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);
512 i386go32_frame_saved_pc (struct frame_info *frame)
514 return read_memory_integer (frame->frame + 4, 4);
517 /* Immediately after a function call, return the saved pc. */
520 i386_saved_pc_after_call (struct frame_info *frame)
522 return read_memory_unsigned_integer (read_register (SP_REGNUM), 4);
525 /* Return number of args passed to a frame.
526 Can return -1, meaning no way to tell. */
529 i386_frame_num_args (struct frame_info *fi)
534 /* This loses because not only might the compiler not be popping the
535 args right after the function call, it might be popping args from
536 both this call and a previous one, and we would say there are
537 more args than there really are. */
541 struct frame_info *pfi;
543 /* On the i386, the instruction following the call could be:
545 addl $imm, %esp - imm/4 args; imm may be 8 or 32 bits
546 anything else - zero args. */
550 frameless = FRAMELESS_FUNCTION_INVOCATION (fi);
552 /* In the absence of a frame pointer, GDB doesn't get correct
553 values for nameless arguments. Return -1, so it doesn't print
554 any nameless arguments. */
557 pfi = get_prev_frame (fi);
560 /* NOTE: This can happen if we are looking at the frame for
561 main, because FRAME_CHAIN_VALID won't let us go into start.
562 If we have debugging symbols, that's not really a big deal;
563 it just means it will only show as many arguments to main as
570 op = read_memory_integer (retpc, 1);
571 if (op == 0x59) /* pop %ecx */
575 op = read_memory_integer (retpc + 1, 1);
577 /* addl $<signed imm 8 bits>, %esp */
578 return (read_memory_integer (retpc + 2, 1) & 0xff) / 4;
582 else if (op == 0x81) /* `add' with 32 bit immediate. */
584 op = read_memory_integer (retpc + 1, 1);
586 /* addl $<imm 32>, %esp */
587 return read_memory_integer (retpc + 2, 4) / 4;
599 /* Parse the first few instructions the function to see what registers
602 We handle these cases:
604 The startup sequence can be at the start of the function, or the
605 function can start with a branch to startup code at the end.
607 %ebp can be set up with either the 'enter' instruction, or "pushl
608 %ebp, movl %esp, %ebp" (`enter' is too slow to be useful, but was
609 once used in the System V compiler).
611 Local space is allocated just below the saved %ebp by either the
612 'enter' instruction, or by "subl $<size>, %esp". 'enter' has a 16
613 bit unsigned argument for space to allocate, and the 'addl'
614 instruction could have either a signed byte, or 32 bit immediate.
616 Next, the registers used by this function are pushed. With the
617 System V compiler they will always be in the order: %edi, %esi,
618 %ebx (and sometimes a harmless bug causes it to also save but not
619 restore %eax); however, the code below is willing to see the pushes
620 in any order, and will handle up to 8 of them.
622 If the setup sequence is at the end of the function, then the next
623 instruction will be a branch back to the start. */
626 i386_frame_init_saved_regs (struct frame_info *fip)
630 CORE_ADDR dummy_bottom;
638 frame_saved_regs_zalloc (fip);
640 /* If the frame is the end of a dummy, compute where the beginning
642 dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH;
644 /* Check if the PC points in the stack, in a dummy frame. */
645 if (dummy_bottom <= fip->pc && fip->pc <= fip->frame)
647 /* All registers were saved by push_call_dummy. */
649 for (i = 0; i < NUM_REGS; i++)
651 addr -= REGISTER_RAW_SIZE (i);
652 fip->saved_regs[i] = addr;
657 pc = get_pc_function_start (fip->pc);
659 locals = i386_get_frame_setup (pc);
663 addr = fip->frame - 4 - locals;
664 for (i = 0; i < 8; i++)
666 op = codestream_get ();
667 if (op < 0x50 || op > 0x57)
669 #ifdef I386_REGNO_TO_SYMMETRY
670 /* Dynix uses different internal numbering. Ick. */
671 fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr;
673 fip->saved_regs[op - 0x50] = addr;
