#include "defs.h"
#include "dwarf2expr.h"
#include "elf/dwarf2.h"
#include "frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
#include "gdbcore.h"
#include "gdbtypes.h"
#include "symtab.h"
#include "objfiles.h"
#include "regcache.h"
#include "gdb_assert.h"
#include "gdb_string.h"
#include "complaints.h"
#include "dwarf2-frame.h"
struct dwarf2_cie
{
ULONGEST cie_pointer;
ULONGEST code_alignment_factor;
LONGEST data_alignment_factor;
ULONGEST return_address_register;
gdb_byte *initial_instructions;
gdb_byte *end;
gdb_byte encoding;
unsigned char saw_z_augmentation;
struct dwarf2_cie *next;
};
struct dwarf2_fde
{
struct dwarf2_cie *cie;
CORE_ADDR initial_location;
CORE_ADDR address_range;
gdb_byte *instructions;
gdb_byte *end;
struct dwarf2_fde *next;
};
static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc);
struct dwarf2_frame_state
{
struct dwarf2_frame_state_reg_info
{
struct dwarf2_frame_state_reg *reg;
int num_regs;
struct dwarf2_frame_state_reg_info *prev;
} regs;
LONGEST cfa_offset;
ULONGEST cfa_reg;
gdb_byte *cfa_exp;
enum {
CFA_UNSET,
CFA_REG_OFFSET,
CFA_EXP
} cfa_how;
CORE_ADDR pc;
struct dwarf2_frame_state_reg_info initial;
LONGEST data_align;
ULONGEST code_align;
ULONGEST retaddr_column;
};
#define cfa_exp_len cfa_reg
static void
dwarf2_frame_state_alloc_regs (struct dwarf2_frame_state_reg_info *rs,
int num_regs)
{
size_t size = sizeof (struct dwarf2_frame_state_reg);
if (num_regs <= rs->num_regs)
return;
rs->reg = (struct dwarf2_frame_state_reg *)
xrealloc (rs->reg, num_regs * size);
memset (rs->reg + rs->num_regs, 0, (num_regs - rs->num_regs) * size);
rs->num_regs = num_regs;
}
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);
struct dwarf2_frame_state_reg *reg;
reg = (struct dwarf2_frame_state_reg *) xmalloc (size);
memcpy (reg, rs->reg, size);
return reg;
}
static void
dwarf2_frame_state_free_regs (struct dwarf2_frame_state_reg_info *rs)
{
if (rs)
{
dwarf2_frame_state_free_regs (rs->prev);
xfree (rs->reg);
xfree (rs);
}
}
static void
dwarf2_frame_state_free (void *p)
{
struct dwarf2_frame_state *fs = p;
dwarf2_frame_state_free_regs (fs->initial.prev);
dwarf2_frame_state_free_regs (fs->regs.prev);
xfree (fs->initial.reg);
xfree (fs->regs.reg);
xfree (fs);
}
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);
int regnum;
gdb_byte *buf;
regnum = DWARF2_REG_TO_REGNUM (reg);
buf = alloca (register_size (gdbarch, regnum));
frame_unwind_register (next_frame, regnum, buf);
return extract_typed_address (buf, builtin_type_void_data_ptr);
}
static void
read_mem (void *baton, gdb_byte *buf, CORE_ADDR addr, size_t len)
{
read_memory (addr, buf, len);
}
static void
no_get_frame_base (void *baton, gdb_byte **start, size_t *length)
{
internal_error (__FILE__, __LINE__,
_("Support for DW_OP_fbreg is unimplemented"));
}
static CORE_ADDR
no_get_tls_address (void *baton, CORE_ADDR offset)
{
internal_error (__FILE__, __LINE__,
_("Support for DW_OP_GNU_push_tls_address is unimplemented"));
}
static CORE_ADDR
execute_stack_op (gdb_byte *exp, ULONGEST len,
struct frame_info *next_frame, CORE_ADDR initial)
{
struct dwarf_expr_context *ctx;
CORE_ADDR result;
ctx = new_dwarf_expr_context ();
ctx->baton = next_frame;
ctx->read_reg = read_reg;
ctx->read_mem = read_mem;
ctx->get_frame_base = no_get_frame_base;
ctx->get_tls_address = no_get_tls_address;
