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* config/pa/tm-hppa.h (FRAME_FIND_SAVED_REGS): Call

Browse source 
hppa_frame_find_saved_regs.
        * hppa-tdep.c (dig_fp_from_stack): Delete function.
        (prologue_inst_adjust_sp): New function.
        (is_branch, inst_saves_gr, inst_saves_fr): New functions.
        (skip_prologue): Completely rewrite to use unwind information.
        (hppa_frame_find_saved_regs): Likewise.
This commit is contained in:
Jeff Law 1994-01-11 19:14:11 +00:00
parent f3fe8934c2
commit c598654a5b
2 changed files with 382 additions and 68 deletions
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11
gdb/ChangeLog
View file

@ -1,3 +1,13 @@
Tue Jan 11 11:10:30 1994 Jeffrey A. Law (law@snake.cs.utah.edu)
* config/pa/tm-hppa.h (FRAME_FIND_SAVED_REGS): Call
hppa_frame_find_saved_regs.
* hppa-tdep.c (dig_fp_from_stack): Delete function.
(prologue_inst_adjust_sp): New function.
(is_branch, inst_saves_gr, inst_saves_fr): New functions.
(skip_prologue): Completely rewrite to use unwind information.
(hppa_frame_find_saved_regs): Likewise.
Tue Jan 11 06:59:10 1994 Jim Kingdon (kingdon@deneb.cygnus.com)
* remote-mips.c (mips_wait): Use new function mips_signal_from_protocol
@ -41,6 +51,7 @@ Mon Jan 10 15:48:36 1994 Tom Lord (lord@rtl.cygnus.com)
* m68k-stub.c, sparc-stub.c: removed spurious introduction of
_filtered io routines from these two files.
>>>>>>> 1.2095
Fri Jan 7 12:42:45 1994 Peter Schauer (pes@regent.e-technik.tu-muenchen.de)
* config/i386/tm-i386v.h, config/m68k/tm-m68k.h, config/mips/tm-mips.h,

439
gdb/hppa-tdep.c
View file

@ -61,9 +61,11 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
static int restore_pc_queue PARAMS ((struct frame_saved_regs *fsr));
static int hppa_alignof PARAMS ((struct type *arg));
static FRAME_ADDR dig_fp_from_stack PARAMS ((FRAME frame,
struct unwind_table_entry *u));
CORE_ADDR frame_saved_pc PARAMS ((FRAME frame));
static int prologue_inst_adjust_sp PARAMS ((unsigned long));
static int is_branch PARAMS ((unsigned long));
static int inst_saves_gr PARAMS ((unsigned long));
static int inst_saves_fr PARAMS ((unsigned long));
/* Routines to extract various sized constants out of hppa
@ -618,7 +620,14 @@ frame_chain (frame)
return read_memory_integer (frame->frame, 4);
/* %r3 was saved somewhere in the stack. Dig it out. */
else
return dig_fp_from_stack (frame, u);
{
struct frame_info *fi;
struct frame_saved_regs saved_regs;
fi = get_frame_info (frame);
get_frame_saved_regs (fi, &saved_regs);
return read_memory_integer (saved_regs.regs[FP_REGNUM], 4);
}
}
else
{
@ -628,52 +637,6 @@ frame_chain (frame)
}
}
/* Given a frame and an unwind descriptor return the value for %fr (aka fp)
which was saved into the stack. FIXME: Why can't we just use the standard
saved_regs stuff? */
static FRAME_ADDR
dig_fp_from_stack (frame, u)
FRAME frame;
struct unwind_table_entry *u;
{
CORE_ADDR pc = u->region_start;
/* Search the function for the save of %r3. */
while (pc != u->region_end)
{
char buf[4];
unsigned long inst;
int status;
/* We need only look for the standard stw %r3,X(%sp) instruction,
the other variants (eg stwm) are only used on the first register
save (eg %r3). */
status = target_read_memory (pc, buf, 4);
inst = extract_unsigned_integer (buf, 4);
if (status != 0)
memory_error (status, pc);
/* Check for stw %r3,X(%sp). */
if ((inst & 0xffffc000) == 0x6bc30000)
{
/* Found the instruction which saves %r3. The offset (relative
to this frame) is framesize + immed14 (derived from the
store instruction). */
int offset = (u->Total_frame_size << 3) + extract_14 (inst);
return read_memory_integer (frame->frame + offset, 4);
}
/* Keep looking. */
pc += 4;
}
warning ("Unable to find %%r3 in stack.\n");
return 0;
}
/* To see if a frame chain is valid, see if the caller looks like it
was compiled with gcc. */
@ -1203,40 +1166,380 @@ skip_trampoline_code (pc, name)
return pc;
}
/* Advance PC across any function entry prologue instructions
to reach some "real" code. */
/* For the given instruction (INST), return any adjustment it makes
to the stack pointer or zero for no adjustment.
