/* 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.
the Free Software Foundation; either version 2, or (at your option)
any later version.
+ In addition to the permissions in the GNU General Public License, the
+ Free Software Foundation gives you unlimited permission to link the
+ compiled version of this file into combinations with other programs,
+ and to distribute those combinations without any restriction coming
+ from the use of this file. (The General Public License restrictions
+ do apply in other respects; for example, they cover modification of
+ the file, and distribution when not linked into a combined
+ executable.)
+
GCC is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
#include "tconfig.h"
#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
#include "dwarf2.h"
#include "unwind.h"
+#ifdef __USING_SJLJ_EXCEPTIONS__
+# define NO_SIZE_OF_ENCODED_VALUE
+#endif
#include "unwind-pe.h"
#include "unwind-dw2-fde.h"
#include "gthr.h"
#define PRE_GCC3_DWARF_FRAME_REGISTERS DWARF_FRAME_REGISTERS
#endif
-/* This is the register and unwind state for a particular frame. */
+#ifndef DWARF_REG_TO_UNWIND_COLUMN
+#define DWARF_REG_TO_UNWIND_COLUMN(REGNO) (REGNO)
+#endif
+
+/* A target can do some update context frobbing. */
+#ifndef MD_FROB_UPDATE_CONTEXT
+#define MD_FROB_UPDATE_CONTEXT(CTX, FS) do { } while (0)
+#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. */
struct _Unwind_Context
{
void *reg[DWARF_FRAME_REGISTERS+1];
};
/* Byte size of every register managed by these routines. */
-static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS];
+static unsigned char dwarf_reg_size_table[DWARF_FRAME_REGISTERS+1];
\f
/* The result of interpreting the frame unwind info for a frame.
read_pointer (const void *p) { const union unaligned *up = p; return up->p; }
static inline int
-read_1u (const void *p) { return *(const unsigned char *)p; }
+read_1u (const void *p) { return *(const unsigned char *) p; }
static inline int
-read_1s (const void *p) { return *(const signed char *)p; }
+read_1s (const void *p) { return *(const signed char *) p; }
static inline int
read_2u (const void *p) { const union unaligned *up = p; return up->u2; }
inline _Unwind_Word
_Unwind_GetGR (struct _Unwind_Context *context, int index)
{
+ int size;
+ void *ptr;
+
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
+ if (index >= (int) sizeof(dwarf_reg_size_table))
+ abort ();
+ size = dwarf_reg_size_table[index];
+ ptr = context->reg[index];
+
/* This will segfault if the register hasn't been saved. */
- return * (_Unwind_Word *) context->reg[index];
+ if (size == sizeof(_Unwind_Ptr))
+ return * (_Unwind_Ptr *) ptr;
+
+ if (size == sizeof(_Unwind_Word))
+ return * (_Unwind_Word *) ptr;
+
+ abort ();
+}
+
+static inline void *
+_Unwind_GetPtr (struct _Unwind_Context *context, int index)
+{
+ return (void *)(_Unwind_Ptr) _Unwind_GetGR (context, 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)
{
- * (_Unwind_Word *) context->reg[index] = val;
+ int size;
+ void *ptr;
+
+ index = DWARF_REG_TO_UNWIND_COLUMN (index);
+ if (index >= (int) sizeof(dwarf_reg_size_table))
+ abort ();
+ size = dwarf_reg_size_table[index];
+ ptr = context->reg[index];
+
+ if (size == sizeof(_Unwind_Ptr))
+ * (_Unwind_Ptr *) ptr = val;
+ else if (size == sizeof(_Unwind_Word))
+ * (_Unwind_Word *) ptr = val;
+ else
+ abort ();
+}
+
+/* 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. */
return (_Unwind_Ptr) context->bases.func;
}
+void *
+_Unwind_FindEnclosingFunction (void *pc)
+{
+ struct dwarf_eh_bases bases;
+ struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases);
+ if (fde)
+ return bases.func;
+ else
+ return NULL;
+}
+
#ifndef __ia64__
_Unwind_Ptr
_Unwind_GetDataRelBase (struct _Unwind_Context *context)
{
/* Binary operations. */
