/* Frame unwinder for frames with DWARF Call Frame Information.
- Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009
+ Copyright (C) 2003, 2004, 2005, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
Contributed by Mark Kettenis.
/* Target address size in bytes. */
int addr_size;
+ /* Target pointer size in bytes. */
+ int ptr_size;
+
/* True if a 'z' augmentation existed. */
unsigned char saw_z_augmentation;
/* The version recorded in the CIE. */
unsigned char version;
+
+ /* The segment size. */
+ unsigned char segment_size;
};
struct dwarf2_cie_table
bfd_vma tbase;
};
-static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc);
+static struct dwarf2_fde *dwarf2_frame_find_fde (CORE_ADDR *pc,
+ CORE_ADDR *out_offset);
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,
+ int ptr_len, const gdb_byte *buf,
unsigned int *bytes_read_ptr,
CORE_ADDR func_base);
\f
CFA_REG_OFFSET,
CFA_EXP
} cfa_how;
- gdb_byte *cfa_exp;
+ const gdb_byte *cfa_exp;
/* Used to implement DW_CFA_remember_state. */
struct dwarf2_frame_state_reg_info *prev;
}
static void
-no_get_frame_base (void *baton, gdb_byte **start, size_t *length)
+no_get_frame_base (void *baton, const gdb_byte **start, size_t *length)
{
internal_error (__FILE__, __LINE__,
_("Support for DW_OP_fbreg is unimplemented"));
_("Support for DW_OP_call_frame_cfa is unimplemented"));
}
+/* Helper function for execute_stack_op. */
+
+static CORE_ADDR
+no_get_frame_pc (void *baton)
+{
+ internal_error (__FILE__, __LINE__,
+ _("Support for DW_OP_GNU_implicit_pointer is unimplemented"));
+}
+
static CORE_ADDR
no_get_tls_address (void *baton, CORE_ADDR offset)
{
_("Support for DW_OP_GNU_push_tls_address is unimplemented"));
}
+/* Helper function for execute_stack_op. */
+
+static void
+no_dwarf_call (struct dwarf_expr_context *ctx, size_t die_offset)
+{
+ internal_error (__FILE__, __LINE__,
+ _("Support for DW_OP_call* is invalid in CFI"));
+}
+
/* Execute the required actions for both the DW_CFA_restore and
DW_CFA_restore_extended instructions. */
static void
}
static CORE_ADDR
-execute_stack_op (gdb_byte *exp, ULONGEST len, int addr_size,
- struct frame_info *this_frame, CORE_ADDR initial)
+execute_stack_op (const gdb_byte *exp, ULONGEST len, int addr_size,
+ CORE_ADDR offset, struct frame_info *this_frame,
+ CORE_ADDR initial, int initial_in_stack_memory)
{
struct dwarf_expr_context *ctx;
CORE_ADDR result;
ctx->gdbarch = get_frame_arch (this_frame);
ctx->addr_size = addr_size;
+ ctx->offset = offset;
ctx->baton = this_frame;
ctx->read_reg = read_reg;
ctx->read_mem = read_mem;
ctx->get_frame_base = no_get_frame_base;
ctx->get_frame_cfa = no_get_frame_cfa;
+ ctx->get_frame_pc = no_get_frame_pc;
ctx->get_tls_address = no_get_tls_address;
+ ctx->dwarf_call = no_dwarf_call;
- dwarf_expr_push (ctx, initial);
+ dwarf_expr_push (ctx, initial, initial_in_stack_memory);
dwarf_expr_eval (ctx, exp, len);
- result = dwarf_expr_fetch (ctx, 0);
- if (ctx->in_reg)
- result = read_reg (this_frame, result);
+ if (ctx->location == DWARF_VALUE_MEMORY)
+ result = dwarf_expr_fetch_address (ctx, 0);
+ else if (ctx->location == DWARF_VALUE_REGISTER)
+ result = read_reg (this_frame, dwarf_expr_fetch (ctx, 0));
+ else
+ {
+ /* This is actually invalid DWARF, but if we ever do run across
+ it somehow, we might as well support it. So, instead, report
+ it as unimplemented. */
+ error (_("Not implemented: computing unwound register using explicit value operator"));
+ }
do_cleanups (old_chain);
\f
static void
-execute_cfa_program (struct dwarf2_fde *fde, gdb_byte *insn_ptr,
- gdb_byte *insn_end, struct frame_info *this_frame,
+execute_cfa_program (struct dwarf2_fde *fde, const gdb_byte *insn_ptr,
+ const gdb_byte *insn_end, struct frame_info *this_frame,
