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* alpha-tdep.c (INSN_OPCODE, MEM_RA, MEM_RB, MEM_DISP, BR_RA)

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(OPR_FUNCTION, OPR_HAS_IMMEDIATE, OPR_RA, OPR_RC, OPR_LIT): New macros.
	(lda_opcode, stq_opcode, bne_opcode, subq_opcode, subq_function):
	New constants.
	(alpha_heuristic_analyze_probing_loop): New function.
	(alpha_heuristic_frame_unwind_cache): In the prologue analysis, detect
	and handle cases when a stack probe loop is generated.
	* alpha-mdebug-tdep.c (alpha_mdebug_frameless): New function.
	(alpha_mdebug_max_frame_size_exceeded): New function.
	(alpha_mdebug_after_prologue): Use alpha_mdebug_frameless.
	(alpha_mdebug_frame_sniffer, alpha_mdebug_frame_base_sniffer):
	Return 0 when the maximum debuggable frame size has been exceeded.
This commit is contained in:
Jerome Guitton 2010-04-23 15:14:22 +00:00
parent e4166a49ea
commit 3a48e6ff66
3 changed files with 183 additions and 2 deletions
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15
gdb/ChangeLog
View File

@ -1,3 +1,18 @@
2010-04-23 Jerome Guitton <guitton@adacore.com>
* alpha-tdep.c (INSN_OPCODE, MEM_RA, MEM_RB, MEM_DISP, BR_RA)
(OPR_FUNCTION, OPR_HAS_IMMEDIATE, OPR_RA, OPR_RC, OPR_LIT): New macros.
(lda_opcode, stq_opcode, bne_opcode, subq_opcode, subq_function):
New constants.
(alpha_heuristic_analyze_probing_loop): New function.
(alpha_heuristic_frame_unwind_cache): In the prologue analysis, detect
and handle cases when a stack probe loop is generated.
* alpha-mdebug-tdep.c (alpha_mdebug_frameless): New function.
(alpha_mdebug_max_frame_size_exceeded): New function.
(alpha_mdebug_after_prologue): Use alpha_mdebug_frameless.
(alpha_mdebug_frame_sniffer, alpha_mdebug_frame_base_sniffer):
Return 0 when the maximum debuggable frame size has been exceeded.
2010-04-23 Joel Brobecker <brobecker@adacore.com>
Fix ARI warning.

36
gdb/alpha-mdebug-tdep.c
View File

@ -136,6 +136,15 @@ find_proc_desc (CORE_ADDR pc)
return proc_desc;
}
/* Return a non-zero result if the function is frameless; zero otherwise. */
static int
alpha_mdebug_frameless (struct mdebug_extra_func_info *proc_desc)
{
return (PROC_FRAME_REG (proc_desc) == ALPHA_SP_REGNUM
&& PROC_FRAME_OFFSET (proc_desc) == 0);
}
/* This returns the PC of the first inst after the prologue. If we can't
find the prologue, then return 0. */
@ -146,8 +155,7 @@ alpha_mdebug_after_prologue (CORE_ADDR pc, struct mdebug_extra_func_info *proc_d
{
/* If function is frameless, then we need to do it the hard way. I
strongly suspect that frameless always means prologueless... */
if (PROC_FRAME_REG (proc_desc) == ALPHA_SP_REGNUM
&& PROC_FRAME_OFFSET (proc_desc) == 0)
if (alpha_mdebug_frameless (proc_desc))
return 0;
}
@ -283,6 +291,20 @@ alpha_mdebug_frame_prev_register (struct frame_info *this_frame,
return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
}
/* Return a non-zero result if the size of the stack frame exceeds the
maximum debuggable frame size (512 Kbytes); zero otherwise. */
static int
alpha_mdebug_max_frame_size_exceeded (struct mdebug_extra_func_info *proc_desc)
{
/* If frame offset is null, we can be in two cases: either the
function is frameless (the stack frame is null) or its
frame exceeds the maximum debuggable frame size (512 Kbytes). */
return (PROC_FRAME_OFFSET (proc_desc) == 0
&& !alpha_mdebug_frameless (proc_desc));
}
static int
alpha_mdebug_frame_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
@ -302,6 +324,11 @@ alpha_mdebug_frame_sniffer (const struct frame_unwind *self,
if (alpha_mdebug_in_prologue (pc, proc_desc))
return 0;
/* If the maximum debuggable frame size has been exceeded, the
proc desc is bogus. Fall back on the heuristic unwinder. */
if (alpha_mdebug_max_frame_size_exceeded (proc_desc))
return 0;
return 1;
}
@ -362,6 +389,11 @@ alpha_mdebug_frame_base_sniffer (struct frame_info *this_frame)
if (proc_desc == NULL)
return NULL;
/* If the maximum debuggable frame size has been exceeded, the
proc desc is bogus. Fall back on the heuristic unwinder. */
if (alpha_mdebug_max_frame_size_exceeded (proc_desc))
return 0;
return &alpha_mdebug_frame_base;
}

