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Tue Nov 12 12:16:40 1996 Michael Snyder <msnyder@cleaver.cygnus.com>

Browse source 
* sh-tdep.c: Add functionality for target function calls.
        * config/sh/tm-sh.h: Add support for target function calls.
This is a safety check-in: everything works, and there'll be another
clean-up round shortly.
This commit is contained in:
Michael Snyder 1996-11-12 20:19:17 +00:00
parent 6f3eea2bdf
commit 69992fc816
3 changed files with 521 additions and 44 deletions
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11
gdb/ChangeLog
View file

@ -1,9 +1,14 @@
Tue Nov 12 12:16:40 1996 Michael Snyder <msnyder@cleaver.cygnus.com>
* sh-tdep.c: Add functionality for target function calls.
* config/sh/tm-sh.h: Add support for target function calls.
start-sanitize-m32r
Tue Nov 12 12:06:58 1996 Michael Snyder <msnyder@cleaver.cygnus.com>
* m32r-tdep.c: Add functionality for target function calls.
* valops.c: Small change to support target function calls.
* config/m32r/tm-m32r.h: Add support for target function calls.
* m32r-tdep.c: Add functionality for target function calls.
* valops.c: Small change to support target function calls.
* config/m32r/tm-m32r.h: Add support for target function calls.
end-sanitize-m32r
Mon Nov 11 17:15:59 1996 Geoffrey Noer <noer@cygnus.com>

86
gdb/config/sh/tm-sh.h
View file

@ -19,6 +19,13 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Contributed by Steve Chamberlain sac@cygnus.com */
#ifdef __STDC__
struct frame_info;
struct frame_saved_regs;
struct value;
struct type;
#endif
#define GDB_TARGET_IS_SH
#define IEEE_FLOAT 1
@ -109,13 +116,13 @@ extern CORE_ADDR sh_skip_prologue ();
Entries beyond the first NUM_REGS are ignored. */
#define REGISTER_NAMES \
{ "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", \
"pc", "pr", "gbr", "vbr", "mach", "macl", "sr", \
{ "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15", \
"pc", "pr", "gbr", "vbr", "mach", "macl", "sr", \
"fpul", "fpscr", \
"fr0", "fr1", "fr2", "fr3", "fr4", "fr5", "fr6", "fr7", \
"fr8", "fr9", "fr10", "fr11", "fr12", "fr13", "fr14", "fr15", \
"ssr", "spc", \
"ssr", "spc", \
"r0b0", "r1b0", "r2b0", "r3b0", "r4b0", "r5b0", "r6b0", "r7b0", \
"r0b1", "r1b1", "r2b1", "r3b1", "r4b1", "r5b1", "r6b1", "r7b1", \
}
@ -130,6 +137,9 @@ extern CORE_ADDR sh_skip_prologue ();
passed to read_register. */
#define R0_REGNUM 0
#define STRUCT_RETURN_REGNUM 2
#define ARG0_REGNUM 4
#define ARGLAST_REGNUM 7
#define FP_REGNUM 14
#define SP_REGNUM 15
#define PC_REGNUM 16
@ -152,25 +162,28 @@ extern CORE_ADDR sh_skip_prologue ();
/* Store the address of the place in which to copy the structure the
subroutine will return. This is called from call_function.
We store structs through a pointer passed in R4 */
We store structs through a pointer passed in R0 */
#define STORE_STRUCT_RETURN(ADDR, SP) \
{ write_register (4, (ADDR)); }
{ write_register (STRUCT_RETURN_REGNUM, (ADDR)); }
#define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH(type) > 1)
/* Extract from an array REGBUF containing the (raw) register state
a function return value of type TYPE, and copy that, in virtual format,
into VALBUF. */
extern void sh_extract_return_value PARAMS ((struct type *, void *, void *));
#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
memcpy (VALBUF, (char *)(REGBUF), TYPE_LENGTH(TYPE))
sh_extract_return_value (TYPE, REGBUF, VALBUF)
/* Write into appropriate registers a function return value
of type TYPE, given in virtual format.
