/* Frame unwinder for frames with DWARF Call Frame Information.
- Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
Contributed by Mark Kettenis.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "dwarf2expr.h"
#include "complaints.h"
#include "dwarf2-frame.h"
+struct comp_unit;
+
/* Call Frame Information (CFI). */
/* Common Information Entry (CIE). */
struct dwarf2_cie
{
+ /* Computation Unit for this CIE. */
+ struct comp_unit *unit;
+
/* Offset into the .debug_frame section where this CIE was found.
Used to identify this CIE. */
ULONGEST cie_pointer;
/* Encoding of addresses. */
gdb_byte encoding;
+ /* Target address size in bytes. */
+ int addr_size;
+
/* True if a 'z' augmentation existed. */
unsigned char saw_z_augmentation;
struct dwarf2_fde *next;
};
+/* A minimal decoding of DWARF2 compilation units. We only decode
+ what's needed to get to the call frame information. */
+
+struct comp_unit
+{
+ /* Keep the bfd convenient. */
+ bfd *abfd;
+
+ struct objfile *objfile;
+
+ /* Linked list of CIEs for this object. */
+ struct dwarf2_cie *cie;
+
+ /* Pointer to the .debug_frame section loaded into memory. */
+ gdb_byte *dwarf_frame_buffer;
+
+ /* Length of the loaded .debug_frame section. */
+ unsigned long dwarf_frame_size;
+
+ /* Pointer to the .debug_frame section. */
+ asection *dwarf_frame_section;
+
+ /* Base for DW_EH_PE_datarel encodings. */
+ bfd_vma dbase;
+
+ /* Base for DW_EH_PE_textrel encodings. */
+ bfd_vma tbase;
+};
+
static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc);
static int dwarf2_frame_adjust_regnum (struct gdbarch *gdbarch, int regnum,
int eh_frame_p);
+
+static CORE_ADDR read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
+ int ptr_len, gdb_byte *buf,
+ unsigned int *bytes_read_ptr,
+ CORE_ADDR func_base);
\f
/* Structure describing a frame state. */
static CORE_ADDR
read_reg (void *baton, int reg)
{
- struct frame_info *next_frame = (struct frame_info *) baton;
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
+ struct frame_info *this_frame = (struct frame_info *) baton;
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
int regnum;
gdb_byte *buf;
- regnum = gdbarch_dwarf2_reg_to_regnum (current_gdbarch, reg);
+ regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, reg);
buf = alloca (register_size (gdbarch, regnum));
- frame_unwind_register (next_frame, regnum, buf);
+ get_frame_register (this_frame, regnum, buf);
/* Convert the register to an integer. This returns a LONGEST
rather than a CORE_ADDR, but unpack_pointer does the same thing
_("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)
+execute_stack_op (gdb_byte *exp, ULONGEST len, int addr_size,
+ struct frame_info *this_frame, CORE_ADDR initial)
{
struct dwarf_expr_context *ctx;
CORE_ADDR result;
ctx = new_dwarf_expr_context ();
- ctx->baton = next_frame;
+ ctx->gdbarch = get_frame_arch (this_frame);
+ ctx->addr_size = addr_size;
+ ctx->baton = this_frame;
ctx->read_reg = read_reg;
ctx->read_mem = read_mem;
ctx->get_frame_base = no_get_frame_base;
result = dwarf_expr_fetch (ctx, 0);
if (ctx->in_reg)
- result = read_reg (next_frame, result);
+ result = read_reg (this_frame, result);
free_dwarf_expr_context (ctx);
\f
static void
-execute_cfa_program (gdb_byte *insn_ptr, gdb_byte *insn_end,
- struct frame_info *next_frame,
- struct dwarf2_frame_state *fs, int eh_frame_p)
+execute_cfa_program (struct dwarf2_fde *fde, gdb_byte *insn_ptr,
+ gdb_byte *insn_end, struct frame_info *this_frame,
+ struct dwarf2_frame_state *fs)
{
- CORE_ADDR pc = frame_pc_unwind (next_frame);
