From e385593eef98ac92be57159e141f4b805dadbbb3 Mon Sep 17 00:00:00 2001
From: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Mon, 30 May 2016 14:14:43 +0200
Subject: [PATCH 2/2] PR 15231: import bare DW_TAG_lexical_block
Local variables in lambdas are not accessible
https://sourceware.org/bugzilla/show_bug.cgi?id=15231
GDB: read_lexical_block_scope
/* Ignore blocks with missing or invalid low and high pc attributes. */
[...]
if (!dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL))
return;
But sometimes there is:
FAIL: gcc-5.3.1-6.fc23.x86_64
<2><92>: Abbrev Number: 11 (DW_TAG_lexical_block)
<3><9c>: Abbrev Number: 13 (DW_TAG_structure_type)
<9d> DW_AT_name : (indirect string, offset: 0x3c): <lambda()>
[...]
Where DW_TAG_lexical_block has no attributes. Such whole subtree is currently
dropped by GDB while I think it should just import all its children DIEs.
It even XFAIL->XPASSes gdb.ada/out_of_line_in_inlined.exp:
commit 0fa7fe506c242b459c4c05d331e7c7d66fb52390
Author: Joel Brobecker <brobecker@adacore.com>
out of line functions nested inside inline functions.
So I have removed that xfail.
gdb/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* dwarf2read.c (enum pc_bounds_kind): Add PC_BOUNDS_INVALID.
(process_psymtab_comp_unit_reader, read_func_scope): Adjust callers.
(read_lexical_block_scope): Import DIEs from bare DW_TAG_lexical_block.
(read_call_site_scope): Adjust callers.
(dwarf2_get_pc_bounds): Implement pc_bounds_invalid.
(dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
gdb/testsuite/ChangeLog
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* gdb.ada/out_of_line_in_inlined.exp: Remove xfails.
* gdb.dwarf2/dw2-lexical-block-bare.exp: New file.
---
gdb/ChangeLog | 10 ++++
gdb/dwarf2read.c | 53 ++++++++++------
gdb/testsuite/ChangeLog | 6 ++
gdb/testsuite/gdb.ada/out_of_line_in_inlined.exp | 6 --
.../gdb.dwarf2/dw2-lexical-block-bare.exp | 70 ++++++++++++++++++++++
5 files changed, 120 insertions(+), 25 deletions(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.exp
### a/gdb/ChangeLog
### b/gdb/ChangeLog
## -1,5 +1,15 @@
2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
+ PR c++/15231
+ * dwarf2read.c (enum pc_bounds_kind): Add PC_BOUNDS_INVALID.
+ (process_psymtab_comp_unit_reader, read_func_scope): Adjust callers.
+ (read_lexical_block_scope): Import DIEs from bare DW_TAG_lexical_block.
+ (read_call_site_scope): Adjust callers.
+ (dwarf2_get_pc_bounds): Implement pc_bounds_invalid.
+ (dwarf2_get_subprogram_pc_bounds, get_scope_pc_bounds): Adjust callers.
+
+2016-05-30 Jan Kratochvil <jan.kratochvil@redhat.com>
+
Code cleanup: dwarf2_get_pc_bounds: -1/0/+1 -> enum
* dwarf2read.c (enum pc_bounds_kind) New.
(dwarf2_get_pc_bounds): Use it in the declaration.
Index: gdb-7.6.1/gdb/dwarf2read.c
===================================================================
--- gdb-7.6.1.orig/gdb/dwarf2read.c 2016-05-30 15:07:34.285853679 +0200
+++ gdb-7.6.1/gdb/dwarf2read.c 2016-05-30 15:08:13.485197538 +0200
@@ -1486,13 +1486,16 @@
struct dwarf2_cu *, struct partial_symtab *);
/* How dwarf2_get_pc_bounds constructed its *LOWPC and *HIGHPC return
- values. */
+ values. Keep the items ordered with increasing constraints compliance. */
enum pc_bounds_kind
{
- /* No valid combination of DW_AT_low_pc, DW_AT_high_pc or DW_AT_ranges
- was found. */
+ /* No attribute DW_AT_low_pc, DW_AT_high_pc or DW_AT_ranges was found. */
PC_BOUNDS_NOT_PRESENT,
+ /* Some of the attributes DW_AT_low_pc, DW_AT_high_pc or DW_AT_ranges
+ were present but they do not form a valid range of PC addresses. */
+ PC_BOUNDS_INVALID,
+
/* Discontiguous range was found - that is DW_AT_ranges was found. */
PC_BOUNDS_RANGES,
@@ -5027,7 +5030,7 @@
first_die = load_partial_dies (reader, info_ptr, 1);
scan_partial_symbols (first_die, &lowpc, &highpc,
- cu_bounds_kind == PC_BOUNDS_NOT_PRESENT, cu);
+ cu_bounds_kind <= PC_BOUNDS_INVALID, cu);
/* If we didn't find a lowpc, set it to highpc to avoid
complaints from `maint check'. */
@@ -5036,7 +5039,7 @@
/* If the compilation unit didn't have an explicit address range,
then use the information extracted from its child dies. */
- if (cu_bounds_kind == PC_BOUNDS_NOT_PRESENT)
+ if (cu_bounds_kind <= PC_BOUNDS_INVALID)
{
best_lowpc = lowpc;
best_highpc = highpc;
@@ -9606,7 +9609,7 @@
/* Ignore functions with missing or invalid low and high pc attributes. */
if (dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL)
- == PC_BOUNDS_NOT_PRESENT)
+ <= PC_BOUNDS_INVALID)
{
attr = dwarf2_attr (die, DW_AT_external, cu);
if (!attr || !DW_UNSND (attr))
@@ -9763,9 +9766,20 @@
as multiple lexical blocks? Handling children in a sane way would
be nasty. Might be easier to properly extend generic blocks to
describe ranges. */
- if (dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL)
- == PC_BOUNDS_NOT_PRESENT)
- return;
+ switch (dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL))
+ {
+ case PC_BOUNDS_NOT_PRESENT:
+ /* DW_TAG_lexical_block has no attributes, process its children as if
+ there was no wrapping by that DW_TAG_lexical_block.