dwarf_expr_push (ctx, initial);
dwarf_expr_eval (ctx, exp, len);
result = dwarf_expr_fetch (ctx, 0);
if (ctx->in_reg)
result = read_reg (next_frame, result);
free_dwarf_expr_context (ctx);
return result;
}
static void
execute_cfa_program (gdb_byte *insn_ptr, gdb_byte *insn_end,
struct frame_info *next_frame,
struct dwarf2_frame_state *fs)
{
CORE_ADDR pc = frame_pc_unwind (next_frame);
int bytes_read;
while (insn_ptr < insn_end && fs->pc <= pc)
{
gdb_byte insn = *insn_ptr++;
ULONGEST utmp, reg;
LONGEST offset;
if ((insn & 0xc0) == DW_CFA_advance_loc)
fs->pc += (insn & 0x3f) * fs->code_align;
else if ((insn & 0xc0) == DW_CFA_offset)
{
reg = insn & 0x3f;
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 = DWARF2_FRAME_REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
}
else if ((insn & 0xc0) == DW_CFA_restore)
{
gdb_assert (fs->initial.reg);
reg = insn & 0x3f;
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
fs->regs.reg[reg] = fs->initial.reg[reg];
}
else
{
switch (insn)
{
case DW_CFA_set_loc:
fs->pc = dwarf2_read_address (insn_ptr, insn_end, &bytes_read);
insn_ptr += bytes_read;
break;
case DW_CFA_advance_loc1:
utmp = extract_unsigned_integer (insn_ptr, 1);
fs->pc += utmp * fs->code_align;
insn_ptr++;
break;
case DW_CFA_advance_loc2:
utmp = extract_unsigned_integer (insn_ptr, 2);
fs->pc += utmp * fs->code_align;
insn_ptr += 2;
break;
case DW_CFA_advance_loc4:
utmp = extract_unsigned_integer (insn_ptr, 4);
fs->pc += utmp * fs->code_align;
insn_ptr += 4;
break;
case DW_CFA_offset_extended:
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
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 = DWARF2_FRAME_REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = offset;
break;
case DW_CFA_restore_extended:
gdb_assert (fs->initial.reg);
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
fs->regs.reg[reg] = fs->initial.reg[reg];
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 = 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 = 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;
case DW_CFA_remember_state:
{
struct dwarf2_frame_state_reg_info *new_rs;
new_rs = XMALLOC (struct dwarf2_frame_state_reg_info);
*new_rs = fs->regs;
fs->regs.reg = dwarf2_frame_state_copy_regs (&fs->regs);
fs->regs.prev = new_rs;
}
break;
case DW_CFA_restore_state:
{
struct dwarf2_frame_state_reg_info *old_rs = fs->regs.prev;
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;
case DW_CFA_def_cfa:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
fs->cfa_offset = utmp;
fs->cfa_how = CFA_REG_OFFSET;
break;
case DW_CFA_def_cfa_register:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
fs->cfa_how = CFA_REG_OFFSET;
break;
case DW_CFA_def_cfa_offset:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
fs->cfa_offset = utmp;
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;
fs->cfa_how = CFA_EXP;
insn_ptr += fs->cfa_exp_len;
break;
case DW_CFA_expression:
insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
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 = DWARF2_FRAME_REG_SAVED_EXP;
insn_ptr += utmp;
break;
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;
break;
case DW_CFA_GNU_window_save:
{
struct gdbarch *gdbarch = get_frame_arch (next_frame);
int size = register_size(gdbarch, 0);
dwarf2_frame_state_alloc_regs (&fs->regs, 32);