Things always get returned in R4/R5 */
Things always get returned in R0/R1 */
#define STORE_RETURN_VALUE(TYPE,VALBUF) \
write_register_bytes (REGISTER_BYTE(4), VALBUF, TYPE_LENGTH (TYPE))
write_register_bytes (REGISTER_BYTE(0), VALBUF, TYPE_LENGTH (TYPE))
/* Extract from an array REGBUF containing the (raw) register state
the address in which a function should return its structure value,
@ -189,7 +202,7 @@ extern CORE_ADDR sh_skip_prologue ();
int f_offset;
#define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
init_extra_frame_info(fromleaf, fi)
sh_init_extra_frame_info(fromleaf, fi)
/* A macro that tells us whether the function invocation represented
by FI does not have a frame on the stack associated with it. If it
@ -198,10 +211,9 @@ extern CORE_ADDR sh_skip_prologue ();
#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
(FRAMELESS) = frameless_look_for_prologue(FI)
#define FRAME_CHAIN(FRAME) sh_frame_chain(FRAME)
#define FRAME_SAVED_PC(FRAME) ((FRAME)->return_pc)
#define FRAME_ARGS_ADDRESS(fi) (fi)->frame
#define FRAME_LOCALS_ADDRESS(fi) (fi)->frame
#define FRAME_SAVED_PC(FRAME) ((FRAME)->return_pc)
#define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
#define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
/* Set VAL to the number of args passed to frame described by FI.
Can set VAL to -1, meaning no way to tell. */
@ -214,6 +226,9 @@ extern CORE_ADDR sh_skip_prologue ();
#define FRAME_ARGS_SKIP 0
extern void sh_frame_find_saved_regs PARAMS ((struct frame_info *fi,
struct frame_saved_regs *fsr));
/* 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
@ -221,20 +236,57 @@ extern CORE_ADDR sh_skip_prologue ();
the address we return for it IS the sp for the next frame. */
#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
frame_find_saved_regs(frame_info, &(frame_saved_regs))
sh_frame_find_saved_regs(frame_info, &(frame_saved_regs))
#define NAMES_HAVE_UNDERSCORE
typedef unsigned short INSN_WORD;
#define CALL_DUMMY_LENGTH 10
extern CORE_ADDR generic_read_register_dummy PARAMS ((struct frame_info *,
int regno));
extern void generic_push_dummy_frame PARAMS ((void));
extern void generic_pop_dummy_frame PARAMS ((void));
extern int generic_pc_in_call_dummy PARAMS ((CORE_ADDR pc,
CORE_ADDR fp,
CORE_ADDR sp));
extern char * generic_find_dummy_frame PARAMS ((CORE_ADDR pc,
CORE_ADDR fp,
CORE_ADDR sp));
extern void sh_push_return_address PARAMS ((CORE_ADDR));
extern CORE_ADDR sh_push_arguments PARAMS ((int nargs,
struct value **args,
CORE_ADDR sp,
unsigned char struct_return,
CORE_ADDR struct_addr));
extern int generic_frame_chain_valid PARAMS((CORE_ADDR, struct frame_info *));
#define CALL_DUMMY { }
#define CALL_DUMMY_LENGTH (0)
#define CALL_DUMMY_START_OFFSET (0)
#define CALL_DUMMY_BREAKPOINT_OFFSET (0)
#define CALL_DUMMY_LOCATION AT_ENTRY_POINT
#define CALL_DUMMY_ADDRESS() (entry_point_address ())
#define PUSH_RETURN_ADDRESS(PC) (sh_push_return_address (PC))
#define FRAME_CHAIN(FRAME) (sh_frame_chain(FRAME))
#define PUSH_DUMMY_FRAME (generic_push_dummy_frame ())
#define FRAME_CHAIN_VALID(FP, FRAME) (generic_frame_chain_valid (FP, FRAME))
#define PC_IN_CALL_DUMMY(PC, SP, FP) (generic_pc_in_call_dummy (PC, SP, FP))
#define FIX_CALL_DUMMY(DUMMYNAME, STARTADDR, FUNADDR, NARGS, ARGS, TYPE, GCCP)
#define PUSH_ARGUMENTS(NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR) \
(SP) = sh_push_arguments (NARGS, ARGS, SP, STRUCT_RETURN, STRUCT_ADDR)
/* Discard from the stack the innermost frame, restoring all saved
registers. */
#define POP_FRAME pop_frame();
#define POP_FRAME sh_pop_frame();
#define NOP {0x20, 0x0b}
#define REGISTER_SIZE 4
#define COERCE_FLOAT_TO_DOUBLE 1

468
gdb/sh-tdep.c
View file

@ -31,6 +31,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#include "gdbcore.h"
#include "value.h"
#include "dis-asm.h"
#include "inferior.h" /* for BEFORE_TEXT_END etc. */
extern int remote_write_size; /* in remote.c */
@ -159,20 +160,54 @@ CORE_ADDR
sh_frame_chain (frame)
struct frame_info *frame;
{
if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
