X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fi386-tdep.c;h=3b981806dc2677d6e56e17d8a0d3750abc05c6bf;hb=237fc4c9cdd1a1df1e53a8321dfd7b147da722fd;hp=efdea9e33695010b63222098fdc8c3bdddcd4d7f;hpb=0818c12a55c2aba820b8f7c7774bcdc698b757ee;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c index efdea9e336..08484bac21 100644 --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -1,13 +1,14 @@ /* Intel 386 target-dependent stuff. - Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, - 1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. + Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, + 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 + 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 + the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, @@ -16,31 +17,40 @@ 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. */ + along with this program. If not, see . */ #include "defs.h" -#include "gdb_string.h" +#include "arch-utils.h" +#include "command.h" +#include "dummy-frame.h" +#include "dwarf2-frame.h" +#include "doublest.h" #include "frame.h" +#include "frame-base.h" +#include "frame-unwind.h" #include "inferior.h" +#include "gdbcmd.h" #include "gdbcore.h" -#include "target.h" -#include "floatformat.h" +#include "gdbtypes.h" +#include "objfiles.h" +#include "osabi.h" +#include "regcache.h" +#include "reggroups.h" +#include "regset.h" #include "symfile.h" #include "symtab.h" -#include "gdbcmd.h" -#include "command.h" -#include "arch-utils.h" -#include "regcache.h" -#include "doublest.h" +#include "target.h" #include "value.h" +#include "dis-asm.h" + #include "gdb_assert.h" +#include "gdb_string.h" #include "i386-tdep.h" +#include "i387-tdep.h" + +/* Register names. */ -/* Names of the registers. The first 10 registers match the register - numbering scheme used by GCC for stabs and DWARF. */ static char *i386_register_names[] = { "eax", "ecx", "edx", "ebx", @@ -56,118 +66,181 @@ static char *i386_register_names[] = "mxcsr" }; -/* i386_register_offset[i] is the offset into the register file of the - start of register number i. We initialize this from - i386_register_size. */ -static int i386_register_offset[I386_SSE_NUM_REGS]; - -/* i386_register_size[i] is the number of bytes of storage in GDB's - register array occupied by register i. */ -static int i386_register_size[I386_SSE_NUM_REGS] = { - 4, 4, 4, 4, - 4, 4, 4, 4, - 4, 4, 4, 4, - 4, 4, 4, 4, - 10, 10, 10, 10, - 10, 10, 10, 10, - 4, 4, 4, 4, - 4, 4, 4, 4, - 16, 16, 16, 16, - 16, 16, 16, 16, - 4 +static const int i386_num_register_names = ARRAY_SIZE (i386_register_names); + +/* Register names for MMX pseudo-registers. */ + +static char *i386_mmx_names[] = +{ + "mm0", "mm1", "mm2", "mm3", + "mm4", "mm5", "mm6", "mm7" }; -/* Return the name of register REG. */ +static const int i386_num_mmx_regs = ARRAY_SIZE (i386_mmx_names); -const char * -i386_register_name (int reg) +static int +i386_mmx_regnum_p (struct gdbarch *gdbarch, int regnum) { - if (reg < 0) - return NULL; - if (reg >= sizeof (i386_register_names) / sizeof (*i386_register_names)) - return NULL; + int mm0_regnum = gdbarch_tdep (gdbarch)->mm0_regnum; + + if (mm0_regnum < 0) + return 0; - return i386_register_names[reg]; + return (regnum >= mm0_regnum && regnum < mm0_regnum + i386_num_mmx_regs); } -/* Return the offset into the register array of the start of register - number REG. */ -int -i386_register_byte (int reg) +/* SSE register? */ + +static int +i386_sse_regnum_p (struct gdbarch *gdbarch, int regnum) { - return i386_register_offset[reg]; + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (I387_NUM_XMM_REGS (tdep) == 0) + return 0; + + return (I387_XMM0_REGNUM (tdep) <= regnum + && regnum < I387_MXCSR_REGNUM (tdep)); } -/* Return the number of bytes of storage in GDB's register array - occupied by register REG. */ +static int +i386_mxcsr_regnum_p (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (I387_NUM_XMM_REGS (tdep) == 0) + return 0; + + return (regnum == I387_MXCSR_REGNUM (tdep)); +} + +/* FP register? */ int -i386_register_raw_size (int reg) +i386_fp_regnum_p (struct gdbarch *gdbarch, int regnum) { - return i386_register_size[reg]; + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (I387_ST0_REGNUM (tdep) < 0) + return 0; + + return (I387_ST0_REGNUM (tdep) <= regnum + && regnum < I387_FCTRL_REGNUM (tdep)); } -/* Convert stabs register number REG to the appropriate register +int +i386_fpc_regnum_p (struct gdbarch *gdbarch, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (I387_ST0_REGNUM (tdep) < 0) + return 0; + + return (I387_FCTRL_REGNUM (tdep) <= regnum + && regnum < I387_XMM0_REGNUM (tdep)); +} + +/* Return the name of register REGNUM. */ + +const char * +i386_register_name (struct gdbarch *gdbarch, int regnum) +{ + if (i386_mmx_regnum_p (gdbarch, regnum)) + return i386_mmx_names[regnum - I387_MM0_REGNUM (gdbarch_tdep (gdbarch))]; + + if (regnum >= 0 && regnum < i386_num_register_names) + return i386_register_names[regnum]; + + return NULL; +} + +/* Convert a dbx register number REG to the appropriate register number used by GDB. */ static int -i386_stab_reg_to_regnum (int reg) +i386_dbx_reg_to_regnum (struct gdbarch *gdbarch, int reg) { - /* This implements what GCC calls the "default" register map. */ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* This implements what GCC calls the "default" register map + (dbx_register_map[]). */ + if (reg >= 0 && reg <= 7) { - /* General registers. */ - return reg; + /* General-purpose registers. The debug info calls %ebp + register 4, and %esp register 5. */ + if (reg == 4) + return 5; + else if (reg == 5) + return 4; + else return reg; } else if (reg >= 12 && reg <= 19) { /* Floating-point registers. */ - return reg - 12 + FP0_REGNUM; + return reg - 12 + I387_ST0_REGNUM (tdep); } else if (reg >= 21 && reg <= 28) { /* SSE registers. */ - return reg - 21 + XMM0_REGNUM; + return reg - 21 + I387_XMM0_REGNUM (tdep); } else if (reg >= 29 && reg <= 36) { /* MMX registers. */ - /* FIXME: kettenis/2001-07-28: Should we have the MMX registers - as pseudo-registers? */ - return reg - 29 + FP0_REGNUM; + return reg - 29 + I387_MM0_REGNUM (tdep); } /* This will hopefully provoke a warning. */ - return NUM_REGS + NUM_PSEUDO_REGS; + return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); } -/* Convert DWARF register number REG to the appropriate register - number used by GDB. */ +/* Convert SVR4 register number REG to the appropriate register number + used by GDB. */ static int -i386_dwarf_reg_to_regnum (int reg) +i386_svr4_reg_to_regnum (struct gdbarch *gdbarch, int reg) { - /* The DWARF register numbering includes %eip and %eflags, and + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* This implements the GCC register map that tries to be compatible + with the SVR4 C compiler for DWARF (svr4_dbx_register_map[]). */ + + /* The SVR4 register numbering includes %eip and %eflags, and numbers the floating point registers differently. */ if (reg >= 0 && reg <= 9) { - /* General registers. */ + /* General-purpose registers. */ return reg; } else if (reg >= 11 && reg <= 18) { /* Floating-point registers. */ - return reg - 11 + FP0_REGNUM; + return reg - 11 + I387_ST0_REGNUM (tdep); } - else if (reg >= 21) + else if (reg >= 21 && reg <= 36) { - /* The SSE and MMX registers have identical numbers as in stabs. */ - return i386_stab_reg_to_regnum (reg); + /* The SSE and MMX registers have the same numbers as with dbx. */ + return i386_dbx_reg_to_regnum (gdbarch, reg); + } + + switch (reg) + { + case 37: return I387_FCTRL_REGNUM (tdep); + case 38: return I387_FSTAT_REGNUM (tdep); + case 39: return I387_MXCSR_REGNUM (tdep); + case 40: return I386_ES_REGNUM; + case 41: return I386_CS_REGNUM; + case 42: return I386_SS_REGNUM; + case 43: return I386_DS_REGNUM; + case 44: return I386_FS_REGNUM; + case 45: return I386_GS_REGNUM; } /* This will hopefully provoke a warning. */ - return NUM_REGS + NUM_PSEUDO_REGS; + return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); } + /* This is the variable that is set with "set disassembly-flavor", and @@ -181,482 +254,798 @@ static const char *valid_flavors[] = NULL }; static const char *disassembly_flavor = att_flavor; + -/* 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 (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 ()); +/* Use the program counter to determine the contents and size of a + breakpoint instruction. Return a pointer to a string of bytes that + encode a breakpoint instruction, store the length of the string in + *LEN and optionally adjust *PC to point to the correct memory + location for inserting the breakpoint. + + On the i386 we have a single breakpoint that fits in a single byte + and can be inserted anywhere. + + This function is 64-bit safe. */ + +static const gdb_byte * +i386_breakpoint_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pc, int *len) +{ + static gdb_byte break_insn[] = { 0xcc }; /* int 3 */ + + *len = sizeof (break_insn); + return break_insn; } + +/* Displaced instruction handling. */ -static void -codestream_seek (CORE_ADDR place) + +static int +i386_absolute_jmp_p (gdb_byte *insn) { - codestream_next_addr = place / CODESTREAM_BUFSIZ; - codestream_next_addr *= CODESTREAM_BUFSIZ; - codestream_cnt = 0; - codestream_fill (1); - while (codestream_tell () != place) - codestream_get (); + /* jmp far (absolute address in operand) */ + if (insn[0] == 0xea) + return 1; + + if (insn[0] == 0xff) + { + /* jump near, absolute indirect (/4) */ + if ((insn[1] & 0x38) == 0x20) + return 1; + + /* jump far, absolute indirect (/5) */ + if ((insn[1] & 0x38) == 0x28) + return 1; + } + + return 0; } -static void -codestream_read (unsigned char *buf, int count) +static int +i386_absolute_call_p (gdb_byte *insn) { - unsigned char *p; - int i; - p = buf; - for (i = 0; i < count; i++) - *p++ = codestream_get (); + /* call far, absolute */ + if (insn[0] == 0x9a) + return 1; + + if (insn[0] == 0xff) + { + /* Call near, absolute indirect (/2) */ + if ((insn[1] & 0x38) == 0x10) + return 1; + + /* Call far, absolute indirect (/3) */ + if ((insn[1] & 0x38) == 0x18) + return 1; + } + + return 0; +} + +static int +i386_ret_p (gdb_byte *insn) +{ + switch (insn[0]) + { + case 0xc2: /* ret near, pop N bytes */ + case 0xc3: /* ret near */ + case 0xca: /* ret far, pop N bytes */ + case 0xcb: /* ret far */ + case 0xcf: /* iret */ + return 1; + + default: + return 0; + } +} + +static int +i386_call_p (gdb_byte *insn) +{ + if (i386_absolute_call_p (insn)) + return 1; + + /* call near, relative */ + if (insn[0] == 0xe8) + return 1; + + return 0; +} + +static int +i386_breakpoint_p (gdb_byte *insn) +{ + return insn[0] == 0xcc; /* int 3 */ +} + +/* Return non-zero if INSN is a system call, and set *LENGTHP to its + length in bytes. Otherwise, return zero. */ +static int +i386_syscall_p (gdb_byte *insn, ULONGEST *lengthp) +{ + if (insn[0] == 0xcd) + { + *lengthp = 2; + return 1; + } + + return 0; +} + +/* Fix up the state of registers and memory after having single-stepped + a displaced instruction. */ +void +i386_displaced_step_fixup (struct gdbarch *gdbarch, + struct displaced_step_closure *closure, + CORE_ADDR from, CORE_ADDR to, + struct regcache *regs) +{ + /* The offset we applied to the instruction's address. + This could well be negative (when viewed as a signed 32-bit + value), but ULONGEST won't reflect that, so take care when + applying it. */ + ULONGEST insn_offset = to - from; + + /* Since we use simple_displaced_step_copy_insn, our closure is a + copy of the instruction. */ + gdb_byte *insn = (gdb_byte *) closure; + + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: fixup (0x%s, 0x%s), " + "insn = 0x%02x 0x%02x ...