linux.h revision 132718
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 GCC. 8 9GCC 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 14GCC 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 GCC; see the file COPYING. If not, write to 21the Free Software Foundation, 59 Temple Place - Suite 330, 22Boston, MA 02111-1307, USA. */ 23 24/* Output at beginning of assembler file. */ 25/* The .file command should always begin the output. */ 26#define TARGET_ASM_FILE_START_FILE_DIRECTIVE true 27 28#define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)"); 29 30/* The svr4 ABI for the i386 says that records and unions are returned 31 in memory. */ 32#undef DEFAULT_PCC_STRUCT_RETURN 33#define DEFAULT_PCC_STRUCT_RETURN 1 34 35/* We arrange for the whole %gs segment to map the tls area. */ 36#undef TARGET_TLS_DIRECT_SEG_REFS_DEFAULT 37#define TARGET_TLS_DIRECT_SEG_REFS_DEFAULT MASK_TLS_DIRECT_SEG_REFS 38 39#undef ASM_COMMENT_START 40#define ASM_COMMENT_START "#" 41 42#undef DBX_REGISTER_NUMBER 43#define DBX_REGISTER_NUMBER(n) \ 44 (TARGET_64BIT ? dbx64_register_map[n] : svr4_dbx_register_map[n]) 45 46/* Output assembler code to FILE to call the profiler. 47 To the best of my knowledge, no Linux libc has required the label 48 argument to mcount. */ 49 50#define NO_PROFILE_COUNTERS 1 51 52#undef MCOUNT_NAME 53#define MCOUNT_NAME "mcount" 54 55/* The GLIBC version of mcount for the x86 assumes that there is a 56 frame, so we cannot allow profiling without a frame pointer. */ 57 58#undef SUBTARGET_FRAME_POINTER_REQUIRED 59#define SUBTARGET_FRAME_POINTER_REQUIRED current_function_profile 60 61#undef SIZE_TYPE 62#define SIZE_TYPE "unsigned int" 63 64#undef PTRDIFF_TYPE 65#define PTRDIFF_TYPE "int" 66 67#undef WCHAR_TYPE 68#define WCHAR_TYPE "long int" 69 70#undef WCHAR_TYPE_SIZE 71#define WCHAR_TYPE_SIZE BITS_PER_WORD 72 73#define TARGET_OS_CPP_BUILTINS() \ 74 do \ 75 { \ 76 LINUX_TARGET_OS_CPP_BUILTINS(); \ 77 if (flag_pic) \ 78 { \ 79 builtin_define ("__PIC__"); \ 80 builtin_define ("__pic__"); \ 81 } \ 82 } \ 83 while (0) 84 85#undef CPP_SPEC 86#ifdef USE_GNULIBC_1 87#define CPP_SPEC "%{posix:-D_POSIX_SOURCE}" 88#else 89#define CPP_SPEC "%{posix:-D_POSIX_SOURCE} %{pthread:-D_REENTRANT}" 90#endif 91 92#undef CC1_SPEC 93#define CC1_SPEC "%(cc1_cpu) %{profile:-p}" 94 95/* Provide a LINK_SPEC appropriate for Linux. Here we provide support 96 for the special GCC options -static and -shared, which allow us to 97 link things in one of these three modes by applying the appropriate 98 combinations of options at link-time. We like to support here for 99 as many of the other GNU linker options as possible. But I don't 100 have the time to search for those flags. I am sure how to add 101 support for -soname shared_object_name. H.J. 102 103 I took out %{v:%{!V:-V}}. It is too much :-(. They can use 104 -Wl,-V. 105 106 When the -shared link option is used a final link is not being 107 done. */ 108 109/* If ELF is the default format, we should not use /lib/elf. */ 110 111#undef LINK_SPEC 112#ifdef