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[commit] Use prologue-value.c for arm_analyze_prologue
- From: Daniel Jacobowitz <drow at false dot org>
- To: gdb-patches at sourceware dot org
- Date: Wed, 10 Oct 2007 10:11:25 -0400
- Subject: [commit] Use prologue-value.c for arm_analyze_prologue
This is a cleanup I've been meaning to do for a while. It switches
the ARM prologue analyzer from an ad-hoc scanner to the mighty slick
prologue-value.[ch] infrastructure. There are no functional changes,
but if someone wants to enhance the prologue analyzer later it should
be a bit simpler. I also removed the no longer required distinction
between frame size and frame offset.
Tested on arm-none-eabi, with the dwarf2 unwinder disabled. Checked in.
--
Daniel Jacobowitz
CodeSourcery
2007-10-10 Daniel Jacobowitz <dan@codesourcery.com>
* arm-tdep.c (struct arm_prologue_cache): Remove frameoffset.
(thumb_analyze_prologue): Move pv_area_store_would_trash call
out of loop. Do not set cache->frameoffset.
(arm_scan_prologue): Use prologue-value mechanism. Do not set
frameoffset. Simplify framesize.
(arm_make_prologue_cache, arm_normal_frame_base): Do not use
frameoffset.
* arm-tdep.h (enum gdb_regnum): Add ARM_IP_REGNUM.
Index: arm-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/arm-tdep.c,v
retrieving revision 1.244
diff -u -p -r1.244 arm-tdep.c
--- arm-tdep.c 8 Oct 2007 12:49:03 -0000 1.244
+++ arm-tdep.c 10 Oct 2007 14:00:28 -0000
@@ -187,13 +187,11 @@ struct arm_prologue_cache
to identify this frame. */
CORE_ADDR prev_sp;
- /* The frame base for this frame is just prev_sp + frame offset -
- frame size. FRAMESIZE is the size of this stack frame, and
- FRAMEOFFSET if the initial offset from the stack pointer (this
- frame's stack pointer, not PREV_SP) to the frame base. */
+ /* The frame base for this frame is just prev_sp - frame size.
+ FRAMESIZE is the distance from the frame pointer to the
+ initial stack pointer. */
int framesize;
- int frameoffset;
/* The register used to hold the frame pointer for this frame. */
int framereg;
@@ -292,7 +290,9 @@ thumb_analyze_prologue (struct gdbarch *
{
int regno;
int mask;
- int stop = 0;
+
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
/* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
whether to save LR (R14). */
@@ -302,19 +302,10 @@ thumb_analyze_prologue (struct gdbarch *
for (regno = ARM_LR_REGNUM; regno >= 0; regno--)
if (mask & (1 << regno))
{
- if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
- {
- stop = 1;
- break;
- }
-
regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM],
-4);
pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
}
-
- if (stop)
- break;
}
else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR
sub sp, #simm */
@@ -370,9 +361,6 @@ thumb_analyze_prologue (struct gdbarch *
return start;
}
- /* frameoffset is unused for this unwinder. */
- cache->frameoffset = 0;
-
if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
{
/* Frame pointer is fp. Frame size is constant. */
@@ -652,14 +640,17 @@ arm_scan_prologue (struct frame_info *ne
struct arm_prologue_cache *cache)
{
struct gdbarch *gdbarch = get_frame_arch (next_frame);
- int regno, sp_offset, fp_offset, ip_offset;
+ int regno;
CORE_ADDR prologue_start, prologue_end, current_pc;
CORE_ADDR prev_pc = frame_pc_unwind (next_frame);
+ pv_t regs[ARM_FPS_REGNUM];
+ struct pv_area *stack;
+ struct cleanup *back_to;
+ CORE_ADDR offset;
/* Assume there is no frame until proven otherwise. */
cache->framereg = ARM_SP_REGNUM;
cache->framesize = 0;
- cache->frameoffset = 0;
/* Check for Thumb prologue. */
if (arm_pc_is_thumb (prev_pc))
@@ -754,7 +745,12 @@ arm_scan_prologue (struct frame_info *ne
in which case it is often (but not always) replaced by
"str lr, [sp, #-4]!". - Michael Snyder, 2002-04-23] */
- sp_offset = fp_offset = ip_offset = 0;
+ for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
+ regs[regno] = pv_register (regno, 0);
+ stack = make_pv_area (ARM_SP_REGNUM);
+ back_to = make_cleanup_free_pv_area (stack);
+
+ regs[ARM_PC_REGNUM] = pv_unknown ();
for (current_pc = prologue_start;
current_pc < prologue_end;
@@ -764,7 +760,7 @@ arm_scan_prologue (struct frame_info *ne
if (insn == 0xe1a0c00d) /* mov ip, sp */
{
- ip_offset = 0;
+ regs[ARM_IP_REGNUM] = regs[ARM_SP_REGNUM];
continue;
}
else if ((insn & 0xfffff000) == 0xe28dc000) /* add ip, sp #n */
@@ -772,7 +768,7 @@ arm_scan_prologue (struct frame_info *ne
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
- ip_offset = imm;
+ regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], imm);
continue;
}
else if ((insn & 0xfffff000) == 0xe24dc000) /* sub ip, sp #n */
@@ -780,13 +776,15 @@ arm_scan_prologue (struct frame_info *ne
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
- ip_offset = -imm;
+ regs[ARM_IP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
continue;
}
else if (insn == 0xe52de004) /* str lr, [sp, #-4]! */
