/* Frame unwinder for frames with DWARF Call Frame Information.
- Copyright 2003 Free Software Foundation, Inc.
+ Copyright 2003, 2004 Free Software Foundation, Inc.
Contributed by Mark Kettenis.
/* Structure describing a frame state. */
-enum dwarf2_reg_rule
-{
- /* Make certain that 0 maps onto the correct enum value - the
- corresponding structure is being initialized using memset zero.
- This indicates that CFI didn't provide any information at all
- about a register - leaving how to obtain it's value totally
- unspecified. */
- REG_UNSPECIFIED = 0,
- /* The term "undefined" comes from the DWARF2 CFI spec which this
- code is moddeling - it indicates that the register's value is
- "undefined". */
- /* NOTE: cagney/2003-09-08: GCC uses the less formal term "unsaved"
- - it's definition is a combination of REG_UNDEFINED and
- REG_UNSPECIFIED - the failure to differentiate the two helps
- explain a few problems with the CFI GCC outputs. */
- REG_UNDEFINED,
- REG_SAVED_OFFSET,
- REG_SAVED_REG,
- REG_SAVED_EXP,
- REG_SAME_VALUE
-};
-
struct dwarf2_frame_state
{
/* Each register save state can be described in terms of a CFA slot,
another register, or a location expression. */
struct dwarf2_frame_state_reg_info
{
- struct dwarf2_frame_state_reg
- {
- union {
- LONGEST offset;
- ULONGEST reg;
- unsigned char *exp;
- } loc;
- ULONGEST exp_len;
- enum dwarf2_reg_rule how;
- } *reg;
+ struct dwarf2_frame_state_reg *reg;
int num_regs;
/* Used to implement DW_CFA_remember_state. */
static struct dwarf2_frame_state_reg *
dwarf2_frame_state_copy_regs (struct dwarf2_frame_state_reg_info *rs)
{
- size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg_info);
+ size_t size = rs->num_regs * sizeof (struct dwarf2_frame_state_reg);
struct dwarf2_frame_state_reg *reg;
reg = (struct dwarf2_frame_state_reg *) xmalloc (size);
read_reg (void *baton, int reg)
{
struct frame_info *next_frame = (struct frame_info *) baton;
+ struct gdbarch *gdbarch = get_frame_arch (next_frame);
int regnum;
char *buf;
regnum = DWARF2_REG_TO_REGNUM (reg);
- buf = (char *) alloca (register_size (current_gdbarch, regnum));
+ buf = (char *) alloca (register_size (gdbarch, regnum));
frame_unwind_register (next_frame, regnum, buf);
return extract_typed_address (buf, builtin_type_void_data_ptr);
}
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
offset = utmp * fs->data_align;
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
else if ((insn & 0xc0) == DW_CFA_restore)
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
offset = utmp * fs->data_align;
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
break;
case DW_CFA_undefined:
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg].how = REG_UNDEFINED;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_UNDEFINED;
break;
case DW_CFA_same_value:
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
- fs->regs.reg[reg].how = REG_SAME_VALUE;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAME_VALUE;
break;
case DW_CFA_register:
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
fs->regs.reg[reg].loc.reg = utmp;
break;
{
struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev;
- gdb_assert (old_rs);
-
- xfree (fs->regs.reg);
- fs->regs = *old_rs;
- xfree (old_rs);
+ if (old_rs == NULL)
+ {
+ complaint (&symfile_complaints, "\
+bad CFI data; mismatched DW_CFA_restore_state at 0x%s", paddr (fs->pc));
+ }
+ else
+ {
+ xfree (fs->regs.reg);
+ fs->regs = *old_rs;
+ xfree (old_rs);
+ }
}
break;
/* cfa_how deliberately not set. */
break;
+ case DW_CFA_nop:
+ break;
+
case DW_CFA_def_cfa_expression:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_exp_len);
fs->cfa_exp = insn_ptr;
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
fs->regs.reg[reg].loc.exp = insn_ptr;
fs->regs.reg[reg].exp_len = utmp;
- fs->regs.reg[reg].how = REG_SAVED_EXP;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_EXP;