USE_GNULIBC_1 113#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 114 %{!shared: \ 115 %{!ibcs: \ 116 %{!static: \ 117 %{rdynamic:-export-dynamic} \ 118 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.1}} \ 119 %{static:-static}}}" 120#else 121#define LINK_SPEC "-m elf_i386 %{shared:-shared} \ 122 %{!shared: \ 123 %{!ibcs: \ 124 %{!static: \ 125 %{rdynamic:-export-dynamic} \ 126 %{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.2}} \ 127 %{static:-static}}}" 128#endif 129 130/* A C statement (sans semicolon) to output to the stdio stream 131 FILE the assembler definition of uninitialized global DECL named 132 NAME whose size is SIZE bytes and alignment is ALIGN bytes. 133 Try to use asm_output_aligned_bss to implement this macro. */ 134 135#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \ 136 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN) 137 138/* A C statement to output to the stdio stream FILE an assembler 139 command to advance the location counter to a multiple of 1<<LOG 140 bytes if it is within MAX_SKIP bytes. 141 142 This is used to align code labels according to Intel recommendations. */ 143 144#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN 145#define ASM_OUTPUT_MAX_SKIP_ALIGN(FILE,LOG,MAX_SKIP) \ 146 do { \ 147 if ((LOG) != 0) { \ 148 if ((MAX_SKIP) == 0) fprintf ((FILE), "\t.p2align %d\n", (LOG)); \ 149 else fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP)); \ 150 } \ 151 } while (0) 152#endif 153 154#if defined(__PIC__) && defined (USE_GNULIBC_1) 155/* This is a kludge. The i386 GNU/Linux dynamic linker needs ___brk_addr, 156 __environ and atexit. We have to make sure they are in the .dynsym 157 section. We do this by forcing the assembler to create undefined 158 references to these symbols in the object file. */ 159#undef CRT_CALL_STATIC_FUNCTION 160#define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \ 161 asm (SECTION_OP "\n\t" \ 162 "call " USER_LABEL_PREFIX #FUNC "\n" \ 163 TEXT_SECTION_ASM_OP "\n\t" \ 164 ".extern ___brk_addr\n\t" \ 165 ".type ___brk_addr,@object\n\t" \ 166 ".extern __environ\n\t" \ 167 ".type __environ,@object\n\t" \ 168 ".extern atexit\n\t" \ 169 ".type atexit,@function"); 170#endif 171 172/* Handle special EH pointer encodings. Absolute, pc-relative, and 173 indirect are handled automatically. */ 174#define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \ 175 do { \ 176 if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_datarel) \ 177 { \ 178 fputs (ASM_LONG, FILE); \ 179 assemble_name (FILE, XSTR (ADDR, 0)); \ 180 fputs (((ENCODING) & DW_EH_PE_indirect ? "@GOT" : "@GOTOFF"), FILE); \ 181 goto DONE; \ 182 } \ 183 } while (0) 184 185/* Used by crtstuff.c to initialize the base of data-relative relocations. 186 These are GOT relative on x86, so return the pic register. */ 187#ifdef __PIC__ 188#define CRT_GET_RFIB_DATA(BASE) \ 189 { \ 190 register void *ebx_ __asm__("ebx"); \ 191 BASE = ebx_; \ 192 } 193#else 194#define CRT_GET_RFIB_DATA(BASE) \ 195 __asm__ ("call\t.LPR%=\n" \ 196 ".LPR%=:\n\t" \ 197 "popl\t%0\n\t" \ 198 /* Due to a GAS bug, this cannot use EAX. That encodes \ 199 smaller than the traditional EBX, which results in the \ 200 offset being off by one. */ \ 201 "addl\t$_GLOBAL_OFFSET_TABLE_+[.