/* DWARF2 exception handling and frame unwind runtime interface routines.
- Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
+ Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003
Free Software Foundation, Inc.
This file is part of GCC.
#include "tconfig.h"
#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
#include "dwarf2.h"
#include "unwind.h"
#include "unwind-pe.h"
#define PRE_GCC3_DWARF_FRAME_REGISTERS DWARF_FRAME_REGISTERS
#endif
+#ifndef DWARF_REG_TO_UNWIND_COLUMN
+#define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO)
+#endif
+
/* This is the register and unwind state for a particular frame. This
provides the information necessary to unwind up past a frame and return
to its caller. */
inline _Unwind_Word
_Unwind_GetGR (struct _Unwind_Context *context, int index)
{
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
/* This will segfault if the register hasn't been saved. */
return * (_Unwind_Word *) context->reg[index];
}
+/* Get the value of the CFA as saved in CONTEXT. */
+
+_Unwind_Word
+_Unwind_GetCFA (struct _Unwind_Context *context)
+{
+ return (_Unwind_Ptr) context->cfa;
+}
+
/* Overwrite the saved value for register REG in CONTEXT with VAL. */
inline void
_Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val)
{
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
* (_Unwind_Word *) context->reg[index] = val;
}
+/* Get the pointer to a register INDEX as saved in CONTEXT. */
+
+static inline void *
+_Unwind_GetGRPtr (struct _Unwind_Context *context, int index)
+{
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
+ return context->reg[index];
+}
+
+/* Set the pointer to a register INDEX as saved in CONTEXT. */
+
+static inline void
+_Unwind_SetGRPtr (struct _Unwind_Context *context, int index, void *p)
+{
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
+ context->reg[index] = p;
+}
+
/* Retrieve the return address for CONTEXT. */
inline _Unwind_Ptr
/* Most things push a result value. */
if ((size_t) stack_elt >= sizeof(stack)/sizeof(*stack))
abort ();
- stack[++stack_elt] = result;
+ stack[stack_elt++] = result;
no_push:;
}
reg = insn & 0x3f;
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Sword) utmp * fs->data_align;
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
- fs->regs.reg[reg].loc.offset = offset;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
+ = REG_SAVED_OFFSET;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
}
else if ((insn & 0xc0) == DW_CFA_restore)
{
reg = insn & 0x3f;
- fs->regs.reg[reg].how = REG_UNSAVED;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_UNSAVED;
}
else switch (insn)
{
insn_ptr = read_uleb128 (insn_ptr, ®);
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Sword) utmp * fs->data_align;
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
- fs->regs.reg[reg].loc.offset = offset;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
+ = REG_SAVED_OFFSET;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
break;
case DW_CFA_restore_extended:
insn_ptr = read_uleb128 (insn_ptr, ®);
- fs->regs.reg[reg].how = REG_UNSAVED;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
break;
case DW_CFA_undefined:
case DW_CFA_same_value:
+ insn_ptr = read_uleb128 (insn_ptr, ®);
+ break;
+
case DW_CFA_nop:
break;
_Unwind_Word reg2;
insn_ptr = read_uleb128 (insn_ptr, ®);
insn_ptr = read_uleb128 (insn_ptr, ®2);
- fs->regs.reg[reg].how = REG_SAVED_REG;
- fs->regs.reg[reg].loc.reg = reg2;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_REG;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.reg = reg2;
}
break;
break;
case DW_CFA_def_cfa_expression:
- insn_ptr = read_uleb128 (insn_ptr, &utmp);
fs->cfa_exp = insn_ptr;
fs->cfa_how = CFA_EXP;
+ insn_ptr = read_uleb128 (insn_ptr, &utmp);
insn_ptr += utmp;
break;
case DW_CFA_expression:
insn_ptr = read_uleb128 (insn_ptr, ®);
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how = REG_SAVED_EXP;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.exp = insn_ptr;
insn_ptr = read_uleb128 (insn_ptr, &utmp);
- fs->regs.reg[reg].how = REG_SAVED_EXP;
- fs->regs.reg[reg].loc.exp = insn_ptr;
insn_ptr += utmp;
break;
insn_ptr = read_uleb128 (insn_ptr, ®);
insn_ptr = read_sleb128 (insn_ptr, &stmp);
offset = stmp * fs->data_align;
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
- fs->regs.reg[reg].loc.offset = offset;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
+ = REG_SAVED_OFFSET;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = offset;
break;
case DW_CFA_def_cfa_sf:
insn_ptr = read_uleb128 (insn_ptr, ®);
insn_ptr = read_uleb128 (insn_ptr, &utmp);
offset = (_Unwind_Word) utmp * fs->data_align;
- fs->regs.reg[reg].how = REG_SAVED_OFFSET;
- fs->regs.reg[reg].loc.offset = -offset;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].how
+ = REG_SAVED_OFFSET;
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (reg)].loc.offset = -offset;
break;
default:
void *cfa;
long i;
+#ifdef EH_RETURN_STACKADJ_RTX
+ /* Special handling here: Many machines do not use a frame pointer,
+ and track the CFA only through offsets from the stack pointer from
+ one frame to the next. In this case, the stack pointer is never
+ stored, so it has no saved address in the context. What we do
+ have is the CFA from the previous stack frame.
