1 /* Intel 386 target-dependent stuff.
2 Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 #include "gdb_string.h"
29 #include "floatformat.h"
33 #include "arch-utils.h"
37 #include "i386-tdep.h"
38 #include "gdb_assert.h"
41 #define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))
43 /* Names of the registers. The first 10 registers match the register
44 numbering scheme used by GCC for stabs and DWARF. */
45 static char *i386_register_names[] =
47 "eax", "ecx", "edx", "ebx",
48 "esp", "ebp", "esi", "edi",
49 "eip", "eflags", "cs", "ss",
50 "ds", "es", "fs", "gs",
51 "st0", "st1", "st2", "st3",
52 "st4", "st5", "st6", "st7",
53 "fctrl", "fstat", "ftag", "fiseg",
54 "fioff", "foseg", "fooff", "fop",
55 "xmm0", "xmm1", "xmm2", "xmm3",
56 "xmm4", "xmm5", "xmm6", "xmm7",
60 /* i386_register_offset[i] is the offset into the register file of the
61 start of register number i. We initialize this from
62 i386_register_size. */
63 static int i386_register_offset[MAX_NUM_REGS];
65 /* i386_register_size[i] is the number of bytes of storage in GDB's
66 register array occupied by register i. */
67 static int i386_register_size[MAX_NUM_REGS] = {
81 /* Return the name of register REG. */
84 i386_register_name (int reg)
88 if (reg >= sizeof (i386_register_names) / sizeof (*i386_register_names))
91 return i386_register_names[reg];
94 /* Return the offset into the register array of the start of register
97 i386_register_byte (int reg)
99 return i386_register_offset[reg];
102 /* Return the number of bytes of storage in GDB's register array
103 occupied by register REG. */
106 i386_register_raw_size (int reg)
108 return i386_register_size[reg];
111 /* Return the size in bytes of the virtual type of register REG. */
114 i386_register_virtual_size (int reg)
116 return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (reg));
119 /* Convert stabs register number REG to the appropriate register
120 number used by GDB. */
123 i386_stab_reg_to_regnum (int reg)
125 /* This implements what GCC calls the "default" register map. */
126 if (reg >= 0 && reg <= 7)
128 /* General registers. */
131 else if (reg >= 12 && reg <= 19)
133 /* Floating-point registers. */
134 return reg - 12 + FP0_REGNUM;
136 else if (reg >= 21 && reg <= 28)
139 return reg - 21 + XMM0_REGNUM;
141 else if (reg >= 29 && reg <= 36)
144 /* FIXME: kettenis/2001-07-28: Should we have the MMX registers
145 as pseudo-registers? */
146 return reg - 29 + FP0_REGNUM;
149 /* This will hopefully provoke a warning. */
150 return NUM_REGS + NUM_PSEUDO_REGS;
153 /* Convert Dwarf register number REG to the appropriate register
154 number used by GDB. */
157 i386_dwarf_reg_to_regnum (int reg)
159 /* The DWARF register numbering includes %eip and %eflags, and
160 numbers the floating point registers differently. */
161 if (reg >= 0 && reg <= 9)
163 /* General registers. */
166 else if (reg >= 11 && reg <= 18)
168 /* Floating-point registers. */
169 return reg - 11 + FP0_REGNUM;
173 /* The SSE and MMX registers have identical numbers as in stabs. */
174 return i386_stab_reg_to_regnum (reg);
177 /* This will hopefully provoke a warning. */
178 return NUM_REGS + NUM_PSEUDO_REGS;
182 /* This is the variable that is set with "set disassembly-flavor", and
183 its legitimate values. */
184 static const char att_flavor[] = "att";
185 static const char intel_flavor[] = "intel";
186 static const char *valid_flavors[] =
192 static const char *disassembly_flavor = att_flavor;
194 /* Stdio style buffering was used to minimize calls to ptrace, but
195 this buffering did not take into account that the code section
196 being accessed may not be an even number of buffers long (even if
197 the buffer is only sizeof(int) long). In cases where the code
198 section size happened to be a non-integral number of buffers long,
199 attempting to read the last buffer would fail. Simply using
200 target_read_memory and ignoring errors, rather than read_memory, is
201 not the correct solution, since legitimate access errors would then
202 be totally ignored. To properly handle this situation and continue
203 to use buffering would require that this code be able to determine
204 the minimum code section size granularity (not the alignment of the
205 section itself, since the actual failing case that pointed out this
206 problem had a section alignment of 4 but was not a multiple of 4
207 bytes long), on a target by target basis, and then adjust it's
208 buffer size accordingly. This is messy, but potentially feasible.