_Unwind_Word first, second;
- if ((stack_elt -= 2) < 0)
- abort ();
- second = stack[stack_elt];
- first = stack[stack_elt + 1];
-
- switch (op)
- {
- case DW_OP_and:
- result = second & first;
- break;
- case DW_OP_div:
- result = (_Unwind_Sword)second / (_Unwind_Sword)first;
- break;
- case DW_OP_minus:
- result = second - first;
- break;
- case DW_OP_mod:
- result = (_Unwind_Sword)second % (_Unwind_Sword)first;
- break;
- case DW_OP_mul:
- result = second * first;
- break;
- case DW_OP_or:
- result = second | first;
- break;
- case DW_OP_plus:
- result = second + first;
- break;
- case DW_OP_shl:
- result = second << first;
- break;
- case DW_OP_shr:
- result = second >> first;
- break;
- case DW_OP_shra:
- result = (_Unwind_Sword)second >> first;
- break;
- case DW_OP_xor:
- result = second ^ first;
- break;
- case DW_OP_le:
- result = (_Unwind_Sword)first <= (_Unwind_Sword)second;
- break;
- case DW_OP_ge:
- result = (_Unwind_Sword)first >= (_Unwind_Sword)second;
- break;
- case DW_OP_eq:
- result = (_Unwind_Sword)first == (_Unwind_Sword)second;
- break;
- case DW_OP_lt:
- result = (_Unwind_Sword)first < (_Unwind_Sword)second;
- break;
- case DW_OP_gt:
- result = (_Unwind_Sword)first > (_Unwind_Sword)second;
- break;
- case DW_OP_ne:
- result = (_Unwind_Sword)first != (_Unwind_Sword)second;
- break;
-
- default:
+ if ((stack_elt -= 2) < 0)
abort ();
- }
+ second = stack[stack_elt];
+ first = stack[stack_elt + 1];
+
+ switch (op)
+ {
+ case DW_OP_and:
+ result = second & first;
+ break;
+ case DW_OP_div:
+ result = (_Unwind_Sword) second / (_Unwind_Sword) first;
+ break;
+ case DW_OP_minus:
+ result = second - first;
+ break;
+ case DW_OP_mod:
+ result = (_Unwind_Sword) second % (_Unwind_Sword) first;
+ break;
+ case DW_OP_mul:
+ result = second * first;
+ break;
+ case DW_OP_or:
+ result = second | first;
+ break;
+ case DW_OP_plus:
+ result = second + first;
+ break;
+ case DW_OP_shl:
+ result = second << first;
+ break;
+ case DW_OP_shr:
+ result = second >> first;
+ break;
+ case DW_OP_shra:
+ result = (_Unwind_Sword) second >> first;
+ break;
+ case DW_OP_xor:
+ result = second ^ first;
+ break;
+ case DW_OP_le:
+ result = (_Unwind_Sword) first <= (_Unwind_Sword) second;
+ break;
+ case DW_OP_ge:
+ result = (_Unwind_Sword) first >= (_Unwind_Sword) second;
+ break;
+ case DW_OP_eq:
+ result = (_Unwind_Sword) first == (_Unwind_Sword) second;
+ break;
+ case DW_OP_lt:
+ result = (_Unwind_Sword) first < (_Unwind_Sword) second;
+ break;
+ case DW_OP_gt:
+ result = (_Unwind_Sword) first > (_Unwind_Sword) second;
+ break;
+ case DW_OP_ne:
+ result = (_Unwind_Sword) first != (_Unwind_Sword) second;
+ break;
+
+ default:
+ abort ();
+ }
}
break;
/* 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;
+ offset = (_Unwind_Sword) utmp * fs->data_align;
+ 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)
{
case DW_CFA_offset_extended:
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;
+ offset = (_Unwind_Sword) utmp * fs->data_align;
+ 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;
-
+
case DW_CFA_remember_state:
{
struct frame_state_reg_info *new_rs;
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, &fs->cfa_reg);
insn_ptr = read_sleb128 (insn_ptr, &fs->cfa_offset);
older PowerPC code. */
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;
+ offset = (_Unwind_Word) utmp * fs->data_align;
+ 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:
}
}
\f
+/* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for
+ its caller and decode it into FS. This function also sets the
+ args_size and lsda members of CONTEXT, as they are really information
+ about the caller's frame. */
+
static _Unwind_Reason_Code
uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs)
{
context->args_size = 0;
context->lsda = 0;