679 fip->saved_regs[PC_REGNUM] = fip->frame + 4;
680 fip->saved_regs[FP_REGNUM] = fip->frame;
683 /* Return PC of first real instruction. */
686 i386_skip_prologue (int pc)
690 static unsigned char pic_pat[6] =
691 { 0xe8, 0, 0, 0, 0, /* call 0x0 */
692 0x5b, /* popl %ebx */
696 if (i386_get_frame_setup (pc) < 0)
699 /* Found valid frame setup -- codestream now points to start of push
700 instructions for saving registers. */
702 /* Skip over register saves. */
703 for (i = 0; i < 8; i++)
705 op = codestream_peek ();
706 /* Break if not `pushl' instrunction. */
707 if (op < 0x50 || op > 0x57)
712 /* The native cc on SVR4 in -K PIC mode inserts the following code
713 to get the address of the global offset table (GOT) into register
718 movl %ebx,x(%ebp) (optional)
721 This code is with the rest of the prologue (at the end of the
722 function), so we have to skip it to get to the first real
723 instruction at the start of the function. */
725 pos = codestream_tell ();
726 for (i = 0; i < 6; i++)
728 op = codestream_get ();
729 if (pic_pat[i] != op)
734 unsigned char buf[4];
737 op = codestream_get ();
738 if (op == 0x89) /* movl %ebx, x(%ebp) */
740 op = codestream_get ();
741 if (op == 0x5d) /* One byte offset from %ebp. */
744 codestream_read (buf, 1);
746 else if (op == 0x9d) /* Four byte offset from %ebp. */
749 codestream_read (buf, 4);
751 else /* Unexpected instruction. */
753 op = codestream_get ();
756 if (delta > 0 && op == 0x81 && codestream_get () == 0xc3)
761 codestream_seek (pos);
765 return (codestream_tell ());
769 i386_push_dummy_frame (void)
771 CORE_ADDR sp = read_register (SP_REGNUM);
774 char regbuf[MAX_REGISTER_RAW_SIZE];
776 sp = push_word (sp, read_register (PC_REGNUM));
777 sp = push_word (sp, read_register (FP_REGNUM));
779 for (regnum = 0; regnum < NUM_REGS; regnum++)
781 read_register_gen (regnum, regbuf);
782 sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum));
784 write_register (SP_REGNUM, sp);
785 write_register (FP_REGNUM, fp);
788 /* Insert the (relative) function address into the call sequence
792 i386_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
793 struct value **args, struct type *type, int gcc_p)
795 int from, to, delta, loc;
797 loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH);
802 *((char *)(dummy) + 1) = (delta & 0xff);
803 *((char *)(dummy) + 2) = ((delta >> 8) & 0xff);
804 *((char *)(dummy) + 3) = ((delta >> 16) & 0xff);
805 *((char *)(dummy) + 4) = ((delta >> 24) & 0xff);
809 i386_pop_frame (void)
811 struct frame_info *frame = get_current_frame ();
814 char regbuf[MAX_REGISTER_RAW_SIZE];
816 fp = FRAME_FP (frame);
817 i386_frame_init_saved_regs (frame);
819 for (regnum = 0; regnum < NUM_REGS; regnum++)
822 addr = frame->saved_regs[regnum];
825 read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum));
826 write_register_bytes (REGISTER_BYTE (regnum), regbuf,
827 REGISTER_RAW_SIZE (regnum));
830 write_register (FP_REGNUM, read_memory_integer (fp, 4));
831 write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
832 write_register (SP_REGNUM, fp + 8);
833 flush_cached_frames ();
837 #ifdef GET_LONGJMP_TARGET
839 /* Figure out where the longjmp will land. Slurp the args out of the
840 stack. We expect the first arg to be a pointer to the jmp_buf
841 structure from which we extract the pc (JB_PC) that we will land
842 at. The pc is copied into PC. This routine returns true on
846 get_longjmp_target (CORE_ADDR *pc)
848 char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
849 CORE_ADDR sp, jb_addr;
851 sp = read_register (SP_REGNUM);
853 if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack. */
855 TARGET_PTR_BIT / TARGET_CHAR_BIT))
858 jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
860 if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
861 TARGET_PTR_BIT / TARGET_CHAR_BIT))
864 *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