209 It probably needs the bfd library's help and support. For now, the
210 buffer size is set to 1. (FIXME -fnf) */
212 #define CODESTREAM_BUFSIZ 1 /* Was sizeof(int), see note above. */
213 static CORE_ADDR codestream_next_addr;
214 static CORE_ADDR codestream_addr;
215 static unsigned char codestream_buf[CODESTREAM_BUFSIZ];
216 static int codestream_off;
217 static int codestream_cnt;
219 #define codestream_tell() (codestream_addr + codestream_off)
220 #define codestream_peek() \
221 (codestream_cnt == 0 ? \
222 codestream_fill(1) : codestream_buf[codestream_off])
223 #define codestream_get() \
224 (codestream_cnt-- == 0 ? \
225 codestream_fill(0) : codestream_buf[codestream_off++])
228 codestream_fill (int peek_flag)
230 codestream_addr = codestream_next_addr;
231 codestream_next_addr += CODESTREAM_BUFSIZ;
233 codestream_cnt = CODESTREAM_BUFSIZ;
234 read_memory (codestream_addr, (char *) codestream_buf, CODESTREAM_BUFSIZ);
237 return (codestream_peek ());
239 return (codestream_get ());
243 codestream_seek (CORE_ADDR place)
245 codestream_next_addr = place / CODESTREAM_BUFSIZ;
246 codestream_next_addr *= CODESTREAM_BUFSIZ;
249 while (codestream_tell () != place)
254 codestream_read (unsigned char *buf, int count)
259 for (i = 0; i < count; i++)
260 *p++ = codestream_get ();
264 /* If the next instruction is a jump, move to its target. */
267 i386_follow_jump (void)
269 unsigned char buf[4];
275 pos = codestream_tell ();
278 if (codestream_peek () == 0x66)
284 switch (codestream_get ())
287 /* Relative jump: if data16 == 0, disp32, else disp16. */
290 codestream_read (buf, 2);
291 delta = extract_signed_integer (buf, 2);
293 /* Include the size of the jmp instruction (including the
299 codestream_read (buf, 4);
300 delta = extract_signed_integer (buf, 4);
306 /* Relative jump, disp8 (ignore data16). */
307 codestream_read (buf, 1);
308 /* Sign-extend it. */
309 delta = extract_signed_integer (buf, 1);
314 codestream_seek (pos);
317 /* Find & return the amount a local space allocated, and advance the
318 codestream to the first register push (if any).
320 If the entry sequence doesn't make sense, return -1, and leave
321 codestream pointer at a random spot. */
324 i386_get_frame_setup (CORE_ADDR pc)
328 codestream_seek (pc);
332 op = codestream_get ();
334 if (op == 0x58) /* popl %eax */
336 /* This function must start with
339 xchgl %eax, (%esp) 0x87 0x04 0x24
340 or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00
342 (the System V compiler puts out the second `xchg'
343 instruction, and the assembler doesn't try to optimize it, so
344 the 'sib' form gets generated). This sequence is used to get
345 the address of the return buffer for a function that returns
348 unsigned char buf[4];
349 static unsigned char proto1[3] = { 0x87, 0x04, 0x24 };
350 static unsigned char proto2[4] = { 0x87, 0x44, 0x24, 0x00 };
352 pos = codestream_tell ();
353 codestream_read (buf, 4);
354 if (memcmp (buf, proto1, 3) == 0)
356 else if (memcmp (buf, proto2, 4) == 0)
359 codestream_seek (pos);
360 op = codestream_get (); /* Update next opcode. */
363 if (op == 0x68 || op == 0x6a)
365 /* This function may start with
377 unsigned char buf[8];
379 /* Skip past the `pushl' instruction; it has either a one-byte
380 or a four-byte operand, depending on the opcode. */
381 pos = codestream_tell ();
386 codestream_seek (pos);
388 /* Read the following 8 bytes, which should be "call _probe" (6
389 bytes) followed by "addl $4,%esp" (2 bytes). */
390 codestream_read (buf, sizeof (buf));
391 if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4)
393 codestream_seek (pos);
394 op = codestream_get (); /* Update next opcode. */
