/* 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, 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"
#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;
/* 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_table
+{
+ int num_entries;
+ struct dwarf2_fde **entries;
+};
+
+/* 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;
+
+ /* Pointer to the .debug_frame section loaded into memory. */
+ gdb_byte *dwarf_frame_buffer;
+
+ /* Length of the loaded .debug_frame section. */
+ bfd_size_type dwarf_frame_size;
+
+ /* Pointer to the .debug_frame section. */
+ asection *dwarf_frame_section;
- struct dwarf2_fde *next;
+ /* 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. */
struct dwarf2_frame_state_reg *reg;
int num_regs;
+ LONGEST cfa_offset;
+ ULONGEST cfa_reg;
+ enum {
+ CFA_UNSET,
+ CFA_REG_OFFSET,
+ CFA_EXP
+ } cfa_how;
+ gdb_byte *cfa_exp;
+
/* Used to implement DW_CFA_remember_state. */
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;
-
/* The PC described by the current frame state. */
CORE_ADDR pc;
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 (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_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)
{
_("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 %s"),
+ gdbarch_register_name
+ (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
+ gdbarch_dwarf2_reg_to_regnum (gdbarch, reg),
+ paddress (gdbarch, 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,
+ int initial_in_stack_memory)
{
struct dwarf_expr_context *ctx;
CORE_ADDR result;
+ struct cleanup *old_chain;
ctx = new_dwarf_expr_context ();
- ctx->baton = next_frame;
+ 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)
- result = read_reg (next_frame, result);
+ 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;
}
\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);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
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
- (gdbarch, gdbarch_dwarf2_reg_to_regnum (gdbarch, reg)),
- gdbarch_dwarf2_reg_to_regnum (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;
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;
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:
if (old_rs == NULL)
{
complaint (&symfile_complaints, _("\
-bad CFI data; mismatched DW_CFA_restore_state at 0x%s"), paddr (fs->pc));
+bad CFI data; mismatched DW_CFA_restore_state at %s"),
+ paddress (gdbarch, fs->pc));
}
else
{
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, &fs->regs.cfa_reg);
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
if (fs->armcc_cfa_offsets_sf)
utmp *= fs->data_align;
- fs->cfa_offset = utmp;
- fs->cfa_how = CFA_REG_OFFSET;
+ fs->regs.cfa_offset = utmp;
+ fs->regs.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_reg = dwarf2_frame_adjust_regnum (gdbarch, fs->cfa_reg,
- eh_frame_p);
- fs->cfa_how = CFA_REG_OFFSET;
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg);
+ fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch,
+ fs->regs.cfa_reg,
+ eh_frame_p);
+ fs->regs.cfa_how = CFA_REG_OFFSET;
break;
case DW_CFA_def_cfa_offset:
if (fs->armcc_cfa_offsets_sf)
utmp *= fs->data_align;
- fs->cfa_offset = utmp;
+ fs->regs.cfa_offset = utmp;
/* cfa_how deliberately not set. */
break;
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;
+ insn_ptr = read_uleb128 (insn_ptr, insn_end,
+ &fs->regs.cfa_exp_len);
+ fs->regs.cfa_exp = insn_ptr;
+ fs->regs.cfa_how = CFA_EXP;
+ insn_ptr += fs->regs.cfa_exp_len;
break;
case DW_CFA_expression:
break;
case DW_CFA_def_cfa_sf:
- insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
- fs->cfa_reg = dwarf2_frame_adjust_regnum (gdbarch, fs->cfa_reg,
- eh_frame_p);
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->regs.cfa_reg);
+ fs->regs.cfa_reg = dwarf2_frame_adjust_regnum (gdbarch,
+ fs->regs.cfa_reg,
+ eh_frame_p);
insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
- fs->cfa_offset = offset * fs->data_align;
- fs->cfa_how = CFA_REG_OFFSET;
+ fs->regs.cfa_offset = offset * fs->data_align;
+ fs->regs.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;
+ fs->regs.cfa_offset = offset * fs->data_align;
/* cfa_how deliberately not set. */
break;
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
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
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
/* 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);
+ 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;
/* 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. */
- switch (fs->cfa_how)
+ /* Calculate the CFA. */
+ switch (fs->regs.cfa_how)
{
case CFA_REG_OFFSET:
- cache->cfa = read_reg (next_frame, fs->cfa_reg);
+ cache->cfa = read_reg (this_frame, fs->regs.cfa_reg);
if (fs->armcc_cfa_offsets_reversed)
- cache->cfa -= fs->cfa_offset;
+ cache->cfa -= fs->regs.cfa_offset;
else
- cache->cfa += fs->cfa_offset;
+ cache->cfa += fs->regs.cfa_offset;
break;
case CFA_EXP:
cache->cfa =
- execute_stack_op (fs->cfa_exp, fs->cfa_exp_len, next_frame, 0);
+ execute_stack_op (fs->regs.cfa_exp, fs->regs.cfa_exp_len,
+ cache->addr_size, this_frame, 0, 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
{
if (cache->reg[regnum].how == DWARF2_FRAME_REG_UNSPECIFIED)
complaint (&symfile_complaints, _("\
-incomplete CFI data; unspecified registers (e.g., %s) at 0x%s"),
+incomplete CFI data; unspecified registers (e.g., %s) at %s"),
gdbarch_register_name (gdbarch, regnum),
- paddr_nz (fs->pc));
+ paddress (gdbarch, fs->pc));
}
else
cache->reg[regnum] = fs->regs.reg[column];
}
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
- (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, 1);
+ 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, 1);
+ 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;
+ 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);
- regnum = gdbarch_dwarf2_reg_to_regnum
- (gdbarch, cache->retaddr_reg.loc.reg);
- pc += frame_unwind_register_unsigned (next_frame, regnum);
- pack_long (valuep, register_type (gdbarch, regnum), pc);
- }
- break;
+ 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;
+}
+
+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. */
- return &dwarf2_frame_unwind;
+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;
-};
+/* 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;
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;
{
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;
}
{
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;
}
}
\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)
+{
+ 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)
{
- cie->next = unit->cie;
- unit->cie = cie;
+ 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_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);
- fde = objfile_data (objfile, dwarf2_frame_objfile_data);
- if (fde == 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;
- }
+ gdb_assert (fde_table->num_entries > 0);
+ if (*pc < offset + fde_table->entries[0]->initial_location)
+ continue;
- fde = fde->next;
- }
+ 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;
LONGEST length;
unsigned int bytes_read;
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 *)
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;
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;
}
+ 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->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++;
}
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->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
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;
- const char *msg;
ptrdiff_t start_offset;
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;
}
\f
-/* FIXME: kettenis/20030504: This still needs to be integrated with
- dwarf2read.c in a better way. */
-
/* Imported from dwarf2read.c. */
-extern asection *dwarf_frame_section;
-extern asection *dwarf_eh_frame_section;
+extern void dwarf2_get_section_info (struct objfile *, const char *, asection **,
+ gdb_byte **, bfd_size_type *);
-/* Imported from dwarf2read.c. */
-extern gdb_byte *dwarf2_read_section (struct objfile *objfile, asection *sectp);
+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;
+ 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.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. */
- if (dwarf_eh_frame_section)
+ 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;
+
+ dwarf2_get_section_info (objfile, ".eh_frame",
+ &unit->dwarf_frame_section,
+ &unit->dwarf_frame_buffer,
+ &unit->dwarf_frame_size);
+ if (unit->dwarf_frame_size)
{
asection *got, *txt;
- 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;
-
/* 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,
+ &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_section,
+ &unit->dwarf_frame_buffer,
+ &unit->dwarf_frame_size);
+ if (unit->dwarf_frame_size)
+ {
+ 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,
+ &cie_table, &fde_table);
+ }
- 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);
+ /* 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. */
}
- if (dwarf_frame_section)
+ /* 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
{
- 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);
+ 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. */