insn_ptr += utmp;
break;
- case DW_CFA_nop:
+ case DW_CFA_offset_extended_sf:
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
+ insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
+ offset *= fs->data_align;
+ dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
+ fs->regs.reg[reg].loc.offset = offset;
+ break;
+
+ case DW_CFA_def_cfa_sf:
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
+ insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
+ fs->cfa_offset = offset * fs->data_align;
+ fs->cfa_how = CFA_REG_OFFSET;
+ break;
+
+ case DW_CFA_def_cfa_offset_sf:
+ insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
+ fs->cfa_offset = offset * fs->data_align;
+ /* cfa_how deliberately not set. */
break;
case DW_CFA_GNU_args_size:
dwarf2_frame_state_free_regs (fs->regs.prev);
fs->regs.prev = NULL;
}
+\f
+
+/* Architecture-specific operations. */
+
+/* Per-architecture data key. */
+static struct gdbarch_data *dwarf2_frame_data;
+
+struct dwarf2_frame_ops
+{
+ /* Pre-initialize the register state REG for register REGNUM. */
+ void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *);
+
+ /* Check whether the frame preceding NEXT_FRAME will be a signal
+ trampoline. */
+ int (*signal_frame_p) (struct gdbarch *, struct frame_info *);
+};
+
+/* Default architecture-specific register state initialization
+ function. */
+
+static void
+dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
+ struct dwarf2_frame_state_reg *reg)
+{
+ /* 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
+ serves as the stack pointer, arrange for it to be filled with the
+ call frame address (CFA). The other registers are marked as
+ unspecified.
+
+ We copy the return address to the program counter, since many
+ parts in GDB assume that it is possible to get the return address
+ by unwinding the program counter register. However, on ISA's
+ with a dedicated return address register, the CFI usually only
+ contains information to unwind that return address register.
+
+ The reason we're treating the stack pointer special here is
+ because in many cases GCC doesn't emit CFI for the stack pointer
+ and implicitly assumes that it is equal to the CFA. This makes
+ some sense since the DWARF specification (version 3, draft 8,
+ p. 102) says that:
+
+ "Typically, the CFA is defined to be the value of the stack
+ pointer at the call site in the previous frame (which may be
+ different from its value on entry to the current frame)."
+
+ However, this isn't true for all platforms supported by GCC
+ (e.g. IBM S/390 and zSeries). Those architectures should provide
+ their own architecture-specific initialization function. */
+
+ if (regnum == PC_REGNUM)
+ reg->how = DWARF2_FRAME_REG_RA;
+ else if (regnum == SP_REGNUM)
+ reg->how = DWARF2_FRAME_REG_CFA;
+}
+
+/* Return a default for the architecture-specific operations. */
+
+static void *
+dwarf2_frame_init (struct obstack *obstack)
+{
+ struct dwarf2_frame_ops *ops;
+
+ ops = OBSTACK_ZALLOC (obstack, struct dwarf2_frame_ops);
+ ops->init_reg = dwarf2_frame_default_init_reg;
+ return ops;
+}
+
+/* Set the architecture-specific register state initialization
+ function for GDBARCH to INIT_REG. */
+
+void
+dwarf2_frame_set_init_reg (struct gdbarch *gdbarch,
+ void (*init_reg) (struct gdbarch *, int,
+ struct dwarf2_frame_state_reg *))
+{
+ struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
+
+ ops->init_reg = init_reg;
+}
+
+/* Pre-initialize the register state REG for register REGNUM. */
+
+static void
+dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
+ struct dwarf2_frame_state_reg *reg)
+{
+ struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
+
+ ops->init_reg (gdbarch, regnum, reg);
+}
+
+/* Set the architecture-specific signal trampoline recognition
+ function for GDBARCH to SIGNAL_FRAME_P. */
+
+void
+dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch,