return frame->frame; /* dummy frame same as caller's frame */
if (!inside_entry_file (frame->pc))
return read_memory_integer (FRAME_FP (frame) + frame->f_offset, 4);
else
return 0;
}
/* Find REGNUM on the stack. Otherwise, it's in an active register. One thing
we might want to do here is to check REGNUM against the clobber mask, and
somehow flag it as invalid if it isn't saved on the stack somewhere. This
would provide a graceful failure mode when trying to get the value of
caller-saves registers for an inner frame. */
CORE_ADDR
sh_find_callers_reg (fi, regnum)
struct frame_info *fi;
int regnum;
{
struct frame_saved_regs fsr;
for (; fi; fi = fi->next)
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
/* When the caller requests PR from the dummy frame, we return PC because
that's where the previous routine appears to have done a call from. */
return generic_read_register_dummy (fi, regnum);
else
{
FRAME_FIND_SAVED_REGS(fi, fsr);
if (fsr.regs[regnum] != 0)
return read_memory_integer (fsr.regs[regnum],
REGISTER_RAW_SIZE(regnum));
}
return read_register (regnum);
}
/* 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. */
/* FIXME! A lot of this should be abstracted out into a sh_scan_prologue
function, and the struct frame_info should have a frame_saved_regs
embedded in it, so we would only have to do this once. */
void
frame_find_saved_regs (fi, fsr)
sh_frame_find_saved_regs (fi, fsr)
struct frame_info *fi;
struct frame_saved_regs *fsr;
{
@ -184,6 +219,16 @@ frame_find_saved_regs (fi, fsr)
int opc;
int insn;
int r3_val = 0;
char * dummy_regs = generic_find_dummy_frame (fi->pc, fi->frame, fi->frame);
if (dummy_regs)
{
/* DANGER! This is ONLY going to work if the char buffer format of
the saved registers is byte-for-byte identical to the
CORE_ADDR regs[NUM_REGS] format used by struct frame_saved_regs! */
memcpy (&fsr->regs, dummy_regs, sizeof(fsr));
return;
}
opc = pc = get_pc_function_start (fi->pc);
@ -276,55 +321,224 @@ frame_find_saved_regs (fi, fsr)
fi->f_offset = depth - where[FP_REGNUM] - 4;
/* Work out the return pc - either from the saved pr or the pr
value */
if (fsr->regs[PR_REGNUM])
fi->return_pc = read_memory_integer (fsr->regs[PR_REGNUM], 4);
else
fi->return_pc = read_register (PR_REGNUM);
}
/* initialize the extra info saved in a FRAME */
void
init_extra_frame_info (fromleaf, fi)
sh_init_extra_frame_info (fromleaf, fi)
int fromleaf;
struct frame_info *fi;
{
struct frame_saved_regs dummy;
struct frame_saved_regs fsr;
if (fi->next)
fi->pc = fi->next->return_pc;
fi->pc = FRAME_SAVED_PC (fi->next);
frame_find_saved_regs (fi, &dummy);
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
{
/* We need to setup fi->frame here because run_stack_dummy gets it wrong
by assuming it's always FP. */
fi->frame = generic_read_register_dummy (fi, SP_REGNUM);
fi->return_pc = generic_read_register_dummy (fi, PC_REGNUM);
fi->f_offset = -(CALL_DUMMY_LENGTH + 4);
fi->leaf_function = 0;
return;
}
else
{
FRAME_FIND_SAVED_REGS (fi, fsr);
fi->return_pc = sh_find_callers_reg (fi, PR_REGNUM);
}
}
/* Discard from the stack the innermost frame,
restoring all saved registers. */
void
pop_frame ()
sh_pop_frame ()
{
register struct frame_info *frame = get_current_frame ();
register CORE_ADDR fp;
register int regnum;
struct frame_saved_regs fsr;
fp = FRAME_FP (frame);
get_frame_saved_regs (frame, &fsr);
if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
generic_pop_dummy_frame ();
else
{
fp = FRAME_FP (frame);
get_frame_saved_regs (frame, &fsr);
/* Copy regs from where they were saved in the frame */
for (regnum = 0; regnum < NUM_REGS; regnum++)
{
/* Copy regs from where they were saved in the frame */
for (regnum = 0; regnum < NUM_REGS; regnum++)
if (fsr.regs[regnum])
write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
write_register (PC_REGNUM, frame->return_pc);
write_register (SP_REGNUM, fp + 4);
}
flush_cached_frames ();
}
/* Function: push_arguments
Setup the function arguments for calling a function in the inferior.