\n", + paddr_nz (from), paddr_nz (to), insn[0], insn[1]); + + /* The list of issues to contend with here is taken from + resume_execution in arch/i386/kernel/kprobes.c, Linux 2.6.20. + Yay for Free Software! */ + + /* Relocate the %eip, if necessary. */ + + /* Except in the case of absolute or indirect jump or call + instructions, or a return instruction, the new eip is relative to + the displaced instruction; make it relative. Well, signal + handler returns don't need relocation either, but we use the + value of %eip to recognize those; see below. */ + if (! i386_absolute_jmp_p (insn) + && ! i386_absolute_call_p (insn) + && ! i386_ret_p (insn)) + { + ULONGEST orig_eip; + ULONGEST insn_len; + + regcache_cooked_read_unsigned (regs, I386_EIP_REGNUM, &orig_eip); + + /* A signal trampoline system call changes the %eip, resuming + execution of the main program after the signal handler has + returned. That makes them like 'return' instructions; we + shouldn't relocate %eip. + + But most system calls don't, and we do need to relocate %eip. + + Our heuristic for distinguishing these cases: if stepping + over the system call instruction left control directly after + the instruction, the we relocate --- control almost certainly + doesn't belong in the displaced copy. Otherwise, we assume + the instruction has put control where it belongs, and leave + it unrelocated. Goodness help us if there are PC-relative + system calls. */ + if (i386_syscall_p (insn, &insn_len) + && orig_eip != to + insn_len) + { + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: syscall changed %%eip; " + "not relocating\n"); + } + else + { + ULONGEST eip = (orig_eip - insn_offset) & 0xffffffffUL; + + /* If we have stepped over a breakpoint, set the %eip to + point at the breakpoint instruction itself. + + (gdbarch_decr_pc_after_break was never something the core + of GDB should have been concerned with; arch-specific + code should be making PC values consistent before + presenting them to GDB.) */ + if (i386_breakpoint_p (insn)) + { + fprintf_unfiltered (gdb_stdlog, + "displaced: stepped breakpoint\n"); + eip--; + } + + regcache_cooked_write_unsigned (regs, I386_EIP_REGNUM, eip); + + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: " + "relocated %%eip from 0x%s to 0x%s\n", + paddr_nz (orig_eip), paddr_nz (eip)); + } + } + + /* If the instruction was PUSHFL, then the TF bit will be set in the + pushed value, and should be cleared. We'll leave this for later, + since GDB already messes up the TF flag when stepping over a + pushfl. */ + + /* If the instruction was a call, the return address now atop the + stack is the address following the copied instruction. We need + to make it the address following the original instruction. */ + if (i386_call_p (insn)) + { + ULONGEST esp; + ULONGEST retaddr; + const ULONGEST retaddr_len = 4; + + regcache_cooked_read_unsigned (regs, I386_ESP_REGNUM, &esp); + retaddr = read_memory_unsigned_integer (esp, retaddr_len); + retaddr = (retaddr - insn_offset) & 0xffffffffUL; + write_memory_unsigned_integer (esp, retaddr_len, retaddr); + + if (debug_displaced) + fprintf_unfiltered (gdb_stdlog, + "displaced: relocated return addr at 0x%s " + "to 0x%s\n", + paddr_nz (esp), + paddr_nz (retaddr)); + } } + + +#ifdef I386_REGNO_TO_SYMMETRY +#error "The Sequent Symmetry is no longer supported." +#endif -/* If the next instruction is a jump, move to its target. */ +/* According to the System V ABI, the registers %ebp, %ebx, %edi, %esi + and %esp "belong" to the calling function. Therefore these + registers should be saved if they're going to be modified. */ -static void -i386_follow_jump (void) +/* The maximum number of saved registers. This should include all + registers mentioned above, and %eip. */ +#define I386_NUM_SAVED_REGS I386_NUM_GREGS + +struct i386_frame_cache { - unsigned char buf[4]; - long delta; + /* Base address. */ + CORE_ADDR base; + LONGEST sp_offset; + CORE_ADDR pc; - int data16; - CORE_ADDR pos; + /* Saved registers. */ + CORE_ADDR saved_regs[I386_NUM_SAVED_REGS]; + CORE_ADDR saved_sp; + int stack_align; + int pc_in_eax; - pos = codestream_tell (); + /* Stack space reserved for local variables. */ + long locals; +}; - data16 = 0; - if (codestream_peek () == 0x66) +/* Allocate and initialize a frame cache. */ + +static struct i386_frame_cache * +i386_alloc_frame_cache (void) +{ + struct i386_frame_cache *cache; + int i; + + cache = FRAME_OBSTACK_ZALLOC (struct i386_frame_cache); + + /* Base address. */ + cache->base = 0; + cache->sp_offset = -4; + cache->pc = 0; + + /* Saved registers. We initialize these to -1 since zero is a valid + offset (that's where %ebp is supposed to be stored). */ + for (i = 0; i < I386_NUM_SAVED_REGS; i++) + cache->saved_regs[i] = -1; + cache->saved_sp = 0; + cache->stack_align = 0; + cache->pc_in_eax = 0; + + /* Frameless until proven otherwise. */ + cache->locals = -1; + + return cache; +} + +/* If the instruction at PC is a jump, return the address of its + target. Otherwise, return PC. */ + +static CORE_ADDR +i386_follow_jump (CORE_ADDR pc) +{ + gdb_byte op; + long delta = 0; + int data16 = 0; + + target_read_memory (pc, &op, 1); + if (op == 0x66) { - codestream_get (); data16 = 1; + op = read_memory_unsigned_integer (pc + 1, 1); } - switch (codestream_get ()) + switch (op) { case 0xe9: /* Relative jump: if data16 == 0, disp32, else disp16. */ if (data16) { - codestream_read (buf, 2); - delta = extract_signed_integer (buf, 2); + delta = read_memory_integer (pc + 2, 2); /* Include the size of the jmp instruction (including the 0x66 prefix). */ - pos += delta + 4; + delta += 4; } else { - codestream_read (buf, 4); - delta = extract_signed_integer (buf, 4); + delta = read_memory_integer (pc + 1, 4); - pos += delta + 5; + /* Include the size of the jmp instruction. */ + delta += 5; } break; case 0xeb: /* Relative jump, disp8 (ignore data16). */ - codestream_read (buf, 1); - /* Sign-extend it. */ - delta = extract_signed_integer (buf, 1); + delta = read_memory_integer (pc + data16 + 1, 1); - pos += delta + 2; + delta += data16 + 2; break; } - codestream_seek (pos); -} -/* Find & return the amount a local space allocated, and advance the - codestream to the first register push (if any). + return pc + delta; +} - If the entry sequence doesn't make sense, return -1, and leave - codestream pointer at a random spot. */ +/* Check whether PC points at a prologue for a function returning a + structure or union. If so, it updates CACHE and returns the + address of the first instruction after the code sequence that + removes the "hidden" argument from the stack or CURRENT_PC, + whichever is smaller. Otherwise, return PC. */ -static long -i386_get_frame_setup (CORE_ADDR pc) +static CORE_ADDR +i386_analyze_struct_return (CORE_ADDR pc, CORE_ADDR current_pc, + struct i386_frame_cache *cache) { - unsigned char op; + /* Functions that return a structure or union start with: + + popl %eax 0x58 + xchgl %eax, (%esp) 0x87 0x04 0x24 + or xchgl %eax, 0(%esp) 0x87 0x44 0x24 0x00 + + (the System V compiler puts out the second `xchg' instruction, + 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. */ + static gdb_byte proto1[3] = { 0x87, 0x04, 0x24 }; + static gdb_byte proto2[4] = { 0x87, 0x44, 0x24, 0x00 }; + gdb_byte buf[4]; + gdb_byte op; - codestream_seek (pc); + if (current_pc <= pc) + return pc; - i386_follow_jump (); + target_read_memory (pc, &op, 1); - op = codestream_get (); + if (op != 0x58) /* popl %eax */ + return pc; - if (op == 0x58) /* popl %eax */ + target_read_memory (pc + 1, buf, 4); + if (memcmp (buf, proto1, 3) != 0 && memcmp (buf, proto2, 4) != 0) + return pc; + + if (current_pc == pc) { - /* 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 V compiler puts out the second `xchg' - instruction, 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. */ + cache->sp_offset += 4; + return current_pc; } - if (op == 0x68 || op == 0x6a) + if (current_pc == pc + 1) { - /* This function may start with + cache->pc_in_eax = 1; + return current_pc; + } + + if (buf[1] == proto1[1]) + return pc + 4; + else + return pc + 5; +} - pushl constant - call _probe - addl $4, %esp +static CORE_ADDR +i386_skip_probe (CORE_ADDR pc) +{ + /* A function may start with + + pushl constant + call _probe + addl $4, %esp - followed by + followed by - pushl %ebp + pushl %ebp - etc. */ - int pos; - unsigned char buf[8]; + etc. */ + gdb_byte buf[8]; + gdb_byte op; - /* 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. */ - } + target_read_memory (pc, &op, 1); - if (op == 0x55) /* pushl %ebp */ + if (op == 0x68 || op == 0x6a) { - /* Check for "movl %esp, %ebp" -- can be written in 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 + int delta; - 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 immediate. */ - 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 a 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 a 32 bit immediate. */ - codestream_read ((unsigned char *) buf, 4); - return extract_signed_integer (buf, 4); - } + /* Skip past the `pushl' instruction; it has either a one-byte or a + four-byte operand, depending on the opcode. */ + if (op == 0x68) + delta = 5; else - { - return 0; - } - } - else if (op == 0xc8) - { - char buf[2]; - /* `enter' with 16 bit unsigned immediate. */ - codestream_read ((unsigned char *) buf, 2); - codestream_get (); /* Flush final byte of enter instruction. */ - return extract_unsigned_integer (buf, 2); + delta = 2; + + /* Read the following 8 bytes, which should be `call _probe' (6 + bytes) followed by `addl $4,%esp' (2 bytes). */ + read_memory (pc + delta, buf, sizeof (buf)); + if (buf[0] == 0xe8 && buf[6] == 0xc4 && buf[7] == 0x4) + pc += delta + sizeof (buf); } - return (-1); -} - -/* Signal trampolines don't have a meaningful frame. The frame - pointer value we use is actually the frame pointer of the calling - frame -- that is, the frame which was in progress when the signal - trampoline was entered. GDB mostly treats this frame pointer value - as a magic cookie. We detect the case of a signal trampoline by - looking at the SIGNAL_HANDLER_CALLER field, which is set based on - PC_IN_SIGTRAMP. - - When a signal trampoline is invoked from a frameless function, we - essentially have two frameless functions in a row. In this case, - we use the same magic cookie for three frames in a row. We detect - this case by seeing whether the next frame has - SIGNAL_HANDLER_CALLER set, and, if it does, checking whether the - current frame is actually frameless. In this case, we need to get - the PC by looking at the SP register value stored in the signal - context. - - This should work in most cases except in horrible situations where - a signal occurs just as we enter a function but before the frame - has been set up. Incidentally, that's just what happens when we - call a function from GDB with a signal pending (there's a test in - the testsuite that makes this happen). Therefore we pretend that - we have a frameless function if we're stopped at the start of a - function. */ - -/* Return non-zero if we're dealing with a frameless signal, that is, - a signal trampoline invoked from a frameless function. */ -static int -i386_frameless_signal_p (struct frame_info *frame) -{ - return (frame->next && frame->next->signal_handler_caller - && (frameless_look_for_prologue (frame) - || frame->pc == get_pc_function_start (frame->pc))); + return pc; } -/* Return the chain-pointer for FRAME. In the case of the i386, the - frame's nominal address is the address of a 4-byte word containing - the calling frame's address. */ +/* GCC 4.1 and later, can put code in the prologue to realign the + stack pointer. Check whether PC points to such code, and update + CACHE accordingly. Return the first instruction after the code + sequence or CURRENT_PC, whichever is smaller. If we don't + recognize the code, return PC. */ static CORE_ADDR -i386_frame_chain (struct frame_info *frame) +i386_analyze_stack_align (CORE_ADDR pc, CORE_ADDR current_pc, + struct i386_frame_cache *cache) { - if (PC_IN_CALL_DUMMY (frame->pc, 0, 0)) - return frame->frame; + /* The register used by the compiler to perform the stack re-alignment + is, in order of preference, either %ecx, %edx, or %eax. GCC should + never use %ebx as it always treats it as callee-saved, whereas + the compiler can only use caller-saved registers. */ + static const gdb_byte insns_ecx[10] = { + 0x8d, 0x4c, 0x24, 0x04, /* leal 4(%esp), %ecx */ + 0x83, 0xe4, 0xf0, /* andl $-16, %esp */ + 0xff, 0x71, 0xfc /* pushl -4(%ecx) */ + }; + static const gdb_byte insns_edx[10] = { + 0x8d, 0x54, 0x24, 0x04, /* leal 4(%esp), %edx */ + 0x83, 0xe4, 0xf0, /* andl $-16, %esp */ + 0xff, 0x72, 0xfc /* pushl -4(%edx) */ + }; + static const gdb_byte insns_eax[10] = { + 0x8d, 0x44, 0x24, 0x04, /* leal 4(%esp), %eax */ + 0x83, 0xe4, 0xf0, /* andl $-16, %esp */ + 0xff, 0x70, 0xfc /* pushl -4(%eax) */ + }; + gdb_byte buf[10]; - if (frame->signal_handler_caller - || i386_frameless_signal_p (frame)) - return frame->frame; + if (target_read_memory (pc, buf, sizeof buf) + || (memcmp (buf, insns_ecx, sizeof buf) != 0 + && memcmp (buf, insns_edx, sizeof buf) != 0 + && memcmp (buf, insns_eax, sizeof buf) != 0)) + return pc; - if (! inside_entry_file (frame->pc)) - return read_memory_unsigned_integer (frame->frame, 4); + if (current_pc > pc + 4) + cache->stack_align = 1; - return 0; + return min (pc + 10, current_pc); } -/* Determine whether the function invocation represented by FRAME does - not have a from on the stack associated with it. If it does not, - return non-zero, otherwise return