397 if (op == 0x55) /* pushl %ebp */
399 /* Check for "movl %esp, %ebp" -- can be written in two ways. */
400 switch (codestream_get ())
403 if (codestream_get () != 0xec)
407 if (codestream_get () != 0xe5)
413 /* Check for stack adjustment
417 NOTE: You can't subtract a 16 bit immediate from a 32 bit
418 reg, so we don't have to worry about a data16 prefix. */
419 op = codestream_peek ();
422 /* `subl' with 8 bit immediate. */
424 if (codestream_get () != 0xec)
425 /* Some instruction starting with 0x83 other than `subl'. */
427 codestream_seek (codestream_tell () - 2);
430 /* `subl' with signed byte immediate (though it wouldn't
431 make sense to be negative). */
432 return (codestream_get ());
437 /* Maybe it is `subl' with a 32 bit immedediate. */
439 if (codestream_get () != 0xec)
440 /* Some instruction starting with 0x81 other than `subl'. */
442 codestream_seek (codestream_tell () - 2);
445 /* It is `subl' with a 32 bit immediate. */
446 codestream_read ((unsigned char *) buf, 4);
447 return extract_signed_integer (buf, 4);
457 /* `enter' with 16 bit unsigned immediate. */
458 codestream_read ((unsigned char *) buf, 2);
459 codestream_get (); /* Flush final byte of enter instruction. */
460 return extract_unsigned_integer (buf, 2);
465 /* Return the chain-pointer for FRAME. In the case of the i386, the
466 frame's nominal address is the address of a 4-byte word containing
467 the calling frame's address. */
470 i386_frame_chain (struct frame_info *frame)
472 if (frame->signal_handler_caller)
475 if (! inside_entry_file (frame->pc))
476 return read_memory_unsigned_integer (frame->frame, 4);
481 /* Determine whether the function invocation represented by FRAME does
482 not have a from on the stack associated with it. If it does not,
483 return non-zero, otherwise return zero. */
486 i386_frameless_function_invocation (struct frame_info *frame)
488 if (frame->signal_handler_caller)
491 return frameless_look_for_prologue (frame);
494 /* Return the saved program counter for FRAME. */
497 i386_frame_saved_pc (struct frame_info *frame)
499 /* FIXME: kettenis/2001-05-09: Conditionalizing the next bit of code
500 on SIGCONTEXT_PC_OFFSET and I386V4_SIGTRAMP_SAVED_PC should be
501 considered a temporary hack. I plan to come up with something
502 better when we go multi-arch. */
503 #if defined (SIGCONTEXT_PC_OFFSET) || defined (I386V4_SIGTRAMP_SAVED_PC)
504 if (frame->signal_handler_caller)
505 return sigtramp_saved_pc (frame);
508 return read_memory_unsigned_integer (frame->frame + 4, 4);
511 /* Immediately after a function call, return the saved pc. */
514 i386_saved_pc_after_call (struct frame_info *frame)
516 return read_memory_unsigned_integer (read_register (SP_REGNUM), 4);
519 /* Return number of args passed to a frame.
520 Can return -1, meaning no way to tell. */
523 i386_frame_num_args (struct frame_info *fi)
528 /* This loses because not only might the compiler not be popping the
529 args right after the function call, it might be popping args from
530 both this call and a previous one, and we would say there are
531 more args than there really are. */
535 struct frame_info *pfi;
537 /* On the i386, the instruction following the call could be:
539 addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
540 anything else - zero args. */
544 frameless = FRAMELESS_FUNCTION_INVOCATION (fi);
546 /* In the absence of a frame pointer, GDB doesn't get correct
547 values for nameless arguments. Return -1, so it doesn't print
548 any nameless arguments. */
551 pfi = get_prev_frame (fi);
554 /* NOTE: This can happen if we are looking at the frame for
555 main, because FRAME_CHAIN_VALID won't let us go into start.
