount' at the start of each function.  */
  82 #ifdef  PROF
  83 /* The mcount code relies on a normal frame pointer being on the stack
  84    to locate our caller, so push one just for its benefit.  */
  85 #define CALL_MCOUNT \
  86   pushl %ebp; movl %esp, %ebp; call JUMPTARGET(mcount); popl %ebp;
  87 #else
  88 #define CALL_MCOUNT             /* Do nothing.  */
  89 #endif
  90
  91 #ifdef  NO_UNDERSCORES
  92 /* Since C identifiers are not normally prefixed with an underscore
  93    on this system, the asm identifier `syscall_error' intrudes on the
  94    C name space.  Make sure we use an innocuous name.  */
  95 #define syscall_error   __syscall_error
  96 #define mcount          _mcount
  97 #endif
  98
  99 #define PSEUDO(name, syscall_name, args)                                      \
 100 lose: SYSCALL_PIC_SETUP                                                       \
 101   jmp JUMPTARGET(syscall_error)                                               \
 102   .globl syscall_error;                                                       \
 103   ENTRY (name)                                                                \
 104   DO_CALL (syscall_name, args);                                               \
 105   jb lose
 106
 107 #undef  PSEUDO_END
 108 #define PSEUDO_END(name)                                                      \
 109   END (name)
 110
 111 #ifdef PIC
 112 #define JUMPTARGET(name)        name##@PLT
 113 #define SYSCALL_PIC_SETUP \
 114     pushl %ebx;                                                               \
 115     call 0f;                                                                  \
 116 0:  popl %ebx;                                                                \
 117     addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx;
 118 #else
 119 #define JUMPTARGET(name)        name
 120 #define SYSCALL_PIC_SETUP       /* Nothing.  */
 121 #endif
 122
 123 /* Local label name for asm code. */
 124 #ifndef L
 125 #define L(name)         name
 126 #endif
 127
 128 #endif  /* __ASSEMBLER__ */