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author | Stan Shebs <shebs@codesourcery.com> | 1999-04-16 01:34:07 +0000 |
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committer | Stan Shebs <shebs@codesourcery.com> | 1999-04-16 01:34:07 +0000 |
commit | 071ea11e85eb9d529cc5eb3d35f6247466a21b99 (patch) | |
tree | 5deda65b8d7b04d1f4cbc534c3206d328e1267ec /gdb/i386-tdep.c | |
parent | 1730ec6b1848f0f32154277f788fb29f88d8475b (diff) | |
download | gdb-071ea11e85eb9d529cc5eb3d35f6247466a21b99.zip gdb-071ea11e85eb9d529cc5eb3d35f6247466a21b99.tar.gz gdb-071ea11e85eb9d529cc5eb3d35f6247466a21b99.tar.bz2 |
Initial creation of sourceware repository
Diffstat (limited to 'gdb/i386-tdep.c')
-rw-r--r-- | gdb/i386-tdep.c | 800 |
1 files changed, 0 insertions, 800 deletions
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c deleted file mode 100644 index 151d626..0000000 --- a/gdb/i386-tdep.c +++ /dev/null @@ -1,800 +0,0 @@ -/* Intel 386 target-dependent stuff. - Copyright (C) 1988, 1989, 1991, 1994, 1995, 1996, 1998 - Free Software Foundation, Inc. - -This file is part of GDB. - -This program is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2 of the License, or -(at your option) any later version. - -This program is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this program; if not, write to the Free Software -Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ - -#include "defs.h" -#include "gdb_string.h" -#include "frame.h" -#include "inferior.h" -#include "gdbcore.h" -#include "target.h" -#include "floatformat.h" -#include "symtab.h" -#include "gdbcmd.h" -#include "command.h" - -static long i386_get_frame_setup PARAMS ((CORE_ADDR)); - -static void i386_follow_jump PARAMS ((void)); - -static void codestream_read PARAMS ((unsigned char *, int)); - -static void codestream_seek PARAMS ((CORE_ADDR)); - -static unsigned char codestream_fill PARAMS ((int)); - -CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR, char *)); - -static int gdb_print_insn_i386 (bfd_vma, disassemble_info *); - -void _initialize_i386_tdep PARAMS ((void)); - -/* This is the variable the is set with "set disassembly-flavor", - and its legitimate values. */ -static char att_flavor[] = "att"; -static char intel_flavor[] = "intel"; -static char *valid_flavors[] = { - att_flavor, - intel_flavor, - NULL -}; -static char *disassembly_flavor = att_flavor; - -/* Get rid of these defines as soon as there are two functions - to implement different disassembly flavors. */ -#define print_insn_i386_att print_insn_i386 -#define print_insn_i386_intel print_insn_i386 - -/* Stdio style buffering was used to minimize calls to ptrace, but this - buffering did not take into account that the code section being accessed - may not be an even number of buffers long (even if the buffer is only - sizeof(int) long). In cases where the code section size happened to - be a non-integral number of buffers long, attempting to read the last - buffer would fail. Simply using target_read_memory and ignoring errors, - rather than read_memory, is not the correct solution, since legitimate - access errors would then be totally ignored. To properly handle this - situation and continue to use buffering would require that this code - be able to determine the minimum code section size granularity (not the - alignment of the section itself, since the actual failing case that - pointed out this problem had a section alignment of 4 but was not a - multiple of 4 bytes long), on a target by target basis, and then - adjust it's buffer size accordingly. This is messy, but potentially - feasible. It probably needs the bfd library's help and support. For - now, the buffer size is set to 1. (FIXME -fnf) */ - -#define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */ -static CORE_ADDR codestream_next_addr; -static CORE_ADDR codestream_addr; -static unsigned char codestream_buf[CODESTREAM_BUFSIZ]; -static int codestream_off; -static int codestream_cnt; - -#define codestream_tell() (codestream_addr + codestream_off) -#define codestream_peek() (codestream_cnt == 0 ? \ - codestream_fill(1): codestream_buf[codestream_off]) -#define codestream_get() (codestream_cnt-- == 0 ? \ - codestream_fill(0) : codestream_buf[codestream_off++]) - -static unsigned char -codestream_fill (peek_flag) - int peek_flag; -{ - codestream_addr = codestream_next_addr; - codestream_next_addr += CODESTREAM_BUFSIZ; - codestream_off = 0; - codestream_cnt = CODESTREAM_BUFSIZ; - read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ); - - if (peek_flag) - return (codestream_peek()); - else - return (codestream_get()); -} - -static void -codestream_seek (place) - CORE_ADDR place; -{ - codestream_next_addr = place / CODESTREAM_BUFSIZ; - codestream_next_addr *= CODESTREAM_BUFSIZ; - codestream_cnt = 0; - codestream_fill (1); - while (codestream_tell() != place) - codestream_get (); -} - -static void -codestream_read (buf, count) - unsigned char *buf; - int count; -{ - unsigned char *p; - int i; - p = buf; - for (i = 0; i < count; i++) - *p++ = codestream_get (); -} - -/* next instruction is a jump, move to target */ - -static void -i386_follow_jump () -{ - unsigned char buf[4]; - long delta; - - int data16; - CORE_ADDR pos; - - pos = codestream_tell (); - - data16 = 0; - if (codestream_peek () == 0x66) - { - codestream_get (); - data16 = 1; - } - - switch (codestream_get ()) - { - case 0xe9: - /* relative jump: if data16 == 0, disp32, else disp16 */ - if (data16) - { - codestream_read (buf, 2); - delta = extract_signed_integer (buf, 2); - - /* include size of jmp inst (including the 0x66 prefix). */ - pos += delta + 4; - } - else - { - codestream_read (buf, 4); - delta = extract_signed_integer (buf, 4); - - pos += delta + 5; - } - break; - case 0xeb: - /* relative jump, disp8 (ignore data16) */ - codestream_read (buf, 1); - /* Sign-extend it. */ - delta = extract_signed_integer (buf, 1); - - pos += delta + 2; - break; - } - codestream_seek (pos); -} - -/* - * find & return amound a local space allocated, and advance codestream to - * first register push (if any) - * - * if entry sequence doesn't make sense, return -1, and leave - * codestream pointer random - */ - -static long -i386_get_frame_setup (pc) - CORE_ADDR pc; -{ - unsigned char op; - - codestream_seek (pc); - - i386_follow_jump (); - - op = codestream_get (); - - if (op == 0x58) /* popl %eax */ - { - /* - * this function must start with - * - * popl %eax 0x58 - * xchgl %eax, (%esp) 0x87 0x04 0x24 - * or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 - * - * (the system 5 compiler puts out the second xchg - * inst, and the assembler doesn't try to optimize it, - * so the 'sib' form gets generated) - * - * this sequence is used to get the address of the return - * buffer for a function that returns a structure - */ - int pos; - unsigned char buf[4]; - static unsigned char proto1[3] = { 0x87,0x04,0x24 }; - static unsigned char proto2[4] = { 0x87,0x44,0x24,0x00 }; - pos = codestream_tell (); - codestream_read (buf, 4); - if (memcmp (buf, proto1, 3) == 0) - pos += 3; - else if (memcmp (buf, proto2, 4) == 0) - pos += 4; - - codestream_seek (pos); - op = codestream_get (); /* update next opcode */ - } - - if (op == 0x68 || op == 0x6a) - { - /* - * this function may start with - * - * pushl constant - * call _probe - * addl $4, %esp - * followed by - * pushl %ebp - * etc. - */ - int pos; - unsigned char buf[8]; - - /* Skip past the pushl instruction; it has either a one-byte - or a four-byte operand, depending on the opcode. */ - pos = codestream_tell (); - if (op == 0x68) - pos += 4; - else - pos += 1; - codestream_seek (pos); - - /* Read the following 8 bytes, which should be "call _probe" (6 bytes) - followed by "addl $4,%esp" (2 bytes). */ - codestream_read (buf, sizeof (buf)); - if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) - pos += sizeof (buf); - codestream_seek (pos); - op = codestream_get (); /* update next opcode */ - } - - if (op == 0x55) /* pushl %ebp */ - { - /* check for movl %esp, %ebp - can be written two ways */ - switch (codestream_get ()) - { - case 0x8b: - if (codestream_get () != 0xec) - return (-1); - break; - case 0x89: - if (codestream_get () != 0xe5) - return (-1); - break; - default: - return (-1); - } - /* check for stack adjustment - * - * subl $XXX, %esp - * - * note: you can't subtract a 16 bit immediate - * from a 32 bit reg, so we don't have to worry - * about a data16 prefix - */ - op = codestream_peek (); - if (op == 0x83) - { - /* subl with 8 bit immed */ - codestream_get (); - if (codestream_get () != 0xec) - /* Some instruction starting with 0x83 other than subl. */ - { - codestream_seek (codestream_tell () - 2); - return 0; - } - /* subl with signed byte immediate - * (though it wouldn't make sense to be negative) - */ - return (codestream_get()); - } - else if (op == 0x81) - { - char buf[4]; - /* Maybe it is subl with 32 bit immedediate. */ - codestream_get(); - if (codestream_get () != 0xec) - /* Some instruction starting with 0x81 other than subl. */ - { - codestream_seek (codestream_tell () - 2); - return 0; - } - /* It is subl with 32 bit immediate. */ - codestream_read ((unsigned char *)buf, 4); - return extract_signed_integer (buf, 4); - } - else - { - return (0); - } - } - else if (op == 0xc8) - { - char buf[2]; - /* enter instruction: arg is 16 bit unsigned immed */ - codestream_read ((unsigned char *)buf, 2); - codestream_get (); /* flush final byte of enter instruction */ - return extract_unsigned_integer (buf, 2); - } - return (-1); -} - -/* Return number of args passed to a frame. - Can return -1, meaning no way to tell. */ - -int -i386_frame_num_args (fi) - struct frame_info *fi; -{ -#if 1 - return -1; -#else - /* This loses because not only might the compiler not be popping the - args right after the function call, it might be popping args from both - this call and a previous one, and we would say there are more args - than there really are. */ - - int retpc; - unsigned char op; - struct frame_info *pfi; - - /* on the 386, the instruction following the call could be: - popl %ecx - one arg - addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits - anything else - zero args */ - - int frameless; - - FRAMELESS_FUNCTION_INVOCATION (fi, frameless); - if (frameless) - /* In the absence of a frame pointer, GDB doesn't get correct values - for nameless arguments. Return -1, so it doesn't print any - nameless arguments. */ - return -1; - - pfi = get_prev_frame_info (fi); - if (pfi == 0) - { - /* Note: this can happen if we are looking at the frame for - main, because FRAME_CHAIN_VALID won't let us go into - start. If we have debugging symbols, that's not really - a big deal; it just means it will only show as many arguments - to main as are declared. */ - return -1; - } - else - { - retpc = pfi->pc; - op = read_memory_integer (retpc, 1); - if (op == 0x59) - /* pop %ecx */ - return 1; - else if (op == 0x83) - { - op = read_memory_integer (retpc+1, 1); - if (op == 0xc4) - /* addl $<signed imm 8 bits>, %esp */ - return (read_memory_integer (retpc+2,1)&0xff)/4; - else - return 0; - } - else if (op == 0x81) - { /* add with 32 bit immediate */ - op = read_memory_integer (retpc+1, 1); - if (op == 0xc4) - /* addl $<imm 32>, %esp */ - return read_memory_integer (retpc+2, 4) / 4; - else - return 0; - } - else - { - return 0; - } - } -#endif -} - -/* - * parse the first few instructions of the function to see - * what registers were stored. - * - * We handle these cases: - * - * The startup sequence can be at the start of the function, - * or the function can start with a branch to startup code at the end. - * - * %ebp can be set up with either the 'enter' instruction, or - * 'pushl %ebp, movl %esp, %ebp' (enter is too slow to be useful, - * but was once used in the sys5 compiler) - * - * Local space is allocated just below the saved %ebp by either the - * 'enter' instruction, or by 'subl $<size>, %esp'. 'enter' has - * a 16 bit unsigned argument for space to allocate, and the - * 'addl' instruction could have either a signed byte, or - * 32 bit immediate. - * - * Next, the registers used by this function are pushed. In - * the sys5 compiler they will always be in the order: %edi, %esi, %ebx - * (and sometimes a harmless bug causes it to also save but not restore %eax); - * however, the code below is willing to see the pushes in any order, - * and will handle up to 8 of them. - * - * If the setup sequence is at the end of the function, then the - * next instruction will be a branch back to the start. - */ - -void -i386_frame_find_saved_regs (fip, fsrp) - struct frame_info *fip; - struct frame_saved_regs *fsrp; -{ - long locals = -1; - unsigned char op; - CORE_ADDR dummy_bottom; - CORE_ADDR adr; - CORE_ADDR pc; - int i; - - memset (fsrp, 0, sizeof *fsrp); - - /* if frame is the end of a dummy, compute where the - * beginning would be - */ - dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; - - /* check if the PC is in the stack, in a dummy frame */ - if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) - { - /* all regs were saved by push_call_dummy () */ - adr = fip->frame; - for (i = 0; i < NUM_REGS; i++) - { - adr -= REGISTER_RAW_SIZE (i); - fsrp->regs[i] = adr; - } - return; - } - - pc = get_pc_function_start (fip->pc); - if (pc != 0) - locals = i386_get_frame_setup (pc); - - if (locals >= 0) - { - adr = fip->frame - 4 - locals; - for (i = 0; i < 8; i++) - { - op = codestream_get (); - if (op < 0x50 || op > 0x57) - break; -#ifdef I386_REGNO_TO_SYMMETRY - /* Dynix uses different internal numbering. Ick. */ - fsrp->regs[I386_REGNO_TO_SYMMETRY(op - 0x50)] = adr; -#else - fsrp->regs[op - 0x50] = adr; -#endif - adr -= 4; - } - } - - fsrp->regs[PC_REGNUM] = fip->frame + 4; - fsrp->regs[FP_REGNUM] = fip->frame; -} - -/* return pc of first real instruction */ - -int -i386_skip_prologue (pc) - int pc; -{ - unsigned char op; - int i; - static unsigned char pic_pat[6] = { 0xe8, 0, 0, 0, 0, /* call 0x0 */ - 0x5b, /* popl %ebx */ - }; - CORE_ADDR pos; - - if (i386_get_frame_setup (pc) < 0) - return (pc); - - /* found valid frame setup - codestream now points to - * start of push instructions for saving registers - */ - - /* skip over register saves */ - for (i = 0; i < 8; i++) - { - op = codestream_peek (); - /* break if not pushl inst */ - if (op < 0x50 || op > 0x57) - break; - codestream_get (); - } - - /* The native cc on SVR4 in -K PIC mode inserts the following code to get - the address of the global offset table (GOT) into register %ebx. - call 0x0 - popl %ebx - movl %ebx,x(%ebp) (optional) - addl y,%ebx - This code is with the rest of the prologue (at the end of the - function), so we have to skip it to get to the first real - instruction at the start of the function. */ - - pos = codestream_tell (); - for (i = 0; i < 6; i++) - { - op = codestream_get (); - if (pic_pat [i] != op) - break; - } - if (i == 6) - { - unsigned char buf[4]; - long delta = 6; - - op = codestream_get (); - if (op == 0x89) /* movl %ebx, x(%ebp) */ - { - op = codestream_get (); - if (op == 0x5d) /* one byte offset from %ebp */ - { - delta += 3; - codestream_read (buf, 1); - } - else if (op == 0x9d) /* four byte offset from %ebp */ - { - delta += 6; - codestream_read (buf, 4); - } - else /* unexpected instruction */ - delta = -1; - op = codestream_get (); - } - /* addl y,%ebx */ - if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) - { - pos += delta + 6; - } - } - codestream_seek (pos); - - i386_follow_jump (); - - return (codestream_tell ()); -} - -void -i386_push_dummy_frame () -{ - CORE_ADDR sp = read_register (SP_REGNUM); - int regnum; - char regbuf[MAX_REGISTER_RAW_SIZE]; - - sp = push_word (sp, read_register (PC_REGNUM)); - sp = push_word (sp, read_register (FP_REGNUM)); - write_register (FP_REGNUM, sp); - for (regnum = 0; regnum < NUM_REGS; regnum++) - { - read_register_gen (regnum, regbuf); - sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); - } - write_register (SP_REGNUM, sp); -} - -void -i386_pop_frame () -{ - struct frame_info *frame = get_current_frame (); - CORE_ADDR fp; - int regnum; - struct frame_saved_regs fsr; - char regbuf[MAX_REGISTER_RAW_SIZE]; - - fp = FRAME_FP (frame); - get_frame_saved_regs (frame, &fsr); - for (regnum = 0; regnum < NUM_REGS; regnum++) - { - CORE_ADDR adr; - adr = fsr.regs[regnum]; - if (adr) - { - read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); - write_register_bytes (REGISTER_BYTE (regnum), regbuf, - REGISTER_RAW_SIZE (regnum)); - } - } - write_register (FP_REGNUM, read_memory_integer (fp, 4)); - write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); - write_register (SP_REGNUM, fp + 8); - flush_cached_frames (); -} - -#ifdef GET_LONGJMP_TARGET - -/* Figure out where the longjmp will land. Slurp the args out of the stack. - We expect the first arg