zero. */ +/* Maximum instruction length we need to handle. */ +#define I386_MAX_MATCHED_INSN_LEN 6 -static int -i386_frameless_function_invocation (struct frame_info *frame) +/* Instruction description. */ +struct i386_insn { - if (frame->signal_handler_caller) - return 0; - - return frameless_look_for_prologue (frame); -} + size_t len; + gdb_byte insn[I386_MAX_MATCHED_INSN_LEN]; + gdb_byte mask[I386_MAX_MATCHED_INSN_LEN]; +}; -/* Assuming FRAME is for a sigtramp routine, return the saved program - counter. */ +/* Search for the instruction at PC in the list SKIP_INSNS. Return + the first instruction description that matches. Otherwise, return + NULL. */ -static CORE_ADDR -i386_sigtramp_saved_pc (struct frame_info *frame) +static struct i386_insn * +i386_match_insn (CORE_ADDR pc, struct i386_insn *skip_insns) { - struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); - CORE_ADDR addr; + struct i386_insn *insn; + gdb_byte op; - addr = tdep->sigcontext_addr (frame); - return read_memory_unsigned_integer (addr + tdep->sc_pc_offset, 4); -} + target_read_memory (pc, &op, 1); + + for (insn = skip_insns; insn->len > 0; insn++) + { + if ((op & insn->mask[0]) == insn->insn[0]) + { + gdb_byte buf[I386_MAX_MATCHED_INSN_LEN - 1]; + int insn_matched = 1; + size_t i; -/* Assuming FRAME is for a sigtramp routine, return the saved stack - pointer. */ + gdb_assert (insn->len > 1); + gdb_assert (insn->len <= I386_MAX_MATCHED_INSN_LEN); -static CORE_ADDR -i386_sigtramp_saved_sp (struct frame_info *frame) -{ - struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); - CORE_ADDR addr; + target_read_memory (pc + 1, buf, insn->len - 1); + for (i = 1; i < insn->len; i++) + { + if ((buf[i - 1] & insn->mask[i]) != insn->insn[i]) + insn_matched = 0; + } - addr = tdep->sigcontext_addr (frame); - return read_memory_unsigned_integer (addr + tdep->sc_sp_offset, 4); + if (insn_matched) + return insn; + } + } + + return NULL; } -/* Return the saved program counter for FRAME. */ +/* Some special instructions that might be migrated by GCC into the + part of the prologue that sets up the new stack frame. Because the + stack frame hasn't been setup yet, no registers have been saved + yet, and only the scratch registers %eax, %ecx and %edx can be + touched. */ + +struct i386_insn i386_frame_setup_skip_insns[] = +{ + /* Check for `movb imm8, r' and `movl imm32, r'. + + ??? Should we handle 16-bit operand-sizes here? */ + + /* `movb imm8, %al' and `movb imm8, %ah' */ + /* `movb imm8, %cl' and `movb imm8, %ch' */ + { 2, { 0xb0, 0x00 }, { 0xfa, 0x00 } }, + /* `movb imm8, %dl' and `movb imm8, %dh' */ + { 2, { 0xb2, 0x00 }, { 0xfb, 0x00 } }, + /* `movl imm32, %eax' and `movl imm32, %ecx' */ + { 5, { 0xb8 }, { 0xfe } }, + /* `movl imm32, %edx' */ + { 5, { 0xba }, { 0xff } }, + + /* Check for `mov imm32, r32'. Note that there is an alternative + encoding for `mov m32, %eax'. + + ??? Should we handle SIB adressing here? + ??? Should we handle 16-bit operand-sizes here? */ + + /* `movl m32, %eax' */ + { 5, { 0xa1 }, { 0xff } }, + /* `movl m32, %eax' and `mov; m32, %ecx' */ + { 6, { 0x89, 0x05 }, {0xff, 0xf7 } }, + /* `movl m32, %edx' */ + { 6, { 0x89, 0x15 }, {0xff, 0xff } }, + + /* Check for `xorl r32, r32' and the equivalent `subl r32, r32'. + Because of the symmetry, there are actually two ways to encode + these instructions; opcode bytes 0x29 and 0x2b for `subl' and + opcode bytes 0x31 and 0x33 for `xorl'. */ + + /* `subl %eax, %eax' */ + { 2, { 0x29, 0xc0 }, { 0xfd, 0xff } }, + /* `subl %ecx, %ecx' */ + { 2, { 0x29, 0xc9 }, { 0xfd, 0xff } }, + /* `subl %edx, %edx' */ + { 2, { 0x29, 0xd2 }, { 0xfd, 0xff } }, + /* `xorl %eax, %eax' */ + { 2, { 0x31, 0xc0 }, { 0xfd, 0xff } }, + /* `xorl %ecx, %ecx' */ + { 2, { 0x31, 0xc9 }, { 0xfd, 0xff } }, + /* `xorl %edx, %edx' */ + { 2, { 0x31, 0xd2 }, { 0xfd, 0xff } }, + { 0 } +}; + +/* Check whether PC points to a no-op instruction. */ static CORE_ADDR -i386_frame_saved_pc (struct frame_info *frame) +i386_skip_noop (CORE_ADDR pc) { - if (PC_IN_CALL_DUMMY (frame->pc, 0, 0)) - return generic_read_register_dummy (frame->pc, frame->frame, - PC_REGNUM); + gdb_byte op; + int check = 1; - if (frame->signal_handler_caller) - return i386_sigtramp_saved_pc (frame); + target_read_memory (pc, &op, 1); - if (i386_frameless_signal_p (frame)) + while (check) { - CORE_ADDR sp = i386_sigtramp_saved_sp (frame->next); - return read_memory_unsigned_integer (sp, 4); + check = 0; + /* Ignore `nop' instruction. */ + if (op == 0x90) + { + pc += 1; + target_read_memory (pc, &op, 1); + check = 1; + } + /* Ignore no-op instruction `mov %edi, %edi'. + Microsoft system dlls often start with + a `mov %edi,%edi' instruction. + The 5 bytes before the function start are + filled with `nop' instructions. + This pattern can be used for hot-patching: + The `mov %edi, %edi' instruction can be replaced by a + near jump to the location of the 5 `nop' instructions + which can be replaced by a 32-bit jump to anywhere + in the 32-bit address space. */ + + else if (op == 0x8b) + { + target_read_memory (pc + 1, &op, 1); + if (op == 0xff) + { + pc += 2; + target_read_memory (pc, &op, 1); + check = 1; + } + } } - - return read_memory_unsigned_integer (frame->frame + 4, 4); + return pc; } -/* Immediately after a function call, return the saved pc. */ +/* Check whether PC points at a code that sets up a new stack frame. + If so, it updates CACHE and returns the address of the first + instruction after the sequence that sets up the frame or LIMIT, + whichever is smaller. If we don't recognize the code, return PC. */ static CORE_ADDR -i386_saved_pc_after_call (struct frame_info *frame) +i386_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR limit, + struct i386_frame_cache *cache) { - if (frame->signal_handler_caller) - return i386_sigtramp_saved_pc (frame); + struct i386_insn *insn; + gdb_byte op; + int skip = 0; - return read_memory_unsigned_integer (read_register (SP_REGNUM), 4); -} + if (limit <= pc) + return limit; -/* Return number of args passed to a frame. - Can return -1, meaning no way to tell. */ + target_read_memory (pc, &op, 1); -static int -i386_frame_num_args (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 i386, 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 = FRAMELESS_FUNCTION_INVOCATION (fi); - 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 (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 + if (op == 0x55) /* pushl %ebp */ { - retpc = pfi->pc; - op = read_memory_integer (retpc, 1); - if (op == 0x59) /* pop %ecx */ - return 1; - else if (op == 0x83) + /* Take into account that we've executed the `pushl %ebp' that + starts this instruction sequence. */ + cache->saved_regs[I386_EBP_REGNUM] = 0; + cache->sp_offset += 4; + pc++; + + /* If that's all, return now. */ + if (limit <= pc) + return limit; + + /* Check for some special instructions that might be migrated by + GCC into the prologue and skip them. At this point in the + prologue, code should only touch the scratch registers %eax, + %ecx and %edx, so while the number of posibilities is sheer, + it is limited. + + Make sure we only skip these instructions if we later see the + `movl %esp, %ebp' that actually sets up the frame. */ + while (pc + skip < limit) { - op = read_memory_integer (retpc + 1, 1); - if (op == 0xc4) - /* addl $, %esp */ - return (read_memory_integer (retpc + 2, 1) & 0xff) / 4; - else - return 0; + insn = i386_match_insn (pc + skip, i386_frame_setup_skip_insns); + if (insn == NULL) + break; + + skip += insn->len; } - else if (op == 0x81) /* `add' with 32 bit immediate. */ + + /* If that's all, return now. */ + if (limit <= pc + skip) + return limit; + + target_read_memory (pc + skip, &op, 1); + + /* Check for `movl %esp, %ebp' -- can be written in two ways. */ + switch (op) { - op = read_memory_integer (retpc + 1, 1); - if (op == 0xc4) - /* addl $, %esp */ - return read_memory_integer (retpc + 2, 4) / 4; - else - return 0; + case 0x8b: + if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xec) + return pc; + break; + case 0x89: + if (read_memory_unsigned_integer (pc + skip + 1, 1) != 0xe5) + return pc; + break; + default: + return pc; + } + + /* OK, we actually have a frame. We just don't know how large + it is yet. Set its size to zero. We'll adjust it if + necessary. We also now commit to skipping the special + instructions mentioned before. */ + cache->locals = 0; + pc += (skip + 2); + + /* If that's all, return now. */ + if (limit <= pc) + return limit; + + /* 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. */ + target_read_memory (pc, &op, 1); + if (op == 0x83) + { + /* `subl' with 8-bit immediate. */ + if (read_memory_unsigned_integer (pc + 1, 1) != 0xec) + /* Some instruction starting with 0x83 other than `subl'. */ + return pc; + + /* `subl' with signed 8-bit immediate (though it wouldn't + make sense to be negative). */ + cache->locals = read_memory_integer (pc + 2, 1); + return pc + 3; + } + else if (op == 0x81) + { + /* Maybe it is `subl' with a 32-bit immediate. */ + if (read_memory_unsigned_integer (pc + 1, 1) != 0xec) + /* Some instruction starting with 0x81 other than `subl'. */ + return pc; + + /* It is `subl' with a 32-bit immediate. */ + cache->locals = read_memory_integer (pc + 2, 4); + return pc + 6; } else { - return 0; + /* Some instruction other than `subl'. */ + return pc; } } -#endif + else if (op == 0xc8) /* enter */ + { + cache->locals = read_memory_unsigned_integer (pc + 1, 2); + return pc + 4; + } + + return pc; } -/* Parse the first few instructions the function to see what registers - were stored. - +/* Check whether PC points at code that saves registers on the stack. + If so, it updates CACHE and returns the address of the first + instruction after the register saves or CURRENT_PC, whichever is + smaller. Otherwise, return PC. */ + +static CORE_ADDR +i386_analyze_register_saves (CORE_ADDR pc, CORE_ADDR current_pc, + struct i386_frame_cache *cache) +{ + CORE_ADDR offset = 0; + gdb_byte op; + int i; + + if (cache->locals > 0) + offset -= cache->locals; + for (i = 0; i < 8 && pc < current_pc; i++) + { + target_read_memory (pc, &op, 1); + if (op < 0x50 || op > 0x57) + break; + + offset -= 4; + cache->saved_regs[op - 0x50] = offset; + cache->sp_offset += 4; + pc++; + } + + return pc; +} + +/* Do a full analysis of the prologue at PC and update CACHE + accordingly. Bail out early if CURRENT_PC is reached. Return the + address where the analysis stopped. + We handle these cases: The startup sequence can be at the start of the function, or the @@ -667,9 +1056,9 @@ i386_frame_num_args (struct frame_info *fi) once used in the System V compiler). Local space is allocated just below the saved %ebp by either the - 'enter' instruction, or by "subl $, %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. + 'enter' instruction, or by "subl $, %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. With the System V compiler they will always be in the order: %edi, %esi, @@ -680,79 +1069,45 @@ i386_frame_num_args (struct frame_info *fi) If the setup sequence is at the end of the function, then the next instruction will be a branch back to the start. */ -static void -i386_frame_init_saved_regs (struct frame_info *fip) +static CORE_ADDR +i386_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc, + struct i386_frame_cache *cache) { - long locals = -1; - unsigned char op; - CORE_ADDR addr; - CORE_ADDR pc; - int i; - - if (fip->saved_regs) - return; - - frame_saved_regs_zalloc (fip); - - pc = get_pc_function_start (fip->pc); - if (pc != 0) - locals = i386_get_frame_setup (pc); - - if (locals >= 0) - { - addr = 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. */ - fip->saved_regs[I386_REGNO_TO_SYMMETRY (op - 0x50)] = addr; -#else - fip->saved_regs[op - 0x50] = addr; -#endif - addr -= 4; - } - } - - fip->saved_regs[PC_REGNUM] = fip->frame + 4; - fip->saved_regs[FP_REGNUM] = fip->frame; + pc = i386_skip_noop (pc); + pc = i386_follow_jump (pc); + pc = i386_analyze_struct_return (pc, current_pc, cache); + pc = i386_skip_probe (pc); + pc = i386_analyze_stack_align (pc, current_pc, cache); + pc = i386_analyze_frame_setup (pc, current_pc, cache); + return i386_analyze_register_saves (pc, current_pc, cache); } /* Return PC of first real instruction. */ static CORE_ADDR -i386_skip_prologue (CORE_ADDR pc) +i386_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc) { - unsigned char op; - int i; - static unsigned char pic_pat[6] = - { 0xe8, 0, 0, 0, 0, /* call 0x0 */ - 0x5b, /* popl %ebx */ + static gdb_byte 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); + struct i386_frame_cache cache; + CORE_ADDR pc; + gdb_byte