linux.h revision 117395
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#define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)"); 37 38/* The svr4 ABI for the i386 says that records and unions are returned 39 in memory. */ 40#undef DEFAULT_PCC_STRUCT_RETURN 41#define DEFAULT_PCC_STRUCT_RETURN 1 42 43#undef ASM_COMMENT_START 44#define ASM_COMMENT_START "#" 45 46#undef DBX_REGISTER_NUMBER 47#define DBX_REGISTER_NUMBER(n) \ 48 (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n]) 49 50/* Output assembler code to FILE to call the profiler. 51 To the best of my knowledge, no Linux libc has required the label 52 argument to mcount. */ 53 54#define NO_PROFILE_COUNTERS 55 56#undef MCOUNT_NAME 57#define MCOUNT_NAME "mcount" 58 59/* The GLIBC version of mcount for the x86 assumes that there is a 60 frame, so we cannot allow profiling without a frame pointer. */ 61 62#undef SUBTARGET_FRAME_POINTER_REQUIRED 63#define SUBTARGET_FRAME_POINTER_REQUIRED current_function_profile 64 65#undef SIZE_TYPE 66#define SIZE_TYPE "unsigned int" 67 68#undef PTRDIFF_TYPE 69#define PTRDIFF_TYPE "int" 70 71#undef WCHAR_TYPE 72#define WCHAR_TYPE "long int" 73 74#undef WCHAR_TYPE_SIZE 75#define WCHAR_TYPE_SIZE BITS_PER_WORD 76 77#define TARGET_OS_CPP_BUILTINS() \ 78 do \ 79 { \ 80 builtin_define_std ("linux"); \ 81 builtin_define_std ("unix"); \ 82 builtin_define ("__ELF__"); \ 83 builtin_define ("__gnu_linux__"); \ 84 builtin_assert ("system=posix"); \ 85 if (flag_pic) \ 86 { \ 87 builtin_define ("__PIC__"); \ 88 builtin_define ("__pic__"); \ 89 } \ 90 } \ 91 while (0) 92 93#undef CPP_SPEC 94#ifdef USE_GNULIBC_1 95#define CPP_SPEC "%{posix:-D_POSIX_SOURCE}" 96#else 97#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}" 98#endif 99 100#undef CC1_SPEC 101#define CC1_SPEC "%(cc1_cpu) %{profile:-p}" 102 103/* Provide a LINK_SPEC appropriate for Linux. Here we provide support 104 for the special GCC options -static and -shared, which allow us to 105 link things in one of these three modes by applying the appropriate 106 combinations of options at link-time. We like to support here for 107 as many of the other GNU linker options as possible. But I don't 108 have the time to search for those flags. I am sure how to add 109 support for -soname shared_object_name. H.J. 110 111 I took out %{v:%{!V:-V}}. It is too much :-(. They can use 112 -Wl,-V. 113 114 When the -shared link option is used a final link is not being 115 done. */ 116 117/* If ELF is the default format, we should not use /lib/elf. */ 118 119#undef LINK_SPEC 120#ifdef USE_GNULIBC_1 121#ifndef LINUX_DEFAULT_ELF 122#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 123 %{!shared: \ 124 %{!ibcs: \ 125 %{!static: \ 126 %{rdynamic:-export-dynamic} \ 127 %{!dynamic-linker:-dynamic-linker /lib/elf/ld-linux.so.1} \ 128 %{!rpath:-rpath /lib/elf/}} %{static:-static}}}" 129#else 130#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 131 %{!shared: \ 132 %{!ibcs: \ 133 %{!static: \ 134 %{rdynamic:-export-dynamic} \ 135 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.1}} \ 136 %{static:-static}}}" 137#endif 138#else 139#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 140 %{!shared: \ 141 %{!ibcs: \ 142 %{!static: \ 143 %{rdynamic:-export-dynamic} \ 144 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2}} \ 145 %{static:-static}}}" 146#endif 147 148/* A C statement (sans semicolon) to output to the stdio stream 149 FILE the assembler definition of uninitialized global DECL named 150 NAME whose size is SIZE bytes and alignment is ALIGN bytes. 151 Try to use asm_output_aligned_bss to implement this macro. */ 152 153#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \ 154 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN) 155 156/* A C statement to output to the stdio stream FILE an assembler 157 command to advance the location counter to a multiple of 1<<LOG 158 bytes if it is within MAX_SKIP bytes. 