diff options
| -rw-r--r-- | gdb/ChangeLog | 12 | ||||
| -rw-r--r-- | gdb/mips-tdep.c | 120 |
2 files changed, 98 insertions, 34 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 984c6f6..6b733ad 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,15 @@ +Fri Nov 12 09:53:26 1993 Jim Kingdon (kingdon@lioth.cygnus.com) + + * mips-tdep.c (init_extra_frame_info): Check to see whether the + registers mentioned in the proc_desc have been saved. This + generalizes mips_in_lenient_prologue in the sense that we keep + searching until we've found saves for all the registers, not just + look for a "lenient prologue" pattern. + * mips-tdep.c: #if 0 lenient prologue code. + + * mips-tdep.c (heuristic_proc_desc): Don't assume a host short + is 16 bits. + Thu Nov 11 19:58:05 1993 Jim Kingdon (kingdon@lioth.cygnus.com) * config/i386/i386sol2.mh: Comment out corelow.o. diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c index f7b4f28..c5f870f 100644 --- a/gdb/mips-tdep.c +++ b/gdb/mips-tdep.c @@ -34,7 +34,9 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define VM_MIN_ADDRESS (unsigned)0x400000 +#if 0 static int mips_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR)); +#endif /* Some MIPS boards don't support floating point, so we permit the user to turn it off. */ @@ -210,16 +212,16 @@ heuristic_proc_desc(start_pc, limit_pc, next_frame) else if ((word & 0xFFE00000) == 0xafa00000) { /* sw reg,offset($sp) */ int reg = (word & 0x001F0000) >> 16; reg_mask |= 1 << reg; - temp_saved_regs.regs[reg] = sp + (short)word; + temp_saved_regs.regs[reg] = sp + (word & 0xffff); } else if ((word & 0xFFFF0000) == 0x27be0000) { /* addiu $30,$sp,size */ - if ((unsigned short)word != frame_size) - reg30 = sp + (unsigned short)word; + if ((word & 0xffff) != frame_size) + reg30 = sp + (word & 0xffff); else if (!has_frame_reg) { int alloca_adjust; has_frame_reg = 1; reg30 = read_next_frame_reg(next_frame, 30); - alloca_adjust = reg30 - (sp + (unsigned short)word); + alloca_adjust = reg30 - (sp + (word & 0xffff)); if (alloca_adjust > 0) { /* FP > SP + frame_size. This may be because /* of an alloca or somethings similar. @@ -233,7 +235,7 @@ heuristic_proc_desc(start_pc, limit_pc, next_frame) else if ((word & 0xFFE00000) == 0xafc00000) { /* sw reg,offset($30) */ int reg = (word & 0x001F0000) >> 16; reg_mask |= 1 << reg; - temp_saved_regs.regs[reg] = reg30 + (short)word; + temp_saved_regs.regs[reg] = reg30 + (word & 0xffff); } } if (has_frame_reg) { @@ -386,38 +388,26 @@ init_extra_frame_info(fci) fci->frame = READ_FRAME_REG(fci, PROC_FRAME_REG(proc_desc)) + PROC_FRAME_OFFSET(proc_desc); - /* If this is the innermost frame, and we are still in the - prologue (loosely defined), then the registers may not have - been saved yet. */ - if (fci->next == NULL - && !PROC_DESC_IS_DUMMY(proc_desc) - && mips_in_lenient_prologue (PROC_LOW_ADDR (proc_desc), fci->pc)) - { - /* Can't just say that the registers are not saved, because they - might get clobbered halfway through the prologue. - heuristic_proc_desc already has the right code to figure out - exactly what has been saved, so use it. As far as I know we - could be doing this (as we do on the 68k, for example) - regardless of whether we are in the prologue; I'm leaving in - the check for being in the prologue only out of conservatism - (I'm not sure whether heuristic_proc_desc handles all cases, - for example). - - This stuff is ugly (and getting uglier by the minute). Probably - the best way to clean it up is to ignore the proc_desc's from - the symbols altogher, and get all the information we need by - examining the prologue (provided we can make the prologue - examining code good enough to get all the cases...). */ - proc_desc = - heuristic_proc_desc (PROC_LOW_ADDR (proc_desc), - fci->pc, - fci->next); - } - if (proc_desc == &temp_proc_desc) *fci->saved_regs = temp_saved_regs; - else + else if (/* In any frame other than the innermost, we assume that all + registers have been saved. This assumes that all register + saves in a function happen before the first function + call. */ + fci->next != NULL + + /* In a dummy frame we know exactly where things are saved. */ + || PROC_DESC_IS_DUMMY (proc_desc) + + /* Not sure exactly what kernel_trap means, but if it means + the kernel saves the registers without a prologue doing it, + we better not examine the prologue to see whether registers + have been saved yet. */ + || kernel_trap) { + /* All the registers which will be saved have been saved, so we + can believe the proc_desc. */ + /* find which general-purpose registers were saved */ reg_position = fci->frame + PROC_REG_OFFSET(proc_desc); mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK(proc_desc); @@ -441,6 +431,58 @@ init_extra_frame_info(fci) reg_position -= 4; } } + else + { + /* We need to figure out whether the registers that the proc_desc + claims are saved have been saved yet. */ + + CORE_ADDR addr; + int status; + char buf[4]; + unsigned long inst; + /* Bitmasks; set if the proc_desc claims the register is saved and we + haven't found a save instruction for it yet. */ + unsigned long gen_mask, float_mask; + + gen_mask = PROC_REG_MASK (proc_desc); + float_mask = PROC_FREG_MASK (proc_desc); + + for (addr = PROC_LOW_ADDR (proc_desc); + addr < fci->pc && (gen_mask | float_mask); + addr += 4) + { + status = read_memory_nobpt (addr, buf, 4); + if (status) + memory_error (status, addr); + inst = extract_unsigned_integer (buf, 4); + if (/* sw reg,n($sp) */ + (inst & 0xffe00000) == 0xafa00000 + + /* sw reg,n($r30) */ + || (inst & 0xffe00000) == 0xafc00000) + { + /* We assume that all saves are relative to the + PROC_FRAME_REG, which is what we used to set up + ->frame. */ + int reg = (inst & 0x001f0000) >> 16; + if (gen_mask & (1 << reg)) + fci->saved_regs.regs[reg] = fci->frame + (inst & 0xffff); + gen_mask &= ~(1 << reg); + } + else if (/* swc1 freg,n($sp) */ + (inst & 0xffe00000) == 0xe7a00000 + + /* swc1 freg,n($r30) */ + (inst & 0xffe00000) == 0xe7c00000) + { + int reg = ((inst & 0x001f0000) >> 16); + if (float_mask & (1 << reg)) + fci->saved_regs.regs[FP0_REGNUM + reg] + = fci->frame + (inst & 0xffff); + float_mask &= ~(1 << reg); + } + } + } /* hack: if argument regs are saved, guess these contain args */ if ((PROC_REG_MASK(proc_desc) & 0xF0) == 0) fci->num_args = -1; @@ -773,6 +815,7 @@ mips_frame_num_args(fip) return -1; } +#if 0 /* Is this a branch with a delay slot? */ static int is_delayed (insn) @@ -788,6 +831,7 @@ is_delayed (insn) | INSN_COND_BRANCH_DELAY | INSN_COND_BRANCH_LIKELY))); } +#endif /* To skip prologues, I use this predicate. Returns either PC itself if the code at PC does not look like a function prologue; otherwise @@ -822,8 +866,10 @@ mips_skip_prologue (pc, lenient) memory_error (status, pc + offset); inst = extract_unsigned_integer (buf, 4); +#if 0 if (lenient && is_delayed (inst)) continue; +#endif if ((inst & 0xffff0000) == 0x27bd0000) /* addiu $sp,$sp,offset */ seen_sp_adjust = 1; @@ -874,6 +920,11 @@ mips_skip_prologue (pc, lenient) #endif } +#if 0 +/* The lenient prologue stuff should be superceded by the code in + init_extra_frame_info which looks to see whether the stores mentioned + in the proc_desc have actually taken place. */ + /* Is address PC in the prologue (loosely defined) for function at STARTADDR? */ @@ -885,6 +936,7 @@ mips_in_lenient_prologue (startaddr, pc) CORE_ADDR end_prologue = mips_skip_prologue (startaddr, 1); return pc >= startaddr && pc < end_prologue; } +#endif /* Given a return value in `regbuf' with a type `valtype', extract and copy its value into `valbuf'. */ |