134
gdb/alpha-tdep.c
View File

@ -46,6 +46,36 @@
#include "alpha-tdep.h"
/* Instruction decoding. The notations for registers, immediates and
opcodes are the same as the one used in Compaq's Alpha architecture
handbook. */
#define INSN_OPCODE(insn) ((insn & 0xfc000000) >> 26)
/* Memory instruction format */
#define MEM_RA(insn) ((insn & 0x03e00000) >> 21)
#define MEM_RB(insn) ((insn & 0x001f0000) >> 16)
#define MEM_DISP(insn) \
(((insn & 0x8000) == 0) ? (insn & 0xffff) : -((-insn) & 0xffff))
static const int lda_opcode = 0x08;
static const int stq_opcode = 0x2d;
/* Branch instruction format */
#define BR_RA(insn) MEM_RA(insn)
static const int bne_opcode = 0x3d;
/* Operate instruction format */
#define OPR_FUNCTION(insn) ((insn & 0xfe0) >> 5)
#define OPR_HAS_IMMEDIATE(insn) ((insn & 0x1000) == 0x1000)
#define OPR_RA(insn) MEM_RA(insn)
#define OPR_RC(insn) ((insn & 0x1f))
#define OPR_LIT(insn) ((insn & 0x1fe000) >> 13)
static const int subq_opcode = 0x10;
static const int subq_function = 0x29;
/* Return the name of the REGNO register.
@ -1000,6 +1030,108 @@ struct alpha_heuristic_unwind_cache
int return_reg;
};
/* If a probing loop sequence starts at PC, simulate it and compute
FRAME_SIZE and PC after its execution. Otherwise, return with PC and
FRAME_SIZE unchanged. */
static void
alpha_heuristic_analyze_probing_loop (struct gdbarch *gdbarch, CORE_ADDR *pc,
int *frame_size)
{
CORE_ADDR cur_pc = *pc;
int cur_frame_size = *frame_size;
int nb_of_iterations, reg_index, reg_probe;
unsigned int insn;
/* The following pattern is recognized as a probing loop:
lda REG_INDEX,NB_OF_ITERATIONS
lda REG_PROBE,<immediate>(sp)
LOOP_START:
stq zero,<immediate>(REG_PROBE)
subq REG_INDEX,0x1,REG_INDEX
lda REG_PROBE,<immediate>(REG_PROBE)
bne REG_INDEX, LOOP_START
lda sp,<immediate>(REG_PROBE)
If anything different is found, the function returns without
changing PC and FRAME_SIZE. Otherwise, PC will point immediately
after this sequence, and FRAME_SIZE will be updated.
*/
/* lda REG_INDEX,NB_OF_ITERATIONS */
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != lda_opcode)
return;
reg_index = MEM_RA (insn);
nb_of_iterations = MEM_DISP (insn);
/* lda REG_PROBE,<immediate>(sp) */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != lda_opcode
|| MEM_RB (insn) != ALPHA_SP_REGNUM)
return;
reg_probe = MEM_RA (insn);
cur_frame_size -= MEM_DISP (insn);
/* stq zero,<immediate>(REG_PROBE) */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != stq_opcode
|| MEM_RA (insn) != 0x1f
|| MEM_RB (insn) != reg_probe)
return;
/* subq REG_INDEX,0x1,REG_INDEX */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != subq_opcode
|| !OPR_HAS_IMMEDIATE (insn)
|| OPR_FUNCTION (insn) != subq_function
|| OPR_LIT(insn) != 1
|| OPR_RA (insn) != reg_index
|| OPR_RC (insn) != reg_index)
return;
/* lda REG_PROBE,<immediate>(REG_PROBE) */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != lda_opcode
|| MEM_RA (insn) != reg_probe
|| MEM_RB (insn) != reg_probe)
return;
cur_frame_size -= MEM_DISP (insn) * nb_of_iterations;
/* bne REG_INDEX, LOOP_START */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != bne_opcode
|| MEM_RA (insn) != reg_index)
return;
/* lda sp,<immediate>(REG_PROBE) */
cur_pc += ALPHA_INSN_SIZE;
insn = alpha_read_insn (gdbarch, cur_pc);
if (INSN_OPCODE (insn) != lda_opcode
|| MEM_RA (insn) != ALPHA_SP_REGNUM
|| MEM_RB (insn) != reg_probe)
return;
cur_frame_size -= MEM_DISP (insn);
*pc = cur_pc;
*frame_size = cur_frame_size;
}
static struct alpha_heuristic_unwind_cache *
alpha_heuristic_frame_unwind_cache (struct frame_info *this_frame,
void **this_prologue_cache,
@ -1116,6 +1248,8 @@ alpha_heuristic_frame_unwind_cache (struct frame_info *this_frame,
frame_reg = ALPHA_GCC_FP_REGNUM;
else if (word == 0x47fe040f) /* bis zero,sp,fp */
frame_reg = ALPHA_GCC_FP_REGNUM;
alpha_heuristic_analyze_probing_loop (gdbarch, &cur_pc, &frame_size);
}
/* If we haven't found a valid return address register yet, keep