/* Try to optimize gcc 2.8 exception frame information.
Exception frame information is emitted for every function in the
- .eh_frame section. Simple information for a function with no
- exceptions looks like this:
+ .eh_frame or .debug_frame sections. Simple information for a function
+ with no exceptions looks like this:
__FRAME_BEGIN__:
.4byte .LLCIE1 / Length of Common Information Entry
.LSCIE1:
+#if .eh_frame
.4byte 0x0 / CIE Identifier Tag
+#elif .debug_frame
+ .4byte 0xffffffff / CIE Identifier Tag
+#endif
.byte 0x1 / CIE Version
.byte 0x0 / CIE Augmentation (none)
.byte 0x1 / ULEB128 0x1 (CIE Code Alignment Factor)
not know this value, it always uses four bytes. We will know the
value at the end of assembly, so we can do better. */
-static int eh_frame_code_alignment PARAMS ((void));
+static int eh_frame_code_alignment PARAMS ((int));
/* Get the code alignment factor from the CIE. */
static int
-eh_frame_code_alignment ()
+eh_frame_code_alignment (in_seg)
+ int in_seg;
{
+ /* ??? Assume .eh_frame and .debug_frame have the same alignment. */
static int code_alignment;
- segT current_seg;
- subsegT current_subseg;
+
fragS *f;
fixS *fix;
int offset;
+ char CIE_id;
char augmentation[10];
int iaug;
if (code_alignment != 0)
return code_alignment;
- /* We should find the CIE at the start of the .eh_frame section. */
+ /* Can't find the alignment if we've changed sections. */
+ if (! in_seg)
+ return -1;
+
+ /* We should find the CIE at the start of the section. */
- current_seg = now_seg;
- current_subseg = now_subseg;
- subseg_new (".eh_frame", 0);
#if defined (BFD_ASSEMBLER) || defined (MANY_SEGMENTS)
f = seg_info (now_seg)->frchainP->frch_root;
#else
#else
fix = *seg_fix_rootP;
#endif
- subseg_set (current_seg, current_subseg);
/* Look through the frags of the section to find the code alignment. */
- /* First make sure that the CIE Identifier Tag is 0. */
+ /* First make sure that the CIE Identifier Tag is 0/-1. */
+
+ if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
+ CIE_id = (char)0xff;
+ else
+ CIE_id = 0;
offset = 4;
while (f != NULL && offset >= f->fr_fix)
}
if (f == NULL
|| f->fr_fix - offset < 4
- || f->fr_literal[offset] != 0
- || f->fr_literal[offset + 1] != 0
- || f->fr_literal[offset + 2] != 0
- || f->fr_literal[offset + 3] != 0)
+ || f->fr_literal[offset] != CIE_id
+ || f->fr_literal[offset + 1] != CIE_id
+ || f->fr_literal[offset + 2] != CIE_id
+ || f->fr_literal[offset + 3] != CIE_id)
{
code_alignment = -1;
return -1;
expressionS *exp;
unsigned int *pnbytes;
{
- static int saw_size;
- static symbolS *size_end_sym;
- static int saw_advance_loc4;
- static fragS *loc4_frag;
- static int loc4_fix;
-
- if (saw_size
- && S_IS_DEFINED (size_end_sym))
+ struct frame_data
+ {
+ symbolS *size_end_sym;
+ fragS *loc4_frag;
+ int saw_size;
+ int saw_advance_loc4;
+ int loc4_fix;
+ };
+
+ static struct frame_data eh_frame_data;
+ static struct frame_data debug_frame_data;
+ struct frame_data *d;
+
+ /* Don't optimize. */
+ if (flag_traditional_format)
+ return 0;
+
+ /* Select the proper section data. */
+ if (strcmp (segment_name (now_seg), ".eh_frame") == 0)
+ d = &eh_frame_data;
+ else if (strcmp (segment_name (now_seg), ".debug_frame") == 0)
+ d = &debug_frame_data;
+ else
