/* 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.
#include "defs.h"
#include "dwarf2expr.h"
-#include "elf/dwarf2.h"
+#include "dwarf2.h"
#include "frame.h"
#include "frame-base.h"
#include "frame-unwind.h"
/* The version recorded in the CIE. */
unsigned char version;
- struct dwarf2_cie *next;
+ /* The segment size. */
+ unsigned char segment_size;
+};
+
+struct dwarf2_cie_table
+{
+ int num_entries;
+ struct dwarf2_cie **entries;
};
/* Frame Description Entry (FDE). */
/* True if this FDE is read from a .eh_frame instead of a .debug_frame
section. */
unsigned char eh_frame_p;
+};
- struct dwarf2_fde *next;
+struct dwarf2_fde_table
+{
+ int num_entries;
+ struct dwarf2_fde **entries;
};
/* A minimal decoding of DWARF2 compilation units. We only decode
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;
_("Support for DW_OP_fbreg is unimplemented"));
}
+/* Helper function for execute_stack_op. */
+
+static CORE_ADDR
+no_get_frame_cfa (void *baton)
+{
+ internal_error (__FILE__, __LINE__,
+ _("Support for DW_OP_call_frame_cfa is unimplemented"));
+}
+
static CORE_ADDR
no_get_tls_address (void *baton, CORE_ADDR offset)
{
static CORE_ADDR
execute_stack_op (gdb_byte *exp, ULONGEST len, int addr_size,
- struct frame_info *this_frame, CORE_ADDR initial)
+ struct frame_info *this_frame, CORE_ADDR initial,
+ int initial_in_stack_memory)
{
struct dwarf_expr_context *ctx;
CORE_ADDR result;
+ struct cleanup *old_chain;
ctx = new_dwarf_expr_context ();
+ old_chain = make_cleanup_free_dwarf_expr_context (ctx);
+
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;
+ ctx->get_frame_cfa = no_get_frame_cfa;
ctx->get_tls_address = no_get_tls_address;
- 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)
+ if (ctx->location == DWARF_VALUE_REGISTER)
result = read_reg (this_frame, result);
+ else if (ctx->location != DWARF_VALUE_MEMORY)
+ {
+ /* 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"));
+ }
- free_dwarf_expr_context (ctx);
+ do_cleanups (old_chain);
return result;
}
CORE_ADDR pc = get_frame_pc (this_frame);
int bytes_read;
struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
while (insn_ptr < insn_end && fs->pc <= pc)
{
break;
case DW_CFA_advance_loc1:
- utmp = extract_unsigned_integer (insn_ptr, 1);
+ utmp = extract_unsigned_integer (insn_ptr, 1, byte_order);
fs->pc += utmp * fs->code_align;
insn_ptr++;
break;
case DW_CFA_advance_loc2:
- utmp = extract_unsigned_integer (insn_ptr, 2);
+ utmp = extract_unsigned_integer (insn_ptr, 2, byte_order);
fs->pc += utmp * fs->code_align;
insn_ptr += 2;
break;
case DW_CFA_advance_loc4:
- utmp = extract_unsigned_integer (insn_ptr, 4);
+ utmp = extract_unsigned_integer (insn_ptr, 4, byte_order);
fs->pc += utmp * fs->code_align;
insn_ptr += 4;
break;
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
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, 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, 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, this_frame, cache->cfa, 1);
return frame_unwind_got_constant (this_frame, regnum, addr);
case DWARF2_FRAME_REG_UNSPECIFIED:
return NULL;
}
+
+/* Compute the CFA for THIS_FRAME, but only if THIS_FRAME came from
+ the DWARF unwinder. This is used to implement
+ DW_OP_call_frame_cfa. */
+
+CORE_ADDR
+dwarf2_frame_cfa (struct frame_info *this_frame)
+{
+ while (get_frame_type (this_frame) == INLINE_FRAME)
+ this_frame = get_prev_frame (this_frame);
+ /* This restriction could be lifted if other unwinders are known to
+ compute the frame base in a way compatible with the DWARF
+ unwinder. */
+ if (! frame_unwinder_is (this_frame, &dwarf2_frame_unwind))
+ error (_("can't compute CFA for this frame"));
+ return get_frame_base (this_frame);
+}
\f
const struct objfile_data *dwarf2_frame_objfile_data;
}
\f
-/* GCC uses a single CIE for all FDEs in a .debug_frame section.