+ int (*signal_frame_p) (struct gdbarch *,
+ struct frame_info *))
+{
+ struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
+
+ ops->signal_frame_p = signal_frame_p;
+}
+
+/* Query the architecture-specific signal frame recognizer for
+ NEXT_FRAME. */
+
+static int
+dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch,
+ struct frame_info *next_frame)
+{
+ struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
+
+ if (ops->signal_frame_p == NULL)
+ return 0;
+ return ops->signal_frame_p (gdbarch, next_frame);
+}
+\f
struct dwarf2_frame_cache
{
dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
{
struct cleanup *old_chain;
+ struct gdbarch *gdbarch = get_frame_arch (next_frame);
const int num_regs = NUM_REGS + NUM_PSEUDO_REGS;
struct dwarf2_frame_cache *cache;
struct dwarf2_frame_state *fs;
to abort), the compiler might optimize away the instruction at
NEXT_FRAME's return address. As a result the return address will
point at some random instruction, and the CFI for that
- instruction is probably wortless to us. GCC's unwinder solves
+ instruction is probably worthless to us. GCC's unwinder solves
this problem by substracting 1 from the return address to get an
address in the middle of a presumed call instruction (or the
instruction in the associated delay slot). This should only be
done for "normal" frames and not for resume-type frames (signal
- handlers, sentinel frames, dummy frames).
-
- frame_unwind_address_in_block does just this.
-
- It's not clear how reliable the method is though - there is the
- potential for the register state pre-call being different to that
- on return. */
+ handlers, sentinel frames, dummy frames). The function
+ frame_unwind_address_in_block does just this. It's not clear how
+ reliable the method is though; there is the potential for the
+ register state pre-call being different to that on return. */
fs->pc = frame_unwind_address_in_block (next_frame);
/* Find the correct FDE. */
internal_error (__FILE__, __LINE__, "Unknown CFA rule.");
}
- /* Initialize things so that all registers are marked as
- unspecified. */
+ /* Initialize the register state. */
{
int regnum;
+
for (regnum = 0; regnum < num_regs; regnum++)
- cache->reg[regnum].how = REG_UNSPECIFIED;
+ dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum]);
}
/* Go through the DWARF2 CFI generated table and save its register
- location information in the cache. */
+ location information in the cache. Note that we don't skip the
+ return address column; it's perfectly all right for it to
+ correspond to a real register. If it doesn't correspond to a
+ real register, or if we shouldn't treat it as such,
+ DWARF2_REG_TO_REGNUM should be defined to return a number outside
+ the range [0, NUM_REGS). */
{
int column; /* CFI speak for "register number". */
+
for (column = 0; column < fs->regs.num_regs; column++)
{
- int regnum;
-
- /* Skip the return address column. */
- if (column == fs->retaddr_column)
- /* NOTE: cagney/2003-06-07: Is this right? What if
- RETADDR_COLUMN corresponds to a real register (and,
- worse, that isn't the PC_REGNUM)? I'm guessing that the
- PC_REGNUM further down is trying to handle this. That
- can't be right though - PC_REGNUM may not be valid (it
- can be -ve). I think, instead when RETADDR_COLUM isn't a
- real register, it should map itself onto frame_pc_unwind. */
- continue;
-
/* Use the GDB register number as the destination index. */
- regnum = DWARF2_REG_TO_REGNUM (column);
+ int regnum = DWARF2_REG_TO_REGNUM (column);
/* If there's no corresponding GDB register, ignore it. */
if (regnum < 0 || regnum >= num_regs)
continue;
/* NOTE: cagney/2003-09-05: CFI should specify the disposition
- of all debug info registers. If it doesn't complain (but
- not too loudly). It turns out that GCC, assumes that an
+ of all debug info registers. If it doesn't, complain (but
+ not too loudly). It turns out that GCC assumes that an