+
+ In very special situations (such as unwind info for signal return),
+ there may be location expressions that use the stack pointer as well.
+
+ Do this conditionally for one frame. This allows the unwind info
+ for one frame to save a copy of the stack pointer from the previous
+ frame, and be able to use much easier CFA mechanisms to do it.
+ Always zap the saved stack pointer value for the next frame; carrying
+ the value over from one frame to another doesn't make sense. */
+
+ _Unwind_Word tmp_sp;
+
+ if (!_Unwind_GetGRPtr (&orig_context, __builtin_dwarf_sp_column ()))
+ {
+ tmp_sp = (_Unwind_Ptr) context->cfa;
+ _Unwind_SetGRPtr (&orig_context, __builtin_dwarf_sp_column (), &tmp_sp);
+ }
+ _Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), NULL);
+#endif
+
/* Compute this frame's CFA. */
switch (fs->cfa_how)
{
case CFA_REG_OFFSET:
- /* Special handling here: Many machines do not use a frame pointer,
- and track the CFA only through offsets from the stack pointer from
- one frame to the next. In this case, the stack pointer is never
- stored, so it has no saved address in the context. What we do
- have is the CFA from the previous stack frame. */
- if (context->reg[fs->cfa_reg] == NULL)
- cfa = context->cfa;
- else
- cfa = (void *) (_Unwind_Ptr) _Unwind_GetGR (context, fs->cfa_reg);
+ cfa = (void *) (_Unwind_Ptr) _Unwind_GetGR (&orig_context, fs->cfa_reg);
cfa += fs->cfa_offset;
break;
case CFA_EXP:
- /* ??? No way of knowing what register number is the stack pointer
- to do the same sort of handling as above. Assume that if the
- CFA calculation is so complicated as to require a stack program
- that this will not be a problem. */
{
const unsigned char *exp = fs->cfa_exp;
_Unwind_Word len;
exp = read_uleb128 (exp, &len);
cfa = (void *) (_Unwind_Ptr)
- execute_stack_op (exp, exp + len, context, 0);
+ execute_stack_op (exp, exp + len, &orig_context, 0);
break;
}
{
case REG_UNSAVED:
break;
+
case REG_SAVED_OFFSET:
- context->reg[i] = cfa + fs->regs.reg[i].loc.offset;
+ _Unwind_SetGRPtr (context, i,
+ (void *) (cfa + fs->regs.reg[i].loc.offset));
break;
+
case REG_SAVED_REG:
- context->reg[i] = orig_context.reg[fs->regs.reg[i].loc.reg];
+ _Unwind_SetGRPtr
+ (context, i,
+ _Unwind_GetGRPtr (&orig_context, fs->regs.reg[i].loc.reg));
break;
+
case REG_SAVED_EXP:
{
const unsigned char *exp = fs->regs.reg[i].loc.exp;
exp = read_uleb128 (exp, &len);
val = execute_stack_op (exp, exp + len, &orig_context,
(_Unwind_Ptr) cfa);
- context->reg[i] = (void *) val;
+ _Unwind_SetGRPtr (context, i, (void *) val);
}
break;
}
{
void *ra = __builtin_extract_return_addr (__builtin_return_address (0));
_Unwind_FrameState fs;
+ _Unwind_Word sp_slot;
memset (context, 0, sizeof (struct _Unwind_Context));
context->ra = ra;
abort ();
/* Force the frame state to use the known cfa value. */
- context->cfa = outer_cfa;
+ sp_slot = (_Unwind_Ptr) outer_cfa;
+ _Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), &sp_slot);
fs.cfa_how = CFA_REG_OFFSET;
- fs.cfa_reg = 0;
+ fs.cfa_reg = __builtin_dwarf_sp_column ();
fs.cfa_offset = 0;
uw_update_context_1 (context, &fs);
{
void *c = current->reg[i];
void *t = target->reg[i];
+
if (t && c && t != c)
memcpy (c, t, dwarf_reg_size_table[i]);
}
- /* We adjust SP by the difference between CURRENT and TARGET's CFA. */
- if (STACK_GROWS_DOWNWARD)
- return target->cfa - current->cfa + target->args_size;
- else
- return current->cfa - target->cfa - target->args_size;
+#ifdef EH_RETURN_STACKADJ_RTX
+ {
+ void *target_cfa;
+
+ /* If the last frame records a saved stack pointer, use it. */
+ if (_Unwind_GetGRPtr (target, __builtin_dwarf_sp_column ()))
+ target_cfa = (void *)(_Unwind_Ptr)
+ _Unwind_GetGR (target, __builtin_dwarf_sp_column ());
+ else
+ target_cfa = target->cfa;
+
+ /* We adjust SP by the difference between CURRENT and TARGET's CFA. */
+ if (STACK_GROWS_DOWNWARD)
+ return target_cfa - current->cfa + target->args_size;
+ else
+ return current->cfa - target_cfa - target->args_size;
+ }
+#else
+ return 0;
+#endif
}
static inline _Unwind_Ptr
OSDN Git Service