+ int eh_frame_p = fde->eh_frame_p;
+ CORE_ADDR pc = get_frame_pc (this_frame);
int bytes_read;
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
while (insn_ptr < insn_end && fs->pc <= pc)
{
}
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
- (current_gdbarch, gdbarch_dwarf2_reg_to_regnum
- (current_gdbarch, reg)),
- gdbarch_dwarf2_reg_to_regnum (current_gdbarch, reg),
- paddr (fs->pc));
+ dwarf2_restore_rule (gdbarch, reg, fs, eh_frame_p);
}
else
{
switch (insn)
{
case DW_CFA_set_loc:
- fs->pc = dwarf2_read_address (insn_ptr, insn_end, &bytes_read);
+ fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding,
+ fde->cie->addr_size, insn_ptr,
+ &bytes_read, fde->initial_location);
+ /* Apply the objfile offset for relocatable objects. */
+ fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets,
+ SECT_OFF_TEXT (fde->cie->unit->objfile));
insn_ptr += bytes_read;
break;
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:
Incidentally that's what GCC does too in its
unwinder. */
{
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
- int size = register_size(gdbarch, 0);
+ int size = register_size (gdbarch, 0);
dwarf2_frame_state_alloc_regs (&fs->regs, 32);
for (reg = 8; reg < 16; 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. */
+ /* Check whether the THIS_FRAME is a signal trampoline. */
int (*signal_frame_p) (struct gdbarch *, struct frame_info *);
/* Convert .eh_frame register number to DWARF register number, or
static void
dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
struct dwarf2_frame_state_reg *reg,
- struct frame_info *next_frame)
+ struct frame_info *this_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
(e.g. IBM S/390 and zSeries). Those architectures should provide
their own architecture-specific initialization function. */
- if (regnum == PC_REGNUM)
+ if (regnum == gdbarch_pc_regnum (gdbarch))
reg->how = DWARF2_FRAME_REG_RA;
- else if (regnum == SP_REGNUM)
+ else if (regnum == gdbarch_sp_regnum (gdbarch))
reg->how = DWARF2_FRAME_REG_CFA;
}
static void
dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
struct dwarf2_frame_state_reg *reg,
- struct frame_info *next_frame)
+ struct frame_info *this_frame)
{
struct dwarf2_frame_ops *ops = gdbarch_data (gdbarch, dwarf2_frame_data);
- ops->init_reg (gdbarch, regnum, reg, next_frame);
+ ops->init_reg (gdbarch, regnum, reg, this_frame);
}
/* Set the architecture-specific signal trampoline recognition
}
/* Query the architecture-specific signal frame recognizer for
- NEXT_FRAME. */
+ THIS_FRAME. */
static int
dwarf2_frame_signal_frame_p (struct gdbarch *gdbarch,
- struct frame_info *next_frame)
+ struct frame_info *this_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);
+ return ops->signal_frame_p (gdbarch, this_frame);
}
/* Set the architecture-specific adjustment of .eh_frame and .debug_frame
/* Return address register. */
struct dwarf2_frame_state_reg retaddr_reg;
+
+ /* Target address size in bytes. */
+ int addr_size;
};
static struct dwarf2_frame_cache *
-dwarf2_frame_cache (struct frame_info *next_frame, void **this_cache)
+dwarf2_frame_cache (struct frame_info *this_frame, void **this_cache)
{
struct cleanup *old_chain;
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
- const int num_regs = gdbarch_num_regs (current_gdbarch)
- + gdbarch_num_pseudo_regs (current_gdbarch);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ const int num_regs = gdbarch_num_regs (gdbarch)
+ + gdbarch_num_pseudo_regs (gdbarch);
struct dwarf2_frame_cache *cache;
struct dwarf2_frame_state *fs;
struct dwarf2_fde *fde;
/* Unwind the PC.