/* skip (stw rp, -20(0,sp)); copy 4,1; copy sp, 4; stwm 1,framesize(sp)
for gcc, or (stw rp, -20(0,sp); stwm 1, framesize(sp) for hcc */
This only handles instructions commonly found in prologues. */
static int
prologue_inst_adjust_sp (inst)
unsigned long inst;
{
/* This must persist across calls. */
static int save_high21;
/* The most common way to perform a stack adjustment ldo X(sp),sp */
if ((inst & 0xffffc000) == 0x37de0000)
return extract_14 (inst);
/* stwm X,D(sp) */
if ((inst & 0xffe00000) == 0x6fc00000)
return extract_14 (inst);
/* addil high21,%r1; ldo low11,(%r1),%r30)
save high bits in save_high21 for later use. */
if ((inst & 0xffe00000) == 0x28200000)
{
save_high21 = extract_21 (inst);
return 0;
}
if ((inst & 0xffff0000) == 0x343e0000)
return save_high21 + extract_14 (inst);
/* fstws as used by the HP compilers. */
if ((inst & 0xffffffe0) == 0x2fd01220)
return extract_5_load (inst);
/* No adjustment. */
return 0;
}
/* Return nonzero if INST is a branch of some kind, else return zero. */
static int
is_branch (inst)
unsigned long inst;
{
switch (inst >> 26)
{
case 0x20:
case 0x21:
case 0x22:
case 0x23:
case 0x28:
case 0x29:
case 0x2a:
case 0x2b:
case 0x30:
case 0x31:
case 0x32:
case 0x33:
case 0x38:
case 0x39:
case 0x3a:
return 1;
default:
return 0;
}
}
/* Return the register number for a GR which is saved by INST or
zero it INST does not save a GR.
Note we only care about full 32bit register stores (that's the only
kind of stores the prologue will use). */
static int
inst_saves_gr (inst)
unsigned long inst;
{
/* Does it look like a stw? */
if ((inst >> 26) == 0x1a)
return extract_5R_store (inst);
/* Does it look like a stwm? */
if ((inst >> 26) == 0x1b)
return extract_5R_store (inst);
return 0;
}
/* Return the register number for a FR which is saved by INST or
zero it INST does not save a FR.
Note we only care about full 64bit register stores (that's the only
kind of stores the prologue will use). */
static int
inst_saves_fr (inst)
unsigned long inst;
{
if ((inst & 0xfc1fffe0) == 0x2c101220)
return extract_5r_store (inst);
return 0;
}
/* Advance PC across any function entry prologue instructions
to reach some "real" code.
