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Re: [PATCH] Fix DW_CFA_restore_extended parsing
On Thu, 2007-12-20 at 14:03 -0800, Jim Blandy wrote:
> On Dec 20, 2007 12:22 PM, Luis Machado <luisgpm@linux.vnet.ibm.com> wrote:
> > This simple patch fixes the issue. Any thoughts? Ok to commit?
>
> The only difference between those two opcodes is in their encoding ---
> the action to be performed is identical. It seems silly to duplicate
> the code. Could you pull the common code out into its own function,
> and then have both cases simply parse their arguments and call the
> function?
Like so?
--
Luis Machado
Software Engineer
IBM Linux Technology Center
2007-12-21 Luis Machado <luisgpm@br.ibm.com>
* dwarf2-frame.c (execute_cfa_program): Call dwarf2_restore_rule
function to handle required actions for the DW_CFA_restore and
DW_CFA_restore_extended instructions.
(dwarf2_restore_rule): New function.
Index: gdb/dwarf2-frame.c
===================================================================
--- gdb.orig/dwarf2-frame.c 2007-10-21 12:33:37.000000000 -0700
+++ gdb/dwarf2-frame.c 2007-12-21 05:54:31.000000000 -0800
@@ -268,6 +268,36 @@
_("Support for DW_OP_GNU_push_tls_address is unimplemented"));
}
+/* Execute the required actions for both the DW_CFA_restore and
+DW_CFA_restore_extended instructions. */
+static void
+dwarf2_restore_rule (struct gdbarch *gdbarch, ULONGEST reg_num,
+ struct dwarf2_frame_state *fs, int eh_frame_p)
+{
+ ULONGEST reg;
+
+ gdb_assert (fs->initial.reg);
+ reg = dwarf2_frame_adjust_regnum (gdbarch, reg_num, eh_frame_p);
+ dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
+
+ /* Check if this register was explicitly initialized in the
+ CIE initial instructions. If not, default the rule to
+ UNSPECIFIED. */
+ if (reg < fs->initial.num_regs)
+ fs->regs.reg[reg] = fs->initial.reg[reg];
+ else
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED;
+
+ if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED)
+ complaint (&symfile_complaints, _("\
+incomplete CFI data; DW_CFA_restore unspecified\n\
+register %s (#%d) at 0x%s"),
+ gdbarch_register_name
+ (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
+ gdbarch_dwarf2_reg_to_regnum (gdbarch, reg),
+ paddr (fs->pc));
+}
+
static CORE_ADDR
execute_stack_op (gdb_byte *exp, ULONGEST len,
struct frame_info *next_frame, CORE_ADDR initial)
@@ -324,23 +354,8 @@
}
else if ((insn & 0xc0) == DW_CFA_restore)
{
- gdb_assert (fs->initial.reg);
reg = insn & 0x3f;
- reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
- dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- if (reg < fs->initial.num_regs)
- fs->regs.reg[reg] = fs->initial.reg[reg];
- else
- fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNSPECIFIED;
-
- if (fs->regs.reg[reg].how == DWARF2_FRAME_REG_UNSPECIFIED)
- complaint (&symfile_complaints, _("\
-incomplete CFI data; DW_CFA_restore unspecified\n\
-register %s (#%d) at 0x%s"),
- gdbarch_register_name
- (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
- gdbarch_dwarf2_reg_to_regnum (gdbarch, reg),
- paddr (fs->pc));
+ dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p);
}
else
{
@@ -378,11 +393,8 @@
break;
case DW_CFA_restore_extended:
- gdb_assert (fs->initial.reg);
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
- reg = dwarf2_frame_adjust_regnum (gdbarch, reg, eh_frame_p);
- dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg] = fs->initial.reg[reg];
+ dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p);
break;
case DW_CFA_undefined: