/* 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"
-
+#include "unwind-dw2.h"
#ifndef __USING_SJLJ_EXCEPTIONS__
#define STACK_GROWS_DOWNWARD 1
#endif
-/* A target can override (perhaps for backward compatibility) how
- many dwarf2 columns are unwound. */
-#ifndef DWARF_FRAME_REGISTERS
-#define DWARF_FRAME_REGISTERS FIRST_PSEUDO_REGISTER
-#endif
-
/* Dwarf frame registers used for pre gcc 3.0 compiled glibc. */
#ifndef PRE_GCC3_DWARF_FRAME_REGISTERS
#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
+
+/* 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. */
};
/* 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.
- This is all symbolic at this point, as none of the values can
- be resolved until the target pc is located. */
-typedef struct
-{
- /* Each register save state can be described in terms of a CFA slot,
- another register, or a location expression. */
- struct frame_state_reg_info
- {
- struct {
- union {
- _Unwind_Word reg;
- _Unwind_Sword offset;
- const unsigned char *exp;
- } loc;
- enum {
- REG_UNSAVED,
- REG_SAVED_OFFSET,
- REG_SAVED_REG,
- REG_SAVED_EXP,
- } how;
- } reg[DWARF_FRAME_REGISTERS+1];
-
- /* Used to implement DW_CFA_remember_state. */
- struct frame_state_reg_info *prev;
- } regs;
-
- /* The CFA can be described in terms of a reg+offset or a
- location expression. */
- _Unwind_Sword cfa_offset;
- _Unwind_Word cfa_reg;
- const unsigned char *cfa_exp;
- enum {
- CFA_UNSET,
- CFA_REG_OFFSET,
- CFA_EXP,
- } cfa_how;
-
- /* The PC described by the current frame state. */
- void *pc;
-
- /* The information we care about from the CIE/FDE. */
- _Unwind_Personality_Fn personality;
- _Unwind_Sword data_align;
- _Unwind_Word code_align;
- unsigned char retaddr_column;
- unsigned char fde_encoding;
- unsigned char lsda_encoding;
- unsigned char saw_z;
- void *eh_ptr;
-} _Unwind_FrameState;
-\f
/* Read unaligned data from the instruction buffer. */
union unaligned
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;
+ const 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)
or NULL if we encountered an undecipherable augmentation. */
static const unsigned char *
-extract_cie_info (struct dwarf_cie *cie, struct _Unwind_Context *context,
+extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context,
_Unwind_FrameState *fs)
{
const unsigned char *aug = cie->augmentation;
data alignment and return address column. */
p = read_uleb128 (p, &fs->code_align);
p = read_sleb128 (p, &fs->data_align);
- fs->retaddr_column = *p++;
+ if (cie->version == 1)
+ fs->retaddr_column = *p++;
+ else
+ p = read_uleb128 (p, &fs->retaddr_column);
fs->lsda_encoding = DW_EH_PE_omit;
/* If the augmentation starts with 'z', then a uleb128 immediately
/* 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;
+ /* FIXME, this is wrong; the CIE might have said that the
+ register was saved somewhere. */
+ 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, ®);
+ fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN(reg)].how = REG_UNSAVED;
+ 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:
static _Unwind_Reason_Code
uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs)
{
- struct dwarf_fde *fde;
- struct dwarf_cie *cie;
+ const struct dwarf_fde *fde;
+ const struct dwarf_cie *cie;
const unsigned char *aug, *insn, *end;
memset (fs, 0, sizeof (*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)
{
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
/* 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
} \
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
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