869 #endif /* GET_LONGJMP_TARGET */
873 i386_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
874 int struct_return, CORE_ADDR struct_addr)
876 sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr);
883 store_address (buf, 4, struct_addr);
884 write_memory (sp, buf, 4);
891 i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
893 /* Do nothing. Everything was already done by i386_push_arguments. */
896 /* These registers are used for returning integers (and on some
897 targets also for returning `struct' and `union' values when their
898 size and alignment match an integer type). */
899 #define LOW_RETURN_REGNUM 0 /* %eax */
900 #define HIGH_RETURN_REGNUM 2 /* %edx */
902 /* Extract from an array REGBUF containing the (raw) register state, a
903 function return value of TYPE, and copy that, in virtual format,
907 i386_extract_return_value (struct type *type, char *regbuf, char *valbuf)
909 int len = TYPE_LENGTH (type);
911 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
912 && TYPE_NFIELDS (type) == 1)
914 i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regbuf, valbuf);
918 if (TYPE_CODE (type) == TYPE_CODE_FLT)
922 warning ("Cannot find floating-point return value.");
923 memset (valbuf, 0, len);
927 /* Floating-point return values can be found in %st(0). Convert
928 its contents to the desired type. This is probably not
929 exactly how it would happen on the target itself, but it is
930 the best we can do. */
931 convert_typed_floating (®buf[REGISTER_BYTE (FP0_REGNUM)],
932 builtin_type_i387_ext, valbuf, type);
936 int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
937 int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
940 memcpy (valbuf, ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], len);
941 else if (len <= (low_size + high_size))
944 ®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)], low_size);
945 memcpy (valbuf + low_size,
946 ®buf[REGISTER_BYTE (HIGH_RETURN_REGNUM)], len - low_size);
949 internal_error (__FILE__, __LINE__,
950 "Cannot extract return value of %d bytes long.", len);
954 /* Write into the appropriate registers a function return value stored
955 in VALBUF of type TYPE, given in virtual format. */
958 i386_store_return_value (struct type *type, char *valbuf)
960 int len = TYPE_LENGTH (type);
962 if (TYPE_CODE (type) == TYPE_CODE_STRUCT
963 && TYPE_NFIELDS (type) == 1)
965 i386_store_return_value (TYPE_FIELD_TYPE (type, 0), valbuf);
969 if (TYPE_CODE (type) == TYPE_CODE_FLT)
972 char buf[FPU_REG_RAW_SIZE];
976 warning ("Cannot set floating-point return value.");
980 /* Returning floating-point values is a bit tricky. Apart from
981 storing the return value in %st(0), we have to simulate the
982 state of the FPU at function return point. */
984 /* Convert the value found in VALBUF to the extended
985 floating-point format used by the FPU. This is probably
986 not exactly how it would happen on the target itself, but
987 it is the best we can do. */
988 convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext);
989 write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf,
992 /* Set the top of the floating-point register stack to 7. The
993 actual value doesn't really matter, but 7 is what a normal
994 function return would end up with if the program started out
995 with a freshly initialized FPU. */
996 fstat = read_register (FSTAT_REGNUM);
998 write_register (FSTAT_REGNUM, fstat);
1000 /* Mark %st(1) through %st(7) as empty. Since we set the top of
1001 the floating-point register stack to 7, the appropriate value
1002 for the tag word is 0x3fff. */
1003 write_register (FTAG_REGNUM, 0x3fff);
1007 int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM);
1008 int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM);
1010 if (len <= low_size)
1011 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len);
1012 else if (len <= (low_size + high_size))
