/* Frame unwinder for frames with DWARF Call Frame Information.
- Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
Contributed by Mark Kettenis.
#include "symtab.h"
#include "objfiles.h"
#include "regcache.h"
+#include "value.h"
#include "gdb_assert.h"
#include "gdb_string.h"
gdb_byte *initial_instructions;
gdb_byte *end;
+ /* Saved augmentation, in case it's needed later. */
+ char *augmentation;
+
/* Encoding of addresses. */
gdb_byte encoding;
/* True if a 'z' augmentation existed. */
unsigned char saw_z_augmentation;
+ /* True if an 'S' augmentation existed. */
+ unsigned char signal_frame;
+
+ /* The version recorded in the CIE. */
+ unsigned char version;
+
struct dwarf2_cie *next;
};
LONGEST data_align;
ULONGEST code_align;
ULONGEST retaddr_column;
+
+ /* Flags for known producer quirks. */
+
+ /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
+ and DW_CFA_def_cfa_offset takes a factored offset. */
+ int armcc_cfa_offsets_sf;
+
+ /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
+ the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
+ int armcc_cfa_offsets_reversed;
};
/* Store the length the expression for the CFA in the `cfa_reg' field,
buf = alloca (register_size (gdbarch, regnum));
frame_unwind_register (next_frame, regnum, buf);
- return extract_typed_address (buf, builtin_type_void_data_ptr);
+
+ /* Convert the register to an integer. This returns a LONGEST
+ rather than a CORE_ADDR, but unpack_pointer does the same thing
+ under the covers, and this makes more sense for non-pointer
+ registers. Maybe read_reg and the associated interfaces should
+ deal with "struct value" instead of CORE_ADDR. */
+ return unpack_long (register_type (gdbarch, regnum), buf);
}
static void
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);
+
+ if (fs->armcc_cfa_offsets_sf)
+ utmp *= fs->data_align;
+
fs->cfa_offset = utmp;
fs->cfa_how = CFA_REG_OFFSET;
break;
case DW_CFA_def_cfa_offset:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
+
+ if (fs->armcc_cfa_offsets_sf)
+ utmp *= fs->data_align;
+
fs->cfa_offset = utmp;
/* cfa_how deliberately not set. */
break;
fs->regs.reg[reg].loc.offset = offset;
break;
+ case DW_CFA_val_offset:
+ 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);
+ offset = utmp * fs->data_align;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET;
+ fs->regs.reg[reg].loc.offset = offset;
+ break;
+
+ case DW_CFA_val_offset_sf:
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
+ dwarf2_frame_state_alloc_regs (&fs->regs, reg + 1);
+ insn_ptr = read_sleb128 (insn_ptr, insn_end, &offset);
+ offset *= fs->data_align;
+ fs->regs.reg[reg].how = DWARF2_FRAME_REG_SAVED_VAL_OFFSET;
+ fs->regs.reg[reg].loc.offset = offset;
+ break;
+
+ case DW_CFA_val_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_VAL_EXP;
+ insn_ptr += utmp;
+ break;
+
case DW_CFA_def_cfa_sf:
insn_ptr = read_uleb128 (insn_ptr, insn_end, &fs->cfa_reg);
if (eh_frame_p)
insn_ptr = read_uleb128 (insn_ptr, insn_end, &utmp);
break;
+ case DW_CFA_GNU_negative_offset_extended:
+ insn_ptr = read_uleb128 (insn_ptr, insn_end, ®);
+ if (eh_frame_p)
+ reg = dwarf2_frame_eh_frame_regnum (gdbarch, reg);
+ insn_ptr = read_uleb128 (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;
+
default:
internal_error (__FILE__, __LINE__, _("Unknown CFI encountered."));
}
return regnum;
return ops->eh_frame_regnum (gdbarch, regnum);
}
+
+static void
+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)
+ 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;
+ }
+}
\f
struct dwarf2_frame_cache
fs->code_align = fde->cie->code_alignment_factor;
fs->retaddr_column = fde->cie->return_address_register;
+ /* 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);
{
case CFA_REG_OFFSET:
cache->cfa = read_reg (next_frame, fs->cfa_reg);
- cache->cfa += fs->cfa_offset;
+ if (fs->armcc_cfa_offsets_reversed)
+ cache->cfa -= fs->cfa_offset;
+ else
+ cache->cfa += fs->cfa_offset;
break;
case CFA_EXP:
}
break;
+ 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;
+
+ 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;
+
case DWARF2_FRAME_REG_UNSPECIFIED:
/* GCC, in its infinite wisdom decided to not provide unwind
information for registers that are "same value". Since
function. frame_pc_unwind(), for a no-return next function, can
end up returning something past the end of this function's body. */
CORE_ADDR block_addr = frame_unwind_address_in_block (next_frame);
- if (!dwarf2_frame_find_fde (&block_addr))
+ struct dwarf2_fde *fde = dwarf2_frame_find_fde (&block_addr);
+ if (!fde)
return NULL;
/* On some targets, signal trampolines may have unwind information.
We need to recognize them so that we set the frame type
correctly. */
- if (dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
- next_frame))
+ if (fde->cie->signal_frame
+ || dwarf2_frame_signal_frame_p (get_frame_arch (next_frame),
+ next_frame))
return &dwarf2_signal_frame_unwind;
return &dwarf2_frame_unwind;
depends on the target address size. */
cie->encoding = DW_EH_PE_absptr;
+ /* 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)
return NULL;
+ cie->version = cie_version;
buf += 1;
/* Interpret the interesting bits of the augmentation. */
- augmentation = (char *) buf;
+ cie->augmentation = augmentation = (char *) buf;
buf += (strlen (augmentation) + 1);
+ /* Ignore armcc augmentations. We only use them for quirks,
+ and that doesn't happen until later. */
+ if (strncmp (augmentation, "armcc", 5) == 0)
+ augmentation += strlen (augmentation);
+
/* The GCC 2.x "eh" augmentation has a pointer immediately
following the augmentation string, so it must be handled
first. */
augmentation++;
}
- /* Otherwise we have an unknown augmentation.
- Bail out unless we saw a 'z' prefix. */
- else
+ /* "S" indicates a signal frame, such that the return
+ address must not be decremented to locate the call frame
+ info for the previous frame; it might even be the first
+ instruction of a function, so decrementing it would take
+ us to a different function. */
+ else if (*augmentation == 'S')
{
- if (cie->initial_instructions == NULL)
- return end;
+ cie->signal_frame = 1;
+ augmentation++;
+ }
- /* Skip unknown augmentations. */
- buf = cie->initial_instructions;
+ /* Otherwise we have an unknown augmentation. Assume that either
+ there is no augmentation data, or we saw a 'z' prefix. */
+ else
+ {
+ if (cie->initial_instructions)
+ buf = cie->initial_instructions;
break;
}
}
projects / deliverable / binutils-gdb.git / blobdiff