- Note that if NEXT_FRAME is never supposed to return (i.e. a call
+ Note that if the next frame is never supposed to return (i.e. a call
to abort), the compiler might optimize away the instruction at
- NEXT_FRAME's return address. As a result the return address will
+ its return address. As a result the return address will
point at some random instruction, and the CFI for that
instruction is probably worthless to us. GCC's unwinder solves
this problem by substracting 1 from the return address to get an
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). The function
- frame_unwind_address_in_block does just this. It's not clear how
+ get_frame_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, NORMAL_FRAME);
+ fs->pc = get_frame_address_in_block (this_frame);
/* Find the correct FDE. */
fde = dwarf2_frame_find_fde (&fs->pc);
fs->data_align = fde->cie->data_alignment_factor;
fs->code_align = fde->cie->code_alignment_factor;
fs->retaddr_column = fde->cie->return_address_register;
+ cache->addr_size = fde->cie->addr_size;
/* Check for "quirks" - known bugs in producers. */
dwarf2_frame_find_quirks (fs, fde);
/* First decode all the insns in the CIE. */
- execute_cfa_program (fde->cie->initial_instructions,
- fde->cie->end, next_frame, fs, fde->eh_frame_p);
+ execute_cfa_program (fde, fde->cie->initial_instructions,
+ fde->cie->end, this_frame, fs);
/* Save the initialized register set. */
fs->initial = fs->regs;
fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs);
/* Then decode the insns in the FDE up to our target PC. */
- execute_cfa_program (fde->instructions, fde->end, next_frame, fs,
- fde->eh_frame_p);
+ execute_cfa_program (fde, fde->instructions, fde->end, this_frame, fs);
- /* Caclulate the CFA. */
+ /* Calculate the CFA. */
switch (fs->cfa_how)
{
case CFA_REG_OFFSET:
- cache->cfa = read_reg (next_frame, fs->cfa_reg);
+ cache->cfa = read_reg (this_frame, fs->cfa_reg);
if (fs->armcc_cfa_offsets_reversed)
cache->cfa -= fs->cfa_offset;
else
case CFA_EXP:
cache->cfa =
- execute_stack_op (fs->cfa_exp, fs->cfa_exp_len, next_frame, 0);
+ execute_stack_op (fs->cfa_exp, fs->cfa_exp_len,
+ cache->addr_size, this_frame, 0);
break;
default:
int regnum;
for (regnum = 0; regnum < num_regs; regnum++)
- dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], next_frame);
+ dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum], this_frame);
}
/* Go through the DWARF2 CFI generated table and save its register
for (column = 0; column < fs->regs.num_regs; column++)
{
/* Use the GDB register number as the destination index. */
- int regnum = gdbarch_dwarf2_reg_to_regnum (current_gdbarch, column);
+ int regnum = gdbarch_dwarf2_reg_to_regnum (gdbarch, column);
/* If there's no corresponding GDB register, ignore it. */
if (regnum < 0 || regnum >= num_regs)
}
static void
-dwarf2_frame_this_id (struct frame_info *next_frame, void **this_cache,
+dwarf2_frame_this_id (struct frame_info *this_frame, void **this_cache,
struct frame_id *this_id)
{
struct dwarf2_frame_cache *cache =
- dwarf2_frame_cache (next_frame, this_cache);
-
- if (cache->undefined_retaddr)
- return;
-
- (*this_id) = frame_id_build (cache->cfa,
- frame_func_unwind (next_frame, NORMAL_FRAME));
-}
-
-static void
-dwarf2_signal_frame_this_id (struct frame_info *next_frame, void **this_cache,
- struct frame_id *this_id)