Use information in the unwind table to determine what exactly should
be in the prologue. */
CORE_ADDR
skip_prologue(pc)
CORE_ADDR pc;
{
char buf[4];
unsigned long inst;
int status;
unsigned long inst, stack_remaining, save_gr, save_fr, save_rp, save_sp;
int status, i;
struct unwind_table_entry *u;
status = target_read_memory (pc, buf, 4);
inst = extract_unsigned_integer (buf, 4);
if (status != 0)
return pc;
u = find_unwind_entry (pc);
if (!u)
return 0;
if (inst == 0x6BC23FD9) /* stw rp,-20(sp) */
/* This is how much of a frame adjustment we need to account for. */
stack_remaining = u->Total_frame_size << 3;
/* Magic register saves we want to know about. */
save_rp = u->Save_RP;
save_sp = u->Save_SP;
/* Turn the Entry_GR field into a bitmask. */
save_gr = 0;
for (i = 3; i < u->Entry_GR + 3; i++)
{
if (read_memory_integer (pc + 4, 4) == 0x8030241) /* copy r3,r1 */
pc += 16;
else if ((read_memory_integer (pc + 4, 4) & ~MASK_14) == 0x68710000) /* stw r1,(r3) */
pc += 8;
/* Frame pointer gets saved into a special location. */
if (u->Save_SP && i == FP_REGNUM)
continue;
save_gr |= (1 << i);
}
/* Turn the Entry_FR field into a bitmask too. */
save_fr = 0;
for (i = 12; i < u->Entry_FR + 12; i++)
save_fr |= (1 << i);
/* Loop until we find everything of interest or hit a branch.
For unoptimized GCC code and for any HP CC code this will never ever
examine any user instructions.
For optimzied GCC code we're faced with problems. GCC will schedule
its prologue and make prologue instructions available for delay slot
filling. The end result is user code gets mixed in with the prologue
and a prologue instruction may be in the delay slot of the first branch
or call.
Some unexpected things are expected with debugging optimized code, so
we allow this routine to walk past user instructions in optimized
GCC code. */
while (save_gr || save_fr || save_rp || save_sp || stack_remaining > 0)
{
status = target_read_memory (pc, buf, 4);
inst = extract_unsigned_integer (buf, 4);
/* Yow! */
if (status != 0)
return pc;
/* Note the interesting effects of this instruction. */
stack_remaining -= prologue_inst_adjust_sp (inst);
/* There is only one instruction used for saving RP into the stack. */
if (inst == 0x6bc23fd9)
save_rp = 0;
/* This is the only way we save SP into the stack. At this time
the HP compilers never bother to save SP into the stack. */
if ((inst & 0xffffc000) == 0x6fc10000)
save_sp = 0;
/* Account for general and floating-point register saves. */
save_gr &= ~(1 << inst_saves_gr (inst));
save_fr &= ~(1 << inst_saves_fr (inst));
/* Quit if we hit any kind of branch. This can happen if a prologue
instruction is in the delay slot of the first call/branch. */
if (is_branch (inst))
break;
/* Bump the PC. */
pc += 4;
}
else if (read_memory_integer (pc, 4) == 0x8030241) /* copy r3,r1 */
pc += 12;
else if ((read_memory_integer (pc, 4) & ~MASK_14) == 0x68710000) /* stw r1,(r3) */
pc += 4;
return pc;
}
/* Put here the code to store, into a struct frame_saved_regs,
the addresses of the saved registers of frame described by FRAME_INFO.
This includes special registers such as pc and fp saved in special
ways in the stack frame. sp is even more special:
the address we return for it IS the sp for the next frame. */
void
hppa_frame_find_saved_regs (frame_info, frame_saved_regs)
struct frame_info *frame_info;
struct frame_saved_regs *frame_saved_regs;
{
CORE_ADDR pc;
struct unwind_table_entry *u;
unsigned long inst, stack_remaining, save_gr, save_fr, save_rp, save_sp;
int status, i, reg;
char buf[4];
int fp_loc = -1;
/* Zero out everything. */
memset (frame_saved_regs, '\0', sizeof (struct frame_saved_regs));
/* Call dummy frames always look the same, so there's no need to
examine the dummy code to determine locations of saved registers;
instead, let find_dummy_frame_regs fill in the correct offsets
for the saved registers. */
if ((frame_info->pc >= frame_info->frame
&& frame_info->pc <= (frame_info->frame + CALL_DUMMY_LENGTH
+ 32 * 4 + (NUM_REGS - FP0_REGNUM) * 8
+ 6 * 4)))
find_dummy_frame_regs (frame_info, frame_saved_regs);
/* Get the starting address of the function referred to by the PC
saved in frame_info. */
pc = get_pc_function_start (frame_info->pc);
/* Yow! */
u = find_unwind_entry (pc);
if (!u)
return;
/* This is how much of a frame adjustment we need to account for. */
stack_remaining = u->Total_frame_size << 3;
/* Magic register saves we want to know about. */
save_rp = u->Save_RP;
save_sp = u->Save_SP;
/* Turn the Entry_GR field into a bitmask. */
save_gr = 0;
for (i = 3; i < u->Entry_GR + 3; i++)
{
/* Frame pointer gets saved into a special location. */
if (u->Save_SP && i == FP_REGNUM)
continue;
save_gr |= (1 << i);
}
/* Turn the Entry_FR field into a bitmask too. */
save_fr = 0;
for (i = 12; i < u->Entry_FR + 12; i++)
save_fr |= (1 << i);
/* Loop until we find everything of interest or hit a branch.