unspecified register implies "same value" when CFI (draft
7) specifies nothing at all. Such a register could equally
be interpreted as "undefined". Also note that this check
- isn't sufficient - it only checks that all registers in the
- range [0 .. max column] are specified - and won't detect
+ isn't sufficient; it only checks that all registers in the
+ range [0 .. max column] are specified, and won't detect
problems when a debug info register falls outside of the
- table. Need a way of iterating through all the valid
+ table. We need a way of iterating through all the valid
DWARF2 register numbers. */
- if (fs->regs.reg[column].how == REG_UNSPECIFIED)
- complaint (&symfile_complaints,
- "Incomplete CFI data; unspecified registers at 0x%s",
- paddr (fs->pc));
-
- cache->reg[regnum] = fs->regs.reg[column];
+ if (fs->regs.reg[column].how == DWARF2_FRAME_REG_UNSPECIFIED)
+ {
+ if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED)
+ complaint (&symfile_complaints, "\
+incomplete CFI data; unspecified registers (e.g., %s) at 0x%s",
+ gdbarch_register_name (gdbarch, regnum),
+ paddr_nz (fs->pc));
+ }
+ else
+ cache->reg[regnum] = fs->regs.reg[column];
}
}
- /* Store the location of the return addess. If the return address
- column (adjusted) is not the same as gdb's PC_REGNUM, then this
- implies a copy from the ra column register. */
- if (fs->retaddr_column < fs->regs.num_regs
- && fs->regs.reg[fs->retaddr_column].how != REG_UNDEFINED)
- {
- /* See comment above about a possibly -ve PC_REGNUM. If this
- assertion fails, it's a problem with this code and not the
- architecture. */
- gdb_assert (PC_REGNUM >= 0);
- cache->reg[PC_REGNUM] = fs->regs.reg[fs->retaddr_column];
- }
- else
- {
- int reg = DWARF2_REG_TO_REGNUM (fs->retaddr_column);
- if (reg != PC_REGNUM)
- {
- /* See comment above about PC_REGNUM being -ve. If this
- assertion fails, it's a problem with this code and not
- the architecture. */
- gdb_assert (PC_REGNUM >= 0);
- cache->reg[PC_REGNUM].loc.reg = reg;
- cache->reg[PC_REGNUM].how = REG_SAVED_REG;
- }
- }
+ /* Eliminate any DWARF2_FRAME_REG_RA rules. */
+ {
+ int regnum;
+
+ for (regnum = 0; regnum < num_regs; regnum++)
+ {
+ if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
+ {
+ struct dwarf2_frame_state_reg *retaddr_reg =
+ &fs->regs.reg[fs->retaddr_column];
+
+ /* It seems rather bizarre to specify an "empty" column as
+ the return adress column. However, this is exactly
+ what GCC does on some targets. It turns out that GCC
+ assumes that the return address can be found in the
+ register corresponding to the return address column.
+ Incidentally, that's how should treat a return address
+ column specifying "same value" too. */
+ if (fs->retaddr_column < fs->regs.num_regs
+ && retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED
+ && retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE)
+ cache->reg[regnum] = *retaddr_reg;
+ else
+ {
+ cache->reg[regnum].loc.reg = fs->retaddr_column;
+ cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG;
+ }
+ }
+ }
+ }
do_cleanups (old_chain);
enum lval_type *lvalp, CORE_ADDR *addrp,
int *realnump, void *valuep)
{
+ struct gdbarch *gdbarch = get_frame_arch (next_frame);
struct dwarf2_frame_cache *cache =
dwarf2_frame_cache (next_frame, this_cache);
switch (cache->reg[regnum].how)
{
- case REG_UNDEFINED:
+ case DWARF2_FRAME_REG_UNDEFINED:
/* If CFI explicitly specified that the value isn't defined,
- mark it as optimized away - the value isn't available. */
+ mark it as optimized away; the value isn't available. */
*optimizedp = 1;
*lvalp = not_lval;
*addrp = 0;
*realnump = -1;
- if (regnum == SP_REGNUM)
- {
- /* GCC defines the CFA as the value of the stack pointer
- just before the call instruction is executed. Do other
- compilers use the same definition? */
- /* DWARF V3 Draft 7 p102: Typically, the CFA is defined to