-{
- struct dwarf2_frame_cache *cache =
- dwarf2_frame_cache (next_frame, this_cache);
+ dwarf2_frame_cache (this_frame, this_cache);
if (cache->undefined_retaddr)
return;
- (*this_id) = frame_id_build (cache->cfa,
- frame_func_unwind (next_frame, SIGTRAMP_FRAME));
+ (*this_id) = frame_id_build (cache->cfa, get_frame_func (this_frame));
}
-static void
-dwarf2_frame_prev_register (struct frame_info *next_frame, void **this_cache,
- int regnum, int *optimizedp,
- enum lval_type *lvalp, CORE_ADDR *addrp,
- int *realnump, gdb_byte *valuep)
+static struct value *
+dwarf2_frame_prev_register (struct frame_info *this_frame, void **this_cache,
+ int regnum)
{
- struct gdbarch *gdbarch = get_frame_arch (next_frame);
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
struct dwarf2_frame_cache *cache =
- dwarf2_frame_cache (next_frame, this_cache);
+ dwarf2_frame_cache (this_frame, this_cache);
+ CORE_ADDR addr;
+ int realnum;
switch (cache->reg[regnum].how)
{
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. */
- *optimizedp = 1;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- {
- /* In some cases, for example %eflags on the i386, we have
- to provide a sane value, even though this register wasn't
- saved. Assume we can get it from NEXT_FRAME. */
- frame_unwind_register (next_frame, regnum, valuep);
- }
- break;
+ return frame_unwind_got_optimized (this_frame, regnum);
case DWARF2_FRAME_REG_SAVED_OFFSET:
- *optimizedp = 0;
- *lvalp = lval_memory;
- *addrp = cache->cfa + cache->reg[regnum].loc.offset;
- *realnump = -1;
- if (valuep)
- {
- /* Read the value in from memory. */
- read_memory (*addrp, valuep, register_size (gdbarch, regnum));
- }
- break;
+ addr = cache->cfa + cache->reg[regnum].loc.offset;
+ return frame_unwind_got_memory (this_frame, regnum, addr);
case DWARF2_FRAME_REG_SAVED_REG:
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realnump = gdbarch_dwarf2_reg_to_regnum
- (current_gdbarch, cache->reg[regnum].loc.reg);
- if (valuep)
- frame_unwind_register (next_frame, (*realnump), valuep);
- break;
+ realnum
+ = gdbarch_dwarf2_reg_to_regnum (gdbarch, cache->reg[regnum].loc.reg);
+ return frame_unwind_got_register (this_frame, regnum, realnum);
case DWARF2_FRAME_REG_SAVED_EXP:
- *optimizedp = 0;
- *lvalp = lval_memory;
- *addrp = execute_stack_op (cache->reg[regnum].loc.exp,
- cache->reg[regnum].exp_len,
- next_frame, cache->cfa);
- *realnump = -1;
- if (valuep)
- {
- /* Read the value in from memory. */
- read_memory (*addrp, valuep, register_size (gdbarch, regnum));
- }
- break;
+ addr = execute_stack_op (cache->reg[regnum].loc.exp,
+ cache->reg[regnum].exp_len,
+ cache->addr_size, this_frame, cache->cfa);
+ return frame_unwind_got_memory (this_frame, regnum, addr);
case DWARF2_FRAME_REG_SAVED_VAL_OFFSET:
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- store_unsigned_integer (valuep, register_size (gdbarch, regnum),
- cache->cfa + cache->reg[regnum].loc.offset);
- break;
+ addr = cache->cfa + cache->reg[regnum].loc.offset;
+ return frame_unwind_got_constant (this_frame, regnum, addr);
case DWARF2_FRAME_REG_SAVED_VAL_EXP:
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- store_unsigned_integer (valuep, register_size (gdbarch, regnum),
- execute_stack_op (cache->reg[regnum].loc.exp,
- cache->reg[regnum].exp_len,
- next_frame, cache->cfa));