For unoptimized GCC code and for any HP CC code this will never ever
examine any user instructions.
For optimzied GCC code we're faced with problems. GCC will schedule
its prologue and make prologue instructions available for delay slot
filling. The end result is user code gets mixed in with the prologue
and a prologue instruction may be in the delay slot of the first branch
or call.
Some unexpected things are expected with debugging optimized code, so
we allow this routine to walk past user instructions in optimized
GCC code. */
while (save_gr || save_fr || save_rp || save_sp || stack_remaining > 0)
{
status = target_read_memory (pc, buf, 4);
inst = extract_unsigned_integer (buf, 4);
/* Yow! */
if (status != 0)
return;
/* Note the interesting effects of this instruction. */
stack_remaining -= prologue_inst_adjust_sp (inst);
/* There is only one instruction used for saving RP into the stack. */
if (inst == 0x6bc23fd9)
{
save_rp = 0;
frame_saved_regs->regs[RP_REGNUM] = frame_info->frame - 20;
}
/* This is the only way we save SP into the stack. At this time
the HP compilers never bother to save SP into the stack. */
if ((inst & 0xffffc000) == 0x6fc10000)
{
save_sp = 0;
frame_saved_regs->regs[SP_REGNUM] = frame_info->frame;
}
/* Account for general and floating-point register saves. */
reg = inst_saves_gr (inst);
if (reg >= 3 && reg <= 18
&& (!u->Save_SP || reg != FP_REGNUM))
{
save_gr &= ~(1 << reg);
/* stwm with a positive displacement is a *post modify*. */
if ((inst >> 26) == 0x1b
&& extract_14 (inst) >= 0)
frame_saved_regs->regs[reg] = frame_info->frame;
else
{
/* Handle code with and without frame pointers. */
if (u->Save_SP)
frame_saved_regs->regs[reg]
= frame_info->frame + extract_14 (inst);
else
frame_saved_regs->regs[reg]
= frame_info->frame + (u->Total_frame_size << 3)
+ extract_14 (inst);
}
}
/* GCC handles callee saved FP regs a little differently.
It emits an instruction to put the value of the start of
the FP store area into %r1. It then uses fstds,ma with
a basereg of %r1 for the stores.
HP CC emits them at the current stack pointer modifying
the stack pointer as it stores each register. */
/* ldo X(%r3),%r1 or ldo X(%r30),%r1. */
if ((inst & 0xffffc000) == 0x34610000
|| (inst & 0xffffc000) == 0x37c10000)
fp_loc = extract_14 (inst);
reg = inst_saves_fr (inst);
if (reg >= 12 && reg <= 21)
{
/* Note +4 braindamage below is necessary because the FP status
registers are internally 8 registers rather than the expected
4 registers. */
save_fr &= ~(1 << reg);
if (fp_loc == -1)
{
/* 1st HP CC FP register store. After this instruction
we've set enough state that the GCC and HPCC code are
both handled in the same manner. */
frame_saved_regs->regs[reg + FP4_REGNUM + 4] = frame_info->frame;
fp_loc = 8;
}
else
{
frame_saved_regs->regs[reg + FP0_REGNUM + 4]
= frame_info->frame + fp_loc;
fp_loc += 8;
}
}
/* Quit if we hit any kind of branch. This can happen if a prologue
instruction is in the delay slot of the first call/branch. */
if (is_branch (inst))
break;
/* Bump the PC. */
pc += 4;
}
}
#ifdef MAINTENANCE_CMDS
static void