struct dwarf2_frame_state *fs)
{
int eh_frame_p = fde->eh_frame_p;
{
case DW_CFA_set_loc:
fs->pc = read_encoded_value (fde->cie->unit, fde->cie->encoding,
- fde->cie->addr_size, insn_ptr,
+ fde->cie->ptr_size, insn_ptr,
&bytes_read, fde->initial_location);
/* Apply the objfile offset for relocatable objects. */
fs->pc += ANOFFSET (fde->cie->unit->objfile->section_offsets,
unwinder. */
{
int size = register_size (gdbarch, 0);
+
dwarf2_frame_state_alloc_regs (&fs->regs, 32);
for (reg = 8; reg < 16; reg++)
{
dwarf2_frame_find_quirks (struct dwarf2_frame_state *fs,
struct dwarf2_fde *fde)
{
- static const char *arm_idents[] = {
- "ARM C Compiler, ADS",
- "Thumb C Compiler, ADS",
- "ARM C++ Compiler, ADS",
- "Thumb C++ Compiler, ADS",
- "ARM/Thumb C/C++ Compiler, RVCT"
- };
- int i;
-
struct symtab *s;
s = find_pc_symtab (fs->pc);
- if (s == NULL || s->producer == NULL)
+ if (s == NULL)
return;
- for (i = 0; i < ARRAY_SIZE (arm_idents); i++)
- if (strncmp (s->producer, arm_idents[i], strlen (arm_idents[i])) == 0)
- {
- if (fde->cie->version == 1)
- fs->armcc_cfa_offsets_sf = 1;
-
- if (fde->cie->version == 1)
- fs->armcc_cfa_offsets_reversed = 1;
-
- /* The reversed offset problem is present in some compilers
- using DWARF3, but it was eventually fixed. Check the ARM
- defined augmentations, which are in the format "armcc" followed
- by a list of one-character options. The "+" option means
- this problem is fixed (no quirk needed). If the armcc
- augmentation is missing, the quirk is needed. */
- if (fde->cie->version == 3
- && (strncmp (fde->cie->augmentation, "armcc", 5) != 0
- || strchr (fde->cie->augmentation + 5, '+') == NULL))
- fs->armcc_cfa_offsets_reversed = 1;
-
- return;
- }
+ if (producer_is_realview (s->producer))
+ {
+ if (fde->cie->version == 1)
+ fs->armcc_cfa_offsets_sf = 1;
+
+ if (fde->cie->version == 1)
+ fs->armcc_cfa_offsets_reversed = 1;
+
+ /* The reversed offset problem is present in some compilers
+ using DWARF3, but it was eventually fixed. Check the ARM
+ defined augmentations, which are in the format "armcc" followed
+ by a list of one-character options. The "+" option means
+ this problem is fixed (no quirk needed). If the armcc
+ augmentation is missing, the quirk is needed. */
+ if (fde->cie->version == 3
+ && (strncmp (fde->cie->augmentation, "armcc", 5) != 0
+ || strchr (fde->cie->augmentation + 5, '+') == NULL))
+ fs->armcc_cfa_offsets_reversed = 1;
+
+ return;
+ }
}
\f
/* Target address size in bytes. */
int addr_size;
+
+ /* The .text offset. */
+ CORE_ADDR text_offset;
};
static struct dwarf2_frame_cache *
fs->pc = get_frame_address_in_block (this_frame);
/* Find the correct FDE. */
- fde = dwarf2_frame_find_fde (&fs->pc);
+ fde = dwarf2_frame_find_fde (&fs->pc, &cache->text_offset);
gdb_assert (fde != NULL);
/* Extract any interesting information from the CIE. */
case CFA_EXP:
cache->cfa =
execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len,
- cache->addr_size, this_frame, 0);
+ cache->addr_size, cache->text_offset,
+ this_frame, 0, 0);
break;
default:
case DWARF2_FRAME_REG_SAVED_EXP:
addr = execute_stack_op (cache->reg[regnum].loc.exp,
cache->reg[regnum].exp_len,
- cache->addr_size, this_frame, cache->cfa);
+ cache->addr_size, cache->text_offset,
+ this_frame, cache->cfa, 1);
return frame_unwind_got_memory (this_frame, regnum, addr);
case DWARF2_FRAME_REG_SAVED_VAL_OFFSET:
case DWARF2_FRAME_REG_SAVED_VAL_EXP:
addr = execute_stack_op (cache->reg[regnum].loc.exp,
cache->reg[regnum].exp_len,
- cache->addr_size, this_frame, cache->cfa);
+ cache->addr_size, cache->text_offset,
+ this_frame, cache->cfa, 1);
return frame_unwind_got_constant (this_frame, regnum, addr);
case DWARF2_FRAME_REG_UNSPECIFIED:
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);
+ struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr, NULL);
+
if (!fde)
return 0;
dwarf2_frame_base_sniffer (struct frame_info *this_frame)
{
CORE_ADDR block_addr = get_frame_address_in_block (this_frame);
- if (dwarf2_frame_find_fde (&block_addr))
+
+ if (dwarf2_frame_find_fde (&block_addr, NULL))
return &dwarf2_frame_base;
return NULL;
static CORE_ADDR
read_encoded_value (struct comp_unit *unit, gdb_byte encoding,
- int ptr_len, gdb_byte *buf, unsigned int *bytes_read_ptr,
+ int ptr_len, const gdb_byte *buf,
+ unsigned int *bytes_read_ptr,
CORE_ADDR func_base)
{
ptrdiff_t offset;
case DW_EH_PE_uleb128:
{
ULONGEST value;
- gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
+ const 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_sleb128:
{
LONGEST value;
- gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
+ const gdb_byte *end_buf = buf + (sizeof (value) + 1) * 8 / 7;
+
*bytes_read_ptr += read_sleb128 (buf, end_buf, &value) - buf;
return base + value;
}
{
struct dwarf2_cie **p_cie;
+ /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to
+ bsearch be non-NULL. */
+ if (cie_table->entries == NULL)
+ {
+ gdb_assert (cie_table->num_entries == 0);
+ return NULL;
+ }
+
p_cie = bsearch (&cie_pointer, cie_table->entries, cie_table->num_entries,
sizeof (cie_table->entries[0]), bsearch_cie_cmp);
if (p_cie != NULL)
{
CORE_ADDR seek_pc = *(CORE_ADDR *) key;
struct dwarf2_fde *fde = *(struct dwarf2_fde **) element;
+
if (seek_pc < fde->initial_location)
return -1;
if (seek_pc < fde->initial_location + fde->address_range)
inital location associated with it into *PC. */
static struct dwarf2_fde *
-dwarf2_frame_find_fde (CORE_ADDR *pc)
+dwarf2_frame_find_fde (CORE_ADDR *pc, CORE_ADDR *out_offset)
{
struct objfile *objfile;
fde_table = objfile_data (objfile, dwarf2_frame_objfile_data);
if (fde_table == NULL)
+ {
+ dwarf2_build_frame_info (objfile);
+ fde_table = objfile_data (objfile, dwarf2_frame_objfile_data);
+ }
+ gdb_assert (fde_table != NULL);
+
+ if (fde_table->num_entries == 0)
continue;
gdb_assert (objfile->section_offsets);
if (p_fde != NULL)
{
*pc = (*p_fde)->initial_location + offset;
+ if (out_offset)
+ *out_offset = offset;
return *p_fde;
}
}
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;
/* Check version number. */
cie_version = read_1_byte (unit->abfd, buf);
- if (cie_version != 1 && cie_version != 3)
+ if (cie_version != 1 && cie_version != 3 && cie_version != 4)
return NULL;
cie->version = cie_version;
buf += 1;
augmentation += 2;
}
+ if (cie->version >= 4)
+ {
+ /* FIXME: check that this is the same as from the CU header. */
+ cie->addr_size = read_1_byte (unit->abfd, buf);
+ ++buf;
+ cie->segment_size = read_1_byte (unit->abfd, buf);
+ ++buf;
+ }
+ else
+ {
+ cie->addr_size = gdbarch_dwarf2_addr_size (gdbarch);
+ cie->segment_size = 0;
+ }
+ /* Address values in .eh_frame sections are defined to have the
+ target's pointer size. Watchout: This breaks frame info for
+ targets with pointer size < address size, unless a .debug_frame
+ section exists as well. */
+ if (eh_frame_p)
+ cie->ptr_size = gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
+ else
+ cie->ptr_size = cie->addr_size;
+
cie->code_alignment_factor =
read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
{
/* Skip. Avoid indirection since we throw away the result. */
gdb_byte encoding = (*buf++) & ~DW_EH_PE_indirect;
- read_encoded_value (unit, encoding, cie->addr_size,
+ read_encoded_value (unit, encoding, cie->ptr_size,
buf, &bytes_read, 0);
buf += bytes_read;
augmentation++;
gdb_assert (fde->cie != NULL);
fde->initial_location =
- read_encoded_value (unit, fde->cie->encoding, fde->cie->addr_size,
+ read_encoded_value (unit, fde->cie->encoding, fde->cie->ptr_size,