1014 write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM),
1016 write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM),
1017 valbuf + low_size, len - low_size);
1020 internal_error (__FILE__, __LINE__,
1021 "Cannot store return value of %d bytes long.", len);
1025 /* Extract from an array REGBUF containing the (raw) register state
1026 the address in which a function should return its structure value,
1030 i386_extract_struct_value_address (char *regbuf)
1032 return extract_address (®buf[REGISTER_BYTE (LOW_RETURN_REGNUM)],
1033 REGISTER_RAW_SIZE (LOW_RETURN_REGNUM));
1037 /* Return the GDB type object for the "standard" data type of data in
1038 register REGNUM. Perhaps %esi and %edi should go here, but
1039 potentially they could be used for things other than address. */
1042 i386_register_virtual_type (int regnum)
1044 if (regnum == PC_REGNUM || regnum == FP_REGNUM || regnum == SP_REGNUM)
1045 return lookup_pointer_type (builtin_type_void);
1047 if (IS_FP_REGNUM (regnum))
1048 return builtin_type_i387_ext;
1050 if (IS_SSE_REGNUM (regnum))
1051 return builtin_type_v4sf;
1053 return builtin_type_int;
1056 /* Return true iff register REGNUM's virtual format is different from
1057 its raw format. Note that this definition assumes that the host
1058 supports IEEE 32-bit floats, since it doesn't say that SSE
1059 registers need conversion. Even if we can't find a counterexample,
1060 this is still sloppy. */
1063 i386_register_convertible (int regnum)
1065 return IS_FP_REGNUM (regnum);
1068 /* Convert data from raw format for register REGNUM in buffer FROM to
1069 virtual format with type TYPE in buffer TO. */
1072 i386_register_convert_to_virtual (int regnum, struct type *type,
1073 char *from, char *to)
1075 gdb_assert (IS_FP_REGNUM (regnum));
1077 /* We only support floating-point values. */
1078 if (TYPE_CODE (type) != TYPE_CODE_FLT)
1080 warning ("Cannot convert floating-point register value "
1081 "to non-floating-point type.");
1082 memset (to, 0, TYPE_LENGTH (type));
1086 /* Convert to TYPE. This should be a no-op if TYPE is equivalent to
1087 the extended floating-point format used by the FPU. */
1088 convert_typed_floating (from, builtin_type_i387_ext, to, type);
1091 /* Convert data from virtual format with type TYPE in buffer FROM to
1092 raw format for register REGNUM in buffer TO. */
1095 i386_register_convert_to_raw (struct type *type, int regnum,
1096 char *from, char *to)
1098 gdb_assert (IS_FP_REGNUM (regnum));
1100 /* We only support floating-point values. */
1101 if (TYPE_CODE (type) != TYPE_CODE_FLT)
1103 warning ("Cannot convert non-floating-point type "
1104 "to floating-point register value.");
1105 memset (to, 0, TYPE_LENGTH (type));
1109 /* Convert from TYPE. This should be a no-op if TYPE is equivalent
1110 to the extended floating-point format used by the FPU. */
1111 convert_typed_floating (from, type, to, builtin_type_i387_ext);
1115 #ifdef I386V4_SIGTRAMP_SAVED_PC
1116 /* Get saved user PC for sigtramp from the pushed ucontext on the
1117 stack for all three variants of SVR4 sigtramps. */
1120 i386v4_sigtramp_saved_pc (struct frame_info *frame)
1122 CORE_ADDR saved_pc_offset = 4;
1125 find_pc_partial_function (frame->pc, &name, NULL, NULL);
1128 if (STREQ (name, "_sigreturn"))
1129 saved_pc_offset = 132 + 14 * 4;
1130 else if (STREQ (name, "_sigacthandler"))
1131 saved_pc_offset = 80 + 14 * 4;
1132 else if (STREQ (name, "sigvechandler"))
1133 saved_pc_offset = 120 + 14 * 4;
1137 return read_memory_integer (frame->next->frame + saved_pc_offset, 4);
1138 return read_memory_integer (read_register (SP_REGNUM) + saved_pc_offset, 4);
1140 #endif /* I386V4_SIGTRAMP_SAVED_PC */
1143 #ifdef STATIC_TRANSFORM_NAME
1144 /* SunPRO encodes the static variables. This is not related to C++
1145 mangling, it is done for C too. */
1148 sunpro_static_transform_name (char *name)
1151 if (IS_STATIC_TRANSFORM_NAME (name))