- That's why we use a simple linked list here. */
+static int
+bsearch_cie_cmp (const void *key, const void *element)
+{
+ ULONGEST cie_pointer = *(ULONGEST *) key;
+ struct dwarf2_cie *cie = *(struct dwarf2_cie **) element;
+
+ if (cie_pointer == cie->cie_pointer)
+ return 0;
+
+ return (cie_pointer < cie->cie_pointer) ? -1 : 1;
+}
+/* Find CIE with the given CIE_POINTER in CIE_TABLE. */
static struct dwarf2_cie *
-find_cie (struct comp_unit *unit, ULONGEST cie_pointer)
+find_cie (struct dwarf2_cie_table *cie_table, ULONGEST cie_pointer)
{
- struct dwarf2_cie *cie = unit->cie;
+ struct dwarf2_cie **p_cie;
- while (cie)
+ /* The C standard (ISO/IEC 9899:TC2) requires the BASE argument to
+ bsearch be non-NULL. */
+ if (cie_table->entries == NULL)
{
- if (cie->cie_pointer == cie_pointer)
- return cie;
-
- cie = cie->next;
+ 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)
+ return *p_cie;
return NULL;
}
+/* Add a pointer to new CIE to the CIE_TABLE, allocating space for it. */
static void
-add_cie (struct comp_unit *unit, struct dwarf2_cie *cie)
+add_cie (struct dwarf2_cie_table *cie_table, struct dwarf2_cie *cie)
{
- cie->next = unit->cie;
- unit->cie = cie;
- cie->unit = unit;
+ const int n = cie_table->num_entries;
+
+ gdb_assert (n < 1
+ || cie_table->entries[n - 1]->cie_pointer < cie->cie_pointer);
+
+ cie_table->entries =
+ xrealloc (cie_table->entries, (n + 1) * sizeof (cie_table->entries[0]));
+ cie_table->entries[n] = cie;
+ cie_table->num_entries = n + 1;
+}
+
+static int
+bsearch_fde_cmp (const void *key, const void *element)
+{
+ 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)
+ return 0;
+ return 1;
}
/* Find the FDE for *PC. Return a pointer to the FDE, and store the
ALL_OBJFILES (objfile)
{
- struct dwarf2_fde *fde;
+ struct dwarf2_fde_table *fde_table;
+ struct dwarf2_fde **p_fde;
CORE_ADDR offset;
+ CORE_ADDR seek_pc;
- fde = objfile_data (objfile, dwarf2_frame_objfile_data);
- if (fde == NULL)
+ 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);
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;
- }
+ gdb_assert (fde_table->num_entries > 0);
+ if (*pc < offset + fde_table->entries[0]->initial_location)
+ continue;
+
+ seek_pc = *pc - offset;
+ p_fde = bsearch (&seek_pc, fde_table->entries, fde_table->num_entries,
+ sizeof (fde_table->entries[0]), bsearch_fde_cmp);
+ if (p_fde != NULL)
+ {
+ *pc = (*p_fde)->initial_location + offset;
+ return *p_fde;
+ }
}
-
return NULL;
}
+/* Add a pointer to new FDE to the FDE_TABLE, allocating space for it. */
static void
-add_fde (struct comp_unit *unit, struct dwarf2_fde *fde)
+add_fde (struct dwarf2_fde_table *fde_table, struct dwarf2_fde *fde)
{
- fde->next = objfile_data (unit->objfile, dwarf2_frame_objfile_data);
- set_objfile_data (unit->objfile, dwarf2_frame_objfile_data, fde);
+ if (fde->address_range == 0)
+ /* Discard useless FDEs. */
+ return;
+
+ fde_table->num_entries += 1;
+ fde_table->entries =
+ xrealloc (fde_table->entries,
+ fde_table->num_entries * sizeof (fde_table->entries[0]));
+ fde_table->entries[fde_table->num_entries - 1] = fde;
}
#ifdef CC_HAS_LONG_LONG
#endif
static gdb_byte *decode_frame_entry (struct comp_unit *unit, gdb_byte *start,
- int eh_frame_p);
+ int eh_frame_p,
+ struct dwarf2_cie_table *cie_table,
+ struct dwarf2_fde_table *fde_table);
/* Decode the next CIE or FDE. Return NULL if invalid input, otherwise
the next byte to be processed. */
static gdb_byte *
-decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p)
+decode_frame_entry_1 (struct comp_unit *unit, gdb_byte *start, int eh_frame_p,
+ struct dwarf2_cie_table *cie_table,
+ struct dwarf2_fde_table *fde_table)
{
struct gdbarch *gdbarch = get_objfile_arch (unit->objfile);
gdb_byte *buf, *end;
cie_pointer = start - unit->dwarf_frame_buffer;
/* Check whether we've already read it. */
- if (find_cie (unit, cie_pointer))