On the Hitachi SH architecture, there are four registers (R4 to R7)
which are dedicated for passing function arguments. Up to the first
four arguments (depending on size) may go into these registers.
The rest go on the stack.
Arguments that are smaller than 4 bytes will still take up a whole
register or a whole 32-bit word on the stack, and will be
right-justified in the register or the stack word. This includes
chars, shorts, and small aggregate types.
Arguments that are larger than 4 bytes may be split between two or
more registers. If there are not enough registers free, an argument
may be passed partly in a register (or registers), and partly on the
stack. This includes doubles, long longs, and larger aggregates.
As far as I know, there is no upper limit to the size of aggregates
that will be passed in this way; in other words, the convention of
passing a pointer to a large aggregate instead of a copy is not used.
An exceptional case exists for struct arguments (and possibly other
aggregates such as arrays) if the size is larger than 4 bytes but
not a multiple of 4 bytes. In this case the argument is never split
between the registers and the stack, but instead is copied in its
entirety onto the stack, AND also copied into as many registers as
there is room for. In other words, space in registers permitting,
two copies of the same argument are passed in. As far as I can tell,
only the one on the stack is used, although that may be a function
of the level of compiler optimization. I suspect this is a compiler
bug. Arguments of these odd sizes are left-justified within the
word (as opposed to arguments smaller than 4 bytes, which are
right-justified).
If the function is to return an aggregate type such as a struct, it
is either returned in the normal return value register R0 (if its
size is no greater than one byte), or else the caller must allocate
space into which the callee will copy the return value (if the size
is greater than one byte). In this case, a pointer to the return
value location is passed into the callee in register R2, which does
not displace any of the other arguments passed in via registers R4
to R7. */
CORE_ADDR
sh_push_arguments (nargs, args, sp, struct_return, struct_addr)
int nargs;
value_ptr *args;
CORE_ADDR sp;
unsigned char struct_return;
CORE_ADDR struct_addr;
{
int argreg;
int argnum;
CORE_ADDR regval;
char *val;
char valbuf[4];
int len;
int push[4]; /* some of the first 4 args may not need to be pushed
onto the stack, because they can go in registers */
/* first force sp to a 4-byte alignment */
sp = sp & ~3;
/* The "struct return pointer" pseudo-argument has its own dedicated
register */
if (struct_return)
write_register (STRUCT_RETURN_REGNUM, struct_addr);
/* Now load as many as possible of the first arguments into registers.
There are 16 bytes in four registers available.
Loop thru args from first to last. */
push[0] = push[1] = push[2] = push[3] = 0;
for (argnum = 0, argreg = ARG0_REGNUM;
argnum < nargs && argreg <= ARGLAST_REGNUM;
argnum++)
{
struct type *type = VALUE_TYPE (args[argnum]);
len = TYPE_LENGTH (type);
switch (TYPE_CODE(type)) {
case TYPE_CODE_STRUCT:
case TYPE_CODE_UNION:
/* case TYPE_CODE_ARRAY: case TYPE_CODE_STRING: */
if (len <= 4 || (len & ~3) == 0)
push[argnum] = 0; /* doesn't get pushed onto stack */
else
push[argnum] = len; /* does get pushed onto stack */
break;
default:
push[argnum] = 0; /* doesn't get pushed onto stack */
}
if (len < 4)
{ /* value gets right-justified in the register */
memcpy(valbuf + (4 - len),
(char *) VALUE_CONTENTS (args[argnum]), len);
val = valbuf;
}
else
val = (char *) VALUE_CONTENTS (args[argnum]);
while (len > 0)
{
write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
regval = extract_address (val, REGISTER_RAW_SIZE (argreg));
write_register (argreg, regval);
len -= REGISTER_RAW_SIZE (argreg);
val += REGISTER_RAW_SIZE (argreg);
argreg++;
if (argreg > ARGLAST_REGNUM)
{
push[argnum] = len; /* ran out of arg passing registers! */
break; /* len bytes remain to go onto stack */
}
}
}
write_register (PC_REGNUM, frame->return_pc);
write_register (SP_REGNUM, fp + 4);
flush_cached_frames ();
/* Now push as many as necessary of the remaining arguments onto the stack.
For args 0 to 3, the arg may have been passed in a register.
