diff options
| -rw-r--r-- | gdb/ChangeLog | 9 | ||||
| -rw-r--r-- | gdb/mips-tdep.c | 140 |
2 files changed, 53 insertions, 96 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 44193ee..99987f8 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,14 @@ 2004-10-14 Joel Brobecker <brobecker@gnat.com> + * mips-tdep.c (mips16_scan_prologue): Merge code from + mips16_skip_prologue. Now return the address of the first + instruction past the function prologue. + (mips16_skip_prologue): Remove, no longer necessary. + (mips_skip_prologue): Replace call to mips16_skip_prologue + by call to mips16_scan_prologue. + +2004-10-14 Joel Brobecker <brobecker@gnat.com> + * mips-tdep.c (mips32_scan_prologue): Merge code from mips32_skip_prologue. Now return the address of the first instruction past the function prologue. diff --git a/gdb/mips-tdep.c b/gdb/mips-tdep.c index 313b8b1..b0e6a27 100644 --- a/gdb/mips-tdep.c +++ b/gdb/mips-tdep.c @@ -2254,9 +2254,10 @@ mips16_get_imm (unsigned short prev_inst, /* previous instruction */ /* Analyze the function prologue from START_PC to LIMIT_PC. Builds - the associated FRAME_CACHE if not null. */ + the associated FRAME_CACHE if not null. + Return the address of the first instruction past the prologue. */ -static void +static CORE_ADDR mips16_scan_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, CORE_ADDR sp, struct frame_info *next_frame, struct mips_frame_cache *this_cache) @@ -2271,6 +2272,10 @@ mips16_scan_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, CORE_ADDR sp, unsigned entry_inst = 0; /* the entry instruction */ int reg, offset; + int extend_bytes = 0; + int prev_extend_bytes; + CORE_ADDR end_prologue_addr = 0; + for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += MIPS16_INSTLEN) { /* Save the previous instruction. If it's an EXTEND, we'll extract @@ -2279,6 +2284,21 @@ mips16_scan_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, CORE_ADDR sp, /* Fetch and decode the instruction. */ inst = (unsigned short) mips_fetch_instruction (cur_pc); + + /* Normally we ignore extend instructions. However, if it is + not followed by a valid prologue instruction, then this + instruction is not part of the prologue either. We must + remember in this case to adjust the end_prologue_addr back + over the extend. */ + if ((inst & 0xf800) == 0xf000) /* extend */ + { + extend_bytes = MIPS16_INSTLEN; + continue; + } + + prev_extend_bytes = extend_bytes; + extend_bytes = 0; + if ((inst & 0xff00) == 0x6300 /* addiu sp */ || (inst & 0xff00) == 0xfb00) /* daddiu sp */ { @@ -2342,6 +2362,19 @@ mips16_scan_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, CORE_ADDR sp, entry_inst = inst; /* save for later processing */ else if ((inst & 0xf800) == 0x1800) /* jal(x) */ cur_pc += MIPS16_INSTLEN; /* 32-bit instruction */ + else if ((inst & 0xff1c) == 0x6704) /* move reg,$a0-$a3 */ + { + /* This instruction is part of the prologue, but we don't + need to do anything special to handle it. */ + } + else + { + /* This instruction is not an instruction typically found + in a prologue, so we must have reached the end of the + prologue. */ + if (end_prologue_addr == 0) + end_prologue_addr = cur_pc - prev_extend_bytes; + } } /* The entry instruction is typically the first instruction in a function, @@ -2396,6 +2429,14 @@ mips16_scan_prologue (CORE_ADDR start_pc, CORE_ADDR limit_pc, CORE_ADDR sp, this_cache->saved_regs[NUM_REGS + mips_regnum (current_gdbarch)->pc] = this_cache->saved_regs[NUM_REGS + RA_REGNUM]; } + + /* If we didn't reach the end of the prologue when scanning the function + instructions, then set end_prologue_addr to the address of the + instruction immediately after the last one we scanned. */ + if (end_prologue_addr == 0) + end_prologue_addr = cur_pc; + + return end_prologue_addr; } /* Mark all the registers as unset in the saved_regs array @@ -4921,99 +4962,6 @@ mips_step_skips_delay (CORE_ADDR pc) extract_unsigned_integer (buf, MIPS_INSTLEN)); } -/* Skip the PC past function prologue instructions (16-bit version). - This is a helper function for mips_skip_prologue. */ - -static CORE_ADDR -mips16_skip_prologue (CORE_ADDR pc, CORE_ADDR end_pc) -{ - int extend_bytes = 0; - int prev_extend_bytes; - - /* Table of instructions likely to be found in a function prologue. */ - static struct - { - unsigned short inst; - unsigned short mask; - } - table[] = - { - { - 0x6300, 0xff00} - , /* addiu $sp,offset */ - { - 0xfb00, 0xff00} - , /* daddiu $sp,offset */ - { - 0xd000, 0xf800} - , /* sw reg,n($sp) */ - { - 0xf900, 0xff00} - , /* sd reg,n($sp) */ - { - 0x6200, 0xff00} - , /* sw $ra,n($sp) */ - { - 0xfa00, 0xff00} - , /* sd $ra,n($sp) */ - { - 0x673d, 0xffff} - , /* move $s1,sp */ - { - 0xd980, 0xff80} - , /* sw $a0-$a3,n($s1) */ - { - 0x6704, 0xff1c} - , /* move reg,$a0-$a3 */ - { - 0xe809, 0xf81f} - , /* entry pseudo-op */ - { - 0x0100, 0xff00} - , /* addiu $s1,$sp,n */ - { - 0, 0} /* end of table marker */ - }; - - /* Skip the typical prologue instructions. These are the stack adjustment - instruction and the instructions that save registers on the stack - or in the gcc frame. */ - for (; pc < end_pc; pc += MIPS16_INSTLEN) - { - unsigned short inst; - int i; - - inst = mips_fetch_instruction (pc); - - /* Normally we ignore an extend instruction. However, if it is - not followed by a valid prologue instruction, we must adjust - the pc back over the extend so that it won't be considered - part of the prologue. */ - if ((inst & 0xf800) == 0xf000) /* extend */ - { - extend_bytes = MIPS16_INSTLEN; - continue; - } - prev_extend_bytes = extend_bytes; - extend_bytes = 0; - - /* Check for other valid prologue instructions besides extend. */ - for (i = 0; table[i].mask != 0; i++) - if ((inst & table[i].mask) == table[i].inst) /* found, get out */ - break; - if (table[i].mask != 0) /* it was in table? */ - continue; /* ignore it */ - else - /* non-prologue */ - { - /* Return the current pc, adjusted backwards by 2 if - the previous instruction was an extend. */ - return pc - prev_extend_bytes; - } - } - return pc; -} - /* To skip prologues, I use this predicate. Returns either PC itself if the code at PC does not look like a function prologue; otherwise returns an address that (if we're lucky) follows the prologue. If @@ -5047,7 +4995,7 @@ mips_skip_prologue (CORE_ADDR pc) limit_pc = pc + 100; /* Magic. */ if (pc_is_mips16 (pc)) - return mips16_skip_prologue (pc, limit_pc); + return mips16_scan_prologue (pc, limit_pc, 0, NULL, NULL); else return mips32_scan_prologue (pc, limit_pc, 0, NULL, NULL); } |