for (reg = 8; reg < 16; reg++)
{
fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_REG;
fs->regs.reg[reg].loc.reg = reg + 16;
}
for (reg = 16; reg < 32; reg++)
{
fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_OFFSET;
fs->regs.reg[reg].loc.offset = (reg - 16) * size;
}
}
break;
case DW_CFA_GNU_args_size:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
break;
default:
internal_error (__FILE__, __LINE__, _("Unknown CFI encountered."));
}
}
}
dwarf2_frame_state_free_regs (fs->regs.prev);
fs->regs.prev = NULL;
}
static struct gdbarch_data *dwarf2_frame_data;
struct dwarf2_frame_ops
{
void (*init_reg) (struct gdbarch *, int, struct dwarf2_frame_state_reg *);
int (*signal_frame_p) (struct gdbarch *, struct frame_info *);
};
static void
dwarf2_frame_default_init_reg (struct gdbarch *gdbarch, int regnum,
struct dwarf2_frame_state_reg *reg)
{
if (regnum == PC_REGNUM)
reg->how = DWARF2_FRAME_REG_RA;
else if (regnum == SP_REGNUM)
reg->how = DWARF2_FRAME_REG_CFA;
}
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;
}
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;
}
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);
}
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;
}
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);
}
struct dwarf2_frame_cache
{
CORE_ADDR cfa;
int undefined_retaddr;
struct dwarf2_frame_state_reg *reg;
struct dwarf2_frame_state_reg retaddr_reg;
};
static 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;
struct dwarf2_fde *fde;
if (*this_cache)
return *this_cache;
cache = FRAME_OBSTACK_ZALLOC (struct dwarf2_frame_cache);
cache->reg = FRAME_OBSTACK_CALLOC (num_regs, struct dwarf2_frame_state_reg);
fs = XMALLOC (struct dwarf2_frame_state);
memset (fs, 0, sizeof (struct dwarf2_frame_state));
old_chain = make_cleanup (dwarf2_frame_state_free, fs);
fs->pc = frame_unwind_address_in_block (next_frame);
fde = dwarf2_frame_find_fde (&fs->pc);
gdb_assert (fde != NULL);
fs->data_align = fde->cie->data_alignment_factor;
fs->code_align = fde->cie->code_alignment_factor;
fs->retaddr_column = fde->cie->return_address_register;
execute_cfa_program (fde->cie->initial_instructions,
fde->cie->end, next_frame, fs);
fs->initial = fs->regs;
fs->initial.reg = dwarf2_frame_state_copy_regs (&fs->regs);
execute_cfa_program (fde->instructions, fde->end, next_frame, fs);
switch (fs->cfa_how)
{
case CFA_REG_OFFSET:
cache->cfa = read_reg (next_frame, fs->cfa_reg);
cache->cfa += fs->cfa_offset;
break;
case CFA_EXP:
cache->cfa =
execute_stack_op (fs->cfa_exp, fs->cfa_exp_len, next_frame, 0);
break;
default:
internal_error (__FILE__, __LINE__, _("Unknown CFA rule."));
}
{
int regnum;
for (regnum = 0; regnum < num_regs; regnum++)
dwarf2_frame_init_reg (gdbarch, regnum, &cache->reg[regnum]);
}
{
int column;
for (column = 0; column < fs->regs.num_regs; column++)
{
int regnum = DWARF2_REG_TO_REGNUM (column);
if (regnum < 0 || regnum >= num_regs)
continue;
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];
}
}
{
int regnum;
for (regnum = 0; regnum < num_regs; regnum++)
{
if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA
|| cache->reg[regnum].how == DWARF2_FRAME_REG_RA_OFFSET)
{
struct dwarf2_frame_state_reg *retaddr_reg =
&fs->regs.reg[fs->retaddr_column];
if (fs->retaddr_column < fs->regs.num_regs
&& retaddr_reg->how != DWARF2_FRAME_REG_UNSPECIFIED
