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2002-11-08 Andrew Cagney <ac131313@redhat.com>

Browse source 
* blockframe.c: Include "dummy-frame.h".
	(struct dummy_frame, dummy_frame_stack)
	(generic_find_dummy_frame, deprecated_generic_find_dummy_frame)
	(generic_pc_in_call_dummy, deprecated_read_register_dummy)
	(generic_push_dummy_frame, generic_save_dummy_frame_tos)
	(generic_save_call_dummy_addr, generic_pop_current_frame)
	(generic_pop_dummy_frame, generic_fix_call_dummy)
	(generic_fix_call_dummy, generic_call_dummy_register_unwind): Move
	dummy frame code from here...
	* dummy-frame.c: ...to here.  New file.
	* dummy-frame.h: New file.
	(generic_call_dummy_register_unwind): Declare.
	(generic_find_dummy_frame): Declare.
	* Makefile.in (SFILES): Add dummy-frame.c.
	(dummy-frame.o): Specify dependencies.
	(dummy_frame_h): Define.
	(COMMON_OBS): Add dummy-frame.o.
	(blockframe.o): Update dependencies.
This commit is contained in:
Andrew Cagney 2002-11-08 19:42:00 +00:00
parent 208d818701
commit 9c1412c1a1
5 changed files with 404 additions and 306 deletions
Download patch file Download diff file Expand all files Collapse all files