- be the value of the stack pointer at the call site in the
- previous frame (which may be different from its value on
- entry to the current frame). */
- /* DWARF V3 Draft 7 p103: The first column of the rules
- defines the rule which computes the CFA value; it may be
- either a register and a signed offset that are added
- together or a DWARF expression that is evaluated. */
- /* FIXME: cagney/2003-07-07: I don't understand this. The
- CFI info should have provided unwind information for the
- SP register and then pointed ->cfa_reg at it, not the
- reverse. Assuming that SP_REGNUM is !-ve, there is a
- very real posibility that CFA is an offset from some
- other register, having nothing to do with the unwound SP
- value. */
- /* FIXME: cagney/2003-09-05: I think I understand. GDB was
- lumping the two states "unspecified" and "undefined"
- together. Here SP_REGNUM was "unspecified", GCC assuming
- that in such a case CFA would be used. This branch of
- the if statement should be deleted - the problem of
- SP_REGNUM is now handed by the case REG_UNSPECIFIED
- below. */
- *optimizedp = 0;
- if (valuep)
- {
- /* Store the value. */
- store_typed_address (valuep, builtin_type_void_data_ptr,
- cache->cfa);
- }
- }
- else if (valuep)
+ if (valuep)
{
/* In some cases, for example %eflags on the i386, we have
to provide a sane value, even though this register wasn't
}
break;
- case REG_SAVED_OFFSET:
+ case DWARF2_FRAME_REG_SAVED_OFFSET:
*optimizedp = 0;
*lvalp = lval_memory;
*addrp = cache->cfa + cache->reg[regnum].loc.offset;
if (valuep)
{
/* Read the value in from memory. */
- read_memory (*addrp, valuep,
- register_size (current_gdbarch, regnum));
+ read_memory (*addrp, valuep, register_size (gdbarch, regnum));
}
break;
- case REG_SAVED_REG:
- regnum = DWARF2_REG_TO_REGNUM (cache->reg[regnum].loc.reg);
- frame_register_unwind (next_frame, regnum,
- optimizedp, lvalp, addrp, realnump, valuep);
+ case DWARF2_FRAME_REG_SAVED_REG:
+ *optimizedp = 0;
+ *lvalp = lval_register;
+ *addrp = 0;
+ *realnump = DWARF2_REG_TO_REGNUM (cache->reg[regnum].loc.reg);
+ if (valuep)
+ frame_unwind_register (next_frame, (*realnump), valuep);
break;
- case REG_SAVED_EXP:
+ case DWARF2_FRAME_REG_SAVED_EXP:
*optimizedp = 0;
*lvalp = lval_memory;
*addrp = execute_stack_op (cache->reg[regnum].loc.exp,
if (valuep)
{
/* Read the value in from memory. */
- read_memory (*addrp, valuep,
- register_size (current_gdbarch, regnum));
+ read_memory (*addrp, valuep, register_size (gdbarch, regnum));
}
break;
- case REG_UNSPECIFIED:
+ case DWARF2_FRAME_REG_UNSPECIFIED:
/* GCC, in its infinite wisdom decided to not provide unwind
information for registers that are "same value". Since
DWARF2 (3 draft 7) doesn't define such behavior, said
"undefined"). Code above issues a complaint about this.
Here just fudge the books, assume GCC, and that the value is
more inner on the stack. */
- if (SP_REGNUM >= 0 && regnum == SP_REGNUM)
- {
- /* Can things get worse? Yep! One of the registers GCC
- forgot to provide unwind information for was the stack
- pointer. Outch! GCC appears to assumes that the CFA
- address can be used - after all it points to the inner
- most address of the previous frame before the function
- call and that's always the same as the stack pointer on
- return, right? Wrong. See GCC's i386 STDCALL option for
- an ABI that has a different entry and return stack
- pointer. */
- /* DWARF V3 Draft 7 p102: Typically, the CFA is defined to
- be the value of the stack pointer at the call site in the
- previous frame (which may be different from its value on
- entry to the current frame). */
- /* DWARF V3 Draft 7 p103: The first column of the rules
- defines the rule which computes the CFA value; it may be
- either a register and a signed offset that are added
- together or a DWARF expression that is evaluated. */
- /* NOTE: cagney/2003-09-05: Should issue a complain.