556 If we have debugging symbols, that's not really a big deal;
557 it just means it will only show as many arguments to main as
564 op = read_memory_integer (retpc, 1);
565 if (op == 0x59) /* pop %ecx */
569 op = read_memory_integer (retpc + 1, 1);
571 /* addl $<signed imm 8 bits>, %esp */
572 return (read_memory_integer (retpc + 2, 1) & 0xff) / 4;
576 else if (op == 0x81) /* `add' with 32 bit immediate. */
578 op = read_memory_integer (retpc + 1, 1);
580 /* addl $<imm 32>, %esp */
581 return read_memory_integer (retpc + 2, 4) / 4;
593 /* Parse the first few instructions the function to see what registers
596 We handle these cases:
598 The startup sequence can be at the start of the function, or the
599 function can start with a branch to startup code at the end.
601 %ebp can be set up with either the 'enter' instruction, or "pushl
602 %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
603 once used in the System V compiler).
605 Local space is allocated just below the saved %ebp by either the
606 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16
607 bit unsigned argument for space to allocate, and the 'addl'
608 instruction could have either a signed byte, or 32 bit immediate.
610 Next, the registers used by this function are pushed. With the
611 System V compiler they will always be in the order: %edi, %esi,
612 %ebx (and sometimes a harmless bug causes it to also save but not
613 restore %eax); however, the code below is willing to see the pushes
614 in any order, and will handle up to 8 of them.
616 If the setup sequence is at the end of the function, then the next
617 instruction will be a branch back to the start. */
620 i386_frame_init_saved_regs (struct frame_info *fip)
624 CORE_ADDR dummy_bottom;
632 frame_saved_regs_zalloc (fip);
634 /* If the frame is the end of a dummy, compute where the beginning
636 dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH;
638 /* Check if the PC points in the stack, in a dummy frame. */
639 if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
641 /* All registers were saved by push_call_dummy. */
643 for (i = 0; i < NUM_REGS; i++)
645 addr -= REGISTER_RAW_SIZE (i);
646 fip->saved_regs[i] = addr;
651 pc = get_pc_function_start (fip->pc);
653 locals = i386_get_frame_setup (pc);
657 addr = fip->frame - 4 - locals;
658 for (i = 0; i < 8; i++)
660 op = codestream_get ();
661 if (op < 0x50 || op > 0x57)
663 #ifdef I386_REGNO_TO_SYMMETRY
664 /* Dynix uses different internal numbering. Ick. */
665 fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr;
667 fip->saved_regs[op - 0x50] = addr;
673 fip->saved_regs[PC_REGNUM] = fip->frame + 4;
674 fip->saved_regs[FP_REGNUM] = fip->frame;
677 /* Return PC of first real instruction. */
680 i386_skip_prologue (int pc)
684 static unsigned char pic_pat[6] =
685 { 0xe8, 0, 0, 0, 0, /* call 0x0 */
686 0x5b, /* popl %ebx */
690 if (i386_get_frame_setup (pc) < 0)
693 /* Found valid frame setup -- codestream now points to start of push
694 instructions for saving registers. */
696 /* Skip over register saves. */
697 for (i = 0; i < 8; i++)
699 op = codestream_peek ();
700 /* Break if not `pushl' instrunction. */
701 if (op < 0x50 || op > 0x57)
706 /* The native cc on SVR4 in -K PIC mode inserts the following code
707 to get the address of the global offset table (GOT) into register
712 movl %ebx,x(%ebp) (optional)
715 This code is with the rest of the prologue (at the end of the
716 function), so we have to skip it to get to the first real
717 instruction at the start of the function. */
719 pos = codestream_tell ();
720 for (i = 0; i < 6; i++)
722 op = codestream_get ();
723 if (pic_pat[i] != op)
728 unsigned char buf[4];
731 op = codestream_get ();
732 if (op == 0x89) /* movl %ebx, x(%ebp) */
734 op = codestream_get ();
735 if (op == 0x5d) /* One byte offset from %ebp. */
738 codestream_read (buf, 1);
740 else if (op == 0x9d) /* Four byte offset from %ebp. */
743 codestream_read (buf, 4);
745 else /* Unexpected instruction. */
747 op = codestream_get ();
750 if (delta > 0 && op == 0x81 && codestream_get () == 0xc3)
755 codestream_seek (pos);
759 return (codestream_tell ());
763 i386_push_dummy_frame (void)
765 CORE_ADDR sp = read_register (SP_REGNUM);
767 char regbuf[MAX_REGISTER_RAW_SIZE];
769 sp = push_word (sp, read_register (PC_REGNUM));
770 sp = push_word (sp, read_register (FP_REGNUM));
771 write_register (FP_REGNUM, sp);