&& retaddr_reg->how != DWARF2_FRAME_REG_SAME_VALUE)
{
if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
cache->reg[regnum] = *retaddr_reg;
else
cache->retaddr_reg = *retaddr_reg;
}
else
{
if (cache->reg[regnum].how == DWARF2_FRAME_REG_RA)
{
cache->reg[regnum].loc.reg = fs->retaddr_column;
cache->reg[regnum].how = DWARF2_FRAME_REG_SAVED_REG;
}
else
{
cache->retaddr_reg.loc.reg = fs->retaddr_column;
cache->retaddr_reg.how = DWARF2_FRAME_REG_SAVED_REG;
}
}
}
}
}
if (fs->retaddr_column < fs->regs.num_regs
&& fs->regs.reg[fs->retaddr_column].how == DWARF2_FRAME_REG_UNDEFINED)
cache->undefined_retaddr = 1;
do_cleanups (old_chain);
*this_cache = cache;
return cache;
}
static void
dwarf2_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);
if (cache->undefined_retaddr)
return;
(*this_id) = frame_id_build (cache->cfa, frame_func_unwind (next_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)
{
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 DWARF2_FRAME_REG_UNDEFINED:
*optimizedp = 1;
*lvalp = not_lval;
*addrp = 0;
*realnump = -1;
if (valuep)
{
frame_unwind_register (next_frame, regnum, valuep);
}
break;
case DWARF2_FRAME_REG_SAVED_OFFSET:
*optimizedp = 0;
*lvalp = lval_memory;
*addrp = cache->cfa + cache->reg[regnum].loc.offset;
*realnump = -1;
if (valuep)
{
read_memory (*addrp, valuep, register_size (gdbarch, regnum));
}
break;
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 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_memory (*addrp, valuep, register_size (gdbarch, regnum));
}
break;
case DWARF2_FRAME_REG_UNSPECIFIED:
*optimizedp = 0;
*lvalp = lval_register;
*addrp = 0;
*realnump = regnum;
if (valuep)
frame_unwind_register (next_frame, (*realnump), valuep);
break;
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_typed_address (valuep, builtin_type_void_data_ptr, cache->cfa);
}
break;
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 = DWARF2_REG_TO_REGNUM (cache->retaddr_reg.loc.reg);
pc += frame_unwind_register_unsigned (next_frame, regnum);
store_typed_address (valuep, builtin_type_void_func_ptr, pc);
}
break;
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_frame_this_id,
dwarf2_frame_prev_register
};
const struct frame_unwind *
dwarf2_frame_sniffer (struct frame_info *next_frame)
{
CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame);
if (!dwarf2_frame_find_fde (&block_addr))
return NULL;
if (dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
next_frame))
return &dwarf2_signal_frame_unwind;
return &dwarf2_frame_unwind;
}
static CORE_ADDR
dwarf2_frame_base_address (struct frame_info *next_frame, void **this_cache)
{
struct dwarf2_frame_cache *cache =
dwarf2_frame_cache (next_frame, this_cache);
return cache->cfa;
}
static const struct frame_base dwarf2_frame_base =
{
&dwarf2_frame_unwind,
dwarf2_frame_base_address,
dwarf2_frame_base_address,
dwarf2_frame_base_address
};
const struct frame_base *
dwarf2_frame_base_sniffer (struct frame_info *next_frame)
{
CORE_ADDR pc = frame_pc_unwind (next_frame);
if (dwarf2_frame_find_fde (&pc))
return &dwarf2_frame_base;
return NULL;
}
struct comp_unit
{
bfd *abfd;
struct objfile *objfile;
struct dwarf2_cie *cie;
gdb_byte *dwarf_frame_buffer;
unsigned long dwarf_frame_size;
asection *dwarf_frame_section;
bfd_vma dbase;
bfd_vma tbase;
};