+ return 0;
+
+ if (d->saw_size && S_IS_DEFINED (d->size_end_sym))
{
/* We have come to the end of the CIE or FDE. See below where
we set saw_size. We must check this first because we may now
be looking at the next size. */
- saw_size = 0;
- saw_advance_loc4 = 0;
+ d->saw_size = 0;
+ d->saw_advance_loc4 = 0;
}
- if (flag_traditional_format)
- {
- /* Don't optimize. */
- }
- else if (strcmp (segment_name (now_seg), ".eh_frame") != 0)
- {
- saw_size = 0;
- saw_advance_loc4 = 0;
- }
- else if (! saw_size
- && *pnbytes == 4)
+ if (! d->saw_size
+ && *pnbytes == 4)
{
/* This might be the size of the CIE or FDE. We want to know
the size so that we don't accidentally optimize across an FDE
if ((exp->X_op == O_symbol || exp->X_op == O_subtract)
&& ! S_IS_DEFINED (exp->X_add_symbol))
{
- saw_size = 1;
- size_end_sym = exp->X_add_symbol;
+ d->saw_size = 1;
+ d->size_end_sym = exp->X_add_symbol;
}
}
- else if (saw_size
+ else if (d->saw_size
&& *pnbytes == 1
&& exp->X_op == O_constant
&& exp->X_add_number == DW_CFA_advance_loc4)
{
/* This might be a DW_CFA_advance_loc4. Record the frag and the
position within the frag, so that we can change it later. */
- saw_advance_loc4 = 1;
+ d->saw_advance_loc4 = 1;
frag_grow (1);
- loc4_frag = frag_now;
- loc4_fix = frag_now_fix ();
+ d->loc4_frag = frag_now;
+ d->loc4_fix = frag_now_fix ();
}
- else if (saw_advance_loc4
+ else if (d->saw_advance_loc4
&& *pnbytes == 4
&& exp->X_op == O_constant)
{
reduced to a constant. We can do the optimization entirely
in this function. */
- saw_advance_loc4 = 0;
+ d->saw_advance_loc4 = 0;
- ca = eh_frame_code_alignment ();
+ ca = eh_frame_code_alignment (1);
if (ca < 0)
{
/* Don't optimize. */
else if (exp->X_add_number % ca == 0
&& exp->X_add_number / ca < 0x40)
{
- loc4_frag->fr_literal[loc4_fix]
+ d->loc4_frag->fr_literal[d->loc4_fix]
= DW_CFA_advance_loc | (exp->X_add_number / ca);
/* No more bytes needed. */
return 1;
}
else if (exp->X_add_number < 0x100)
{
- loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc1;
+ d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc1;
*pnbytes = 1;
}
else if (exp->X_add_number < 0x10000)
{
- loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc2;
+ d->loc4_frag->fr_literal[d->loc4_fix] = DW_CFA_advance_loc2;
*pnbytes = 2;
}
}
- else if (saw_advance_loc4
+ else if (d->saw_advance_loc4
&& *pnbytes == 4
&& exp->X_op == O_subtract)
{
-
/* This is a case we can optimize. The expression was not
reduced, so we can not finish the optimization until the end
of the assembly. We set up a variant frag which we handle
later. */
- saw_advance_loc4 = 0;
+ d->saw_advance_loc4 = 0;
frag_var (rs_cfa, 4, 0, 0, make_expr_symbol (exp),
- loc4_fix, (char *) loc4_frag);
+ d->loc4_fix, (char *) d->loc4_frag);
return 1;
}
else
- saw_advance_loc4 = 0;
+ d->saw_advance_loc4 = 0;
return 0;
}
offsetT diff;
int ret;
- ca = eh_frame_code_alignment ();
+ ca = eh_frame_code_alignment (0);
diff = resolve_symbol_value (frag->fr_symbol, 0);
if (ca < 0)
{
int ca;
- ca = eh_frame_code_alignment ();
+ ca = eh_frame_code_alignment (0);
assert (ca > 0 && diff % ca == 0 && diff / ca < 0x40);
loc4_frag->fr_literal[loc4_fix] = DW_CFA_advance_loc | (diff / ca);
}
projects / deliverable / binutils-gdb.git / commitdiff