772 for (regnum = 0; regnum < NUM_REGS; regnum++)
774 read_register_gen (regnum, regbuf);
775 sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum));
777 write_register (SP_REGNUM, sp);
780 /* Insert the (relative) function address into the call sequence
784 i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
785 struct value **args, struct type *type, int gcc_p)
787 int from, to, delta, loc;
789 loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH);
794 *((char *)(dummy) + 1) = (delta & 0xff);
795 *((char *)(dummy) + 2) = ((delta >> 8) & 0xff);
796 *((char *)(dummy) + 3) = ((delta >> 16) & 0xff);
797 *((char *)(dummy) + 4) = ((delta >> 24) & 0xff);
801 i386_pop_frame (void)
803 struct frame_info *frame = get_current_frame ();
806 char regbuf[MAX_REGISTER_RAW_SIZE];
808 fp = FRAME_FP (frame);
809 i386_frame_init_saved_regs (frame);
811 for (regnum = 0; regnum < NUM_REGS; regnum++)
814 addr = frame->saved_regs[regnum];
817 read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum));
818 write_register_bytes (REGISTER_BYTE (regnum), regbuf,
819 REGISTER_RAW_SIZE (regnum));
822 write_register (FP_REGNUM, read_memory_integer (fp, 4));
823 write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
824 write_register (SP_REGNUM, fp + 8);
825 flush_cached_frames ();
829 #ifdef GET_LONGJMP_TARGET
831 /* Figure out where the longjmp will land. Slurp the args out of the
832 stack. We expect the first arg to be a pointer to the jmp_buf
833 structure from which we extract the pc (JB_PC) that we will land
834 at. The pc is copied into PC. This routine returns true on
838 get_longjmp_target (CORE_ADDR *pc)
840 char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
841 CORE_ADDR sp, jb_addr;
843 sp = read_register (SP_REGNUM);
845 if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack. */
847 TARGET_PTR_BIT / TARGET_CHAR_BIT))
850 jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
852 if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
853 TARGET_PTR_BIT / TARGET_CHAR_BIT))
856 *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
861 #endif /* GET_LONGJMP_TARGET */
865 i386_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
866 int struct_return, CORE_ADDR struct_addr)
868 sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr);
875 store_address (buf, 4, struct_addr);
876 write_memory (sp, buf, 4);
883 i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
885 /* Do nothing. Everything was already done by i386_push_arguments. */
888 /* These registers are used for returning integers (and on some
889 targets also for returning `struct' and `union' values when their
890 size and alignment match an integer type). */
891 #define LOW_RETURN_REGNUM 0 /* %eax */
892 #define HIGH_RETURN_REGNUM 2 /* %edx */
894 /* Extract from an array REGBUF containing the (raw) register state, a
895 function return value of TYPE, and copy that, in virtual format,
899 i386_extract_return_value (struct type *type, char *regbuf, char *valbuf)
901 int len = TYPE_LENGTH (type);
903 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
904 && TYPE_NFIELDS (type) == 1)
906 i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regbuf, valbuf);
910 if (TYPE_CODE (type) == TYPE_CODE_FLT)
914 warning ("Cannot find floating-point return value.");
915 memset (valbuf, 0, len);
919 /* Floating-point return values can be found in %st(0). Convert
920 its contents to the desired type. This is probably not
921 exactly how it would happen on the target itself, but it is
922 the best we can do. */
923 convert_typed_floating (®buf[REGISTER_BYTE (FP0_REGNUM)],
924 builtin_type_i387_ext, valbuf, type);
928 int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
929 int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
932 memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len);
933 else if (len <= (low_size + high_size))
936 ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size);
937 memcpy (valbuf + low_size,
938 ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size);
941 internal_error (__FILE__, __LINE__,
942 "Cannot extract return value of %d bytes long.", len);
946 /* Write into the appropriate registers a function return value stored
947 in VALBUF of type TYPE, given in virtual format. */
950 i386_store_return_value (struct type *type, char *valbuf)
952 int len = TYPE_LENGTH (type);
954 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
955 && TYPE_NFIELDS (type) == 1)
