From cea15572cd414fca65f31f7bc1c9b89bfd0cc998 Mon Sep 17 00:00:00 2001 From: Kazuhiro Inaoka Date: Thu, 7 Oct 2004 01:21:53 +0000 Subject: [PATCH] 2004-10-07 Kei Sakamoto * m32r-tdep.c (decode_prologue): Support functions written in assembler language. Recognize trap instructions as the end of prologue. (m32r_frame_unwind_cache): Ditto. (m32r_skip_prologue): Extend search limit. Quit analyzing prologue if pc's location is not readable. --- gdb/ChangeLog | 9 +++++ gdb/m32r-tdep.c | 112 ++++++++++++++++++++++++++++++++++++-------------------- 2 files changed, 81 insertions(+), 40 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 72a2bba..e8fa592 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2004-10-07 Kei Sakamoto + + * m32r-tdep.c (decode_prologue): Support functions written + in assembler language. Recognize trap instructions as the + end of prologue. + (m32r_frame_unwind_cache): Ditto. + (m32r_skip_prologue): Extend search limit. Quit analyzing + prologue if pc's location is not readable. + 2004-10-06 Paul N. Hilfinger * Makefile.in (.l.c): Do conversions of names of alloc and free diff --git a/gdb/m32r-tdep.c b/gdb/m32r-tdep.c index 3d8dfec..0afd261 100644 --- a/gdb/m32r-tdep.c +++ b/gdb/m32r-tdep.c @@ -1,6 +1,6 @@ /* Target-dependent code for Renesas M32R, for GDB. - Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2003 Free Software + Copyright 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of GDB. @@ -256,53 +256,53 @@ m32r_store_return_value (struct type *type, struct regcache *regcache, /* This is required by skip_prologue. The results of decoding a prologue should be cached because this thrashing is getting nuts. */ -static void +static int decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, - CORE_ADDR *pl_endptr) + CORE_ADDR *pl_endptr, unsigned long *framelength) { unsigned long framesize; int insn; int op1; - int maybe_one_more = 0; CORE_ADDR after_prologue = 0; + CORE_ADDR after_push = 0; CORE_ADDR after_stack_adjust = 0; CORE_ADDR current_pc; + LONGEST return_value; framesize = 0; after_prologue = 0; for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2) { + /* Check if current pc's location is readable. */ + if (!safe_read_memory_integer (current_pc, 2, &return_value)) + return -1; + insn = read_memory_unsigned_integer (current_pc, 2); + if (insn == 0x0000) + break; + /* If this is a 32 bit instruction, we dont want to examine its immediate data as though it were an instruction */ if (current_pc & 0x02) { - /* Clear the parallel execution bit from 16 bit instruction */ - if (maybe_one_more) - { - /* The last instruction was a branch, usually terminates - the series, but if this is a parallel instruction, - it may be a stack framing instruction */ - if (!(insn & 0x8000)) - { - /* nope, we are really done */ - break; - } - } /* decode this instruction further */ insn &= 0x7fff; } else { - if (maybe_one_more) - break; /* This isnt the one more */ if (insn & 0x8000) { if (current_pc == scan_limit) scan_limit += 2; /* extend the search */ + current_pc += 2; /* skip the immediate data */ + + /* Check if current pc's location is readable. */ + if (!safe_read_memory_integer (current_pc, 2, &return_value)) + return -1; + if (insn == 0x8faf) /* add3 sp, sp, xxxx */ /* add 16 bit sign-extended offset */ { @@ -312,6 +312,8 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, else { if (((insn >> 8) == 0xe4) /* ld24 r4, xxxxxx; sub sp, r4 */ + && safe_read_memory_integer (current_pc + 2, 2, + &return_value) && read_memory_unsigned_integer (current_pc + 2, 2) == 0x0f24) /* subtract 24 bit sign-extended negative-offset */ @@ -324,7 +326,7 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, framesize += insn; } } - after_prologue = current_pc; + after_push = current_pc + 2; continue; } } @@ -363,17 +365,23 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, after_prologue = current_pc + 2; break; /* end of stack adjustments */ } + /* Nop looks like a branch, continue explicitly */ if (insn == 0x7000) { after_prologue = current_pc + 2; continue; /* nop