linux.h revision 90075
1/* Definitions for Intel 386 running Linux-based GNU systems with ELF format. 2 Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2001, 2002 3 Free Software Foundation, Inc. 4 Contributed by Eric Youngdale. 5 Modified for stabs-in-ELF by H.J. Lu. 6 7This file is part of GNU CC. 8 9GNU CC is free software; you can redistribute it and/or modify 10it under the terms of the GNU General Public License as published by 11the Free Software Foundation; either version 2, or (at your option) 12any later version. 13 14GNU CC is distributed in the hope that it will be useful, 15but WITHOUT ANY WARRANTY; without even the implied warranty of 16MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17GNU General Public License for more details. 18 19You should have received a copy of the GNU General Public License 20along with GNU CC; see the file COPYING. If not, write to 21the Free Software Foundation, 59 Temple Place - Suite 330, 22Boston, MA 02111-1307, USA. */ 23 24#define LINUX_DEFAULT_ELF 25 26/* Output at beginning of assembler file. */ 27/* The .file command should always begin the output. */ 28#undef ASM_FILE_START 29#define ASM_FILE_START(FILE) \ 30 do { \ 31 output_file_directive (FILE, main_input_filename); \ 32 if (ix86_asm_dialect == ASM_INTEL) \ 33 fputs ("\t.intel_syntax\n", FILE); \ 34 } while (0) 35 36#undef TARGET_VERSION 37#define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)"); 38 39/* The svr4 ABI for the i386 says that records and unions are returned 40 in memory. */ 41#undef DEFAULT_PCC_STRUCT_RETURN 42#define DEFAULT_PCC_STRUCT_RETURN 1 43 44#undef ASM_COMMENT_START 45#define ASM_COMMENT_START "#" 46 47#undef DBX_REGISTER_NUMBER 48#define DBX_REGISTER_NUMBER(n) \ 49 (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n]) 50 51/* Output assembler code to FILE to call the profiler. 52 To the best of my knowledge, no Linux libc has required the label 53 argument to mcount. */ 54 55#define NO_PROFILE_COUNTERS 56 57#undef FUNCTION_PROFILER 58#define FUNCTION_PROFILER(FILE, LABELNO) \ 59{ \ 60 if (flag_pic) \ 61 fprintf (FILE, "\tcall\t*mcount@GOT(%%ebx)\n"); \ 62 else \ 63 fprintf (FILE, "\tcall\tmcount\n"); \ 64} 65 66/* True if it is possible to profile code that does not have a frame 67 pointer. 68 69 The GLIBC version of mcount for the x86 assumes that there is a 70 frame, so we cannot allow profiling without a frame pointer. */ 71 72#undef TARGET_ALLOWS_PROFILING_WITHOUT_FRAME_POINTER 73#define TARGET_ALLOWS_PROFILING_WITHOUT_FRAME_POINTER false 74 75#undef SIZE_TYPE 76#define SIZE_TYPE "unsigned int" 77 78#undef PTRDIFF_TYPE 79#define PTRDIFF_TYPE "int" 80 81#undef WCHAR_TYPE 82#define WCHAR_TYPE "long int" 83 84#undef WCHAR_TYPE_SIZE 85#define WCHAR_TYPE_SIZE BITS_PER_WORD 86 87#undef CPP_PREDEFINES 88#define CPP_PREDEFINES "-D__ELF__ -Dunix -Dlinux -Asystem=posix" 89 90#undef CPP_SPEC 91#ifdef USE_GNULIBC_1 92#define CPP_SPEC "%(cpp_cpu) %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{posix:-D_POSIX_SOURCE}" 93#else 94#define CPP_SPEC "%(cpp_cpu) %{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}" 95#endif 96 97#undef CC1_SPEC 98#define CC1_SPEC "%(cc1_cpu) %{profile:-p}" 99 100/* Provide a LINK_SPEC appropriate for Linux. Here we provide support 101 for