-.LPR%=],%0" \ 202 : "=d"(BASE)) 203#endif 204 205#undef NEED_INDICATE_EXEC_STACK 206#define NEED_INDICATE_EXEC_STACK 1 207 208/* Do code reading to identify a signal frame, and set the frame 209 state data appropriately. See unwind-dw2.c for the structs. */ 210 211#ifdef IN_LIBGCC2 212/* There's no sys/ucontext.h for some (all?) libc1, so no 213 signal-turned-exceptions for them. There's also no configure-run for 214 the target, so we can't check on (e.g.) HAVE_SYS_UCONTEXT_H. Using the 215 target libc1 macro should be enough. */ 216#if !(defined (USE_GNULIBC_1) || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 0)) 217#include <signal.h> 218#include <sys/ucontext.h> 219 220#define MD_FALLBACK_FRAME_STATE_FOR(CONTEXT, FS, SUCCESS) \ 221 do { \ 222 unsigned char *pc_ = (CONTEXT)->ra; \ 223 struct sigcontext *sc_; \ 224 long new_cfa_; \ 225 \ 226 /* popl %eax ; movl $__NR_sigreturn,%eax ; int $0x80 */ \ 227 if (*(unsigned short *)(pc_+0) == 0xb858 \ 228 && *(unsigned int *)(pc_+2) == 119 \ 229 && *(unsigned short *)(pc_+6) == 0x80cd) \ 230 sc_ = (CONTEXT)->cfa + 4; \ 231 /* movl $__NR_rt_sigreturn,%eax ; int $0x80 */ \ 232 else if (*(unsigned char *)(pc_+0) == 0xb8 \ 233 && *(unsigned int *)(pc_+1) == 173 \ 234 && *(unsigned short *)(pc_+5) == 0x80cd) \ 235 { \ 236 struct rt_sigframe { \ 237 int sig; \ 238 struct siginfo *pinfo; \ 239 void *puc; \ 240 struct siginfo info; \ 241 struct ucontext uc; \ 242 } *rt_ = (CONTEXT)->cfa; \ 243 sc_ = (struct sigcontext *) &rt_->uc.uc_mcontext; \ 244 } \ 245 else \ 246 break; \ 247 \ 248 new_cfa_ = sc_->esp; \ 249 (FS)->cfa_how = CFA_REG_OFFSET; \ 250 (FS)->cfa_reg = 4; \ 251 (FS)->cfa_offset = new_cfa_ - (long) (CONTEXT)->cfa; \ 252 \ 253 /* The SVR4 register numbering macros aren't usable in libgcc. */ \ 254 (FS)->regs.reg[0].how = REG_SAVED_OFFSET; \ 255 (FS)->regs.reg[0].loc.offset = (long)&sc_->eax - new_cfa_; \ 256 (FS)->regs.reg[3].how = REG_SAVED_OFFSET; \ 257 (FS)->regs.reg[3].loc.offset = (long)&sc_->ebx - new_cfa_; \ 258 (FS)->regs.reg[1].how = REG_SAVED_OFFSET; \ 259 (FS)->regs.reg[1].loc.offset = (long)&sc_->ecx - new_cfa_; \ 260 (FS)->regs.reg[2].how = REG_SAVED_OFFSET; \ 261 (FS)->regs.reg[2].loc.offset = (long)&sc_->edx - new_cfa_; \ 262 (FS)->regs.reg[6].how = REG_SAVED_OFFSET; \ 263 (FS)->regs.reg[6].loc.offset = (long)&sc_->esi - new_cfa_; \ 264 (FS)->regs.reg[7].how = REG_SAVED_OFFSET; \ 265 (FS)->regs.reg[7].loc.offset = (long)&sc_->edi - new_cfa_; \ 266 (FS)->regs.reg[5].how = REG_SAVED_OFFSET; \ 267 (FS)->regs.reg[5].loc.offset = (long)&sc_->ebp - new_cfa_; \ 268 (FS)->regs.reg[8].how = REG_SAVED_OFFSET; \ 269 (FS)->regs.reg[8].loc.offset = (long)&sc_->eip - new_cfa_; \ 270 (FS)->retaddr_column = 8; \ 271 goto SUCCESS; \ 272 } while (0) 273#endif /* not USE_GNULIBC_1 */ 274#endif /* IN_LIBGCC2 */ 275