+ if (find_cie (cie_table, cie_pointer))
return end;
cie = (struct dwarf2_cie *)
/* 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_ptr_bit (gdbarch) / TARGET_CHAR_BIT;
+ cie->segment_size = 0;
+ }
+
cie->code_alignment_factor =
read_unsigned_leb128 (unit->abfd, buf, &bytes_read);
buf += bytes_read;
cie->initial_instructions = buf;
cie->end = end;
+ cie->unit = unit;
- add_cie (unit, cie);
+ add_cie (cie_table, cie);
}
else
{
fde = (struct dwarf2_fde *)
obstack_alloc (&unit->objfile->objfile_obstack,
sizeof (struct dwarf2_fde));
- fde->cie = find_cie (unit, cie_pointer);
+ fde->cie = find_cie (cie_table, 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);
+ eh_frame_p, cie_table, fde_table);
+ fde->cie = find_cie (cie_table, cie_pointer);
}
gdb_assert (fde->cie != NULL);
fde->eh_frame_p = eh_frame_p;
- add_fde (unit, fde);
+ add_fde (fde_table, fde);
}
return end;
/* Read a CIE or FDE in BUF and decode it. */
static gdb_byte *
-decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p)
+decode_frame_entry (struct comp_unit *unit, gdb_byte *start, int eh_frame_p,
+ struct dwarf2_cie_table *cie_table,
+ struct dwarf2_fde_table *fde_table)
{
enum { NONE, ALIGN4, ALIGN8, FAIL } workaround = NONE;
gdb_byte *ret;
while (1)
{
- ret = decode_frame_entry_1 (unit, start, eh_frame_p);
+ ret = decode_frame_entry_1 (unit, start, eh_frame_p,
+ cie_table, fde_table);
if (ret != NULL)
break;
extern void dwarf2_get_section_info (struct objfile *, const char *, asection **,
gdb_byte **, bfd_size_type *);
+static int
+qsort_fde_cmp (const void *a, const void *b)
+{
+ struct dwarf2_fde *aa = *(struct dwarf2_fde **)a;
+ struct dwarf2_fde *bb = *(struct dwarf2_fde **)b;
+
+ if (aa->initial_location == bb->initial_location)
+ {
+ if (aa->address_range != bb->address_range
+ && aa->eh_frame_p == 0 && bb->eh_frame_p == 0)
+ /* Linker bug, e.g. gold/10400.
+ Work around it by keeping stable sort order. */
+ return (a < b) ? -1 : 1;
+ else
+ /* Put eh_frame entries after debug_frame ones. */
+ return aa->eh_frame_p - bb->eh_frame_p;
+ }
+
+ return (aa->initial_location < bb->initial_location) ? -1 : 1;
+}
+
void
dwarf2_build_frame_info (struct objfile *objfile)
{
struct comp_unit *unit;
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;
+
+ fde_table.num_entries = 0;
+ fde_table.entries = NULL;
/* Build a minimal decoding of the DWARF2 compilation unit. */
unit = (struct comp_unit *) obstack_alloc (&objfile->objfile_obstack,
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. */
dwarf2_get_section_info (objfile, ".eh_frame",
&unit->dwarf_frame_section,
&unit->dwarf_frame_buffer,
{
asection *got, *txt;
- unit->cie = NULL;
/* 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
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 = decode_frame_entry (unit, frame_ptr, 1,
+ &cie_table, &fde_table);
+
+ if (cie_table.num_entries != 0)
+ {
+ /* Reinit cie_table: debug_frame has different CIEs. */
+ xfree (cie_table.entries);
+ cie_table.num_entries = 0;
+ cie_table.entries = NULL;
+ }
}
dwarf2_get_section_info (objfile, ".debug_frame",
&unit->dwarf_frame_size);
if (unit->dwarf_frame_size)
{
- unit->cie = NULL;
-
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);
+ frame_ptr = decode_frame_entry (unit, frame_ptr, 0,
+ &cie_table, &fde_table);
+ }
+
+ /* Discard the cie_table, it is no longer needed. */
+ if (cie_table.num_entries != 0)
+ {
+ xfree (cie_table.entries);
+ cie_table.entries = NULL; /* Paranoia. */
+ cie_table.num_entries = 0; /* Paranoia. */
+ }
+
+ /* 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 *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);
+
+ /* 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];
+
+ 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);
+
+ /* 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. */
projects / deliverable / binutils-gdb.git / blobdiff