- break;
+ addr = execute_stack_op (cache->reg[regnum].loc.exp,
+ cache->reg[regnum].exp_len,
+ cache->addr_size, this_frame, cache->cfa);
+ return frame_unwind_got_constant (this_frame, regnum, addr);
case DWARF2_FRAME_REG_UNSPECIFIED:
/* GCC, in its infinite wisdom decided to not provide unwind
"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. */
- *optimizedp = 0;
- *lvalp = lval_register;
- *addrp = 0;
- *realnump = regnum;
- if (valuep)
- frame_unwind_register (next_frame, (*realnump), valuep);
- break;
+ return frame_unwind_got_register (this_frame, regnum, regnum);
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;
+ return frame_unwind_got_register (this_frame, regnum, regnum);
case DWARF2_FRAME_REG_CFA:
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- pack_long (valuep, register_type (gdbarch, regnum), cache->cfa);
- break;
+ return frame_unwind_got_address (this_frame, regnum, cache->cfa);
case DWARF2_FRAME_REG_CFA_OFFSET:
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- pack_long (valuep, register_type (gdbarch, regnum),
- cache->cfa + cache->reg[regnum].loc.offset);
- break;
+ addr = cache->cfa + cache->reg[regnum].loc.offset;
+ return frame_unwind_got_address (this_frame, regnum, addr);
case DWARF2_FRAME_REG_RA_OFFSET:
- *optimizedp = 0;
- *lvalp = not_lval;
- *addrp = 0;
- *realnump = -1;
- if (valuep)
- {
- CORE_ADDR pc = cache->reg[regnum].loc.offset;
-
- regnum = gdbarch_dwarf2_reg_to_regnum
- (current_gdbarch, cache->retaddr_reg.loc.reg);
- pc += frame_unwind_register_unsigned (next_frame, regnum);
- pack_long (valuep, register_type (gdbarch, regnum), pc);
- }
- break;
+ addr = cache->reg[regnum].loc.offset;
+ regnum = gdbarch_dwarf2_reg_to_regnum
+ (gdbarch, cache->retaddr_reg.loc.reg);
+ addr += get_frame_register_unsigned (this_frame, regnum);
+ return frame_unwind_got_address (this_frame, regnum, addr);
+
+ case DWARF2_FRAME_REG_FN:
+ return cache->reg[regnum].loc.fn (this_frame, this_cache, regnum);
default:
internal_error (__FILE__, __LINE__, _("Unknown register rule."));
}
}
-static const struct frame_unwind dwarf2_frame_unwind =
-{
- NORMAL_FRAME,
- dwarf2_frame_this_id,
- dwarf2_frame_prev_register
-};
-
-static const struct frame_unwind dwarf2_signal_frame_unwind =
-{
- SIGTRAMP_FRAME,
- dwarf2_signal_frame_this_id,
- dwarf2_frame_prev_register
-};
-
-const struct frame_unwind *
-dwarf2_frame_sniffer (struct frame_info *next_frame)
+static int
+dwarf2_frame_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame, void **this_cache)
{
/* Grab an address that is guarenteed to reside somewhere within the
- function. frame_pc_unwind(), for a no-return next function, can
+ function. get_frame_pc(), with a no-return next function, can
end up returning something past the end of this function's body.
If the frame we're sniffing for is a signal frame whose start
address is placed on the stack by the OS, its FDE must
- extend one byte before its start address or we will miss it. */
- CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame,
- NORMAL_FRAME);
+ extend one byte before its start address or we could potentially
+ select the FDE of the previous function. */
+ CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr);
if (!fde)
- return NULL;
+ return 0;
/* On some targets, signal trampolines may have unwind information.