occurs between pushes */ } + /* End of prolog if any of these are trap instructions */ + if ((insn & 0xfff0) == 0x10f0) + { + after_prologue = current_pc; + break; + } /* End of prolog if any of these are branch instructions */ if ((op1 == 0x7000) || (op1 == 0xb000) || (op1 == 0xf000)) { after_prologue = current_pc; - maybe_one_more = 1; continue; } /* Some of the branch instructions are mixed with other types */ @@ -383,12 +391,14 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, if ((subop == 0x0ec0) || (subop == 0x0fc0)) { after_prologue = current_pc; - maybe_one_more = 1; continue; /* jmp , jl */ } } } + if (framelength) + *framelength = framesize; + if (current_pc >= scan_limit) { if (pl_endptr) @@ -400,6 +410,13 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, { *pl_endptr = after_stack_adjust; } + else if (after_push != 0) + /* We did not find a "mv fp,sp", but we DID find + a push. Is it safe to use that as the + end of the prologue? I just don't know. */ + { + *pl_endptr = after_push; + } else /* We reached the end of the loop without finding the end of the prologue. No way to win -- we should report failure. @@ -407,25 +424,29 @@ decode_prologue (CORE_ADDR start_pc, CORE_ADDR scan_limit, GDB will set a breakpoint at the start of the function (etc.) */ *pl_endptr = start_pc; } - return; + return 0; } + if (after_prologue == 0) after_prologue = current_pc; if (pl_endptr) *pl_endptr = after_prologue; + + return 0; } /* decode_prologue */ /* Function: skip_prologue Find end of function prologue */ -#define DEFAULT_SEARCH_LIMIT 44 +#define DEFAULT_SEARCH_LIMIT 128 CORE_ADDR m32r_skip_prologue (CORE_ADDR pc) { CORE_ADDR func_addr, func_end; struct symtab_and_line sal; + LONGEST return_value; /* See what the symbol table says */ @@ -447,11 +468,18 @@ m32r_skip_prologue (CORE_ADDR pc) } else func_end = pc + DEFAULT_SEARCH_LIMIT; - decode_prologue (pc, func_end, &sal.end); + + /* If pc's location is not readable, just quit. */ + if (!safe_read_memory_integer (pc, 4, &return_value)) + return pc; + + /* Find the end of prologue. */ + if (decode_prologue (pc, func_end, &sal.end, NULL) < 0) + return pc; + return sal.end; } - struct m32r_unwind_cache { /* The previous frame's inner most stack address. Used as this @@ -480,13 +508,14 @@ static struct m32r_unwind_cache * m32r_frame_unwind_cache (struct frame_info *next_frame, void **this_prologue_cache) { - CORE_ADDR pc; + CORE_ADDR pc, scan_limit; ULONGEST prev_sp; ULONGEST this_base; - unsigned long op; + unsigned long op, op2; int i; struct m32r_unwind_cache *info; + if ((*this_prologue_cache)) return (*this_prologue_cache); @@ -496,10 +525,11 @@ m32r_frame_unwind_cache (struct frame_info *next_frame, info->size = 0; info->sp_offset = 0; - info->uses_frame = 0; + + scan_limit = frame_pc_unwind (next_frame); for (pc = frame_func_unwind (next_frame); - pc > 0 && pc < frame_pc_unwind (next_frame); pc += 2) + pc > 0 && pc < scan_limit; pc += 2) { if ((pc & 2) == 0) { @@ -513,18 +543,19 @@ m32r_frame_unwind_cache (struct frame_info *next_frame, short n = op & 0xffff; info->sp_offset += n; } - else if (((op >> 8) == 0xe4) /* ld24 r4, xxxxxx; sub sp, r4 */ - && get_frame_memory_unsigned (next_frame, pc + 4, + else if (((op >> 8) == 0xe4) + && get_frame_memory_unsigned (next_frame, pc + 2, 2) == 0x0f24) { + /* ld24 r4, xxxxxx; sub sp, r4 */ unsigned long n = op & 0xffffff; info->sp_offset += n; - pc += 2; + pc += 2; /* skip sub instruction */ } - else - break; - pc += 2; + if (pc == scan_limit) + scan_limit += 2; /* extend the search */ + pc += 2; /* skip the immediate data */ continue; } } @@ -549,12 +580,13 @@ m32r_frame_unwind_cache (struct frame_info *next_frame, /* mv fp, sp */ info->uses_frame = 1; info->r13_offset = info->sp_offset; + break; /* end of stack adjustments */ + } + else if ((op & 0xfff0) == 0x10f0) + { + /* end of prologue if this is a trap instruction */ + break; /* end of stack adjustments */ } - else if (op == 0x7000) - /* nop */ - continue; - else - break; } info->size = -info->sp_offset; -- 2.7.4