- Unfortunatly it turns out that DWARF2 CFI has a problem.
- Since CFI specifies the location at which a register was
- saved (not its value) it isn't possible to specify
- something like "unwound(REG) == REG + constant" using CFI
- as will almost always occure with the stack pointer. I
- guess CFI should be point SP at CFA. Ref: danielj,
- "Describing unsaved stack pointers", posted to dwarf2
- list 2003-08-15. */
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- /* Store the value. */
- store_typed_address (valuep, builtin_type_void_data_ptr,
- cache->cfa);
- }
- else
- /* Assume that the register can be found in the next inner
- most frame. */
- frame_register_unwind (next_frame, regnum,
- optimizedp, lvalp, addrp, realnump, valuep);
+ *optimizedp = 0;
+ *lvalp = lval_register;
+ *addrp = 0;
+ *realnump = regnum;
+ if (valuep)
+ frame_unwind_register (next_frame, (*realnump), valuep);
break;
- case REG_SAME_VALUE:
- frame_register_unwind (next_frame, regnum,
- optimizedp, lvalp, addrp, realnump, valuep);
+ case DWARF2_FRAME_REG_SAME_VALUE:
+ *optimizedp = 0;
+ *lvalp = lval_register;
+ *addrp = 0;
+ *realnump = regnum;
+ if (valuep)
+ frame_unwind_register (next_frame, (*realnump), valuep);
+ break;
+
+ case DWARF2_FRAME_REG_CFA:
+ *optimizedp = 0;
+ *lvalp = not_lval;
+ *addrp = 0;
+ *realnump = -1;
+ if (valuep)
+ {
+ /* Store the value. */
+ store_typed_address (valuep, builtin_type_void_data_ptr, cache->cfa);
+ }
break;
default:
dwarf2_frame_prev_register
};
+static const struct frame_unwind dwarf2_signal_frame_unwind =
+{
+ SIGTRAMP_FRAME,
+ dwarf2_frame_this_id,
+ dwarf2_frame_prev_register
+};
+
const struct frame_unwind *
dwarf2_frame_sniffer (struct frame_info *next_frame)
{
function. frame_pc_unwind(), for a no-return next function, can
end up returning something past the end of this function's body. */
CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame);
- if (dwarf2_frame_find_fde (&block_addr))
- return &dwarf2_frame_unwind;
+ if (!dwarf2_frame_find_fde (&block_addr))
+ return NULL;
- return NULL;
+ /* On some targets, signal trampolines may have unwind information.
+ We need to recognize them so that we set the frame type
+ correctly. */
+
+ if (dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
+ next_frame))
+ return &dwarf2_signal_frame_unwind;
+
+ return &dwarf2_frame_unwind;
}
\f
/* Linked list of CIEs for this object. */
struct dwarf2_cie *cie;
- /* Address size for this unit - from unit header. */
- unsigned char addr_size;
-
/* Pointer to the .debug_frame section loaded into memory. */
char *dwarf_frame_buffer;
/* Base for DW_EH_PE_datarel encodings. */
bfd_vma dbase;
+
+ /* Base for DW_EH_PE_textrel encodings. */
+ bfd_vma tbase;
};
-const struct objfile_data *dwarf2_frame_data;
+const struct objfile_data *dwarf2_frame_objfile_data;
static unsigned int
read_1_byte (bfd *bfd, char *buf)
static CORE_ADDR
read_encoded_value (struct comp_unit *unit, unsigned char encoding,
- char *buf, unsigned int *bytes_read_ptr)
+ unsigned char *buf, unsigned int *bytes_read_ptr)
{
int ptr_len = size_of_encoded_value (DW_EH_PE_absptr);
ptrdiff_t offset;
break;
case DW_EH_PE_pcrel:
base = bfd_get_section_vma (unit->bfd, unit->dwarf_frame_section);
- base += (buf - unit->dwarf_frame_buffer);