159 160 This is used to align code labels according to Intel recommendations. */ 161 162#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN 163#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ 164 do { \ 165 if ((LOG) != 0) { \ 166 if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ 167 else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ 168 } \ 169 } while (0) 170#endif 171 172#if defined(__PIC__) && defined (USE_GNULIBC_1) 173/* This is a kludge. The i386 GNU/Linux dynamic linker needs ___brk_addr, 174 __environ and atexit. We have to make sure they are in the .dynsym 175 section. We do this by forcing the assembler to create undefined 176 references to these symbols in the object file. */ 177#undef CRT_CALL_STATIC_FUNCTION 178#define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \ 179 asm (SECTION_OP "\n\t" \ 180 "call " USER_LABEL_PREFIX #FUNC "\n" \ 181 TEXT_SECTION_ASM_OP "\n\t" \ 182 ".extern ___brk_addr\n\t" \ 183 ".type ___brk_addr,@object\n\t" \ 184 ".extern __environ\n\t" \ 185 ".type __environ,@object\n\t" \ 186 ".extern atexit\n\t" \ 187 ".type atexit,@function"); 188#endif 189 190/* Handle special EH pointer encodings. Absolute, pc-relative, and 191 indirect are handled automatically. */ 192#define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \ 193 do { \ 194 if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel) \ 195 { \ 196 fputs (ASM_LONG, FILE); \ 197 assemble_name (FILE, XSTR (ADDR, 0)); \ 198 fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \ 199 goto DONE; \ 200 } \ 201 } while (0) 202 203/* Used by crtstuff.c to initialize the base of data-relative relocations. 204 These are GOT relative on x86, so return the pic register. */ 205#ifdef __PIC__ 206#define CRT_GET_RFIB_DATA(BASE) \ 207 { \ 208 register void *ebx_ __asm__("ebx"); \ 209 BASE = ebx_; \ 210 } 211#else 212#define CRT_GET_RFIB_DATA(BASE) \ 213 __asm__ ("call\t.LPR%=\n" \ 214 ".LPR%=:\n\t" \ 215 "popl\t%0\n\t" \ 216 /* Due to a GAS bug, this cannot use EAX. That encodes \ 217 smaller than the traditional EBX, which results in the \ 218 offset being off by one. */ \ 219 "addl\t$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0" \ 220 : "=d"(BASE)) 221#endif 222 223/* Do code reading to identify a signal frame, and set the frame 224 state data appropriately. See unwind-dw2.c for the structs. */ 225 226#ifdef IN_LIBGCC2 227/* There's no sys/ucontext.h for some (all?) libc1, so no 228 signal-turned-exceptions for them. There's also no configure-run for 229 the target, so we can't check on (e.g.) HAVE_SYS_UCONTEXT_H. Using the 230 target libc1 macro should be enough. */ 231#ifndef USE_GNULIBC_1 232#include <signal.h> 233#include <sys/ucontext.h> 234 235#define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS) \ 236 do { \ 237 unsigned char *pc_ = (CONTEXT)->ra; \ 238 struct sigcontext *sc_; \ 239 long new_cfa_; \ 240 \ 241 /* popl %eax ; movl $__NR_sigreturn,%eax ; int $0x80 */ \ 242 if (*(unsigned short *)(pc_+0) == 0xb858 \ 243 && *(unsigned int *)(pc_+2) == 119 \ 244 && *(unsigned short *)(pc_+6) == 0x80cd) \ 245 sc_ = (CONTEXT)->cfa + 4; \ 246 /* movl $__NR_rt_sigreturn,%eax ; int $0x80 */ \ 247 else if (*(unsigned char *)(pc_+0) == 0xb8 \ 248 && *(unsigned int *)(pc_+1) == 173 \ 249 && *(unsigned short *)(pc_+5) == 0x80cd) \ 250 { \ 251 struct rt_sigframe { \ 252 int sig; \ 253 struct siginfo *pinfo; \ 254 void *puc; \ 255 struct siginfo info; \ 256 struct ucontext uc; \ 257 } *rt_ = (CONTEXT)->cfa; \ 258 sc_ = (struct sigcontext *) &rt_->uc.uc_mcontext; \ 259 } \ 260 else \ 261 break; \ 262 \ 263 new_cfa_ = sc_->esp; \ 264 (FS)->cfa_how = CFA_REG_OFFSET; \ 265 (FS)->cfa_reg = 4; \ 266 (FS)->cfa_offset = new_cfa_ - (long) (CONTEXT)->cfa; \ 267 \ 268 /* The SVR4 register numbering macros aren't usable in libgcc. */ \ 269 (FS)->regs.reg[0].how = REG_SAVED_OFFSET; \ 270 (FS)->regs.reg[0].loc.offset = (long)&sc_->eax - new_cfa_; \ 271 (FS)->regs.reg[3].how = REG_SAVED_OFFSET; \ 272 (FS)->regs.reg[3].loc.offset = (long)&sc_->ebx - new_cfa_; \ 273 (FS)->regs.reg[1].how = REG_SAVED_OFFSET; \ 274 (FS)->regs.reg[1].loc.offset = (long)&sc_->ecx - new_cfa_; \ 275 (FS)->regs.reg[2].how = REG_SAVED_OFFSET; \ 276 (FS)->regs.reg[2].loc.offset = (long)&sc_->edx - new_cfa_; \ 277 (FS)->regs.reg[6].how = REG_SAVED_OFFSET; \ 278 (FS)->regs.reg[6].loc.offset = (long)&sc_->esi - new_cfa_; \ 279 (FS)->regs.reg[7].how = REG_SAVED_OFFSET; \ 280 (FS)->regs.reg[7].loc.offset = (long)&sc_->edi - new_cfa_; \ 281 (FS)->regs.reg[5].how = REG_SAVED_OFFSET; \ 282 (FS)->regs.reg[5].loc.offset = (long)&sc_->ebp - new_cfa_; \ 283 (FS)->regs.reg[8].how = REG_SAVED_OFFSET; \ 284 (FS)->regs.reg[8].loc.offset = (long)&sc_->eip - new_cfa_; \ 285 (FS)->retaddr_column = 8; \ 286 goto SUCCESS; \ 287 } while (0) 288#endif /* not USE_GNULIBC_1 */ 289#endif /* IN_LIBGCC2 */ 290