Loop thru args from last to first. */
for (argnum = nargs-1; argnum >= 0; --argnum)
{
if (argnum < 4 && push[argnum] == 0)
continue; /* no need to push this arg */
len = TYPE_LENGTH (VALUE_TYPE (args[argnum]));
if (len < 4)
{
memcpy(valbuf + (4 - len),
(char *) VALUE_CONTENTS (args[argnum]), len);
val = valbuf;
}
else
val = (char *) VALUE_CONTENTS (args[argnum]);
if (argnum < 4)
if (len > push[argnum]) /* some part may already be in a reg */
{
val += (len - push[argnum]);
len = push[argnum];
}
sp -= (len + 3) & ~3;
write_memory (sp, val, len);
}
return sp;
}
/* Function: push_return_address (pc)
Set up the return address for the inferior function call.
Necessary for targets where we don't actually execute a JSR/BSR instruction */
void
sh_push_return_address (pc)
CORE_ADDR pc;
{
write_register (PR_REGNUM, entry_point_address ());
}
/* Command to set the processor type. */
@ -400,7 +614,7 @@ sh_set_processor_type (str)
/* Print the registers in a form similar to the E7000 */
static void
show_regs (args, from_tty)
sh_show_regs (args, from_tty)
char *args;
int from_tty;
{
@ -430,7 +644,23 @@ show_regs (args, from_tty)
read_register (14),
read_register (15));
}
void
sh_extract_return_value (type, regbuf, valbuf)
struct type *type;
void *regbuf;
void *valbuf;
{
int len = TYPE_LENGTH(type);
if (len <= 4)
memcpy (valbuf, ((char *) regbuf) + 4 - len, len);
else if (len <= 8)
memcpy (valbuf, ((char *) regbuf) + 8 - len, len);
else
error ("bad size for return value");
}
void
_initialize_sh_tdep ()
{
@ -451,9 +681,199 @@ Set this to be able to access processor-type-specific registers.\n\
tmp_sh_processor_type = strsave (DEFAULT_SH_TYPE);
sh_set_processor_type_command (strsave (DEFAULT_SH_TYPE), 0);
add_com ("regs", class_vars, show_regs, "Print all registers");
add_com ("regs", class_vars, sh_show_regs, "Print all registers");
/* Reduce the remote write size because some CMONs can't take
more than 400 bytes in a packet. 300 seems like a safe bet. */
remote_write_size = 300;
}
/*
* DUMMY FRAMES
*
* The following code serves to maintain the dummy stack frames for
* inferior function calls (ie. when gdb calls into the inferior via
* call_function_by_hand). This code saves the machine state before
* the call in host memory, so it must maintain an independant stack
* and keep it consistant etc. I am attempting to make this code
* generic enough to be used by many targets.
*
* The cheapest and most generic way to do CALL_DUMMY on a new target
* is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to zero,
* and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember to define
* PUSH_RETURN_ADDRESS, because there won't be a call instruction to do it.
*/
/* Dummy frame. This saves the processor state just prior to setting up the
inferior function call. On most targets, the registers are saved on the
target stack, but that really slows down function calls. */
struct dummy_frame
{
struct dummy_frame *next;
CORE_ADDR pc;
CORE_ADDR fp;
CORE_ADDR sp;
char regs[REGISTER_BYTES];
};
static struct dummy_frame *dummy_frame_stack = NULL;
/* Function: find_dummy_frame(pc, fp, sp)
Search the stack of dummy frames for one matching the given PC, FP and SP.