+ base += ((char *) buf - unit->dwarf_frame_buffer);
break;
case DW_EH_PE_datarel:
base = unit->dbase;
break;
+ case DW_EH_PE_textrel:
+ base = unit->tbase;
+ break;
+ case DW_EH_PE_funcrel:
+ /* FIXME: kettenis/20040501: For now just pretend
+ DW_EH_PE_funcrel is equivalent to DW_EH_PE_absptr. For
+ reading the initial location of an FDE it should be treated
+ as such, and currently that's the only place where this code
+ is used. */
+ base = 0;
+ break;
case DW_EH_PE_aligned:
base = 0;
- offset = buf - unit->dwarf_frame_buffer;
+ offset = (char *) buf - unit->dwarf_frame_buffer;
if ((offset % ptr_len) != 0)
{
*bytes_read_ptr = ptr_len - (offset % ptr_len);
internal_error (__FILE__, __LINE__, "Invalid or unsupported encoding");
}
- if ((encoding & 0x0f) == 0x00)
+ if ((encoding & 0x07) == 0x00)
encoding |= encoding_for_size (ptr_len);
switch (encoding & 0x0f)
{
+ case DW_EH_PE_uleb128:
+ {
+ ULONGEST value;
+ unsigned char *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
+ *bytes_read_ptr += read_uleb128 (buf, end_buf, &value) - buf;
+ return base + value;
+ }
case DW_EH_PE_udata2:
*bytes_read_ptr += 2;
return (base + bfd_get_16 (unit->abfd, (bfd_byte *) buf));
case DW_EH_PE_udata8:
*bytes_read_ptr += 8;
return (base + bfd_get_64 (unit->abfd, (bfd_byte *) buf));
+ case DW_EH_PE_sleb128:
+ {
+ LONGEST value;
+ char *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
+ *bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf;
+ return base + value;
+ }
case DW_EH_PE_sdata2:
*bytes_read_ptr += 2;
return (base + bfd_get_signed_16 (unit->abfd, (bfd_byte *) buf));
struct dwarf2_fde *fde;
CORE_ADDR offset;
- fde = objfile_data (objfile, dwarf2_frame_data);
+ fde = objfile_data (objfile, dwarf2_frame_objfile_data);
if (fde == NULL)
continue;
static void
add_fde (struct comp_unit *unit, struct dwarf2_fde *fde)
{
- fde->next = objfile_data (unit->objfile, dwarf2_frame_data);
- set_objfile_data (unit->objfile, dwarf2_frame_data, fde);
+ fde->next = objfile_data (unit->objfile, dwarf2_frame_objfile_data);
+ set_objfile_data (unit->objfile, dwarf2_frame_objfile_data, fde);
}
#ifdef CC_HAS_LONG_LONG
/* This is a CIE. */
struct dwarf2_cie *cie;
char *augmentation;
+ unsigned int cie_version;
/* Record the offset into the .debug_frame section of this CIE. */
cie_pointer = start - unit->dwarf_frame_buffer;
return end;
cie = (struct dwarf2_cie *)
- obstack_alloc (&unit->objfile->psymbol_obstack,
+ obstack_alloc (&unit->objfile->objfile_obstack,
sizeof (struct dwarf2_cie));
cie->initial_instructions = NULL;
cie->cie_pointer = cie_pointer;
/* The encoding for FDE's in a normal .debug_frame section
- depends on the target address size as specified in the
- Compilation Unit Header. */
- cie->encoding = encoding_for_size (unit->addr_size);
+ depends on the target address size. */
+ cie->encoding = DW_EH_PE_absptr;
/* Check version number. */
- if (read_1_byte (unit->abfd, buf) != DW_CIE_VERSION)
+ cie_version = read_1_byte (unit->abfd, buf);
+ if (cie_version != 1 && cie_version != 3)
return NULL;
buf += 1;
read_signed_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
- cie->return_address_register = read_1_byte (unit->abfd, buf);
- buf += 1;
+ if (cie_version == 1)
+ {
+ cie->return_address_register = read_1_byte (unit->abfd, buf);