1153 /* For file-local statics there will be a period, a bunch of
1154 junk (the contents of which match a string given in the
1155 N_OPT), a period and the name. For function-local statics
1156 there will be a bunch of junk (which seems to change the
1157 second character from 'A' to 'B'), a period, the name of the
1158 function, and the name. So just skip everything before the
1160 p = strrchr (name, '.');
1166 #endif /* STATIC_TRANSFORM_NAME */
1169 /* Stuff for WIN32 PE style DLL's but is pretty generic really. */
1172 skip_trampoline_code (CORE_ADDR pc, char *name)
1174 if (pc && read_memory_unsigned_integer (pc, 2) == 0x25ff) /* jmp *(dest) */
1176 unsigned long indirect = read_memory_unsigned_integer (pc + 2, 4);
1177 struct minimal_symbol *indsym =
1178 indirect ? lookup_minimal_symbol_by_pc (indirect) : 0;
1179 char *symname = indsym ? SYMBOL_NAME (indsym) : 0;
1183 if (strncmp (symname, "__imp_", 6) == 0
1184 || strncmp (symname, "_imp_", 5) == 0)
1185 return name ? 1 : read_memory_unsigned_integer (indirect, 4);
1188 return 0; /* Not a trampoline. */
1192 /* We have two flavours of disassembly. The machinery on this page
1193 deals with switching between those. */
1196 gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info)
1198 if (disassembly_flavor == att_flavor)
1199 return print_insn_i386_att (memaddr, info);
1200 else if (disassembly_flavor == intel_flavor)
1201 return print_insn_i386_intel (memaddr, info);
1202 /* Never reached -- disassembly_flavour is always either att_flavor
1204 internal_error (__FILE__, __LINE__, "failed internal consistency check");
1210 i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1212 struct gdbarch_tdep *tdep;
1213 struct gdbarch *gdbarch;
1215 /* For the moment there is only one i386 architecture. */
1217 return arches->gdbarch;
1219 /* Allocate space for the new architecture. */
1220 tdep = XMALLOC (struct gdbarch_tdep);
1221 gdbarch = gdbarch_alloc (&info, tdep);
1223 /* FIXME: kettenis/2001-11-24: Although not all IA-32 processors
1224 have the SSE registers, it's easier to set the default to 8. */
1225 tdep->num_xmm_regs = 8;
1227 set_gdbarch_use_generic_dummy_frames (gdbarch, 0);
1229 /* Call dummy code. */
1230 set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
1231 set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 5);
1232 set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1);
1233 set_gdbarch_call_dummy_p (gdbarch, 1);
1234 set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0);
1236 set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register);
1237 set_gdbarch_push_arguments (gdbarch, i386_push_arguments);
1239 set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_on_stack);
1241 /* NOTE: tm-i386nw.h and tm-i386v4.h override this. */
1242 set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid);
1244 /* NOTE: tm-i386aix.h, tm-i386bsd.h, tm-i386os9k.h, tm-linux.h,
1245 tm-ptx.h, tm-symmetry.h currently override this. Sigh. */
1246 set_gdbarch_num_regs (gdbarch, NUM_GREGS + NUM_FREGS + NUM_SSE_REGS);
1251 /* Provide a prototype to silence -Wmissing-prototypes. */
1252 void _initialize_i386_tdep (void);
1255 _initialize_i386_tdep (void)
1257 register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init);
1259 /* Initialize the table saying where each register starts in the
1265 for (i = 0; i < MAX_NUM_REGS; i++)
1267 i386_register_offset[i] = offset;
1268 offset += i386_register_size[i];
1272 tm_print_insn = gdb_print_insn_i386;
1273 tm_print_insn_info.mach = bfd_lookup_arch (bfd_arch_i386, 0)->mach;
1275 /* Add the variable that controls the disassembly flavor. */
1277 struct cmd_list_element *new_cmd;
1279 new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
1281 &disassembly_flavor,
1283 Set the disassembly flavor, the valid values are \"att\" and \"intel\", \
1284 and the default value is \"att\".",
1286 add_show_from_set (new_cmd, &showlist);