buf, &bytes_read, 0);
buf += bytes_read;
fde->address_range =
read_encoded_value (unit, fde->cie->encoding & 0x0f,
- fde->cie->addr_size, buf, &bytes_read, 0);
+ fde->cie->ptr_size, buf, &bytes_read, 0);
buf += bytes_read;
/* A 'z' augmentation in the CIE implies the presence of an
{
enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
gdb_byte *ret;
- const char *msg;
ptrdiff_t start_offset;
while (1)
gdb_byte *frame_ptr;
struct dwarf2_cie_table cie_table;
struct dwarf2_fde_table fde_table;
+ struct dwarf2_fde_table *fde_table2;
cie_table.num_entries = 0;
cie_table.entries = NULL;
cie_table.num_entries = 0; /* Paranoia. */
}
- if (fde_table.num_entries != 0)
+ /* Copy fde_table to obstack: it is needed at runtime. */
+ fde_table2 = (struct dwarf2_fde_table *)
+ obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2));
+
+ if (fde_table.num_entries == 0)
+ {
+ fde_table2->entries = NULL;
+ fde_table2->num_entries = 0;
+ }
+ else
{
- struct dwarf2_fde_table *fde_table2;
- int i, j;
+ struct dwarf2_fde *fde_prev = NULL;
+ struct dwarf2_fde *first_non_zero_fde = NULL;
+ int i;
/* Prepare FDE table for lookups. */
qsort (fde_table.entries, fde_table.num_entries,
sizeof (fde_table.entries[0]), qsort_fde_cmp);
- /* Copy fde_table to obstack: it is needed at runtime. */
- fde_table2 = (struct dwarf2_fde_table *)
- obstack_alloc (&objfile->objfile_obstack, sizeof (*fde_table2));
+ /* Check for leftovers from --gc-sections. The GNU linker sets
+ the relevant symbols to zero, but doesn't zero the FDE *end*
+ ranges because there's no relocation there. It's (offset,
+ length), not (start, end). On targets where address zero is
+ just another valid address this can be a problem, since the
+ FDEs appear to be non-empty in the output --- we could pick
+ out the wrong FDE. To work around this, when overlaps are
+ detected, we prefer FDEs that do not start at zero.
+
+ Start by finding the first FDE with non-zero start. Below
+ we'll discard all FDEs that start at zero and overlap this
+ one. */
+ for (i = 0; i < fde_table.num_entries; i++)
+ {
+ struct dwarf2_fde *fde = fde_table.entries[i];
- /* Since we'll be doing bsearch, squeeze out identical (except for
- eh_frame_p) fde entries so bsearch result is predictable. */
- for (i = 0, j = 0; j < fde_table.num_entries; ++i)
- {
- const int k = j;
-
- obstack_grow (&objfile->objfile_obstack, &fde_table.entries[j],
- sizeof (fde_table.entries[0]));
- while (++j < fde_table.num_entries
- && (fde_table.entries[k]->initial_location ==
- fde_table.entries[j]->initial_location))
- /* Skip. */;
- }
+ if (fde->initial_location != 0)
+ {
+ first_non_zero_fde = fde;
+ break;
+ }
+ }
+
+ /* Since we'll be doing bsearch, squeeze out identical (except
+ for eh_frame_p) fde entries so bsearch result is predictable.
+ Also discard leftovers from --gc-sections. */
+ fde_table2->num_entries = 0;
+ for (i = 0; i < fde_table.num_entries; i++)
+ {
+ struct dwarf2_fde *fde = fde_table.entries[i];
+
+ if (fde->initial_location == 0
+ && first_non_zero_fde != NULL
+ && (first_non_zero_fde->initial_location
+ < fde->initial_location + fde->address_range))
+ continue;
+
+ if (fde_prev != NULL
+ && fde_prev->initial_location == fde->initial_location)
+ continue;
+
+ obstack_grow (&objfile->objfile_obstack, &fde_table.entries[i],
+ sizeof (fde_table.entries[0]));
+ ++fde_table2->num_entries;
+ fde_prev = fde;
+ }
fde_table2->entries = obstack_finish (&objfile->objfile_obstack);
- fde_table2->num_entries = i;
- set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2);
/* Discard the original fde_table. */
xfree (fde_table.entries);
}
+
+ set_objfile_data (objfile, dwarf2_frame_objfile_data, fde_table2);
}
/* Provide a prototype to silence -Wmissing-prototypes. */