{
- sp_offset -= 4;
- cache->saved_regs[ARM_LR_REGNUM].addr = sp_offset;
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[ARM_LR_REGNUM]);
continue;
}
else if ((insn & 0xffff0000) == 0xe92d0000)
@@ -796,12 +794,15 @@ arm_scan_prologue (struct frame_info *ne
{
int mask = insn & 0xffff;
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+
/* Calculate offsets of saved registers. */
for (regno = ARM_PC_REGNUM; regno >= 0; regno--)
if (mask & (1 << regno))
{
- sp_offset -= 4;
- cache->saved_regs[regno].addr = sp_offset;
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -4);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 4, regs[regno]);
}
}
else if ((insn & 0xffffc000) == 0xe54b0000 || /* strb rx,[r11,#-n] */
@@ -823,22 +824,24 @@ arm_scan_prologue (struct frame_info *ne
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
- fp_offset = -imm + ip_offset;
- cache->framereg = ARM_FP_REGNUM;
+ regs[ARM_FP_REGNUM] = pv_add_constant (regs[ARM_IP_REGNUM], -imm);
}
else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
{
unsigned imm = insn & 0xff; /* immediate value */
unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
imm = (imm >> rot) | (imm << (32 - rot));
- sp_offset -= imm;
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -imm);
}
else if ((insn & 0xffff7fff) == 0xed6d0103 /* stfe f?, [sp, -#c]! */
&& gdbarch_tdep (gdbarch)->have_fpa_registers)
{
- sp_offset -= 12;
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
regno = ARM_F0_REGNUM + ((insn >> 12) & 0x07);
- cache->saved_regs[regno].addr = sp_offset;
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 12, regs[regno]);
}
else if ((insn & 0xffbf0fff) == 0xec2d0200 /* sfmfd f0, 4, [sp!] */
&& gdbarch_tdep (gdbarch)->have_fpa_registers)
@@ -846,6 +849,9 @@ arm_scan_prologue (struct frame_info *ne
int n_saved_fp_regs;
unsigned int fp_start_reg, fp_bound_reg;
+ if (pv_area_store_would_trash (stack, regs[ARM_SP_REGNUM]))
+ break;
+
if ((insn & 0x800) == 0x800) /* N0 is set */
{
if ((insn & 0x40000) == 0x40000) /* N1 is set */
@@ -865,8 +871,9 @@ arm_scan_prologue (struct frame_info *ne
fp_bound_reg = fp_start_reg + n_saved_fp_regs;
for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
{
- sp_offset -= 12;
- cache->saved_regs[fp_start_reg++].addr = sp_offset;
+ regs[ARM_SP_REGNUM] = pv_add_constant (regs[ARM_SP_REGNUM], -12);
+ pv_area_store (stack, regs[ARM_SP_REGNUM], 12,
+ regs[fp_start_reg++]);
}
}
else if ((insn & 0xf0000000) != 0xe0000000)
@@ -879,14 +886,32 @@ arm_scan_prologue (struct frame_info *ne
continue;
}
- /* The frame size is just the negative of the offset (from the
- original SP) of the last thing thing we pushed on the stack.
- The frame offset is [new FP] - [new SP]. */
- cache->framesize = -sp_offset;
- if (cache->framereg == ARM_FP_REGNUM)
- cache->frameoffset = fp_offset - sp_offset;
+ /* The frame size is just the distance from the frame register
+ to the original stack pointer. */
+ if (pv_is_register (regs[ARM_FP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Frame pointer is fp. */
+ cache->framereg = ARM_FP_REGNUM;
+ cache->framesize = -regs[ARM_FP_REGNUM].k;
+ }
+ else if (pv_is_register (regs[ARM_SP_REGNUM], ARM_SP_REGNUM))
+ {
+ /* Try the stack pointer... this is a bit desperate. */
+ cache->framereg = ARM_SP_REGNUM;
+ cache->framesize = -regs[ARM_SP_REGNUM].k;
+ }
else
- cache->frameoffset = 0;
+ {
+ /* We're just out of luck. We don't know where the frame is. */
+ cache->framereg = -1;
+ cache->framesize = 0;
+ }
+
+ for (regno = 0; regno < ARM_FPS_REGNUM; regno++)
+ if (pv_area_find_reg (stack, gdbarch, regno, &offset))
+ cache->saved_regs[regno].addr = offset;
+
+ do_cleanups (back_to);
}
static struct arm_prologue_cache *
@@ -905,7 +930,7 @@ arm_make_prologue_cache (struct frame_in
if (unwound_fp == 0)
return cache;
- cache->prev_sp = unwound_fp + cache->framesize - cache->frameoffset;
+ cache->prev_sp = unwound_fp + cache->framesize;
/* Calculate actual addresses of saved registers using offsets
determined by arm_scan_prologue. */
@@ -1057,7 +1082,7 @@ arm_normal_frame_base (struct frame_info
*this_cache = arm_make_prologue_cache (next_frame);
cache = *this_cache;
- return cache->prev_sp + cache->frameoffset - cache->framesize;
+ return cache->prev_sp - cache->framesize;
}
struct frame_base arm_normal_base = {
Index: arm-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/arm-tdep.h,v
retrieving revision 1.27
diff -u -p -r1.27 arm-tdep.h
--- arm-tdep.h 27 Sep 2007 18:48:33 -0000 1.27
+++ arm-tdep.h 10 Oct 2007 14:00:28 -0000
@@ -29,6 +29,7 @@ enum gdb_regnum {
ARM_A1_REGNUM = 0, /* first integer-like argument */
ARM_A4_REGNUM = 3, /* last integer-like argument */
ARM_AP_REGNUM = 11,
+ ARM_IP_REGNUM = 12,
ARM_SP_REGNUM = 13, /* Contains address of top of stack */
ARM_LR_REGNUM = 14, /* address to return to from a function call */
ARM_PC_REGNUM = 15, /* Contains program counter */