+ bytes_read = 1;
+ }
+ else
+ cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf,
+ &bytes_read);
+ buf += bytes_read;
cie->saw_z_augmentation = (*augmentation == 'z');
if (cie->saw_z_augmentation)
/* "P" indicates a personality routine in the CIE augmentation. */
else if (*augmentation == 'P')
{
- /* Skip. */
- buf += size_of_encoded_value (*buf++);
+ /* Skip. Avoid indirection since we throw away the result. */
+ unsigned char encoding = (*buf++) & ~DW_EH_PE_indirect;
+ read_encoded_value (unit, encoding, buf, &bytes_read);
+ buf += bytes_read;
augmentation++;
}
return NULL;
fde = (struct dwarf2_fde *)
- obstack_alloc (&unit->objfile->psymbol_obstack,
+ obstack_alloc (&unit->objfile->objfile_obstack,
sizeof (struct dwarf2_fde));
fde->cie = find_cie (unit, cie_pointer);
if (fde->cie == NULL)
return ret;
}
-
\f
/* FIXME: kettenis/20030504: This still needs to be integrated with
dwarf2read.c in a better way. */
/* Imported from dwarf2read.c. */
-extern file_ptr dwarf_frame_offset;
-extern unsigned int dwarf_frame_size;
extern asection *dwarf_frame_section;
-extern file_ptr dwarf_eh_frame_offset;
-extern unsigned int dwarf_eh_frame_size;
extern asection *dwarf_eh_frame_section;
/* Imported from dwarf2read.c. */
-extern char *dwarf2_read_section (struct objfile *objfile, file_ptr offset,
- unsigned int size, asection *sectp);
+extern char *dwarf2_read_section (struct objfile *objfile, asection *sectp);
void
dwarf2_build_frame_info (struct objfile *objfile)
/* Build a minimal decoding of the DWARF2 compilation unit. */
unit.abfd = objfile->obfd;
unit.objfile = objfile;
- unit.addr_size = objfile->obfd->arch_info->bits_per_address / 8;
unit.dbase = 0;
+ unit.tbase = 0;
/* First add the information from the .eh_frame section. That way,
the FDEs from that section are searched last. */
- if (dwarf_eh_frame_offset)
+ if (dwarf_eh_frame_section)
{
- asection *got;
+ asection *got, *txt;
unit.cie = NULL;
unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
- dwarf_eh_frame_offset,
- dwarf_eh_frame_size,
dwarf_eh_frame_section);
- unit.dwarf_frame_size = dwarf_eh_frame_size;
+ unit.dwarf_frame_size = bfd_get_section_size (dwarf_eh_frame_section);
unit.dwarf_frame_section = dwarf_eh_frame_section;
/* FIXME: kettenis/20030602: This is the DW_EH_PE_datarel base
if (got)
unit.dbase = got->vma;
+ /* GCC emits the DW_EH_PE_textrel encoding type on sh and ia64
+ so far. */
+ txt = bfd_get_section_by_name (unit.abfd, ".text");
+ if (txt)
+ unit.tbase = txt->vma;
+
frame_ptr = unit.dwarf_frame_buffer;
while (frame_ptr < unit.dwarf_frame_buffer + unit.dwarf_frame_size)
frame_ptr = decode_frame_entry (&unit, frame_ptr, 1);
}
- if (dwarf_frame_offset)
+ if (dwarf_frame_section)
{
unit.cie = NULL;
unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
- dwarf_frame_offset,
- dwarf_frame_size,
dwarf_frame_section);
- unit.dwarf_frame_size = dwarf_frame_size;
+ unit.dwarf_frame_size = bfd_get_section_size (dwarf_frame_section);
unit.dwarf_frame_section = dwarf_frame_section;
frame_ptr = unit.dwarf_frame_buffer;
void
_initialize_dwarf2_frame (void)
{
- dwarf2_frame_data = register_objfile_data ();
+ dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init);
+ dwarf2_frame_objfile_data = register_objfile_data ();
}