diff options
Diffstat (limited to 'gdb/m32r-tdep.c')
| -rw-r--r-- | gdb/m32r-tdep.c | 68 |
1 files changed, 51 insertions, 17 deletions
diff --git a/gdb/m32r-tdep.c b/gdb/m32r-tdep.c index a449223..98fca39 100644 --- a/gdb/m32r-tdep.c +++ b/gdb/m32r-tdep.c @@ -93,17 +93,24 @@ m32r_scan_prologue (fi, fsr) /* this code essentially duplicates skip_prologue, but we need the start address below. */ + if (fsr) + memset (fsr->regs, '\000', sizeof fsr->regs); + if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end)) { sal = find_pc_line (prologue_start, 0); if (sal.line == 0) /* no line info, use current PC */ - prologue_end = fi->pc; + if (prologue_start != entry_point_address ()) + prologue_end = fi->pc; + else + return 0; /* _start has no frame or prologue */ else if (sal.end < prologue_end) /* next line begins after fn end */ prologue_end = sal.end; /* (probably means no prologue) */ } else - prologue_end = prologue_start + 100; /* We're in the boondocks */ + prologue_end = prologue_start + 48; /* We're in the boondocks: allow for */ + /* 16 pushes, an add, and "mv fp,sp" */ prologue_end = min (prologue_end, fi->pc); @@ -111,26 +118,39 @@ m32r_scan_prologue (fi, fsr) rp (and other regs), adjust sp and such. */ framesize = 0; - memset (fsr->regs, '\000', sizeof fsr->regs); - for (current_pc = prologue_start; current_pc < prologue_end; current_pc += 2) { int insn; int regno; insn = read_memory_unsigned_integer (current_pc, 2); - if (insn & 0x80) /* Four byte instruction? */ + if (insn & 0x8000) /* Four byte instruction? */ current_pc += 2; if ((insn & 0xf0ff) == 0x207f) { /* st reg, @-sp */ framesize += 4; regno = ((insn >> 8) & 0xf); - fsr->regs[regno] = framesize; + if (fsr) /* save_regs offset */ + fsr->regs[regno] = framesize; } - else if ((insn >> 8) == 0x4f) { /* addi sp */ - framesize += -((char) (insn & 0xff)); /* offset */ + else if ((insn >> 8) == 0x4f) /* addi sp, xx */ + /* add 8 bit sign-extended offset */ + framesize += -((char) (insn & 0xff)); + else if (insn == 0x8faf) /* add3 sp, sp, xxxx */ + /* add 16 bit sign-extended offset */ + framesize += -((short) read_memory_unsigned_integer (current_pc, 2)); + else if (((insn >> 8) == 0xe4) && /* ld24 r4, xxxxxx ; sub sp, r4 */ + read_memory_unsigned_integer (current_pc + 2, 2) == 0x0f24) + { /* subtract 24 bit sign-extended negative-offset */ + insn = read_memory_unsigned_integer (current_pc - 2, 4); + if (insn & 0x00800000) /* sign extend */ + insn |= 0xff000000; /* negative */ + else + insn &= 0x00ffffff; /* positive */ + framesize += insn; + } + else if (insn == 0x1d8f) /* mv fp, sp */ break; /* end of stack adjustments */ - } } return framesize; } @@ -152,11 +172,13 @@ m32r_init_extra_frame_info (fi) fi->pc = FRAME_SAVED_PC (fi->next); framesize = m32r_scan_prologue (fi, &fi->fsr); - +#if 0 if (PC_IN_CALL_DUMMY (fi->pc, NULL, NULL)) fi->frame = dummy_frame_stack->sp; - else if (!fi->next) - fi->frame = read_register (SP_REGNUM); + else +#endif + if (!fi->next) + fi->frame = read_register (SP_REGNUM); for (reg = 0; reg < NUM_REGS; reg++) if (fi->fsr.regs[reg] != 0) @@ -208,11 +230,19 @@ m32r_frame_chain (fi) struct frame_info *fi; { CORE_ADDR saved_fp = fi->fsr.regs[FP_REGNUM]; - - if (saved_fp == 0) - return 0; /* frameless assembly language fn (such as _start) */ - - return read_memory_integer (saved_fp, 4); + CORE_ADDR fn_start, fn_end; + + if (saved_fp != 0) + return read_memory_integer (saved_fp, 4); + else { + if (find_pc_partial_function (fi->pc, 0, &fn_start, &fn_end)) + if (fn_start == entry_point_address ()) + return 0; /* in _start fn, don't chain further */ + else + return read_register (FP_REGNUM); + else /* in the woods, what to do? */ + return 0; /* for now, play it safe and give up... */ + } } /* All we do here is record SP and FP on the call dummy stack */ @@ -240,9 +270,13 @@ int m32r_pc_in_call_dummy (pc) CORE_ADDR pc; { +#if 0 return dummy_frame_stack && pc >= CALL_DUMMY_ADDRESS () && pc <= CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK; +#else + return 0; +#endif } /* Discard from the stack the innermost frame, |