op; + int i; - /* Found valid frame setup -- codestream now points to start of push - instructions for saving registers. */ + cache.locals = -1; + pc = i386_analyze_prologue (start_pc, 0xffffffff, &cache); + if (cache.locals < 0) + return start_pc; - /* Skip over register saves. */ - for (i = 0; i < 8; i++) - { - op = codestream_peek (); - /* Break if not `pushl' instrunction. */ - if (op < 0x50 || op > 0x57) - break; - codestream_get (); - } + /* Found valid frame setup. */ /* 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 - + %ebx: + call 0x0 popl %ebx movl %ebx,x(%ebp) (optional) @@ -762,198 +1117,457 @@ i386_skip_prologue (CORE_ADDR pc) 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 (); + target_read_memory (pc + i, &op, 1); if (pic_pat[i] != op) break; } if (i == 6) { - unsigned char buf[4]; - long delta = 6; + int delta = 6; + + target_read_memory (pc + delta, &op, 1); - op = codestream_get (); if (op == 0x89) /* movl %ebx, x(%ebp) */ { - op = codestream_get (); + op = read_memory_unsigned_integer (pc + delta + 1, 1); + if (op == 0x5d) /* One byte offset from %ebp. */ - { - delta += 3; - codestream_read (buf, 1); - } + delta += 3; else if (op == 0x9d) /* Four byte offset from %ebp. */ - { - delta += 6; - codestream_read (buf, 4); - } + delta += 6; else /* Unexpected instruction. */ - delta = -1; - op = codestream_get (); + delta = 0; + + target_read_memory (pc + delta, &op, 1); } + /* addl y,%ebx */ - if (delta > 0 && op == 0x81 && codestream_get () == 0xc3) + if (delta > 0 && op == 0x81 + && read_memory_unsigned_integer (pc + delta + 1, 1) == 0xc3) { - pos += delta + 6; + pc += delta + 6; } } - codestream_seek (pos); - i386_follow_jump (); + /* If the function starts with a branch (to startup code at the end) + the last instruction should bring us back to the first + instruction of the real code. */ + if (i386_follow_jump (start_pc) != start_pc) + pc = i386_follow_jump (pc); - return (codestream_tell ()); + return pc; } -/* Use the program counter to determine the contents and size of a - breakpoint instruction. Return a pointer to a string of bytes that - encode a breakpoint instruction, store the length of the string in - *LEN and optionally adjust *PC to point to the correct memory - location for inserting the breakpoint. +/* This function is 64-bit safe. */ - On the i386 we have a single breakpoint that fits in a single byte - and can be inserted anywhere. */ - -static const unsigned char * -i386_breakpoint_from_pc (CORE_ADDR *pc, int *len) +static CORE_ADDR +i386_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) { - static unsigned char break_insn[] = { 0xcc }; /* int 3 */ - - *len = sizeof (break_insn); - return break_insn; + gdb_byte buf[8]; + + frame_unwind_register (next_frame, gdbarch_pc_regnum (gdbarch), buf); + return extract_typed_address (buf, builtin_type_void_func_ptr); } + -/* Push the return address (pointing to the call dummy) onto the stack - and return the new value for the stack pointer. */ +/* Normal frames. */ -static CORE_ADDR -i386_push_return_address (CORE_ADDR pc, CORE_ADDR sp) +static struct i386_frame_cache * +i386_frame_cache (struct frame_info *this_frame, void **this_cache) { - char buf[4]; + struct i386_frame_cache *cache; + gdb_byte buf[4]; + int i; + + if (*this_cache) + return *this_cache; + + cache = i386_alloc_frame_cache (); + *this_cache = cache; + + /* In principle, for normal frames, %ebp holds the frame pointer, + which holds the base address for the current stack frame. + However, for functions that don't need it, the frame pointer is + optional. For these "frameless" functions the frame pointer is + actually the frame pointer of the calling frame. Signal + trampolines are just a special case of a "frameless" function. + They (usually) share their frame pointer with the frame that was + in progress when the signal occurred. */ + + get_frame_register (this_frame, I386_EBP_REGNUM, buf); + cache->base = extract_unsigned_integer (buf, 4); + if (cache->base == 0) + return cache; + + /* For normal frames, %eip is stored at 4(%ebp). */ + cache->saved_regs[I386_EIP_REGNUM] = 4; + + cache->pc = get_frame_func (this_frame); + if (cache->pc != 0) + i386_analyze_prologue (cache->pc, get_frame_pc (this_frame), cache); + + if (cache->stack_align) + { + /* Saved stack pointer has been saved in %ecx. */ + get_frame_register (this_frame, I386_ECX_REGNUM, buf); + cache->saved_sp = extract_unsigned_integer(buf, 4); + } + + if (cache->locals < 0) + { + /* We didn't find a valid frame, which means that CACHE->base + currently holds the frame pointer for our calling frame. If + we're at the start of a function, or somewhere half-way its + prologue, the function's frame probably hasn't been fully + setup yet. Try to reconstruct the base address for the stack + frame by looking at the stack pointer. For truly "frameless" + functions this might work too. */ + + if (cache->stack_align) + { + /* We're halfway aligning the stack. */ + cache->base = ((cache->saved_sp - 4) & 0xfffffff0) - 4; + cache->saved_regs[I386_EIP_REGNUM] = cache->saved_sp - 4; + + /* This will be added back below. */ + cache->saved_regs[I386_EIP_REGNUM] -= cache->base; + } + else + { + get_frame_register (this_frame, I386_ESP_REGNUM, buf); + cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset; + } + } + + /* Now that we have the base address for the stack frame we can + calculate the value of %esp in the calling frame. */ + if (cache->saved_sp == 0) + cache->saved_sp = cache->base + 8; - store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); - write_memory (sp - 4, buf, 4); - return sp - 4; + /* Adjust all the saved registers such that they contain addresses + instead of offsets. */ + for (i = 0; i < I386_NUM_SAVED_REGS; i++) + if (cache->saved_regs[i] != -1) + cache->saved_regs[i] += cache->base; + + return cache; } static void -i386_do_pop_frame (struct frame_info *frame) +i386_frame_this_id (struct frame_info *this_frame, void **this_cache, + struct frame_id *this_id) { - CORE_ADDR fp; - int regnum; - char regbuf[I386_MAX_REGISTER_SIZE]; + struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); + + /* This marks the outermost frame. */ + if (cache->base == 0) + return; + + /* See the end of i386_push_dummy_call. */ + (*this_id) = frame_id_build (cache->base + 8, cache->pc); +} + +static struct value * +i386_frame_prev_register (struct frame_info *this_frame, void **this_cache, + int regnum) +{ + struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); + + gdb_assert (regnum >= 0); - fp = FRAME_FP (frame); - i386_frame_init_saved_regs (frame); + /* The System V ABI says that: - for (regnum = 0; regnum < NUM_REGS; regnum++) + "The flags register contains the system flags, such as the + direction flag and the carry flag. The direction flag must be + set to the forward (that is, zero) direction before entry and + upon exit from a function. Other user flags have no specified + role in the standard calling sequence and are not preserved." + + To guarantee the "upon exit" part of that statement we fake a + saved flags register that has its direction flag cleared. + + Note that GCC doesn't seem to rely on the fact that the direction + flag is cleared after a function return; it always explicitly + clears the flag before operations where it matters. + + FIXME: kettenis/20030316: I'm not quite sure whether this is the + right thing to do. The way we fake the flags register here makes + it impossible to change it. */ + + if (regnum == I386_EFLAGS_REGNUM) { - CORE_ADDR addr; - addr = frame->saved_regs[regnum]; - if (addr) - { - read_memory (addr, regbuf, REGISTER_RAW_SIZE (regnum)); - write_register_bytes (REGISTER_BYTE (regnum), regbuf, - REGISTER_RAW_SIZE (regnum)); - } + ULONGEST val; + + val = get_frame_register_unsigned (this_frame, regnum); + val &= ~(1 << 10); + return frame_unwind_got_constant (this_frame, regnum, val); } - 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 (); + + if (regnum == I386_EIP_REGNUM && cache->pc_in_eax) + return frame_unwind_got_register (this_frame, regnum, I386_EAX_REGNUM); + + if (regnum == I386_ESP_REGNUM && cache->saved_sp) + return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp); + + if (regnum < I386_NUM_SAVED_REGS && cache->saved_regs[regnum] != -1) + return frame_unwind_got_memory (this_frame, regnum, + cache->saved_regs[regnum]); + + return frame_unwind_got_register (this_frame, regnum, regnum); +} + +static const struct frame_unwind i386_frame_unwind = +{ + NORMAL_FRAME, + i386_frame_this_id, + i386_frame_prev_register, + NULL, + default_frame_sniffer +}; + + +/* Signal trampolines. */ + +static struct i386_frame_cache * +i386_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache) +{ + struct i386_frame_cache *cache; + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); + CORE_ADDR addr; + gdb_byte buf[4]; + + if (*this_cache) + return *this_cache; + + cache = i386_alloc_frame_cache (); + + get_frame_register (this_frame, I386_ESP_REGNUM, buf); + cache->base = extract_unsigned_integer (buf, 4) - 4; + + addr = tdep->sigcontext_addr (this_frame); + if (tdep->sc_reg_offset) + { + int i; + + gdb_assert (tdep->sc_num_regs <= I386_NUM_SAVED_REGS); + + for (i = 0; i < tdep->sc_num_regs; i++) + if (tdep->sc_reg_offset[i] != -1) + cache->saved_regs[i] = addr + tdep->sc_reg_offset[i]; + } + else + { + cache->saved_regs[I386_EIP_REGNUM] = addr + tdep->sc_pc_offset; + cache->saved_regs[I386_ESP_REGNUM] = addr + tdep->sc_sp_offset; + } + + *this_cache = cache; + return cache; } static void -i386_pop_frame (void) +i386_sigtramp_frame_this_id (struct frame_info *this_frame, void **this_cache, + struct frame_id *this_id) +{ + struct i386_frame_cache *cache = + i386_sigtramp_frame_cache (this_frame, this_cache); + + /* See the end of i386_push_dummy_call. */ + (*this_id) = frame_id_build (cache->base + 8, get_frame_pc (this_frame)); +} + +static struct value * +i386_sigtramp_frame_prev_register (struct frame_info *this_frame, + void **this_cache, int regnum) +{ + /* Make sure we've initialized the cache. */ + i386_sigtramp_frame_cache (this_frame, this_cache); + + return i386_frame_prev_register (this_frame, this_cache, regnum); +} + +static int +i386_sigtramp_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (get_frame_arch (this_frame)); + + /* We shouldn't even bother if we don't have a sigcontext_addr + handler. */ + if (tdep->sigcontext_addr == NULL) + return 0; + + if (tdep->sigtramp_p != NULL) + { + if (tdep->sigtramp_p (this_frame)) + return 1; + } + + if (tdep->sigtramp_start != 0) + { + CORE_ADDR pc = get_frame_pc (this_frame); + + gdb_assert (tdep->sigtramp_end != 0); + if (pc >= tdep->sigtramp_start && pc < tdep->sigtramp_end) + return 1; + } + + return 0; +} + +static const struct frame_unwind i386_sigtramp_frame_unwind = +{ + SIGTRAMP_FRAME, + i386_sigtramp_frame_this_id, + i386_sigtramp_frame_prev_register, + NULL, + i386_sigtramp_frame_sniffer +}; + + +static CORE_ADDR +i386_frame_base_address (struct frame_info *this_frame, void **this_cache) { - generic_pop_current_frame (i386_do_pop_frame); + struct i386_frame_cache *cache = i386_frame_cache (this_frame, this_cache); + + return cache->base; +} + +static const struct frame_base i386_frame_base = +{ + &i386_frame_unwind, + i386_frame_base_address, + i386_frame_base_address, + i386_frame_base_address +}; + +static struct frame_id +i386_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) +{ + CORE_ADDR fp; + + fp = get_frame_register_unsigned (this_frame, I386_EBP_REGNUM); + + /* See the end of i386_push_dummy_call. */ + return frame_id_build (fp + 8, get_frame_pc (this_frame)); } /* 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 address that we will land at. - This address is copied into PC. This routine returns true on + This address is copied into PC. This routine returns non-zero on success. */ static int -i386_get_longjmp_target (CORE_ADDR *pc) +i386_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc) { - char buf[4]; + gdb_byte buf[4]; CORE_ADDR sp, jb_addr; - int jb_pc_offset = gdbarch_tdep (current_gdbarch)->jb_pc_offset; + struct gdbarch *gdbarch = get_frame_arch (frame); + int jb_pc_offset = gdbarch_tdep (gdbarch)->jb_pc_offset; /* If JB_PC_OFFSET is -1, we have no way to find out where the longjmp will land. */ if (jb_pc_offset == -1) return 0; - sp = read_register (SP_REGNUM); + get_frame_register (frame, I386_ESP_REGNUM, buf); + sp = extract_unsigned_integer (buf, 4); if (target_read_memory (sp + 4, buf, 4)) return 0; - jb_addr = extract_address (buf, 4); + jb_addr = extract_unsigned_integer (buf, 4); if (target_read_memory (jb_addr + jb_pc_offset, buf, 4)) return 0; - *pc = extract_address (buf, 4); + *pc = extract_unsigned_integer (buf, 4); return 1; } static CORE_ADDR -i386_push_arguments (int nargs, struct value **args, CORE_ADDR sp, - int struct_return, CORE_ADDR struct_addr) +i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function, + struct regcache *regcache, CORE_ADDR bp_addr, int nargs, + struct value **args, CORE_ADDR sp, int struct_return, + CORE_ADDR struct_addr) { - sp = default_push_arguments (nargs, args, sp, struct_return, struct_addr); - - if (struct_return) + gdb_byte buf[4]; + int i; + + /* Push arguments in reverse order. */ + for (i = nargs - 1; i >= 0; i--) { - char buf[4]; + int len = TYPE_LENGTH (value_enclosing_type (args[i])); + + /* The System V ABI says that: + + "An argument's size is increased, if necessary, to make it a + multiple of [32-bit] words. This may require tail padding, + depending on the size of the argument." + + This makes sure the stack stays word-aligned. */ + sp -= (len + 3) & ~3; + write_memory (sp, value_contents_all (args[i]), len); + } + /* Push value address. */ + if (struct_return) + { sp -= 4; - store_address (buf, 4, struct_addr); + store_unsigned_integer (buf, 4, struct_addr); write_memory (sp, buf, 4); } - return sp; -} - -static void -i386_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) -{ - /* Do nothing. Everything was already done by i386_push_arguments. */ + /* Store return address. */ + sp -= 4; + store_unsigned_integer (buf, 4, bp_addr); + write_memory (sp, buf, 4); + + /* Finally, update the stack pointer... */ + store_unsigned_integer (buf, 4, sp); + regcache_cooked_write (regcache, I386_ESP_REGNUM, buf); + + /* ...and fake a frame pointer. */ + regcache_cooked_write (regcache, I386_EBP_REGNUM, buf); + + /* MarkK wrote: This "+ 8" is all over the place: + (i386_frame_this_id, i386_sigtramp_frame_this_id, + i386_dummy_id). It's there, since all frame unwinders for + a given target have to agree (within a certain margin) on the + definition of the stack address of a frame. Otherwise + frame_id_inner() won't work correctly. Since DWARF2/GCC uses the + stack address *before* the function call as a frame's CFA. On + the i386, when %ebp is used as a frame pointer, the offset + between the contents %ebp and the CFA as defined by GCC. */ + return sp + 8; } /* These registers are used for returning integers (and on some targets also for returning `struct' and `union' values when their size and alignment match an integer type). */ -#define LOW_RETURN_REGNUM 0 /* %eax */ -#define HIGH_RETURN_REGNUM 2 /* %edx */ +#define LOW_RETURN_REGNUM I386_EAX_REGNUM /* %eax */ +#define HIGH_RETURN_REGNUM I386_EDX_REGNUM /* %edx */ -/* Extract from an array REGBUF containing the (raw) register state, a - function return value of TYPE, and copy that, in virtual format, - into VALBUF. */ +/* Read, for architecture GDBARCH, a function return value of TYPE + from REGCACHE, and copy that into VALBUF. */ static void -i386_extract_return_value (struct type *type, struct regcache *regcache, - char *valbuf) +i386_extract_return_value (struct gdbarch *gdbarch, struct type *type, + struct regcache *regcache, gdb_byte *valbuf) { + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int len = TYPE_LENGTH (type); - char buf[I386_MAX_REGISTER_SIZE]; - - if (TYPE_CODE (type) == TYPE_CODE_STRUCT - && TYPE_NFIELDS (type) == 1) - { - i386_extract_return_value (TYPE_FIELD_TYPE (type, 0), regcache, valbuf); - return; - } + gdb_byte buf[I386_MAX_REGISTER_SIZE]; if (TYPE_CODE (type) == TYPE_CODE_FLT) { - if (FP0_REGNUM == 0) + if (tdep->st0_regnum < 0) { - warning ("Cannot find floating-point return value."); + warning (_("Cannot find floating-point return value.")); memset (valbuf, 0, len); return; } @@ -962,13 +1576,13 @@ i386_extract_return_value (struct type *type, struct regcache *regcache, its contents to the desired type. This is probably not exactly how it would happen on the target itself, but it is the best we can do. */ - regcache_raw_read (regcache, FP0_REGNUM, buf); + regcache_raw_read (regcache, I386_ST0_REGNUM, buf); convert_typed_floating (buf, builtin_type_i387_ext, valbuf, type); } else { - int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); - int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); + int low_size = register_size (gdbarch, LOW_RETURN_REGNUM); + int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM); if (len <= low_size) { @@ -984,33 +1598,28 @@ i386_extract_return_value (struct type *type, struct regcache *regcache, } else internal_error (__FILE__, __LINE__, - "Cannot extract return value of %d bytes long.", len); + _("Cannot extract return value of %d bytes long."), len); } } -/* Write into the appropriate registers a function return value stored - in VALBUF of type TYPE, given in virtual format. */ +/* Write, for architecture GDBARCH, a function return value of TYPE + from VALBUF into REGCACHE. */ static void -i386_store_return_value (struct type *type, char *valbuf) +i386_store_return_value (struct gdbarch *gdbarch, struct type *type, + struct regcache *regcache, const gdb_byte *valbuf) { + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); int len = TYPE_LENGTH (type); - if (TYPE_CODE (type) == TYPE_CODE_STRUCT - && TYPE_NFIELDS (type) == 1) - { - i386_store_return_value (TYPE_FIELD_TYPE (type, 0), valbuf); - return; - } - if (TYPE_CODE (type) == TYPE_CODE_FLT) { - unsigned int fstat; - char buf[FPU_REG_RAW_SIZE]; + ULONGEST fstat; + gdb_byte buf[I386_MAX_REGISTER_SIZE]; - if (FP0_REGNUM == 0) + if (tdep->st0_regnum < 0) { - warning ("Cannot set floating-point return value."); + warning (_("Cannot set floating-point return value.")); return; } @@ -1023,51 +1632,39 @@ i386_store_return_value (struct type *type, char *valbuf) not exactly how it would happen on the target itself, but it is the best we can do. */ convert_typed_floating (valbuf, type, buf, builtin_type_i387_ext); - write_register_bytes (REGISTER_BYTE (FP0_REGNUM), buf, - FPU_REG_RAW_SIZE); + regcache_raw_write (regcache, I386_ST0_REGNUM, buf); /* Set the top of the floating-point register stack to 7. The actual value doesn't really matter, but 7 is what a normal function return would end up with if the program started out with a freshly initialized FPU. */ - fstat = read_register (FSTAT_REGNUM); + regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat); fstat |= (7 << 11); - write_register (FSTAT_REGNUM, fstat); + regcache_raw_write_unsigned (regcache, I387_FSTAT_REGNUM (tdep), fstat); /* Mark %st(1) through %st(7) as empty. Since we set the top of the floating-point register stack to 7, the appropriate value for the tag word is 0x3fff. */ - write_register (FTAG_REGNUM, 0x3fff); + regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM (tdep), 0x3fff); } else { - int low_size = REGISTER_RAW_SIZE (LOW_RETURN_REGNUM); - int high_size = REGISTER_RAW_SIZE (HIGH_RETURN_REGNUM); + int low_size = register_size (gdbarch, LOW_RETURN_REGNUM); + int high_size = register_size (gdbarch, HIGH_RETURN_REGNUM); if (len <= low_size) - write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), valbuf, len); + regcache_raw_write_part (regcache, LOW_RETURN_REGNUM, 0, len, valbuf); else if (len <= (low_size + high_size)) { - write_register_bytes (REGISTER_BYTE (LOW_RETURN_REGNUM), - valbuf, low_size); - write_register_bytes (REGISTER_BYTE (HIGH_RETURN_REGNUM), - valbuf + low_size, len - low_size); + regcache_raw_write (regcache, LOW_RETURN_REGNUM, valbuf); + regcache_raw_write_part (regcache, HIGH_RETURN_REGNUM, 0, + len - low_size, valbuf + low_size); } else internal_error (__FILE__, __LINE__, - "Cannot store return value of %d bytes long.", len); + _("Cannot store return value of %d bytes long."), len); } } - -/* Extract from an array REGBUF containing the (raw) register state - the address in which a function should return its structure value, - as a CORE_ADDR. */ - -static CORE_ADDR -i386_extract_struct_value_address (struct regcache *regcache) -{ - return regcache_raw_read_as_address (regcache, LOW_RETURN_REGNUM); -} /* This is the variable that is set with "set struct-convention", and @@ -1084,138 +1681,586 @@ static const char *valid_conventions[] = }; static const char *struct_convention = default_struct_convention; +/* Return non-zero if TYPE, which is assumed to be a structure, + a union type, or an array type, should be returned in registers + for architecture GDBARCH. */ + static int -i386_use_struct_convention (int gcc_p, struct type *type) +i386_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + enum type_code code = TYPE_CODE (type); + int len = TYPE_LENGTH (type); + + gdb_assert (code == TYPE_CODE_STRUCT + || code == TYPE_CODE_UNION + || code == TYPE_CODE_ARRAY); + + if (struct_convention == pcc_struct_convention + || (struct_convention == default_struct_convention + && tdep->struct_return == pcc_struct_return)) + return 0; + + /* Structures consisting of a single `float', `double' or 'long + double' member are returned in %st(0). */ + if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) + { + type = check_typedef (TYPE_FIELD_TYPE (type, 0)); + if (TYPE_CODE (type) == TYPE_CODE_FLT) + return (len == 4 || len == 8 || len == 12); + } + + return (len == 1 || len == 2 || len == 4 || len == 8); +} + +/* Determine, for architecture GDBARCH, how a return value of TYPE + should be returned. If it is supposed to be returned in registers, + and READBUF is non-zero, read the appropriate value from REGCACHE, + and copy it into READBUF. If WRITEBUF is non-zero, write the value + from WRITEBUF into REGCACHE. */ + +static enum return_value_convention +i386_return_value (struct gdbarch *gdbarch, struct type *func_type, + struct type *type, struct regcache *regcache, + gdb_byte *readbuf, const gdb_byte *writebuf) { - enum struct_return struct_return; + enum type_code code = TYPE_CODE (type); + + if (((code == TYPE_CODE_STRUCT + || code == TYPE_CODE_UNION + || code == TYPE_CODE_ARRAY) + && !i386_reg_struct_return_p (gdbarch, type)) + /* 128-bit decimal float uses the struct return convention. */ + || (code == TYPE_CODE_DECFLOAT && TYPE_LENGTH (type) == 16)) + { + /* The System V ABI says that: - if (struct_convention == default_struct_convention) - struct_return = gdbarch_tdep (current_gdbarch)->struct_return; - else if (struct_convention == pcc_struct_convention) - struct_return = pcc_struct_return; - else - struct_return = reg_struct_return; + "A function that returns a structure or union also sets %eax + to the value of the original address of the caller's area + before it returns. Thus when the caller receives control + again, the address of the returned object resides in register + %eax and can be used to access the object." + + So the ABI guarantees that we can always find the return + value just after the function has returned. */ + + /* Note that the ABI doesn't mention functions returning arrays, + which is something possible in certain languages such as Ada. + In this case, the value is returned as if it was wrapped in + a record, so the convention applied to records also applies + to arrays. */ - return generic_use_struct_convention (struct_return == reg_struct_return, - type); + if (readbuf) + { + ULONGEST addr; + + regcache_raw_read_unsigned (regcache, I386_EAX_REGNUM, &addr); + read_memory (addr, readbuf, TYPE_LENGTH (type)); + } + + return RETURN_VALUE_ABI_RETURNS_ADDRESS; + } + + /* This special case is for structures consisting of a single + `float', `double' or 'long double' member. These structures are + returned in %st(0). For these structures, we call ourselves + recursively, changing TYPE into the type of the first member of + the structure. Since that should work for all structures that + have only one member, we don't bother to check the member's type + here. */ + if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) + { + type = check_typedef (TYPE_FIELD_TYPE (type, 0)); + return i386_return_value (gdbarch, func_type, type, regcache, + readbuf, writebuf); + } + + if (readbuf) + i386_extract_return_value (gdbarch, type, regcache, readbuf); + if (writebuf) + i386_store_return_value (gdbarch, type, regcache, writebuf); + + return RETURN_VALUE_REGISTER_CONVENTION; } +/* Type for %eflags. */ +struct type *i386_eflags_type; + +/* Type for %mxcsr. */ +struct type *i386_mxcsr_type; + +/* Construct types for ISA-specific registers. */ +static void +i386_init_types (void) +{ + struct type *type; + + type = init_flags_type ("builtin_type_i386_eflags", 4); + append_flags_type_flag (type, 0, "CF"); + append_flags_type_flag (type, 1, NULL); + append_flags_type_flag (type, 2, "PF"); + append_flags_type_flag (type, 4, "AF"); + append_flags_type_flag (type, 6, "ZF"); + append_flags_type_flag (type, 7, "SF"); + append_flags_type_flag (type, 8, "TF"); + append_flags_type_flag (type, 9, "IF"); + append_flags_type_flag (type, 10, "DF"); + append_flags_type_flag (type, 11, "OF"); + append_flags_type_flag (type, 14, "NT"); + append_flags_type_flag (type, 16, "RF"); + append_flags_type_flag (type, 17, "VM"); + append_flags_type_flag (type, 18, "AC"); + append_flags_type_flag (type, 19, "VIF"); + append_flags_type_flag (type, 20, "VIP"); + append_flags_type_flag (type, 21, "ID"); + i386_eflags_type = type; + + type = init_flags_type ("builtin_type_i386_mxcsr", 4); + append_flags_type_flag (type, 0, "IE"); + append_flags_type_flag (type, 1, "DE"); + append_flags_type_flag (type, 2, "ZE"); + append_flags_type_flag (type, 3, "OE"); + append_flags_type_flag (type, 4, "UE"); + append_flags_type_flag (type, 5, "PE"); + append_flags_type_flag (type, 6, "DAZ"); + append_flags_type_flag (type, 7, "IM"); + append_flags_type_flag (type, 8, "DM"); + append_flags_type_flag (type, 9, "ZM"); + append_flags_type_flag (type, 10, "OM"); + append_flags_type_flag (type, 11, "UM"); + append_flags_type_flag (type, 12, "PM"); + append_flags_type_flag (type, 15, "FZ"); + i386_mxcsr_type = type; +} + +/* Construct vector type for MMX registers. */ +struct type * +i386_mmx_type (struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (!tdep->i386_mmx_type) + { + /* The type we're building is this: */ +#if 0 + union __gdb_builtin_type_vec64i + { + int64_t uint64; + int32_t v2_int32[2]; + int16_t v4_int16[4]; + int8_t v8_int8[8]; + }; +#endif + + struct type *t; + + t = init_composite_type ("__gdb_builtin_type_vec64i", TYPE_CODE_UNION); + append_composite_type_field (t, "uint64", builtin_type_int64); + append_composite_type_field (t, "v2_int32", + init_vector_type (builtin_type_int32, 2)); + append_composite_type_field (t, "v4_int16", + init_vector_type (builtin_type_int16, 4)); + append_composite_type_field (t, "v8_int8", + init_vector_type (builtin_type_int8, 8)); + + TYPE_FLAGS (t) |= TYPE_FLAG_VECTOR; + TYPE_NAME (t) = "builtin_type_vec64i"; + tdep->i386_mmx_type = t; + } + + return tdep->i386_mmx_type; +} + +struct type * +i386_sse_type (struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (!tdep->i386_sse_type) + { + /* The type we're building is this: */ +#if 0 + union __gdb_builtin_type_vec128i + { + int128_t uint128; + int64_t v2_int64[2]; + int32_t v4_int32[4]; + int16_t v8_int16[8]; + int8_t v16_int8[16]; + double v2_double[2]; + float v4_float[4]; + }; +#endif + + struct type *t; + + t = init_composite_type ("__gdb_builtin_type_vec128i", TYPE_CODE_UNION); + append_composite_type_field (t, "v4_float", + init_vector_type (builtin_type_float, 4)); + append_composite_type_field (t, "v2_double", + init_vector_type (builtin_type_double, 2)); + append_composite_type_field (t, "v16_int8", + init_vector_type (builtin_type_int8, 16)); + append_composite_type_field (t, "v8_int16", + init_vector_type (builtin_type_int16, 8)); + append_composite_type_field (t, "v4_int32", + init_vector_type (builtin_type_int32, 4)); + append_composite_type_field (t, "v2_int64", + init_vector_type (builtin_type_int64, 2)); + append_composite_type_field (t, "uint128", builtin_type_int128); + + TYPE_FLAGS (t) |= TYPE_FLAG_VECTOR; + TYPE_NAME (t) = "builtin_type_vec128i"; + tdep->i386_sse_type = t; + } + + return tdep->i386_sse_type; +} + /* Return the GDB type object for the "standard" data type of data in register REGNUM. Perhaps %esi and %edi should go here, but potentially they could be used for things other than address. */ static struct type * -i386_register_virtual_type (int regnum) +i386_register_type (struct gdbarch *gdbarch, int regnum) { - if (regnum == PC_REGNUM || regnum == FP_REGNUM || regnum == SP_REGNUM) - return lookup_pointer_type (builtin_type_void); + if (regnum == I386_EIP_REGNUM) + return builtin_type_void_func_ptr; - if (IS_FP_REGNUM (regnum)) + if (regnum == I386_EFLAGS_REGNUM) + return i386_eflags_type; + + if (regnum == I386_EBP_REGNUM || regnum == I386_ESP_REGNUM) + return builtin_type_void_data_ptr; + + if (i386_fp_regnum_p (gdbarch, regnum)) return builtin_type_i387_ext; - if (IS_SSE_REGNUM (regnum)) - return builtin_type_vec128i; + if (i386_mmx_regnum_p (gdbarch, regnum)) + return i386_mmx_type (gdbarch); + + if (i386_sse_regnum_p (gdbarch, regnum)) + return i386_sse_type (gdbarch); + + if (regnum == I387_MXCSR_REGNUM (gdbarch_tdep (gdbarch))) + return i386_mxcsr_type; return builtin_type_int; } -/* Return true iff register REGNUM's virtual format is different from - its raw format. Note that this definition assumes that the host - supports IEEE 32-bit floats, since it doesn't say that SSE - registers need conversion. Even if we can't find a counterexample, - this is still sloppy. */ +/* Map a cooked register onto a raw register or memory. For the i386, + the MMX registers need to be mapped onto floating point registers. */ + +static int +i386_mmx_regnum_to_fp_regnum (struct regcache *regcache, int regnum) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (get_regcache_arch (regcache)); + int mmxreg, fpreg; + ULONGEST fstat; + int tos; + + mmxreg = regnum - tdep->mm0_regnum; + regcache_raw_read_unsigned (regcache, I387_FSTAT_REGNUM (tdep), &fstat); + tos = (fstat >> 11) & 0x7; + fpreg = (mmxreg + tos) % 8; + + return (I387_ST0_REGNUM (tdep) + fpreg); +} + +static void +i386_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache, + int regnum, gdb_byte *buf) +{ + if (i386_mmx_regnum_p (gdbarch, regnum)) + { + gdb_byte mmx_buf[MAX_REGISTER_SIZE]; + int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum); + + /* Extract (always little endian). */ + regcache_raw_read (regcache, fpnum, mmx_buf); + memcpy (buf, mmx_buf, register_size (gdbarch, regnum)); + } + else + regcache_raw_read (regcache, regnum, buf); +} + +static void +i386_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache, + int regnum, const gdb_byte *buf) +{ + if (i386_mmx_regnum_p (gdbarch, regnum)) + { + gdb_byte mmx_buf[MAX_REGISTER_SIZE]; + int fpnum = i386_mmx_regnum_to_fp_regnum (regcache, regnum); + + /* Read ... */ + regcache_raw_read (regcache, fpnum, mmx_buf); + /* ... Modify ... (always little endian). */ + memcpy (mmx_buf, buf, register_size (gdbarch, regnum)); + /* ... Write. */ + regcache_raw_write (regcache, fpnum, mmx_buf); + } + else + regcache_raw_write (regcache, regnum, buf); +} + + +/* Return the register number of the register allocated by GCC after + REGNUM, or -1 if there is no such register. */ + +static int +i386_next_regnum (int regnum) +{ + /* GCC allocates the registers in the order: + + %eax, %edx, %ecx, %ebx, %esi, %edi, %ebp, %esp, ... + + Since storing a variable in %esp doesn't make any sense we return + -1 for %ebp and for %esp itself. */ + static int next_regnum[] = + { + I386_EDX_REGNUM, /* Slot for %eax. */ + I386_EBX_REGNUM, /* Slot for %ecx. */ + I386_ECX_REGNUM, /* Slot for %edx. */ + I386_ESI_REGNUM, /* Slot for %ebx. */ + -1, -1, /* Slots for %esp and %ebp. */ + I386_EDI_REGNUM, /* Slot for %esi. */ + I386_EBP_REGNUM /* Slot for %edi. */ + }; + + if (regnum >= 0 && regnum < sizeof (next_regnum) / sizeof (next_regnum[0])) + return next_regnum[regnum]; + + return -1; +} + +/* Return nonzero if a value of type TYPE stored in register REGNUM + needs any special handling. */ static int -i386_register_convertible (int regnum) +i386_convert_register_p (struct gdbarch *gdbarch, int regnum, struct type *type) +{ + int len = TYPE_LENGTH (type); + + /* Values may be spread across multiple registers. Most debugging + formats aren't expressive enough to specify the locations, so + some heuristics is involved. Right now we only handle types that + have a length that is a multiple of the word size, since GCC + doesn't seem to put any other types into registers. */ + if (len > 4 && len % 4 == 0) + { + int last_regnum = regnum; + + while (len > 4) + { + last_regnum = i386_next_regnum (last_regnum); + len -= 4; + } + + if (last_regnum != -1) + return 1; + } + + return i387_convert_register_p (gdbarch, regnum, type); +} + +/* Read a value of type TYPE from register REGNUM in frame FRAME, and + return its contents in TO. */ + +static void +i386_register_to_value (struct frame_info *frame, int regnum, + struct type *type, gdb_byte *to) +{ + struct gdbarch *gdbarch = get_frame_arch (frame); + int len = TYPE_LENGTH (type); + + /* FIXME: kettenis/20030609: What should we do if REGNUM isn't + available in FRAME (i.e. if it wasn't saved)? */ + + if (i386_fp_regnum_p (gdbarch, regnum)) + { + i387_register_to_value (frame, regnum, type, to); + return; + } + + /* Read a value spread across multiple registers. */ + + gdb_assert (len > 4 && len % 4 == 0); + + while (len > 0) + { + gdb_assert (regnum != -1); + gdb_assert (register_size (gdbarch, regnum) == 4); + + get_frame_register (frame, regnum, to); + regnum = i386_next_regnum (regnum); + len -= 4; + to += 4; + } +} + +/* Write the contents FROM of a value of type TYPE into register + REGNUM in frame FRAME. */ + +static void +i386_value_to_register (struct frame_info *frame, int regnum, + struct type *type, const gdb_byte *from) +{ + int len = TYPE_LENGTH (type); + + if (i386_fp_regnum_p (get_frame_arch (frame), regnum)) + { + i387_value_to_register (frame, regnum, type, from); + return; + } + + /* Write a value spread across multiple registers. */ + + gdb_assert (len > 4 && len % 4 == 0); + + while (len > 0) + { + gdb_assert (regnum != -1); + gdb_assert (register_size (get_frame_arch (frame), regnum) == 4); + + put_frame_register (frame, regnum, from); + regnum = i386_next_regnum (regnum); + len -= 4; + from += 4; + } +} + +/* Supply register REGNUM from the buffer specified by GREGS and LEN + in the general-purpose register set REGSET to register cache + REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ + +void +i386_supply_gregset (const struct regset *regset, struct regcache *regcache, + int regnum, const void *gregs, size_t len) +{ + const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); + const gdb_byte *regs = gregs; + int i; + + gdb_assert (len == tdep->sizeof_gregset); + + for (i = 0; i < tdep->gregset_num_regs; i++) + { + if ((regnum == i || regnum == -1) + && tdep->gregset_reg_offset[i] != -1) + regcache_raw_supply (regcache, i, regs + tdep->gregset_reg_offset[i]); + } +} + +/* Collect register REGNUM from the register cache REGCACHE and store + it in the buffer specified by GREGS and LEN as described by the + general-purpose register set REGSET. If REGNUM is -1, do this for + all registers in REGSET. */ + +void +i386_collect_gregset (const struct regset *regset, + const struct regcache *regcache, + int regnum, void *gregs, size_t len) { - return IS_FP_REGNUM (regnum); + const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); + gdb_byte *regs = gregs; + int i; + + gdb_assert (len == tdep->sizeof_gregset); + + for (i = 0; i < tdep->gregset_num_regs; i++) + { + if ((regnum == i || regnum == -1) + && tdep->gregset_reg_offset[i] != -1) + regcache_raw_collect (regcache, i, regs + tdep->gregset_reg_offset[i]); + } } -/* Convert data from raw format for register REGNUM in buffer FROM to - virtual format with type TYPE in buffer TO. */ +/* Supply register REGNUM from the buffer specified by FPREGS and LEN + in the floating-point register set REGSET to register cache + REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ static void -i386_register_convert_to_virtual (int regnum, struct type *type, - char *from, char *to) +i386_supply_fpregset (const struct regset *regset, struct regcache *regcache, + int regnum, const void *fpregs, size_t len) { - gdb_assert (IS_FP_REGNUM (regnum)); + const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); - /* We only support floating-point values. */ - if (TYPE_CODE (type) != TYPE_CODE_FLT) + if (len == I387_SIZEOF_FXSAVE) { - warning ("Cannot convert floating-point register value " - "to non-floating-point type."); - memset (to, 0, TYPE_LENGTH (type)); + i387_supply_fxsave (regcache, regnum, fpregs); return; } - /* Convert to TYPE. This should be a no-op if TYPE is equivalent to - the extended floating-point format used by the FPU. */ - convert_typed_floating (from, builtin_type_i387_ext, to, type); + gdb_assert (len == tdep->sizeof_fpregset); + i387_supply_fsave (regcache, regnum, fpregs); } -/* Convert data from virtual format with type TYPE in buffer FROM to - raw format for register REGNUM in buffer TO. */ +/* Collect register REGNUM from the register cache REGCACHE and store + it in the buffer specified by FPREGS