957 i386_store_return_value (TYPE_FIELD_TYPE (type, 0), valbuf);
961 if (TYPE_CODE (type) == TYPE_CODE_FLT)
964 char buf[FPU_REG_RAW_SIZE];
968 warning ("Cannot set floating-point return value.");
972 /* Returning floating-point values is a bit tricky. Apart from
973 storing the return value in %st(0), we have to simulate the
974 state of the FPU at function return point. */
976 /* Convert the value found in VALBUF to the extended
977 floating-point format used by the FPU. This is probably
978 not exactly how it would happen on the target itself, but
979 it is the best we can do. */
980 convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext);
981 write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf,
984 /* Set the top of the floating-point register stack to 7. The
985 actual value doesn't really matter, but 7 is what a normal
986 function return would end up with if the program started out
987 with a freshly initialized FPU. */
988 fstat = read_register (FSTAT_REGNUM);
990 write_register (FSTAT_REGNUM, fstat);
992 /* Mark %st(1) through %st(7) as empty. Since we set the top of
993 the floating-point register stack to 7, the appropriate value
994 for the tag word is 0x3fff. */
995 write_register (FTAG_REGNUM, 0x3fff);
999 int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
1000 int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
1002 if (len <= low_size)
1003 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len);
1004 else if (len <= (low_size + high_size))
1006 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM),
1008 write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM),
1009 valbuf + low_size, len - low_size);
1012 internal_error (__FILE__, __LINE__,
1013 "Cannot store return value of %d bytes long.", len);
1017 /* Extract from an array REGBUF containing the (raw) register state
1018 the address in which a function should return its structure value,
1022 i386_extract_struct_value_address (char *regbuf)
1024 return extract_address (®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)],
1025 REGISTER_RAW_SIZE (LOW_RETURN_REGNUM));
1029 /* Return the GDB type object for the "standard" data type of data in
1030 register REGNUM. Perhaps %esi and %edi should go here, but
1031 potentially they could be used for things other than address. */
1034 i386_register_virtual_type (int regnum)
1036 if (regnum == PC_REGNUM || regnum == FP_REGNUM || regnum == SP_REGNUM)
1037 return lookup_pointer_type (builtin_type_void);
1039 if (IS_FP_REGNUM (regnum))
1040 return builtin_type_i387_ext;
1042 if (IS_SSE_REGNUM (regnum))
1043 return builtin_type_v4sf;
1045 return builtin_type_int;
1048 /* Return true iff register REGNUM's virtual format is different from
1049 its raw format. Note that this definition assumes that the host
1050 supports IEEE 32-bit floats, since it doesn't say that SSE
1051 registers need conversion. Even if we can't find a counterexample,
1052 this is still sloppy. */
1055 i386_register_convertible (int regnum)
1057 return IS_FP_REGNUM (regnum);
1060 /* Convert data from raw format for register REGNUM in buffer FROM to
1061 virtual format with type TYPE in buffer TO. */
1064 i386_register_convert_to_virtual (int regnum, struct type *type,
1065 char *from, char *to)
1067 gdb_assert (IS_FP_REGNUM (regnum));
1069 /* We only support floating-point values. */
1070 if (TYPE_CODE (type) != TYPE_CODE_FLT)
1072 warning ("Cannot convert floating-point register value "
1073 "to non-floating-point type.");
1074 memset (to, 0, TYPE_LENGTH (type));
1078 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
1079 the extended floating-point format used by the FPU. */
1080 convert_typed_floating (from, builtin_type_i387_ext, to, type);
1083 /* Convert data from virtual format with type TYPE in buffer FROM to
1084 raw format for register REGNUM in buffer TO. */
1087 i386_register_convert_to_raw (struct type *type, int regnum,
1088 char *from, char *to)
1090 gdb_assert (IS_FP_REGNUM (regnum));
1092 /* We only support floating-point values. */
1093 if (TYPE_CODE (type) != TYPE_CODE_FLT)
1095 warning ("Cannot convert non-floating-point type "
1096 "to floating-point register value.");
1097 memset (to, 0, TYPE_LENGTH (type));
1101 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
1102 to the extended floating-point format used by the FPU. */
1103 convert_typed_floating (from, type, to, builtin_type_i387_ext);