We need to recognize them so that we set the frame type
correctly. */
if (fde->cie->signal_frame
- || dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
- next_frame))
- return &dwarf2_signal_frame_unwind;
+ || dwarf2_frame_signal_frame_p (get_frame_arch (this_frame),
+ this_frame))
+ return self->type == SIGTRAMP_FRAME;
+
+ return self->type != SIGTRAMP_FRAME;
+}
- return &dwarf2_frame_unwind;
+static const struct frame_unwind dwarf2_frame_unwind =
+{
+ NORMAL_FRAME,
+ dwarf2_frame_this_id,
+ dwarf2_frame_prev_register,
+ NULL,
+ dwarf2_frame_sniffer
+};
+
+static const struct frame_unwind dwarf2_signal_frame_unwind =
+{
+ SIGTRAMP_FRAME,
+ dwarf2_frame_this_id,
+ dwarf2_frame_prev_register,
+ NULL,
+ dwarf2_frame_sniffer
+};
+
+/* Append the DWARF-2 frame unwinders to GDBARCH's list. */
+
+void
+dwarf2_append_unwinders (struct gdbarch *gdbarch)
+{
+ frame_unwind_append_unwinder (gdbarch, &dwarf2_frame_unwind);
+ frame_unwind_append_unwinder (gdbarch, &dwarf2_signal_frame_unwind);
}
\f
response to the "info frame" command. */
static CORE_ADDR
-dwarf2_frame_base_address (struct frame_info *next_frame, void **this_cache)
+dwarf2_frame_base_address (struct frame_info *this_frame, void **this_cache)
{
struct dwarf2_frame_cache *cache =
- dwarf2_frame_cache (next_frame, this_cache);
+ dwarf2_frame_cache (this_frame, this_cache);
return cache->cfa;
}
};
const struct frame_base *
-dwarf2_frame_base_sniffer (struct frame_info *next_frame)
+dwarf2_frame_base_sniffer (struct frame_info *this_frame)
{
- CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame,
- NORMAL_FRAME);
+ CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
if (dwarf2_frame_find_fde (&block_addr))
return &dwarf2_frame_base;
return NULL;
}
\f
-/* A minimal decoding of DWARF2 compilation units. We only decode
- what's needed to get to the call frame information. */
-
-struct comp_unit
-{
- /* Keep the bfd convenient. */
- bfd *abfd;
-
- struct objfile *objfile;
-
- /* Linked list of CIEs for this object. */
- struct dwarf2_cie *cie;
-
- /* Pointer to the .debug_frame section loaded into memory. */
- gdb_byte *dwarf_frame_buffer;
-
- /* Length of the loaded .debug_frame section. */
- unsigned long dwarf_frame_size;
-
- /* Pointer to the .debug_frame section. */
- asection *dwarf_frame_section;
-
- /* 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_objfile_data;
static unsigned int
}
}
-static unsigned int
-size_of_encoded_value (gdb_byte encoding)
-{
- if (encoding == DW_EH_PE_omit)
- return 0;
-
- switch (encoding & 0x07)
- {
- case DW_EH_PE_absptr:
- return TYPE_LENGTH (builtin_type_void_data_ptr);
- case DW_EH_PE_udata2:
- return 2;
- case DW_EH_PE_udata4:
- return 4;
- case DW_EH_PE_udata8:
- return 8;
- default:
- internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
- }
-}
-
static CORE_ADDR
read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
- gdb_byte *buf, unsigned int *bytes_read_ptr)
+ int ptr_len, gdb_byte *buf, unsigned int *bytes_read_ptr,
+ CORE_ADDR func_base)
{
- int ptr_len = size_of_encoded_value (DW_EH_PE_absptr);
ptrdiff_t offset;
CORE_ADDR base;
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;
+ base = func_base;
break;
case DW_EH_PE_aligned:
base = 0;
{
cie->next = unit->cie;
unit->cie = cie;
+ cie->unit = unit;
}
/* Find the FDE for *PC. Return a pointer to the FDE, and store the
static gdb_byte *
decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p)
{
+ struct gdbarch *gdbarch = get_objfile_arch (unit->objfile);
gdb_byte *buf, *end;
LONGEST length;
unsigned int bytes_read;
depends on the target address size. */
cie->encoding = DW_EH_PE_absptr;
+ /* The target address size. For .eh_frame FDEs this is considered