the special GCC options -static and -shared, which allow us to 102 link things in one of these three modes by applying the appropriate 103 combinations of options at link-time. We like to support here for 104 as many of the other GNU linker options as possible. But I don't 105 have the time to search for those flags. I am sure how to add 106 support for -soname shared_object_name. H.J. 107 108 I took out %{v:%{!V:-V}}. It is too much :-(. They can use 109 -Wl,-V. 110 111 When the -shared link option is used a final link is not being 112 done. */ 113 114/* If ELF is the default format, we should not use /lib/elf. */ 115 116#undef LINK_SPEC 117#ifdef USE_GNULIBC_1 118#ifndef LINUX_DEFAULT_ELF 119#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 120 %{!shared: \ 121 %{!ibcs: \ 122 %{!static: \ 123 %{rdynamic:-export-dynamic} \ 124 %{!dynamic-linker:-dynamic-linker /lib/elf/ld-linux.so.1} \ 125 %{!rpath:-rpath /lib/elf/}} %{static:-static}}}" 126#else 127#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 128 %{!shared: \ 129 %{!ibcs: \ 130 %{!static: \ 131 %{rdynamic:-export-dynamic} \ 132 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.1}} \ 133 %{static:-static}}}" 134#endif 135#else 136#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 137 %{!shared: \ 138 %{!ibcs: \ 139 %{!static: \ 140 %{rdynamic:-export-dynamic} \ 141 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2}} \ 142 %{static:-static}}}" 143#endif 144 145/* A C statement (sans semicolon) to output to the stdio stream 146 FILE the assembler definition of uninitialized global DECL named 147 NAME whose size is SIZE bytes and alignment is ALIGN bytes. 148 Try to use asm_output_aligned_bss to implement this macro. */ 149 150#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \ 151 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN) 152 153/* A C statement to output to the stdio stream FILE an assembler 154 command to advance the location counter to a multiple of 1<<LOG 155 bytes if it is within MAX_SKIP bytes. 156 157 This is used to align code labels according to Intel recommendations. */ 158 159#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN 160#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ 161 do { \ 162 if ((LOG) != 0) { \ 163 if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ 164 else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ 165 } \ 166 } while (0) 167#endif 168 169#if defined(__PIC__) && defined (USE_GNULIBC_1) 170/* This is a kludge. The i386 GNU/Linux dynamic linker needs ___brk_addr, 171 __environ and atexit. We have to make sure they are in the .dynsym 172 section. We do this by forcing the assembler to create undefined 173 references to these symbols in the object file. */ 174#undef CRT_CALL_STATIC_FUNCTION 175#define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \ 176 asm (SECTION_OP "\n\t" \ 177 "call " USER_LABEL_PREFIX #FUNC "\n" \ 178 TEXT_SECTION_ASM_OP "\n\t" \ 179 ".extern ___brk_addr\n\t" \ 180 ".type ___brk_addr,@object\n\t" \ 181 ".extern __environ\n\t" \ 182 ".type __environ,@object\n\t" \ 183 ".extern atexit\n\t" \ 184 ".type atexit,@function"); 185#endif 186 187/* Handle special EH pointer encodings. Absolute, pc-relative, and 188 indirect are handled automatically. */ 189#define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \ 190 do { \ 191 if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel) \ 192 { \ 193 fputs (ASM_LONG, FILE); \ 194 assemble_name (FILE, XSTR (ADDR, 0)); \ 195 fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \ 196 goto DONE; \ 197 } \ 198 } while (0) 199 200/* Used by crtstuff.c to initialize the base of data-relative relocations. 