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authorNick Clifton <nickc@redhat.com>2012-06-28 11:31:14 +0000
committerNick Clifton <nickc@redhat.com>2012-06-28 11:31:14 +0000
commit453dc3f0101420a5f44b50e4f0425ac8edc64e0c (patch)
tree70f247ca991b7ad91ea6d54951d8adff26848308 /gas/dwarf2dbg.c
parent1d7975eb5300c59c69e1c15cfc98fa8894a5a906 (diff)
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* dwarf2dbg.c (DWARF2_USE_FIXED_ADVANCE_PC): Enable when using
linker relaxation. (dwarf2_gen_line_info): Generate real, local, labels for line numbers. (dwarf2dbg_convert_frag): Do not finalize the computation of the frag's symbol value when linker relaxation is enabled. (ADDR_DELTA_LIMIT): Define. (size_fixed_inc_line_addr): Use ADDR_DELTA_LIMIT. (emit_fixed_inc_line_addr): Likewise. * write.c (fixup_segment): If the subtraction of two symbols cannot be resolved but is valid, then prevent bogus range warnings by pre-biasing add_number. * config/tc-h8300.h (DWARF2_USE_FIXED_ADVANCE_PC): Define to 0. * gas/lns/lns.exp: Use alternate lns-common test for targets enabling linker relaxation. * gas/lns/lns-big-delta.d: Allow for output from architectures with 32-bit addresses.
Diffstat (limited to 'gas/dwarf2dbg.c')
-rw-r--r--gas/dwarf2dbg.c38
1 files changed, 33 insertions, 5 deletions
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index f428f0d..2ec329a 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -119,7 +119,7 @@
opcodes and variable-length operands cannot be used. If this macro is
nonzero, use the DW_LNS_fixed_advance_pc opcode instead. */
#ifndef DWARF2_USE_FIXED_ADVANCE_PC
-# define DWARF2_USE_FIXED_ADVANCE_PC 0
+# define DWARF2_USE_FIXED_ADVANCE_PC linkrelax
#endif
/* First special line opcde - leave room for the standard opcodes.
@@ -361,7 +361,17 @@ dwarf2_gen_line_info (addressT ofs, struct dwarf2_line_info *loc)
filenum = loc->filenum;
dwarf2_push_line (loc);
- dwarf2_flush_pending_lines (symbol_temp_new (now_seg, ofs, frag_now));
+ if (linkrelax)
+ {
+ char name[120];
+
+ /* Use a non-fake name for the line number location,
+ so that it can be referred to by relocations. */
+ sprintf (name, ".Loc.%u.%u", line, filenum);
+ dwarf2_flush_pending_lines (symbol_new (name, now_seg, ofs, frag_now));
+ }
+ else
+ dwarf2_flush_pending_lines (symbol_temp_new (now_seg, ofs, frag_now));
}
/* Returns the current source information. If .file directives have
@@ -1064,6 +1074,7 @@ out_inc_line_addr (int line_delta, addressT addr_delta)
line and address information, but it is required if linker relaxation
could change the code offsets. The following two routines *must* be
kept in sync. */
+#define ADDR_DELTA_LIMIT 50000
static int
size_fixed_inc_line_addr (int line_delta, addressT addr_delta)
@@ -1074,7 +1085,7 @@ size_fixed_inc_line_addr (int line_delta, addressT addr_delta)
if (line_delta != INT_MAX)
len = 1 + sizeof_leb128 (line_delta, 1);
- if (addr_delta > 50000)
+ if (addr_delta > ADDR_DELTA_LIMIT)
{
/* DW_LNS_extended_op */
len += 1 + sizeof_leb128 (sizeof_address + 1, 0);
@@ -1122,7 +1133,7 @@ emit_fixed_inc_line_addr (int line_delta, addressT addr_delta, fragS *frag,
which this function would not be used) could change the operand by
an unknown amount. If the address increment is getting close to
the limit, just reset the address. */
- if (addr_delta > 50000)
+ if (addr_delta > ADDR_DELTA_LIMIT)
{
symbolS *to_sym;
expressionS exp;
@@ -1231,7 +1242,24 @@ dwarf2dbg_convert_frag (fragS *frag)
{
offsetT addr_diff;
- addr_diff = resolve_symbol_value (frag->fr_symbol);
+ if (DWARF2_USE_FIXED_ADVANCE_PC)
+ {
+ /* If linker relaxation is enabled then the distance bewteen the two
+ symbols in the frag->fr_symbol expression might change. Hence we
+ cannot rely upon the value computed by resolve_symbol_value.
+ Instead we leave the expression unfinalized and allow
+ emit_fixed_inc_line_addr to create a fixup (which later becomes a
+ relocation) that will allow the linker to correctly compute the
+ actual address difference. We have to use a fixed line advance for
+ this as we cannot (easily) relocate leb128 encoded values. */
+ int saved_finalize_syms = finalize_syms;
+
+ finalize_syms = 0;
+ addr_diff = resolve_symbol_value (frag->fr_symbol);
+ finalize_syms = saved_finalize_syms;
+ }
+ else
+ addr_diff = resolve_symbol_value (frag->fr_symbol);
/* fr_var carries the max_chars that we created the fragment with.
fr_subtype carries the current expected length. We must, of