This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
Re: [PATCH]: Handle sparc skipping unimp instruction with dwarf2
From: "Mark Kettenis" <mark.kettenis@xs4all.nl>
Date: Wed, 5 Apr 2006 11:30:07 +0200 (CEST)
> > This is very easy to fix with just a little bit of infrastructure
> > adjustments. What we do is we pass in the fs->pc to the dwarf2 reg
> > init function. We use this PC to find out if the function we are
> > analyzing returns a struct or not. If so, we adjust the PC and NPC
> > by 4.
>
> Rather than passing the PC, I think you should actually pass down
> NEXT_FRAME. Other targets might have different requirements, and you
> can unwind the PC from NEXT_FRAME in the sparc code.
>
> Oh, and could you rename sparc32_dwarf2_struct_return_p() to
> sparc32_struct_return_p() and make sparc32_frame_cache() use that function
> too? The check isn't really dwarf2-specific and duplication of code
> is bad!
Easier said than done :-) The else block of that code can't be used in
the dwarf2 case, because when we can't find the "sym" for the function
it wants to have the sparc frame cache information, such as whether
this is a frameless function or not. It uses this to determine
whether to look at O7 or I7 as the return address register.
I tried to consolidate as much as I could. In the dwarf2 case,
if we have dwarf2 unwind information, and we can't find a symbol
for the same function, we've got other problems right? :-) The
only other option I can think of is to pass in the retaddr_column
to the ->init_reg() method but that seems unnecessary.
Anyways, how does this look? Ok to commit?
2006-04-05 David S. Miller <davem@sunset.davemloft.net>
* dwarf2-frame.c (dwarf2_frame_ops init_reg): Add "next_frame"
argument.
(dwarf2_frame_default_init_reg): Likewise.
(dwarf2_frame_set_init_reg): Update init_reg arg.
(dwarf2_frame_init_reg): Take "next_frame" and pass it to
ops->init_reg().
(dwarf2_frame_cache): Pass next_frame to dwarf2_frame_init_reg.
* dwarf2-frame.h (dwarf2-frame_set_init_reg): Update declaration.
* cris-tdep.c (cris_dwarf2_frame_init_reg): Add next_frame arg.
* s390-tdep.c (s390_dwarf2_frame_init_reg): Likewise.
* sh-tdep.c (sh_dwarf2_frame_init_reg): Likewise.
* sparc64-tdep.c (sparc64_dwarf2_frame_init_reg): Likewise.
* sparc-tdep.c (sparc32_struct_return_from_sym): New function.
(sparc32_frame_cache): Call it.
(sparc32_dwarf2_struct_return_p): New function.
(sparc_dwarf2_frame_init_reg): Use it to determine if the function
returns a structure and thus we have to indicate the return PC and
NPC are 4 bytes later than usual.
--- ./dwarf2-frame.h.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./dwarf2-frame.h 2006-04-05 11:57:19.000000000 -0700
@@ -79,7 +79,8 @@ struct dwarf2_frame_state_reg
extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
void (*init_reg) (struct gdbarch *, int,
- struct dwarf2_frame_state_reg *));
+ struct dwarf2_frame_state_reg *,
+ struct frame_info *));
/* Set the architecture-specific signal trampoline recognition
function for GDBARCH to SIGNAL_FRAME_P. */
--- ./dwarf2-frame.c.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./dwarf2-frame.c 2006-04-05 11:58:38.000000000 -0700
@@ -506,7 +506,8 @@ static struct gdbarch_data *dwarf2_frame
struct dwarf2_frame_ops
{
/* Pre-initialize the register state REG for register REGNUM. */
- void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *);
+ void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *,
+ struct frame_info *);
/* Check whether the frame preceding NEXT_FRAME will be a signal
trampoline. */
@@ -518,7 +519,8 @@ struct dwarf2_frame_ops
static void
dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
/* If we have a register that acts as a program counter, mark it as
a destination for the return address. If we have a register that
@@ -570,7 +572,8 @@ dwarf2_frame_init (struct obstack *obsta
void
dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
void (*init_reg) (struct gdbarch *, int,
- struct dwarf2_frame_state_reg *))
+ struct dwarf2_frame_state_reg *,
+ struct frame_info *))
{
struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