1107 #ifdef I386V4_SIGTRAMP_SAVED_PC
1108 /* Get saved user PC for sigtramp from the pushed ucontext on the
1109 stack for all three variants of SVR4 sigtramps. */
1112 i386v4_sigtramp_saved_pc (struct frame_info *frame)
1114 CORE_ADDR saved_pc_offset = 4;
1117 find_pc_partial_function (frame->pc, &name, NULL, NULL);
1120 if (STREQ (name, "_sigreturn"))
1121 saved_pc_offset = 132 + 14 * 4;
1122 else if (STREQ (name, "_sigacthandler"))
1123 saved_pc_offset = 80 + 14 * 4;
1124 else if (STREQ (name, "sigvechandler"))
1125 saved_pc_offset = 120 + 14 * 4;
1129 return read_memory_integer (frame->next->frame + saved_pc_offset, 4);
1130 return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4);
1132 #endif /* I386V4_SIGTRAMP_SAVED_PC */
1135 #ifdef STATIC_TRANSFORM_NAME
1136 /* SunPRO encodes the static variables. This is not related to C++
1137 mangling, it is done for C too. */
1140 sunpro_static_transform_name (char *name)
1143 if (IS_STATIC_TRANSFORM_NAME (name))
1145 /* For file-local statics there will be a period, a bunch of
1146 junk (the contents of which match a string given in the
1147 N_OPT), a period and the name. For function-local statics
1148 there will be a bunch of junk (which seems to change the
1149 second character from 'A' to 'B'), a period, the name of the
1150 function, and the name. So just skip everything before the
1152 p = strrchr (name, '.');
1158 #endif /* STATIC_TRANSFORM_NAME */
1161 /* Stuff for WIN32 PE style DLL's but is pretty generic really. */
1164 skip_trampoline_code (CORE_ADDR pc, char *name)
1166 if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */
1168 unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4);
1169 struct minimal_symbol *indsym =
1170 indirect ? lookup_minimal_symbol_by_pc (indirect) : 0;
1171 char *symname = indsym ? SYMBOL_NAME (indsym) : 0;
1175 if (strncmp (symname, "__imp_", 6) == 0
1176 || strncmp (symname, "_imp_", 5) == 0)
1177 return name ? 1 : read_memory_unsigned_integer (indirect, 4);
1180 return 0; /* Not a trampoline. */
1184 /* We have two flavours of disassembly. The machinery on this page
1185 deals with switching between those. */
1188 gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info)
1190 if (disassembly_flavor == att_flavor)
1191 return print_insn_i386_att (memaddr, info);
1192 else if (disassembly_flavor == intel_flavor)
1193 return print_insn_i386_intel (memaddr, info);
1194 /* Never reached -- disassembly_flavour is always either att_flavor
1196 internal_error (__FILE__, __LINE__, "failed internal consistency check");
1202 i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1204 struct gdbarch_tdep *tdep;
1205 struct gdbarch *gdbarch;
1207 /* For the moment there is only one i386 architecture. */
1209 return arches->gdbarch;
1211 /* Allocate space for the new architecture. */
1212 tdep = XMALLOC (struct gdbarch_tdep);
1213 gdbarch = gdbarch_alloc (&info, tdep);
1215 set_gdbarch_use_generic_dummy_frames (gdbarch, 0);
1217 /* Call dummy code. */
1218 set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
1219 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 5);
1220 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1221 set_gdbarch_call_dummy_p (gdbarch, 1);
1222 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1224 set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
1225 set_gdbarch_push_arguments (gdbarch, i386_push_arguments);
1227 set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack);
1229 /* NOTE: tm-i386nw.h and tm-i386v4.h override this. */
1230 set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid);
1235 /* Provide a prototype to silence -Wmissing-prototypes. */
1236 void _initialize_i386_tdep (void);
1239 _initialize_i386_tdep (void)
1241 register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init);
1243 /* Initialize the table saying where each register starts in the
1249 for (i = 0; i < MAX_NUM_REGS; i++)
1251 i386_register_offset[i] = offset;
1252 offset += i386_register_size[i];
1256 tm_print_insn = gdb_print_insn_i386;
1257 tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach;
1259 /* Add the variable that controls the disassembly flavor. */
1261 struct cmd_list_element *new_cmd;
1263 new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
1265 &disassembly_flavor,
1267 Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1268 and the default value is \"att\".",
1270 add_show_from_set (new_cmd, &showlist);