/* ehopt.c--optimize gcc exception frame information.
- Copyright (C) 1998-2018 Free Software Foundation, Inc.
+ Copyright (C) 1998-2023 Free Software Foundation, Inc.
Written by Ian Lance Taylor <ian@cygnus.com>.
This file is part of GAS, the GNU Assembler.
#include "as.h"
#include "subsegs.h"
-#include "struc-symbol.h"
/* We include this ELF file, even though we may not be assembling for
ELF, since the exception frame information is always in a format
int z_augmentation;
};
-static int get_cie_info (struct cie_info *);
-
/* Extract information from the CIE. */
static int
{
fragS *f;
fixS *fix;
- int offset;
+ unsigned int offset;
char CIE_id;
char augmentation[10];
int iaug;
/* First make sure that the CIE Identifier Tag is 0/-1. */
- if (strncmp (segment_name (now_seg), ".debug_frame", 12) == 0)
+ if (startswith (segment_name (now_seg), ".debug_frame"))
CIE_id = (char)0xff;
else
CIE_id = 0;
state_error,
};
+struct frame_data
+{
+ enum frame_state state;
+
+ int cie_info_ok;
+ struct cie_info cie_info;
+
+ symbolS *size_end_sym;
+ fragS *loc4_frag;
+ int loc4_fix;
+
+ int aug_size;
+ int aug_shift;
+};
+
+static struct eh_state
+{
+ struct frame_data eh_data;
+ struct frame_data debug_data;
+} frame;
+
/* This function is called from emit_expr. It looks for cases which
we can optimize.
int
check_eh_frame (expressionS *exp, unsigned int *pnbytes)
{
- struct frame_data
- {
- enum frame_state state;
-
- int cie_info_ok;
- struct cie_info cie_info;
-
- symbolS *size_end_sym;
- fragS *loc4_frag;
- int loc4_fix;
-
- int aug_size;
- int aug_shift;
- };
-
- static struct frame_data eh_frame_data;
- static struct frame_data debug_frame_data;
struct frame_data *d;
/* Don't optimize. */
#endif
/* Select the proper section data. */
- if (strncmp (segment_name (now_seg), ".eh_frame", 9) == 0
+ if (startswith (segment_name (now_seg), ".eh_frame")
&& segment_name (now_seg)[9] != '_')
- d = &eh_frame_data;
- else if (strncmp (segment_name (now_seg), ".debug_frame", 12) == 0)
- d = &debug_frame_data;
+ d = &frame.eh_data;
+ else if (startswith (segment_name (now_seg), ".debug_frame"))
+ d = &frame.debug_data;
else
return 0;
{
/* This might be a DW_CFA_advance_loc4. Record the frag and the
position within the frag, so that we can change it later. */
- frag_grow (1);
+ frag_grow (1 + 4);
d->state = state_saw_loc4;
d->loc4_frag = frag_now;
d->loc4_fix = frag_now_fix ();
|| exp->X_op == O_right_shift)
&& d->cie_info.code_alignment > 1)
{
- if (exp->X_add_symbol->bsym
- && exp->X_op_symbol->bsym
- && exp->X_add_symbol->sy_value.X_op == O_subtract
- && exp->X_op_symbol->sy_value.X_op == O_constant
+ if (symbol_symbolS (exp->X_add_symbol)
+ && symbol_constant_p (exp->X_op_symbol)
+ && S_GET_SEGMENT (exp->X_op_symbol) == absolute_section
&& ((exp->X_op == O_divide
- ? exp->X_op_symbol->sy_value.X_add_number
- : (offsetT) 1 << exp->X_op_symbol->sy_value.X_add_number)
+ ? *symbol_X_add_number (exp->X_op_symbol)
+ : (offsetT) 1 << *symbol_X_add_number (exp->X_op_symbol))
== (offsetT) d->cie_info.code_alignment))
{
- /* This is a case we can optimize as well. 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. */
- frag_var (rs_cfa, 4, 0, d->cie_info.code_alignment << 3,
- make_expr_symbol (&exp->X_add_symbol->sy_value),
- d->loc4_fix, (char *) d->loc4_frag);
- return 1;
+ expressionS *symval;
+
+ symval = symbol_get_value_expression (exp->X_add_symbol);
+ if (symval->X_op == O_subtract)
+ {
+ /* This is a case we can optimize as well. 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. */
+ frag_var (rs_cfa, 4, 0, d->cie_info.code_alignment << 3,
+ make_expr_symbol (symval),
+ d->loc4_fix, (char *) d->loc4_frag);
+ return 1;
+ }
}
}
break;
gas_assert (ca > 0);
diff /= ca;
- if (diff < 0x40)
+ if (diff == 0)
+ ret = -1;
+ else if (diff < 0x40)
ret = 0;
else if (diff < 0x100)
ret = 1;
else
ret = 4;
- frag->fr_subtype = (frag->fr_subtype & ~7) | ret;
+ frag->fr_subtype = (frag->fr_subtype & ~7) | (ret & 7);
return ret;
}
int oldsize, newsize;
oldsize = frag->fr_subtype & 7;
+ if (oldsize == 7)
+ oldsize = -1;
newsize = eh_frame_estimate_size_before_relax (frag);
return newsize - oldsize;
}
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 2);
break;
- default:
+ case 4:
md_number_to_chars (frag->fr_literal + frag->fr_fix, diff, 4);
break;
+
+ case 7:
+ gas_assert (diff == 0);
+ frag->fr_fix -= 8;
+ break;
+
+ default:
+ abort ();
}
frag->fr_fix += frag->fr_subtype & 7;
frag->fr_subtype = 0;
frag->fr_offset = 0;
}
+
+void
+eh_begin (void)
+{
+ memset (&frame, 0, sizeof (frame));
+}