304
gdb/blockframe.c
View file

@ -35,17 +35,10 @@
#include "annotate.h"
#include "regcache.h"
#include "gdb_assert.h"
#include "dummy-frame.h"
/* Prototypes for exported functions. */
static void generic_call_dummy_register_unwind (struct frame_info *frame,
void **cache,
int regnum,
int *optimized,
enum lval_type *lval,
CORE_ADDR *addrp,
int *realnum,
void *raw_buffer);
static void frame_saved_regs_register_unwind (struct frame_info *frame,
void **cache,
int regnum,
@ -1107,244 +1100,6 @@ pc_in_call_dummy_at_entry_point (CORE_ADDR pc, CORE_ADDR sp,
}
/*
* GENERIC 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 we must maintain an independent 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 no call instruction will be
* being executed by the target. Also FRAME_CHAIN_VALID as
* generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
* generic_fix_call_dummy. */
/* Dummy frame. This saves the processor state just prior to setting
up the inferior function call. Older targets save the registers
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;
CORE_ADDR top;
struct regcache *regcache;
/* Address range of the call dummy code. Look for PC in the range
[LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */
CORE_ADDR call_lo;
CORE_ADDR call_hi;
};
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 and
FP/SP. Unlike PC_IN_CALL_DUMMY, this function doesn't need to
adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
to call this function after the PC has been adjusted. */
static struct regcache *
generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
struct dummy_frame *dummyframe;
for (dummyframe = dummy_frame_stack; dummyframe != NULL;
dummyframe = dummyframe->next)
{
/* Does the PC fall within the dummy frame's breakpoint
instruction. If not, discard this one. */
if (!(pc >= dummyframe->call_lo && pc < dummyframe->call_hi))
continue;
/* Does the FP match? */
if (dummyframe->top != 0)
{
/* If the target architecture explicitly saved the
top-of-stack before the inferior function call, assume
that that same architecture will always pass in an FP
(frame base) value that eactly matches that saved TOS.
Don't check the saved SP and SP as they can lead to false
hits. */
if (fp != dummyframe->top)
continue;
}
else
{
/* An older target that hasn't explicitly or implicitly
saved the dummy frame's top-of-stack. Try matching the
FP against the saved SP and FP. NOTE: If you're trying
to fix a problem with GDB not correctly finding a dummy
frame, check the comments that go with FRAME_ALIGN() and
SAVE_DUMMY_FRAME_TOS(). */
if (fp != dummyframe->fp && fp != dummyframe->sp)
continue;
}
/* The FP matches this dummy frame. */
return dummyframe->regcache;
}
return 0;
}
char *
deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
{
struct regcache *regcache = generic_find_dummy_frame (pc, fp);
if (regcache == NULL)
return NULL;
return deprecated_grub_regcache_for_registers (regcache);
}
/* Function: pc_in_call_dummy (pc, sp, fp)
Return true if the PC falls in a dummy frame created by gdb for an
inferior call. The code below which allows DECR_PC_AFTER_BREAK is
for infrun.c, which may give the function a PC without that
subtracted out. */
int
generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
{
struct dummy_frame *dummyframe;
for (dummyframe = dummy_frame_stack;
dummyframe != NULL;
dummyframe = dummyframe->next)
{
if ((pc >= dummyframe->call_lo)
&& (pc < dummyframe->call_hi + DECR_PC_AFTER_BREAK))
return 1;
}
return 0;
}
/* Function: read_register_dummy
Find a saved register from before GDB calls a function in the inferior */
CORE_ADDR
deprecated_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
{
struct regcache *dummy_regs = generic_find_dummy_frame (pc, fp);
if (dummy_regs)
{
/* NOTE: cagney/2002-08-12: Replaced a call to
regcache_raw_read_as_address() with a call to
regcache_cooked_read_unsigned(). The old, ...as_address
function was eventually calling extract_unsigned_integer (via
extract_address) to unpack the registers value. The below is
doing an unsigned extract so that it is functionally
equivalent. The read needs to be cooked as, otherwise, it
will never correctly return the value of a register in the
[NUM_REGS .. NUM_REGS+NUM_PSEUDO_REGS) range. */
ULONGEST val;
regcache_cooked_read_unsigned (dummy_regs, regno, &val);
return val;
}
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 (void)
{
struct dummy_frame *dummy_frame;
CORE_ADDR fp = (get_current_frame ())->frame;
/* 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 (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
{
dummy_frame_stack = dummy_frame->next;
regcache_xfree (dummy_frame->regcache);
xfree (dummy_frame);
dummy_frame = dummy_frame_stack;
}
else
dummy_frame = dummy_frame->next;
dummy_frame = xmalloc (sizeof (struct dummy_frame));
dummy_frame->regcache = regcache_xmalloc (current_gdbarch);
dummy_frame->pc = read_pc ();
dummy_frame->sp = read_sp ();
dummy_frame->top = 0;
dummy_frame->fp = fp;
regcache_cpy (dummy_frame->regcache, current_regcache);
dummy_frame->next = dummy_frame_stack;
dummy_frame_stack = dummy_frame;
}
void
generic_save_dummy_frame_tos (CORE_ADDR sp)
{
dummy_frame_stack->top = sp;
}
/* Record the upper/lower bounds on the address of the call dummy. */
void
generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi)
{
dummy_frame_stack->call_lo = lo;
dummy_frame_stack->call_hi = hi;
}
/* Restore the machine state from either the saved dummy stack or a
real stack frame. */
void
generic_pop_current_frame (void (*popper) (struct frame_info * frame))
{
struct frame_info *frame = get_current_frame ();
if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
generic_pop_dummy_frame ();
else
(*popper) (frame);
}
/* Function: pop_dummy_frame
Restore the machine state from a saved dummy stack frame. */
void
generic_pop_dummy_frame (void)
{
struct dummy_frame *dummy_frame = dummy_frame_stack;
/* FIXME: what if the first frame isn't the right one, eg..
because one call-by-hand function has done a longjmp into another one? */
if (!dummy_frame)
error ("Can't pop dummy frame!");
dummy_frame_stack = dummy_frame->next;
regcache_cpy (current_regcache, dummy_frame->regcache);
flush_cached_frames ();
regcache_xfree (dummy_frame->regcache);
xfree (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 */
@ -1373,63 +1128,6 @@ generic_func_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
&& !inside_entry_func ((fi)->pc));
}
/* Function: fix_call_dummy
Stub function. Generic dummy frames typically do not need to fix
the frame being created */
void
generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
struct value **args, struct type *type, int gcc_p)
{
return;
}
/* Given a call-dummy dummy-frame, return the registers. Here the
register value is taken from the local copy of the register buffer. */
static void
generic_call_dummy_register_unwind (struct frame_info *frame, void **cache,
int regnum, int *optimized,
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnum, void *bufferp)
{
gdb_assert (frame != NULL);
gdb_assert (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame));
/* Describe the register's location. Generic dummy frames always
have the register value in an ``expression''. */
*optimized = 0;
*lvalp = not_lval;
*addrp = 0;
*realnum = -1;
/* If needed, find and return the value of the register. */
if (bufferp != NULL)
{
struct regcache *registers;
#if 1
/* Get the address of the register buffer that contains all the
saved registers for this dummy frame. Cache that address. */
registers = (*cache);
if (registers == NULL)
{
registers = generic_find_dummy_frame (frame->pc, frame->frame);
(*cache) = registers;
}
#else
/* Get the address of the register buffer that contains the
saved registers and then extract the value from that. */
registers = generic_find_dummy_frame (frame->pc, frame->frame);
#endif
gdb_assert (registers != NULL);
/* Return the actual value. */
/* Use the regcache_cooked_read() method so that it, on the fly,
constructs either a raw or pseudo register from the raw
register cache. */
regcache_cooked_read (registers, regnum, bufferp);
}
}
/* Return the register saved in the simplistic ``saved_regs'' cache.
If the value isn't here AND a value is needed, try the next inner
most frame. */