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* 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.
This commit is contained in:
Joel Brobecker 2004-10-15 04:29:23 +00:00
parent 391df1c063
commit 1c645fec9f
2 changed files with 53 additions and 96 deletions
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9
gdb/ChangeLog
View File

@ -1,3 +1,12 @@
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

140
gdb/mips-tdep.c
View File

@ -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);
}