const struct objfile_data *dwarf2_frame_objfile_data;
static unsigned int
read_1_byte (bfd *abfd, gdb_byte *buf)
{
return bfd_get_8 (abfd, buf);
}
static unsigned int
read_4_bytes (bfd *abfd, gdb_byte *buf)
{
return bfd_get_32 (abfd, buf);
}
static ULONGEST
read_8_bytes (bfd *abfd, gdb_byte *buf)
{
return bfd_get_64 (abfd, buf);
}
static ULONGEST
read_unsigned_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
{
ULONGEST result;
unsigned int num_read;
int shift;
gdb_byte byte;
result = 0;
shift = 0;
num_read = 0;
do
{
byte = bfd_get_8 (abfd, (bfd_byte *) buf);
buf++;
num_read++;
result |= ((byte & 0x7f) << shift);
shift += 7;
}
while (byte & 0x80);
*bytes_read_ptr = num_read;
return result;
}
static LONGEST
read_signed_leb128 (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
{
LONGEST result;
int shift;
unsigned int num_read;
gdb_byte byte;
result = 0;
shift = 0;
num_read = 0;
do
{
byte = bfd_get_8 (abfd, (bfd_byte *) buf);
buf++;
num_read++;
result |= ((byte & 0x7f) << shift);
shift += 7;
}
while (byte & 0x80);
if (shift < 8 * sizeof (result) && (byte & 0x40))
result |= -(((LONGEST)1) << shift);
*bytes_read_ptr = num_read;
return result;
}
static ULONGEST
read_initial_length (bfd *abfd, gdb_byte *buf, unsigned int *bytes_read_ptr)
{
LONGEST result;
result = bfd_get_32 (abfd, buf);
if (result == 0xffffffff)
{
result = bfd_get_64 (abfd, buf + 4);
*bytes_read_ptr = 12;
}
else
*bytes_read_ptr = 4;
return result;
}
static gdb_byte
encoding_for_size (unsigned int size)
{
switch (size)
{
case 2:
return DW_EH_PE_udata2;
case 4:
return DW_EH_PE_udata4;
case 8:
return DW_EH_PE_udata8;
default:
internal_error (__FILE__, __LINE__, _("Unsupported address size"));
}
}
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 = size_of_encoded_value (DW_EH_PE_absptr);
ptrdiff_t offset;
CORE_ADDR base;
if (encoding & DW_EH_PE_indirect)
internal_error (__FILE__, __LINE__,
_("Unsupported encoding: DW_EH_PE_indirect"));
*bytes_read_ptr = 0;
switch (encoding & 0x70)
{
case DW_EH_PE_absptr:
base = 0;
break;
case DW_EH_PE_pcrel:
base = bfd_get_section_vma (unit->bfd, unit->dwarf_frame_section);
base += (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:
base = 0;
break;
case DW_EH_PE_aligned:
base = 0;
offset = buf - unit->dwarf_frame_buffer;
if ((offset % ptr_len) != 0)
{
*bytes_read_ptr = ptr_len - (offset % ptr_len);
buf += *bytes_read_ptr;
}
break;
default:
internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
}
if ((encoding & 0x07) == 0x00)
encoding |= encoding_for_size (ptr_len);
switch (encoding & 0x0f)
{
case DW_EH_PE_uleb128:
{
ULONGEST value;
gdb_byte *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_udata4:
*bytes_read_ptr += 4;
return (base + bfd_get_32 (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;
gdb_byte *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));
case DW_EH_PE_sdata4:
*bytes_read_ptr += 4;
return (base + bfd_get_signed_32 (unit->abfd, (bfd_byte *) buf));
case DW_EH_PE_sdata8:
*bytes_read_ptr += 8;
return (base + bfd_get_signed_64 (unit->abfd, (bfd_byte *) buf));
default:
internal_error (__FILE__, __LINE__, _("Invalid or unsupported encoding"));
}
}
static struct dwarf2_cie *
find_cie (struct comp_unit *unit, ULONGEST cie_pointer)
{
struct dwarf2_cie *cie = unit->cie;
while (cie)
{
if (cie->cie_pointer == cie_pointer)
return cie;
cie = cie->next;