This is the work-horse for pc_in_call_dummy and read_register_dummy */
char *
generic_find_dummy_frame (pc, fp, sp)
CORE_ADDR pc;
CORE_ADDR fp;
CORE_ADDR sp;
{
struct dummy_frame * dummyframe;
CORE_ADDR bkpt_address;
extern CORE_ADDR text_end;
#if CALL_DUMMY_LOCATION == AT_ENTRY_POINT
bkpt_address = entry_point_address () + CALL_DUMMY_BREAKPOINT_OFFSET;
if (pc != bkpt_address &&
pc != bkpt_address + DECR_PC_AFTER_BREAK)
return 0;
#endif /* AT_ENTRY_POINT */
#if CALL_DUMMY_LOCATION == BEFORE_TEXT_END
bkpt_address = text_end - CALL_DUMMY_LENGTH + CALL_DUMMY_BREAKPOINT_OFFSET;
if (pc != bkpt_address &&
pc != bkpt_address + DECR_PC_AFTER_BREAK)
return 0;
#endif /* BEFORE_TEXT_END */
#if CALL_DUMMY_LOCATION == AFTER_TEXT_END
bkpt_address = text_end + CALL_DUMMY_BREAKPOINT_OFFSET;
if (pc != bkpt_address &&
pc != bkpt_address + DECR_PC_AFTER_BREAK)
return 0;
#endif /* AFTER_TEXT_END */
for (dummyframe = dummy_frame_stack;
dummyframe;
dummyframe = dummyframe->next)
if (fp == dummyframe->fp ||
sp == dummyframe->sp)
{
#if CALL_DUMMY_LOCATION == ON_STACK
CORE_ADDR bkpt_offset; /* distance from original frame ptr to bkpt */
if (1 INNER_THAN 2)
bkpt_offset = CALL_DUMMY_BREAK_OFFSET;
else
bkpt_offset = CALL_DUMMY_LENGTH - CALL_DUMMY_BREAK_OFFSET;
if (pc + bkpt_offset == dummyframe->fp ||
pc + bkpt_offset == dummyframe->sp ||
pc + bkpt_offset + DECR_PC_AFTER_BREAK == dummyframe->fp ||
pc + bkpt_offset + DECR_PC_AFTER_BREAK == dummyframe->sp)
#endif /* ON_STACK */
return dummyframe->regs;
}
return 0;
}
/* Function: pc_in_call_dummy (pc, fp, sp)
Return true if this is a dummy frame created by gdb for an inferior call */
int
generic_pc_in_call_dummy (pc, fp, sp)
CORE_ADDR pc;
CORE_ADDR fp;
CORE_ADDR sp;
{
/* if find_dummy_frame succeeds, then PC is in a call dummy */
return (generic_find_dummy_frame (pc, fp, sp) != 0);
}
/* Function: read_register_dummy (pc, fp, sp, regno)
Find a saved register from before GDB calls a function in the inferior */
CORE_ADDR
generic_read_register_dummy (fi, regno)
struct frame_info *fi;
int regno;
{
char *dummy_regs = generic_find_dummy_frame (fi->pc, fi->frame, NULL);
if (dummy_regs)
return extract_address (&dummy_regs[REGISTER_BYTE (regno)],
REGISTER_RAW_SIZE(regno));
else
return 0;
}
/* Save all the registers on the dummy frame stack. Most ports save the
registers on the target stack. This results in lots of unnecessary memory
references, which are slow when debugging via a serial line. Instead, we
save all the registers internally, and never write them to the stack. The
registers get restored when the called function returns to the entry point,
where a breakpoint is laying in wait. */
void
generic_push_dummy_frame ()
{
struct dummy_frame *dummy_frame;
CORE_ADDR fp = read_register(FP_REGNUM);
/* check to see if there are stale dummy frames,
perhaps left over from when a longjump took us out of a
function that was called by the debugger */
dummy_frame = dummy_frame_stack;
while (dummy_frame)
if (dummy_frame->fp INNER_THAN fp) /* stale -- destroy! */
{
dummy_frame_stack = dummy_frame->next;
free (dummy_frame);
dummy_frame = dummy_frame_stack;
}
else
dummy_frame = dummy_frame->next;
dummy_frame = xmalloc (sizeof (struct dummy_frame));
read_register_bytes (0, dummy_frame->regs, REGISTER_BYTES);
dummy_frame->pc = read_register (PC_REGNUM);
dummy_frame->fp = read_register (FP_REGNUM);
dummy_frame->sp = read_register (SP_REGNUM);
dummy_frame->next = dummy_frame_stack;
dummy_frame_stack = dummy_frame;
}
/* Function: pop_dummy_frame
Restore the machine state from a saved dummy stack frame. */
void
generic_pop_dummy_frame ()
{
struct dummy_frame *dummy_frame = dummy_frame_stack;
if (!dummy_frame)
error ("Can't pop dummy frame!");
dummy_frame_stack = dummy_frame->next;
write_register_bytes (0, dummy_frame->regs, REGISTER_BYTES);
free (dummy_frame);
}
/* Function: frame_chain_valid
Returns true for a user frame or a call_function_by_hand dummy frame,
and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
int
generic_frame_chain_valid (fp, fi)
CORE_ADDR fp;
struct frame_info *fi;
{
if (PC_IN_CALL_DUMMY(FRAME_SAVED_PC(fi), fp, fp))
return 1; /* don't prune CALL_DUMMY frames */
else /* fall back to default algorithm (see frame.h) */
return (fp != 0 && !inside_entry_file (FRAME_SAVED_PC(fi)));
}