201 These are GOT relative on x86, so return the pic register. */ 202#ifdef __PIC__ 203#define CRT_GET_RFIB_DATA(BASE) \ 204 { \ 205 register void *ebx_ __asm__("ebx"); \ 206 BASE = ebx_; \ 207 } 208#else 209#define CRT_GET_RFIB_DATA(BASE) \ 210 __asm__ ("call\t.LPR%=\n" \ 211 ".LPR%=:\n\t" \ 212 "popl\t%0\n\t" \ 213 /* Due to a GAS bug, this cannot use EAX. That encodes \ 214 smaller than the traditional EBX, which results in the \ 215 offset being off by one. */ \ 216 "addl\t$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0" \ 217 : "=d"(BASE)) 218#endif 219 220/* Do code reading to identify a signal frame, and set the frame 221 state data appropriately. See unwind-dw2.c for the structs. */ 222 223#ifdef IN_LIBGCC2 224#include <signal.h> 225#include <sys/ucontext.h> 226#endif 227 228#define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS) \ 229 do { \ 230 unsigned char *pc_ = (CONTEXT)->ra; \ 231 struct sigcontext *sc_; \ 232 long new_cfa_; \ 233 \ 234 /* popl %eax ; movl $__NR_sigreturn,%eax ; int $0x80 */ \ 235 if (*(unsigned short *)(pc_+0) == 0xb858 \ 236 && *(unsigned int *)(pc_+2) == 119 \ 237 && *(unsigned short *)(pc_+6) == 0x80cd) \ 238 sc_ = (CONTEXT)->cfa + 4; \ 239 /* movl $__NR_rt_sigreturn,%eax ; int $0x80 */ \ 240 else if (*(unsigned char *)(pc_+0) == 0xb8 \ 241 && *(unsigned int *)(pc_+1) == 173 \ 242 && *(unsigned short *)(pc_+5) == 0x80cd) \ 243 { \ 244 struct rt_sigframe { \ 245 int sig; \ 246 struct siginfo *pinfo; \ 247 void *puc; \ 248 struct siginfo info; \ 249 struct ucontext uc; \ 250 } *rt_ = (CONTEXT)->cfa; \ 251 sc_ = (struct sigcontext *) &rt_->uc.uc_mcontext; \ 252 } \ 253 else \ 254 break; \ 255 \ 256 new_cfa_ = sc_->esp; \ 257 (FS)->cfa_how = CFA_REG_OFFSET; \ 258 (FS)->cfa_reg = 4; \ 259 (FS)->cfa_offset = new_cfa_ - (long) (CONTEXT)->cfa; \ 260 \ 261 /* The SVR4 register numbering macros aren't usable in libgcc. */ \ 262 (FS)->regs.reg[0].how = REG_SAVED_OFFSET; \ 263 (FS)->regs.reg[0].loc.offset = (long)&sc_->eax - new_cfa_; \ 264 (FS)->regs.reg[3].how = REG_SAVED_OFFSET; \ 265 (FS)->regs.reg[3].loc.offset = (long)&sc_->ebx - new_cfa_; \ 266 (FS)->regs.reg[1].how = REG_SAVED_OFFSET; \ 267 (FS)->regs.reg[1].loc.offset = (long)&sc_->ecx - new_cfa_; \ 268 (FS)->regs.reg[2].how = REG_SAVED_OFFSET; \ 269 (FS)->regs.reg[2].loc.offset = (long)&sc_->edx - new_cfa_; \ 270 (FS)->regs.reg[6].how = REG_SAVED_OFFSET; \ 271 (FS)->regs.reg[6].loc.offset = (long)&sc_->esi - new_cfa_; \ 272 (FS)->regs.reg[7].how = REG_SAVED_OFFSET; \ 273 (FS)->regs.reg[7].loc.offset = (long)&sc_->edi - new_cfa_; \ 274 (FS)->regs.reg[5].how = REG_SAVED_OFFSET; \ 275 (FS)->regs.reg[5].loc.offset = (long)&sc_->ebp - new_cfa_; \ 276 (FS)->regs.reg[8].how = REG_SAVED_OFFSET; \ 277 (FS)->regs.reg[8].loc.offset = (long)&sc_->eip - new_cfa_; \ 278 (FS)->retaddr_column = 8; \ 279 goto SUCCESS; \ 280 } while (0) 281