to be a pointer to the jmp_buf structure from which - we extract the pc (JB_PC) that we will land at. The pc is copied into PC. - This routine returns true on success. */ - -int -get_longjmp_target(pc) - CORE_ADDR *pc; -{ - char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; - CORE_ADDR sp, jb_addr; - - sp = read_register (SP_REGNUM); - - if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ - buf, - TARGET_PTR_BIT / TARGET_CHAR_BIT)) - return 0; - - jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); - - if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, - TARGET_PTR_BIT / TARGET_CHAR_BIT)) - return 0; - - *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); - - return 1; -} - -#endif /* GET_LONGJMP_TARGET */ - -void -i386_extract_return_value(type, regbuf, valbuf) - struct type *type; - char regbuf[REGISTER_BYTES]; - char *valbuf; -{ -/* On AIX, floating point values are returned in floating point registers. */ -#ifdef I386_AIX_TARGET - if (TYPE_CODE_FLT == TYPE_CODE(type)) - { - double d; - /* 387 %st(0), gcc uses this */ - floatformat_to_double (&floatformat_i387_ext, - ®buf[REGISTER_BYTE(FP0_REGNUM)], - &d); - store_floating (valbuf, TYPE_LENGTH (type), d); - } - else -#endif /* I386_AIX_TARGET */ - { - memcpy (valbuf, regbuf, TYPE_LENGTH (type)); - } -} - -#ifdef I386V4_SIGTRAMP_SAVED_PC -/* Get saved user PC for sigtramp from the pushed ucontext on the stack - for all three variants of SVR4 sigtramps. */ - -CORE_ADDR -i386v4_sigtramp_saved_pc (frame) - struct frame_info *frame; -{ - CORE_ADDR saved_pc_offset = 4; - char *name = NULL; - - find_pc_partial_function (frame->pc, &name, NULL, NULL); - if (name) - { - if (STREQ (name, "_sigreturn")) - saved_pc_offset = 132 + 14 * 4; - else if (STREQ (name, "_sigacthandler")) - saved_pc_offset = 80 + 14 * 4; - else if (STREQ (name, "sigvechandler")) - saved_pc_offset = 120 + 14 * 4; - } - - if (frame->next) - return read_memory_integer (frame->next->frame + saved_pc_offset, 4); - return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4); -} -#endif /* I386V4_SIGTRAMP_SAVED_PC */ - -#ifdef STATIC_TRANSFORM_NAME -/* SunPRO encodes the static variables. This is not related to C++ mangling, - it is done for C too. */ - -char * -sunpro_static_transform_name (name) - char *name; -{ - char *p; - if (IS_STATIC_TRANSFORM_NAME (name)) - { - /* For file-local statics there will be a period, a bunch - of junk (the contents of which match a string given in the - N_OPT), a period and the name. For function-local statics - there will be a bunch of junk (which seems to change the - second character from 'A' to 'B'), a period, the name of the - function, and the name. So just skip everything before the - last period. */ - p = strrchr (name, '.'); - if (p != NULL) - name = p + 1; - } - return name; -} -#endif /* STATIC_TRANSFORM_NAME */ - - - -/* Stuff for WIN32 PE style DLL's but is pretty generic really. */ - -CORE_ADDR -skip_trampoline_code (pc, name) - CORE_ADDR pc; - char *name; -{ - if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */ - { - unsigned long indirect = read_memory_unsigned_integer (pc+2, 4); - struct minimal_symbol *indsym = - indirect ? lookup_minimal_symbol_by_pc (indirect) : 0; - char *symname = indsym ? SYMBOL_NAME(indsym) : 0; - - if (symname) - { - if (strncmp (symname,"__imp_", 6) == 0 - || strncmp (symname,"_imp_", 5) == 0) - return name ? 1 : read_memory_unsigned_integer (indirect, 4); - } - } - return 0; /* not a trampoline */ -} - -static int -gdb_print_insn_i386 (memaddr, info) - bfd_vma memaddr; - disassemble_info * info; -{ - if (disassembly_flavor == att_flavor) - print_insn_i386_att (memaddr, info); - else if (disassembly_flavor == intel_flavor) - print_insn_i386_intel (memaddr, info); - -} - -void -_initialize_i386_tdep () -{ - tm_print_insn = gdb_print_insn_i386; - tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach; - - /* Add the variable that controls the disassembly flavor */ - add_show_from_set( - add_set_enum_cmd ("disassembly-flavor", no_class, - valid_flavors, - (char *) &disassembly_flavor, - "Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ -and the default value is \"att\".", - &setlist), - &showlist); - - -} |