+ equal to the size of a target pointer. For .dwarf_frame FDEs,
+ this is supposed to be the target address size from the associated
+ CU header. FIXME: We do not have a good way to determine the
+ latter. Always use the target pointer size for now. */
+ cie->addr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
+
/* We'll determine the final value later, but we need to
initialize it conservatively. */
cie->signal_frame = 0;
if (augmentation[0] == 'e' && augmentation[1] == 'h')
{
/* Skip. */
- buf += TYPE_LENGTH (builtin_type_void_data_ptr);
+ buf += gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
augmentation += 2;
}
cie->return_address_register = read_unsigned_leb128 (unit->abfd, buf,
&bytes_read);
cie->return_address_register
- = dwarf2_frame_adjust_regnum (current_gdbarch,
+ = dwarf2_frame_adjust_regnum (gdbarch,
cie->return_address_register,
eh_frame_p);
{
/* Skip. Avoid indirection since we throw away the result. */
gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect;
- read_encoded_value (unit, encoding, buf, &bytes_read);
+ read_encoded_value (unit, encoding, cie->addr_size,
+ buf, &bytes_read, 0);
buf += bytes_read;
augmentation++;
}
gdb_assert (fde->cie != NULL);
fde->initial_location =
- read_encoded_value (unit, fde->cie->encoding, buf, &bytes_read);
+ read_encoded_value (unit, fde->cie->encoding, fde->cie->addr_size,
+ buf, &bytes_read, 0);
buf += bytes_read;
fde->address_range =
- read_encoded_value (unit, fde->cie->encoding & 0x0f, buf, &bytes_read);
+ read_encoded_value (unit, fde->cie->encoding & 0x0f,
+ fde->cie->addr_size, buf, &bytes_read, 0);
buf += bytes_read;
/* A 'z' augmentation in the CIE implies the presence of an
void
dwarf2_build_frame_info (struct objfile *objfile)
{
- struct comp_unit unit;
+ struct comp_unit *unit;
gdb_byte *frame_ptr;
/* Build a minimal decoding of the DWARF2 compilation unit. */
- unit.abfd = objfile->obfd;
- unit.objfile = objfile;
- unit.dbase = 0;
- unit.tbase = 0;
+ unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack,
+ sizeof (struct comp_unit));
+ unit->abfd = objfile->obfd;
+ unit->objfile = objfile;
+ 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. */
{
asection *got, *txt;
- unit.cie = NULL;
- unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
- dwarf_eh_frame_section);
+ unit->cie = NULL;
+ unit->dwarf_frame_buffer = dwarf2_read_section (objfile,
+ dwarf_eh_frame_section);
- unit.dwarf_frame_size = bfd_get_section_size (dwarf_eh_frame_section);
- unit.dwarf_frame_section = dwarf_eh_frame_section;
+ 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
that is used for the i386/amd64 target, which currently is
the only target in GCC that supports/uses the
DW_EH_PE_datarel encoding. */
- got = bfd_get_section_by_name (unit.abfd, ".got");
+ got = bfd_get_section_by_name (unit->abfd, ".got");
if (got)
- unit.dbase = got->vma;
+ 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");
+ txt = bfd_get_section_by_name (unit->abfd, ".text");
if (txt)
- unit.tbase = txt->vma;
+ 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);
+ 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_section)
{
- unit.cie = NULL;
- unit.dwarf_frame_buffer = dwarf2_read_section (objfile,
- dwarf_frame_section);
- unit.dwarf_frame_size = bfd_get_section_size (dwarf_frame_section);
- unit.dwarf_frame_section = dwarf_frame_section;
-
- 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, 0);
+ unit->cie = NULL;
+ unit->dwarf_frame_buffer = dwarf2_read_section (objfile,
+ dwarf_frame_section);
+ unit->dwarf_frame_size = bfd_get_section_size (dwarf_frame_section);
+ unit->dwarf_frame_section = dwarf_frame_section;
+
+ 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, 0);
}
}