+ if (context->ra == 0)
+ return _URC_END_OF_STACK;
+
fde = _Unwind_Find_FDE (context->ra - 1, &context->bases);
if (fde == NULL)
{
execute_cfa_program (insn, end, context, fs);
/* Locate augmentation for the fde. */
- aug = (unsigned char *)fde + sizeof (*fde);
+ aug = (unsigned char *) fde + sizeof (*fde);
aug += 2 * size_of_encoded_value (fs->fde_encoding);
insn = NULL;
if (fs->saw_z)
return state_in;
}
\f
+typedef union { _Unwind_Ptr ptr; _Unwind_Word word; } _Unwind_SpTmp;
+
+static inline void
+_Unwind_SetSpColumn (struct _Unwind_Context *context, void *cfa,
+ _Unwind_SpTmp *tmp_sp)
+{
+ int size = dwarf_reg_size_table[__builtin_dwarf_sp_column ()];
+
+ if (size == sizeof(_Unwind_Ptr))
+ tmp_sp->ptr = (_Unwind_Ptr) cfa;
+ else if (size == sizeof(_Unwind_Word))
+ tmp_sp->word = (_Unwind_Ptr) cfa;
+ else
+ abort ();
+ _Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), tmp_sp);
+}
+
static void
uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs)
{
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_SpTmp tmp_sp;
+
+ if (!_Unwind_GetGRPtr (&orig_context, __builtin_dwarf_sp_column ()))
+ _Unwind_SetSpColumn (&orig_context, context->cfa, &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 = _Unwind_GetPtr (&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;
}
+
+ MD_FROB_UPDATE_CONTEXT (context, fs);
}
+/* CONTEXT describes the unwind state for a frame, and FS describes the FDE
+ of its caller. Update CONTEXT to refer to the caller as well. Note
+ that the args_size and lsda members are not updated here, but later in
+ uw_frame_state_for. */
+
static void
uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs)
{
/* Compute the return address now, since the return address column
can change from frame to frame. */
context->ra = __builtin_extract_return_addr
- ((void *) (_Unwind_Ptr) _Unwind_GetGR (context, fs->retaddr_column));
+ (_Unwind_GetPtr (context, fs->retaddr_column));
}
\f
/* Fill in CONTEXT for top-of-stack. The only valid registers at this
level will be the return address and the CFA. */
-
+
#define uw_init_context(CONTEXT) \
do \
{ \
} \
while (0)
+static inline void
+init_dwarf_reg_size_table (void)
+{
+ __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
+}
+
static void
uw_init_context_1 (struct _Unwind_Context *context,
void *outer_cfa, void *outer_ra)
{
void *ra = __builtin_extract_return_addr (__builtin_return_address (0));
_Unwind_FrameState fs;
+ _Unwind_SpTmp sp_slot;
memset (context, 0, sizeof (struct _Unwind_Context));
context->ra = ra;
if (uw_frame_state_for (context, &fs) != _URC_NO_REASON)
abort ();
+#if __GTHREADS
+ {
+ static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT;
+ if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0
+ || dwarf_reg_size_table[0] == 0)
+ init_dwarf_reg_size_table ();
+ }
+#else
+ if (dwarf_reg_size_table[0] == 0)
+ init_dwarf_reg_size_table ();
+#endif
+
/* Force the frame state to use the known cfa value. */
- context->cfa = outer_cfa;
+ _Unwind_SetSpColumn (context, outer_cfa, &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);
} \
while (0)
-static inline void
-init_dwarf_reg_size_table (void)
-{
- __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table);
-}
-
static long
uw_install_context_1 (struct _Unwind_Context *current,
struct _Unwind_Context *target)
{
long i;
-#if __GTHREADS
- {
- static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT;
- if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0
- || dwarf_reg_size_table[0] == 0)
- init_dwarf_reg_size_table ();
- }
-#else
- if (dwarf_reg_size_table[0] == 0)
- init_dwarf_reg_size_table ();
-#endif
-
for (i = 0; i < DWARF_FRAME_REGISTERS; ++i)
{
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 = _Unwind_GetPtr (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