binutils/binutils-gas-dwarf-skip-empty-functions.patch
Nick Clifton 4a4bd90398 Rebase to GNU Binutils 2.39.
- Retire: binutils-CVE-2019-1010204.patch
- Retire: binutils-use-long-long.patch
- Retire: binutils-section-type.patch
- Retire: binutils-gas-loc-view.patch
- Retire: binutils-do-not-use-debuginfod.patch
- Retire: binutils-indirect-symbols.patch
- Retire: binutils-s390x-static-PIE.patch
- Retire: binutils-link-following.patch
- Retire: binutils-x86-non-canonical-references.patch
- Retire: binutils-ppc64-DT_RELR-relocs.patch
- Retire: binutils-ppc-gas-machine-directive.patch
2022-08-12 15:22:59 +01:00

94 lines
3.2 KiB
Diff

From b53c44bfe31fb036f212275b6d70edd5eee7b088 Mon Sep 17 00:00:00 2001
From: Jan Beulich via Binutils <binutils@sourceware.org>
Date: Tue, 9 Aug 2022 13:12:03 +0200
Subject: [PATCH] gas/Dwarf: properly skip zero-size functions
PR gas/29451
While out_debug_abbrev() properly skips such functions, out_debug_info()
mistakenly didn't. It needs to calculate the high_pc expression ahead of
time, in order to skip emitting any data for the function if the value
is zero.
The one case which would still leave a zero-size entry is when
symbol_get_obj(symp)->size ends up evaluating to zero. I hope we can
expect that to not be the case, otherwise we'd need to have a way to
post-process .debug_info contents between resolving expressions and
actually writing the data out to the file. Even then it wouldn't be
entirely obvious in which way to alter the data.
---
gas/dwarf2dbg.c | 39 ++++++++++++++++++++-------------------
1 file changed, 20 insertions(+), 19 deletions(-)
diff --git a/gas/dwarf2dbg.c b/gas/dwarf2dbg.c
index 868ec79ee2c..f346bd6a412 100644
--- a/gas/dwarf2dbg.c
+++ b/gas/dwarf2dbg.c
@@ -2882,6 +2882,7 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT str_seg,
{
const char *name;
size_t len;
+ expressionS size = { .X_op = O_constant };
/* Skip warning constructs (see above). */
if (symbol_get_bfdsym (symp)->flags & BSF_WARNING)
@@ -2895,6 +2896,18 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT str_seg,
if (!S_IS_DEFINED (symp) || !S_IS_FUNCTION (symp))
continue;
+#if defined (OBJ_ELF) /* || defined (OBJ_MAYBE_ELF) */
+ size.X_add_number = S_GET_SIZE (symp);
+ if (size.X_add_number == 0 && IS_ELF
+ && symbol_get_obj (symp)->size != NULL)
+ {
+ size.X_op = O_add;
+ size.X_op_symbol = make_expr_symbol (symbol_get_obj (symp)->size);
+ }
+#endif
+ if (size.X_op == O_constant && size.X_add_number == 0)
+ continue;
+
subseg_set (str_seg, 0);
name_sym = symbol_temp_new_now_octets ();
name = S_GET_NAME (symp);
@@ -2920,29 +2933,17 @@ out_debug_info (segT info_seg, segT abbrev_seg, segT line_seg, segT str_seg,
emit_expr (&exp, sizeof_address);
/* DW_AT_high_pc */
- exp.X_op = O_constant;
-#if defined (OBJ_ELF) /* || defined (OBJ_MAYBE_ELF) */
- exp.X_add_number = S_GET_SIZE (symp);
- if (exp.X_add_number == 0 && IS_ELF
- && symbol_get_obj (symp)->size != NULL)
- {
- exp.X_op = O_add;
- exp.X_op_symbol = make_expr_symbol (symbol_get_obj (symp)->size);
- }
-#else
- exp.X_add_number = 0;
-#endif
if (DWARF2_VERSION < 4)
{
- if (exp.X_op == O_constant)
- exp.X_op = O_symbol;
- exp.X_add_symbol = symp;
- emit_expr (&exp, sizeof_address);
+ if (size.X_op == O_constant)
+ size.X_op = O_symbol;
+ size.X_add_symbol = symp;
+ emit_expr (&size, sizeof_address);
}
- else if (exp.X_op == O_constant)
- out_uleb128 (exp.X_add_number);
+ else if (size.X_op == O_constant)
+ out_uleb128 (size.X_add_number);
else
- emit_leb128_expr (symbol_get_value_expression (exp.X_op_symbol), 0);
+ emit_leb128_expr (symbol_get_value_expression (size.X_op_symbol), 0);
}
/* End of children. */
--
2.37.1