and LEN as described by the + floating-point register set REGSET. If REGNUM is -1, do this for + all registers in REGSET. */ static void -i386_register_convert_to_raw (struct type *type, int regnum, - char *from, char *to) +i386_collect_fpregset (const struct regset *regset, + const struct regcache *regcache, + int regnum, void *fpregs, size_t len) { - gdb_assert (IS_FP_REGNUM (regnum)); + const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); - /* We only support floating-point values. */ - if (TYPE_CODE (type) != TYPE_CODE_FLT) + if (len == I387_SIZEOF_FXSAVE) { - warning ("Cannot convert non-floating-point type " - "to floating-point register value."); - memset (to, 0, TYPE_LENGTH (type)); + i387_collect_fxsave (regcache, regnum, fpregs); return; } - /* Convert from TYPE. This should be a no-op if TYPE is equivalent - to the extended floating-point format used by the FPU. */ - convert_typed_floating (from, type, to, builtin_type_i387_ext); + gdb_assert (len == tdep->sizeof_fpregset); + i387_collect_fsave (regcache, regnum, fpregs); } - -#ifdef STATIC_TRANSFORM_NAME -/* SunPRO encodes the static variables. This is not related to C++ - mangling, it is done for C too. */ +/* Return the appropriate register set for the core section identified + by SECT_NAME and SECT_SIZE. */ -char * -sunpro_static_transform_name (char *name) +const struct regset * +i386_regset_from_core_section (struct gdbarch *gdbarch, + const char *sect_name, size_t sect_size) { - char *p; - if (IS_STATIC_TRANSFORM_NAME (name)) + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + if (strcmp (sect_name, ".reg") == 0 && sect_size == tdep->sizeof_gregset) { - /* 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; + if (tdep->gregset == NULL) + tdep->gregset = regset_alloc (gdbarch, i386_supply_gregset, + i386_collect_gregset); + return tdep->gregset; } - return name; + + if ((strcmp (sect_name, ".reg2") == 0 && sect_size == tdep->sizeof_fpregset) + || (strcmp (sect_name, ".reg-xfp") == 0 + && sect_size == I387_SIZEOF_FXSAVE)) + { + if (tdep->fpregset == NULL) + tdep->fpregset = regset_alloc (gdbarch, i386_supply_fpregset, + i386_collect_fpregset); + return tdep->fpregset; + } + + return NULL; } -#endif /* STATIC_TRANSFORM_NAME */ /* Stuff for WIN32 PE style DLL's but is pretty generic really. */ CORE_ADDR -skip_trampoline_code (CORE_ADDR pc, char *name) +i386_pe_skip_trampoline_code (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; + char *symname = indsym ? SYMBOL_LINKAGE_NAME (indsym) : 0; if (symname) { @@ -1228,12 +2273,16 @@ skip_trampoline_code (CORE_ADDR pc, char *name) } -/* Return non-zero if PC and NAME show that we are in a signal - trampoline. */ +/* Return whether the THIS_FRAME corresponds to a sigtramp + routine. */ static int -i386_pc_in_sigtramp (CORE_ADDR pc, char *name) +i386_sigtramp_p (struct frame_info *this_frame) { + CORE_ADDR pc = get_frame_pc (this_frame); + char *name; + + find_pc_partial_function (pc, &name, NULL, NULL); return (name && strcmp ("_sigtramp", name) == 0); } @@ -1242,15 +2291,16 @@ i386_pc_in_sigtramp (CORE_ADDR pc, char *name) deals with switching between those. */ static int -gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info) +i386_print_insn (bfd_vma pc, struct disassemble_info *info) { - if (disassembly_flavor == att_flavor) - return print_insn_i386_att (memaddr, info); - else if (disassembly_flavor == intel_flavor) - return print_insn_i386_intel (memaddr, info); - /* Never reached -- disassembly_flavour is always either att_flavor - or intel_flavor. */ - internal_error (__FILE__, __LINE__, "failed internal consistency check"); + gdb_assert (disassembly_flavor == att_flavor + || disassembly_flavor == intel_flavor); + + /* FIXME: kettenis/20020915: Until disassembler_options is properly + constified, cast to prevent a compiler warning. */ + info->disassembler_options = (char *) disassembly_flavor; + + return print_insn_i386 (pc, info); } @@ -1261,49 +2311,36 @@ gdb_print_insn_i386 (bfd_vma memaddr, disassemble_info *info) /* System V Release 4 (SVR4). */ +/* Return whether THIS_FRAME corresponds to a SVR4 sigtramp + routine. */ + static int -i386_svr4_pc_in_sigtramp (CORE_ADDR pc, char *name) +i386_svr4_sigtramp_p (struct frame_info *this_frame) { + CORE_ADDR pc = get_frame_pc (this_frame); + char *name; + + /* UnixWare uses _sigacthandler. The origin of the other symbols is + currently unknown. */ + find_pc_partial_function (pc, &name, NULL, NULL); return (name && (strcmp ("_sigreturn", name) == 0 || strcmp ("_sigacthandler", name) == 0 || strcmp ("sigvechandler", name) == 0)); } -/* Get address of the pushed ucontext (sigcontext) on the stack for - all three variants of SVR4 sigtramps. */ +/* Assuming THIS_FRAME is for a SVR4 sigtramp routine, return the + address of the associated sigcontext (ucontext) structure. */ static CORE_ADDR -i386_svr4_sigcontext_addr (struct frame_info *frame) +i386_svr4_sigcontext_addr (struct frame_info *this_frame) { - int sigcontext_offset = -1; - char *name = NULL; - - find_pc_partial_function (frame->pc, &name, NULL, NULL); - if (name) - { - if (strcmp (name, "_sigreturn") == 0) - sigcontext_offset = 132; - else if (strcmp (name, "_sigacthandler") == 0) - sigcontext_offset = 80; - else if (strcmp (name, "sigvechandler") == 0) - sigcontext_offset = 120; - } - - gdb_assert (sigcontext_offset != -1); - - if (frame->next) - return frame->next->frame + sigcontext_offset; - return read_register (SP_REGNUM) + sigcontext_offset; -} - + gdb_byte buf[4]; + CORE_ADDR sp; -/* DJGPP. */ + get_frame_register (this_frame, I386_ESP_REGNUM, buf); + sp = extract_unsigned_integer (buf, 4); -static int -i386_go32_pc_in_sigtramp (CORE_ADDR pc, char *name) -{ - /* DJGPP doesn't have any special frames for signal handlers. */ - return 0; + return read_memory_unsigned_integer (sp + 8, 4); } @@ -1312,8 +2349,8 @@ i386_go32_pc_in_sigtramp (CORE_ADDR pc, char *name) void i386_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { - /* We typically use stabs-in-ELF with the DWARF register numbering. */ - set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); + /* We typically use stabs-in-ELF with the SVR4 register numbering. */ + set_gdbarch_stab_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum); } /* System V Release 4 (SVR4). */ @@ -1326,13 +2363,13 @@ i386_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* System V Release 4 uses ELF. */ i386_elf_init_abi (info, gdbarch); - /* FIXME: kettenis/20020511: Why do we override this function here? */ - set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid); + /* System V Release 4 has shared libraries. */ + set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); - set_gdbarch_pc_in_sigtramp (gdbarch, i386_svr4_pc_in_sigtramp); + tdep->sigtramp_p = i386_svr4_sigtramp_p; tdep->sigcontext_addr = i386_svr4_sigcontext_addr; - tdep->sc_pc_offset = 14 * 4; - tdep->sc_sp_offset = 7 * 4; + tdep->sc_pc_offset = 36 + 14 * 4; + tdep->sc_sp_offset = 36 + 17 * 4; tdep->jb_pc_offset = 20; } @@ -1344,63 +2381,132 @@ i386_go32_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); - set_gdbarch_pc_in_sigtramp (gdbarch, i386_go32_pc_in_sigtramp); + /* DJGPP doesn't have any special frames for signal handlers. */ + tdep->sigtramp_p = NULL; tdep->jb_pc_offset = 36; } + + +/* i386 register groups. In addition to the normal groups, add "mmx" + and "sse". */ -/* NetWare. */ +static struct reggroup *i386_sse_reggroup; +static struct reggroup *i386_mmx_reggroup; static void -i386_nw_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +i386_init_reggroups (void) { - struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + i386_sse_reggroup = reggroup_new ("sse", USER_REGGROUP); + i386_mmx_reggroup = reggroup_new ("mmx", USER_REGGROUP); +} - /* FIXME: kettenis/20020511: Why do we override this function here? */ - set_gdbarch_frame_chain_valid (gdbarch, func_frame_chain_valid); +static void +i386_add_reggroups (struct gdbarch *gdbarch) +{ + reggroup_add (gdbarch, i386_sse_reggroup); + reggroup_add (gdbarch, i386_mmx_reggroup); + reggroup_add (gdbarch, general_reggroup); + reggroup_add (gdbarch, float_reggroup); + reggroup_add (gdbarch, all_reggroup); + reggroup_add (gdbarch, save_reggroup); + reggroup_add (gdbarch, restore_reggroup); + reggroup_add (gdbarch, vector_reggroup); + reggroup_add (gdbarch, system_reggroup); +} - tdep->jb_pc_offset = 24; +int +i386_register_reggroup_p (struct gdbarch *gdbarch, int regnum, + struct reggroup *group) +{ + int sse_regnum_p = (i386_sse_regnum_p (gdbarch, regnum) + || i386_mxcsr_regnum_p (gdbarch, regnum)); + int fp_regnum_p = (i386_fp_regnum_p (gdbarch, regnum) + || i386_fpc_regnum_p (gdbarch, regnum)); + int mmx_regnum_p = (i386_mmx_regnum_p (gdbarch, regnum)); + + if (group == i386_mmx_reggroup) + return mmx_regnum_p; + if (group == i386_sse_reggroup) + return sse_regnum_p; + if (group == vector_reggroup) + return (mmx_regnum_p || sse_regnum_p); + if (group == float_reggroup) + return fp_regnum_p; + if (group == general_reggroup) + return (!fp_regnum_p && !mmx_regnum_p && !sse_regnum_p); + + return default_register_reggroup_p (gdbarch, regnum, group); } +/* Get the ARGIth function argument for the current function. */ + +static CORE_ADDR +i386_fetch_pointer_argument (struct frame_info *frame, int argi, + struct type *type) +{ + CORE_ADDR sp = get_frame_register_unsigned (frame, I386_ESP_REGNUM); + return read_memory_unsigned_integer (sp + (4 * (argi + 1)), 4); +} + + static struct gdbarch * i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) { struct gdbarch_tdep *tdep; struct gdbarch *gdbarch; - enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; - - /* Try to determine the OS ABI of the object we're loading. */ - if (info.abfd != NULL) - osabi = gdbarch_lookup_osabi (info.abfd); - /* Find a candidate among extant architectures. */ - for (arches = gdbarch_list_lookup_by_info (arches, &info); - arches != NULL; - arches = gdbarch_list_lookup_by_info (arches->next, &info)) - { - /* Make sure the OS ABI selection matches. */ - tdep = gdbarch_tdep (arches->gdbarch); - if (tdep && tdep->osabi == osabi) - return arches->gdbarch; - } + /* If there is already a candidate, use it. */ + arches = gdbarch_list_lookup_by_info (arches, &info); + if (arches != NULL) + return arches->gdbarch; /* Allocate space for the new architecture. */ - tdep = XMALLOC (struct gdbarch_tdep); + tdep = XCALLOC (1, struct gdbarch_tdep); gdbarch = gdbarch_alloc (&info, tdep); - tdep->osabi = osabi; + /* General-purpose registers. */ + tdep->gregset = NULL; + tdep->gregset_reg_offset = NULL; + tdep->gregset_num_regs = I386_NUM_GREGS; + tdep->sizeof_gregset = 0; - /* The i386 default settings don't include the SSE registers. - FIXME: kettenis/20020614: They do include the FPU registers for - now, which probably is not quite right. */ - tdep->num_xmm_regs = 0; + /* Floating-point registers. */ + tdep->fpregset = NULL; + tdep->sizeof_fpregset = I387_SIZEOF_FSAVE; + + /* The default settings include the FPU registers, the MMX registers + and the SSE registers. This can be overridden for a specific ABI + by adjusting the members `st0_regnum', `mm0_regnum' and + `num_xmm_regs' of `struct gdbarch_tdep', otherwise the registers + will show up in the output of "info all-registers". Ideally we + should try to autodetect whether they are available, such that we + can prevent "info all-registers" from displaying registers that + aren't available. + + NOTE: kevinb/2003-07-13: ... if it's a choice between printing + [the SSE registers] always (even when they don't exist) or never + showing them to the user (even when they do exist), I prefer the + former over the latter. */ + + tdep->st0_regnum = I386_ST0_REGNUM; + + /* The MMX registers are implemented as pseudo-registers. Put off + calculating the register number for %mm0 until we know the number + of raw registers. */ + tdep->mm0_regnum = 0; + + /* I386_NUM_XREGS includes %mxcsr, so substract one. */ + tdep->num_xmm_regs = I386_NUM_XREGS - 1; tdep->jb_pc_offset = -1; tdep->struct_return = pcc_struct_return; tdep->sigtramp_start = 0; tdep->sigtramp_end = 0; + tdep->sigtramp_p = i386_sigtramp_p; tdep->sigcontext_addr = NULL; + tdep->sc_reg_offset = NULL; tdep->sc_pc_offset = -1; tdep->sc_sp_offset = -1; @@ -1408,87 +2514,79 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) the i387 extended floating-point format. In fact, of all targets in the GCC 2.95 tree, only OSF/1 does it different, and insists on having a `long double' that's not `long' at all. */ - set_gdbarch_long_double_format (gdbarch, &floatformat_i387_ext); + set_gdbarch_long_double_format (gdbarch, floatformats_i387_ext); - /* Although the i386 extended floating-point has only 80 significant + /* Although the i387 extended floating-point has only 80 significant bits, a `long double' actually takes up 96, probably to enforce alignment. */ set_gdbarch_long_double_bit (gdbarch, 96); - /* NOTE: tm-i386aix.h, tm-i386bsd.h, tm-i386os9k.h, tm-ptx.h, - tm-symmetry.h currently override this. Sigh. */ - set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS); - - set_gdbarch_sp_regnum (gdbarch, 4); - set_gdbarch_fp_regnum (gdbarch, 5); - set_gdbarch_pc_regnum (gdbarch, 8); - set_gdbarch_ps_regnum (gdbarch, 9); - set_gdbarch_fp0_regnum (gdbarch, 16); - - /* Use the "default" register numbering scheme for stabs and COFF. */ - set_gdbarch_stab_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum); - set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_stab_reg_to_regnum); - - /* Use the DWARF register numbering scheme for DWARF and DWARF 2. */ - set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); - set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_dwarf_reg_to_regnum); - - /* We don't define ECOFF_REG_TO_REGNUM, since ECOFF doesn't seem to + /* The default ABI includes general-purpose registers, + floating-point registers, and the SSE registers. */ + set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS); + set_gdbarch_register_name (gdbarch, i386_register_name); + set_gdbarch_register_type (gdbarch, i386_register_type); + + /* Register numbers of various important registers. */ + set_gdbarch_sp_regnum (gdbarch, I386_ESP_REGNUM); /* %esp */ + set_gdbarch_pc_regnum (gdbarch, I386_EIP_REGNUM); /* %eip */ + set_gdbarch_ps_regnum (gdbarch, I386_EFLAGS_REGNUM); /* %eflags */ + set_gdbarch_fp0_regnum (gdbarch, I386_ST0_REGNUM); /* %st(0) */ + + /* NOTE: kettenis/20040418: GCC does have two possible register + numbering schemes on the i386: dbx and SVR4. These schemes + differ in how they number %ebp, %esp, %eflags, and the + floating-point registers, and are implemented by the arrays + dbx_register_map[] and svr4_dbx_register_map in + gcc/config/i386.c. GCC also defines a third numbering scheme in + gcc/config/i386.c, which it designates as the "default" register + map used in 64bit mode. This last register numbering scheme is + implemented in dbx64_register_map, and is used for AMD64; see + amd64-tdep.c. + + Currently, each GCC i386 target always uses the same register + numbering scheme across all its supported debugging formats + i.e. SDB (COFF), stabs and DWARF 2. This is because + gcc/sdbout.c, gcc/dbxout.c and gcc/dwarf2out.c all use the + DBX_REGISTER_NUMBER macro which is defined by each target's + respective config header in a manner independent of the requested + output debugging format. + + This does not match the arrangement below, which presumes that + the SDB and stabs numbering schemes differ from the DWARF and + DWARF 2 ones. The reason for this arrangement is that it is + likely to get the numbering scheme for the target's + default/native debug format right. For targets where GCC is the + native compiler (FreeBSD, NetBSD, OpenBSD, GNU/Linux) or for + targets where the native toolchain uses a different numbering + scheme for a particular debug format (stabs-in-ELF on Solaris) + the defaults below will have to be overridden, like + i386_elf_init_abi() does. */ + + /* Use the dbx register numbering scheme for stabs and COFF. */ + set_gdbarch_stab_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum); + set_gdbarch_sdb_reg_to_regnum (gdbarch, i386_dbx_reg_to_regnum); + + /* Use the SVR4 register numbering scheme for DWARF and DWARF 2. */ + set_gdbarch_dwarf_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum); + set_gdbarch_dwarf2_reg_to_regnum (gdbarch, i386_svr4_reg_to_regnum); + + /* We don't set gdbarch_stab_reg_to_regnum, since ECOFF doesn't seem to be in use on any of the supported i386 targets. */ - set_gdbarch_register_name (gdbarch, i386_register_name); - set_gdbarch_register_size (gdbarch, 4); - set_gdbarch_register_bytes (gdbarch, I386_SIZEOF_GREGS + I386_SIZEOF_FREGS); - set_gdbarch_register_byte (gdbarch, i386_register_byte); - set_gdbarch_register_raw_size (gdbarch, i386_register_raw_size); - set_gdbarch_max_register_raw_size (gdbarch, I386_MAX_REGISTER_SIZE); - set_gdbarch_max_register_virtual_size (gdbarch, I386_MAX_REGISTER_SIZE); - set_gdbarch_register_virtual_type (gdbarch, i386_register_virtual_type); + set_gdbarch_print_float_info (gdbarch, i387_print_float_info); set_gdbarch_get_longjmp_target (gdbarch, i386_get_longjmp_target); - set_gdbarch_use_generic_dummy_frames (gdbarch, 1); - /* Call dummy code. */ - set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT); - set_gdbarch_call_dummy_address (gdbarch, entry_point_address); - set_gdbarch_call_dummy_start_offset (gdbarch, 0); - set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0); - set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1); - set_gdbarch_call_dummy_length (gdbarch, 0); - set_gdbarch_call_dummy_p (gdbarch, 1); - set_gdbarch_call_dummy_words (gdbarch, NULL); - set_gdbarch_sizeof_call_dummy_words (gdbarch, 0); - set_gdbarch_call_dummy_stack_adjust_p (gdbarch, 0); - set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy); - - set_gdbarch_register_convertible (gdbarch, i386_register_convertible); - set_gdbarch_register_convert_to_virtual (gdbarch, - i386_register_convert_to_virtual); - set_gdbarch_register_convert_to_raw (gdbarch, i386_register_convert_to_raw); - - set_gdbarch_get_saved_register (gdbarch, generic_get_saved_register); - set_gdbarch_push_arguments (gdbarch, i386_push_arguments); - - set_gdbarch_pc_in_call_dummy (gdbarch, pc_in_call_dummy_at_entry_point); - - /* "An argument's size is increased, if necessary, to make it a - multiple of [32-bit] words. This may require tail padding, - depending on the size of the argument" -- from the x86 ABI. */ - set_gdbarch_parm_boundary (gdbarch, 32); - - set_gdbarch_extract_return_value (gdbarch, i386_extract_return_value); - set_gdbarch_push_arguments (gdbarch, i386_push_arguments); - set_gdbarch_push_dummy_frame (gdbarch, generic_push_dummy_frame); - set_gdbarch_push_return_address (gdbarch, i386_push_return_address); - set_gdbarch_pop_frame (gdbarch, i386_pop_frame); - set_gdbarch_store_struct_return (gdbarch, i386_store_struct_return); - set_gdbarch_store_return_value (gdbarch, i386_store_return_value); - set_gdbarch_extract_struct_value_address (gdbarch, - i386_extract_struct_value_address); - set_gdbarch_use_struct_convention (gdbarch, i386_use_struct_convention); - - set_gdbarch_frame_init_saved_regs (gdbarch, i386_frame_init_saved_regs); + set_gdbarch_push_dummy_call (gdbarch, i386_push_dummy_call); + + set_gdbarch_convert_register_p (gdbarch, i386_convert_register_p); + set_gdbarch_register_to_value (gdbarch, i386_register_to_value); + set_gdbarch_value_to_register (gdbarch, i386_value_to_register); + + set_gdbarch_return_value (gdbarch, i386_return_value); + set_gdbarch_skip_prologue (gdbarch, i386_skip_prologue); /* Stack grows downward. */ @@ -1496,27 +2594,50 @@ i386_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) set_gdbarch_breakpoint_from_pc (gdbarch, i386_breakpoint_from_pc); set_gdbarch_decr_pc_after_break (gdbarch, 1); - set_gdbarch_function_start_offset (gdbarch, 0); - - /* The following redefines make backtracing through sigtramp work. - They manufacture a fake sigtramp frame and obtain the saved pc in - sigtramp from the sigcontext structure which is pushed by the - kernel on the user stack, along with a pointer to it. */ + set_gdbarch_max_insn_length (gdbarch, I386_MAX_INSN_LEN); set_gdbarch_frame_args_skip (gdbarch, 8); - set_gdbarch_frameless_function_invocation (gdbarch, - i386_frameless_function_invocation); - set_gdbarch_frame_chain (gdbarch, i386_frame_chain); - set_gdbarch_frame_chain_valid (gdbarch, generic_file_frame_chain_valid); - set_gdbarch_frame_saved_pc (gdbarch, i386_frame_saved_pc); - set_gdbarch_frame_args_address (gdbarch, default_frame_address); - set_gdbarch_frame_locals_address (gdbarch, default_frame_address); - set_gdbarch_saved_pc_after_call (gdbarch, i386_saved_pc_after_call); - set_gdbarch_frame_num_args (gdbarch, i386_frame_num_args); - set_gdbarch_pc_in_sigtramp (gdbarch, i386_pc_in_sigtramp); + + /* Wire in the MMX registers. */ + set_gdbarch_num_pseudo_regs (gdbarch, i386_num_mmx_regs); + set_gdbarch_pseudo_register_read (gdbarch, i386_pseudo_register_read); + set_gdbarch_pseudo_register_write (gdbarch, i386_pseudo_register_write); + + set_gdbarch_print_insn (gdbarch, i386_print_insn); + + set_gdbarch_dummy_id (gdbarch, i386_dummy_id); + + set_gdbarch_unwind_pc (gdbarch, i386_unwind_pc); + + /* Add the i386 register groups. */ + i386_add_reggroups (gdbarch); + set_gdbarch_register_reggroup_p (gdbarch, i386_register_reggroup_p); + + /* Helper for function argument information. */ + set_gdbarch_fetch_pointer_argument (gdbarch, i386_fetch_pointer_argument); + + /* Hook in the DWARF CFI frame unwinder. */ + dwarf2_append_unwinders (gdbarch); + + frame_base_set_default (gdbarch, &i386_frame_base); /* Hook in ABI-specific overrides, if they have been registered. */ - gdbarch_init_osabi (info, gdbarch, osabi); + gdbarch_init_osabi (info, gdbarch); + + frame_unwind_append_unwinder (gdbarch, &i386_sigtramp_frame_unwind); + frame_unwind_append_unwinder (gdbarch, &i386_frame_unwind); + + /* If we have a register mapping, enable the generic core file + support, unless it has already been enabled. */ + if (tdep->gregset_reg_offset + && !gdbarch_regset_from_core_section_p (gdbarch)) + set_gdbarch_regset_from_core_section (gdbarch, + i386_regset_from_core_section); + + /* Unless support for MMX has been disabled, make %mm0 the first + pseudo-register. */ + if (tdep->mm0_regnum == 0) + tdep->mm0_regnum = gdbarch_num_regs (gdbarch); return gdbarch; } @@ -1530,12 +2651,6 @@ i386_coff_osabi_sniffer (bfd *abfd) return GDB_OSABI_UNKNOWN; } - -static enum gdb_osabi -i386_nlm_osabi_sniffer (bfd *abfd) -{ - return GDB_OSABI_NETWARE; -} /* Provide a prototype to silence -Wmissing-prototypes. */ @@ -1546,59 +2661,37 @@ _initialize_i386_tdep (void) { register_gdbarch_init (bfd_arch_i386, i386_gdbarch_init); - /* Initialize the table saying where each register starts in the - register file. */ - { - int i, offset; - - offset = 0; - for (i = 0; i < I386_SSE_NUM_REGS; i++) - { - i386_register_offset[i] = offset; - offset += i386_register_size[i]; - } - } - - 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. */ - { - struct cmd_list_element *new_cmd; - - new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class, - valid_flavors, - &disassembly_flavor, - "\ -Set the disassembly flavor, the valid values are \"att\" and \"intel\", \ -and the default value is \"att\".", - &setlist); - add_show_from_set (new_cmd, &showlist); - } + add_setshow_enum_cmd ("disassembly-flavor", no_class, valid_flavors, + &disassembly_flavor, _("\ +Set the disassembly flavor."), _("\ +Show the disassembly flavor."), _("\ +The valid values are \"att\" and \"intel\", and the default value is \"att\"."), + NULL, + NULL, /* FIXME: i18n: */ + &setlist, &showlist); /* Add the variable that controls the convention for returning structs. */ - { - struct cmd_list_element *new_cmd; - - new_cmd = add_set_enum_cmd ("struct-convention", no_class, - valid_conventions, - &struct_convention, "\ -Set the convention for returning small structs, valid values \ -are \"default\", \"pcc\" and \"reg\", and the default value is \"default\".", - &setlist); - add_show_from_set (new_cmd, &showlist); - } + add_setshow_enum_cmd ("struct-convention", no_class, valid_conventions, + &struct_convention, _("\ +Set the convention for returning small structs."), _("\ +Show the convention for returning small structs."), _("\ +Valid values are \"default\", \"pcc\" and \"reg\", and the default value\n\ +is \"default\"."), + NULL, + NULL, /* FIXME: i18n: */ + &setlist, &showlist); gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_coff_flavour, i386_coff_osabi_sniffer); - gdbarch_register_osabi_sniffer (bfd_arch_i386, bfd_target_nlm_flavour, - i386_nlm_osabi_sniffer); - gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_SVR4, + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_SVR4, i386_svr4_init_abi); - gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_GO32, + gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_GO32, i386_go32_init_abi); - gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETWARE, - i386_nw_init_abi); + + /* Initialize the i386-specific register groups & types. */ + i386_init_reggroups (); + i386_init_types(); }