}
return NULL;
}
static void
add_cie (struct comp_unit *unit, struct dwarf2_cie *cie)
{
cie->next = unit->cie;
unit->cie = cie;
}
static struct dwarf2_fde *
dwarf2_frame_find_fde (CORE_ADDR *pc)
{
struct objfile *objfile;
ALL_OBJFILES (objfile)
{
struct dwarf2_fde *fde;
CORE_ADDR offset;
fde = objfile_data (objfile, dwarf2_frame_objfile_data);
if (fde == NULL)
continue;
gdb_assert (objfile->section_offsets);
offset = ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
while (fde)
{
if (*pc >= fde->initial_location + offset
&& *pc < fde->initial_location + offset + fde->address_range)
{
*pc = fde->initial_location + offset;
return fde;
}
fde = fde->next;
}
}
return NULL;
}
static void
add_fde (struct comp_unit *unit, struct dwarf2_fde *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
#define DW64_CIE_ID 0xffffffffffffffffULL
#else
#define DW64_CIE_ID ~0
#endif
static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start,
int eh_frame_p);
static gdb_byte *
decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p)
{
gdb_byte *buf, *end;
LONGEST length;
unsigned int bytes_read;
int dwarf64_p;
ULONGEST cie_id;
ULONGEST cie_pointer;
buf = start;
length = read_initial_length (unit->abfd, buf, &bytes_read);
buf += bytes_read;
end = buf + length;
if (end > unit->dwarf_frame_buffer + unit->dwarf_frame_size)
return NULL;
if (length == 0)
return end;
dwarf64_p = (bytes_read == 12);
if (eh_frame_p)
cie_id = 0;
else if (dwarf64_p)
cie_id = DW64_CIE_ID;
else
cie_id = DW_CIE_ID;
if (dwarf64_p)
{
cie_pointer = read_8_bytes (unit->abfd, buf);
buf += 8;
}
else
{
cie_pointer = read_4_bytes (unit->abfd, buf);
buf += 4;
}
if (cie_pointer == cie_id)
{
struct dwarf2_cie *cie;
char *augmentation;
unsigned int cie_version;
cie_pointer = start - unit->dwarf_frame_buffer;
if (find_cie (unit, cie_pointer))
return end;
cie = (struct dwarf2_cie *)
obstack_alloc (&unit->objfile->objfile_obstack,
sizeof (struct dwarf2_cie));
cie->initial_instructions = NULL;
cie->cie_pointer = cie_pointer;
cie->encoding = DW_EH_PE_absptr;
cie_version = read_1_byte (unit->abfd, buf);
if (cie_version != 1 && cie_version != 3)
return NULL;
buf += 1;
augmentation = (char *) buf;
buf += (strlen (augmentation) + 1);
if (augmentation[0] == 'e' && augmentation[1] == 'h')
{
buf += TYPE_LENGTH (builtin_type_void_data_ptr);
augmentation += 2;
}
cie->code_alignment_factor =
read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
cie->data_alignment_factor =
read_signed_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
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)
{
ULONGEST length;
length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
if (buf > end)
return NULL;
cie->initial_instructions = buf + length;
augmentation++;
}
while (*augmentation)
{
if (*augmentation == 'L')
{
buf++;
augmentation++;
}
else if (*augmentation == 'R')
{
cie->encoding = *buf++;
augmentation++;
}
else if (*augmentation == 'P')
{
gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect;
read_encoded_value (unit, encoding, buf, &bytes_read);
buf += bytes_read;
augmentation++;
}
else
{
if (cie->initial_instructions == NULL)
return end;
buf = cie->initial_instructions;
break;
}
}
cie->initial_instructions = buf;
cie->end = end;
add_cie (unit, cie);
}
else
{
struct dwarf2_fde *fde;
if (eh_frame_p)
{
