(__strncat_g): Improve last patch.
[kopensolaris-gnu/glibc.git] / 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__ */