@@ -581,11 +584,12 @@ dwarf2_frame_set_init_reg (struct gdbarc
static void
dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
- ops->init_reg (gdbarch, regnum, reg);
+ ops->init_reg (gdbarch, regnum, reg, next_frame);
}
/* Set the architecture-specific signal trampoline recognition
@@ -713,7 +717,7 @@ dwarf2_frame_cache (struct frame_info *n
int regnum;
for (regnum = 0; regnum < num_regs; regnum++)
- dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum]);
+ dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], next_frame);
}
/* Go through the DWARF2 CFI generated table and save its register
--- ./cris-tdep.c.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./cris-tdep.c 2006-04-05 11:59:07.000000000 -0700
@@ -1852,7 +1852,8 @@ cris_dwarf2_reg_to_regnum (int reg)
static void
cris_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
/* The return address column. */
if (regnum == PC_REGNUM)
--- ./s390-tdep.c.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./s390-tdep.c 2006-04-05 11:59:20.000000000 -0700
@@ -2279,7 +2279,8 @@ s390_unwind_sp (struct gdbarch *gdbarch,
static void
s390_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
--- ./sh-tdep.c.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./sh-tdep.c 2006-04-05 11:59:32.000000000 -0700
@@ -2123,7 +2123,8 @@ sh_sh2a_register_sim_regno (int nr)
static void
sh_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
/* Mark the PC as the destination for the return address. */
if (regnum == PC_REGNUM)
--- ./sparc64-tdep.c.~1~ 2006-04-05 11:32:55.000000000 -0700
+++ ./sparc64-tdep.c 2006-04-05 11:59:49.000000000 -0700
@@ -1106,7 +1106,8 @@ sparc64_return_value (struct gdbarch *gd
static void
sparc64_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
switch (regnum)
{
--- ./sparc-tdep.c.~1~ 2006-04-05 11:34:52.000000000 -0700
+++ ./sparc-tdep.c 2006-04-05 12:07:20.000000000 -0700
@@ -680,6 +680,23 @@ sparc_frame_cache (struct frame_info *ne
return cache;
}
+static int
+sparc32_struct_return_from_sym (struct symbol *sym)
+{
+ struct type *type = check_typedef (SYMBOL_TYPE (sym));
+ enum type_code code = TYPE_CODE (type);
+
+ if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
+ {
+ type = check_typedef (TYPE_TARGET_TYPE (type));
+ if (sparc_structure_or_union_p (type)
+ || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16))
+ return 1;
+ }
+
+ return 0;
+}
+
struct sparc_frame_cache *
sparc32_frame_cache (struct frame_info *next_frame, void **this_cache)
{
@@ -694,16 +711,7 @@ sparc32_frame_cache (struct frame_info *
sym = find_pc_function (cache->pc);
if (sym)
{
- struct type *type = check_typedef (SYMBOL_TYPE (sym));
- enum type_code code = TYPE_CODE (type);
-
- if (code == TYPE_CODE_FUNC || code == TYPE_CODE_METHOD)
- {
- type = check_typedef (TYPE_TARGET_TYPE (type));
- if (sparc_structure_or_union_p (type)
- || (sparc_floating_p (type) && TYPE_LENGTH (type) == 16))
- cache->struct_return_p = 1;
- }
+ cache->struct_return_p = sparc32_struct_return_from_sym (sym);
}
else
{
@@ -995,10 +1003,24 @@ sparc32_stabs_argument_has_addr (struct
|| (sparc_floating_p (type) && TYPE_LENGTH (type) == 16));
}
+static int
+sparc32_dwarf2_struct_return_p (struct frame_info *next_frame)
+{
+ CORE_ADDR pc = frame_unwind_address_in_block (next_frame);
+ struct symbol *sym = find_pc_function (pc);
+
+ if (sym)
+ return sparc32_struct_return_from_sym (sym);
+ return 0;
+}
+
static void
sparc32_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
- struct dwarf2_frame_state_reg *reg)
+ struct dwarf2_frame_state_reg *reg,
+ struct frame_info *next_frame)
{
+ int off;
+
switch (regnum)
{
case SPARC_G0_REGNUM:
@@ -1011,12 +1033,14 @@ sparc32_dwarf2_frame_init_reg (struct gd
reg->how = DWARF2_FRAME_REG_CFA;
break;
case SPARC32_PC_REGNUM:
- reg->how = DWARF2_FRAME_REG_RA_OFFSET;
- reg->loc.offset = 8;
- break;
case SPARC32_NPC_REGNUM:
reg->how = DWARF2_FRAME_REG_RA_OFFSET;
- reg->loc.offset = 12;
+ off = 8;
+ if (sparc32_dwarf2_struct_return_p (next_frame))
+ off += 4;
+ if (regnum == SPARC32_NPC_REGNUM)
+ off += 4;
+ reg->loc.offset = off;
break;
}
}