cie_pointer = buf - unit->dwarf_frame_buffer - cie_pointer;
cie_pointer -= (dwarf64_p ? 8 : 4);
}
if (cie_pointer >= unit->dwarf_frame_size)
return NULL;
fde = (struct dwarf2_fde *)
obstack_alloc (&unit->objfile->objfile_obstack,
sizeof (struct dwarf2_fde));
fde->cie = find_cie (unit, cie_pointer);
if (fde->cie == NULL)
{
decode_frame_entry (unit, unit->dwarf_frame_buffer + cie_pointer,
eh_frame_p);
fde->cie = find_cie (unit, cie_pointer);
}
gdb_assert (fde->cie != NULL);
fde->initial_location =
read_encoded_value (unit, fde->cie->encoding, buf, &bytes_read);
buf += bytes_read;
fde->address_range =
read_encoded_value (unit, fde->cie->encoding & 0x0f, buf, &bytes_read);
buf += bytes_read;
if (fde->cie->saw_z_augmentation)
{
ULONGEST length;
length = read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read + length;
if (buf > end)
return NULL;
}
fde->instructions = buf;
fde->end = end;
add_fde (unit, fde);
}
return end;
}
static gdb_byte *
decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p)
{
enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
gdb_byte *ret;
const char *msg;
ptrdiff_t start_offset;
while (1)
{
ret = decode_frame_entry_1 (unit, start, eh_frame_p);
if (ret != NULL)
break;
start_offset = start - unit->dwarf_frame_buffer;
if (workaround < ALIGN4 && (start_offset & 3) != 0)
{
start += 4 - (start_offset & 3);
workaround = ALIGN4;
continue;
}
if (workaround < ALIGN8 && (start_offset & 7) != 0)
{
start += 8 - (start_offset & 7);
workaround = ALIGN8;
continue;
}
workaround = FAIL;
ret = unit->dwarf_frame_buffer + unit->dwarf_frame_size;
break;
}
switch (workaround)
{
case NONE:
break;
case ALIGN4:
complaint (&symfile_complaints,
_("Corrupt data in %s:%s; align 4 workaround apparently succeeded"),
unit->dwarf_frame_section->owner->filename,
unit->dwarf_frame_section->name);
break;
case ALIGN8:
complaint (&symfile_complaints,
_("Corrupt data in %s:%s; align 8 workaround apparently succeeded"),
unit->dwarf_frame_section->owner->filename,
unit->dwarf_frame_section->name);
break;
default:
complaint (&symfile_complaints,
_("Corrupt data in %s:%s"),
unit->dwarf_frame_section->owner->filename,
unit->dwarf_frame_section->name);
break;
}
return ret;
}
extern asection *dwarf_frame_section;
extern asection *dwarf_eh_frame_section;
extern char *dwarf2_read_section (struct objfile *objfile, bfd *, asection *sectp);
void
dwarf2_build_frame_info (struct objfile *objfile)
{
struct comp_unit unit;
gdb_byte *frame_ptr;
unit.abfd = objfile->obfd;
unit.objfile = objfile;
unit.dbase = 0;
unit.tbase = 0;
if (dwarf_eh_frame_section)
{
asection *got, *txt;
unit.cie = NULL;
unit.dwarf_frame_buffer = dwarf2_read_section (objfile, objfile->obfd,
dwarf_eh_frame_section);
unit.dwarf_frame_size = bfd_get_section_size (dwarf_eh_frame_section);
unit.dwarf_frame_section = dwarf_eh_frame_section;
got = bfd_get_section_by_name (unit.abfd, ".got");
if (got)
unit.dbase = got->vma;
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_section)
{
unit.cie = NULL;
unit.dwarf_frame_buffer = dwarf2_read_section (objfile, objfile->obfd,
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);
}
}
void _initialize_dwarf2_frame (void);
void
_initialize_dwarf2_frame (void)
{
dwarf2_frame_data = gdbarch_data_register_pre_init (dwarf2_frame_init);
dwarf2_frame_objfile_data = register_objfile_data ();
}