+ GCC does no longer produces such DWARF since GCC r224161. */
+ for (child_die = die->child;
+ child_die != NULL && child_die->tag;
+ child_die = sibling_die (child_die))
+ process_die (child_die, cu);
+ return;
+ case PC_BOUNDS_INVALID:
+ return;
+ }
lowpc += baseaddr;
highpc += baseaddr;
@@ -9970,7 +9984,7 @@
/* DW_AT_entry_pc should be preferred. */
if (dwarf2_get_pc_bounds (target_die, &lowpc, NULL, target_cu, NULL)
- == PC_BOUNDS_NOT_PRESENT)
+ <= PC_BOUNDS_INVALID)
complaint (&symfile_complaints,
_("DW_AT_GNU_call_site_target target DIE has invalid "
"low pc, for referencing DIE 0x%x [in module %s]"),
@@ -10249,7 +10263,7 @@
/* Get low and high pc attributes from a die. See enum pc_bounds_kind
definition for the return value. *LOWPC and *HIGHPC are set iff
- PC_BOUNDS_NOT_PRESENT is not returned. */
+ neither PC_BOUNDS_NOT_PRESENT nor PC_BOUNDS_INVALID are returned. */
static enum pc_bounds_kind
dwarf2_get_pc_bounds (struct die_info *die, CORE_ADDR *lowpc,
@@ -10260,7 +10274,7 @@
struct attribute *attr_high;
CORE_ADDR low = 0;
CORE_ADDR high = 0;
- enum pc_bounds_kind ret = PC_BOUNDS_NOT_PRESENT;
+ enum pc_bounds_kind ret;
attr_high = dwarf2_attr (die, DW_AT_high_pc, cu);
if (attr_high)
@@ -10277,7 +10291,7 @@
}
else
/* Found high w/o low attribute. */
- return PC_BOUNDS_NOT_PRESENT;
+ return PC_BOUNDS_INVALID;
/* Found consecutive range of addresses. */
ret = PC_BOUNDS_HIGH_LOW;
@@ -10299,15 +10313,17 @@
/* Value of the DW_AT_ranges attribute is the offset in the
.debug_ranges section. */
if (!dwarf2_ranges_read (ranges_offset, &low, &high, cu, pst))
- return PC_BOUNDS_NOT_PRESENT;
+ return PC_BOUNDS_INVALID;
/* Found discontinuous range of addresses. */
ret = PC_BOUNDS_RANGES;
}
+ else
+ return PC_BOUNDS_NOT_PRESENT;
}
/* read_partial_die has also the strict LOW < HIGH requirement. */
if (high <= low)
- return PC_BOUNDS_NOT_PRESENT;
+ return PC_BOUNDS_INVALID;
/* When using the GNU linker, .gnu.linkonce. sections are used to
eliminate duplicate copies of functions and vtables and such.
@@ -10318,7 +10334,7 @@
If this is a discarded function, mark the pc bounds as invalid,
so that GDB will ignore it. */
if (low == 0 && !dwarf2_per_objfile->has_section_at_zero)
- return PC_BOUNDS_NOT_PRESENT;
+ return PC_BOUNDS_INVALID;
*lowpc = low;
if (highpc)
@@ -10339,8 +10355,7 @@
CORE_ADDR low, high;
struct die_info *child = die->child;
- if (dwarf2_get_pc_bounds (die, &low, &high, cu, NULL)
- != PC_BOUNDS_NOT_PRESENT)
+ if (dwarf2_get_pc_bounds (die, &low, &high, cu, NULL) >= PC_BOUNDS_RANGES)
{
*lowpc = min (*lowpc, low);
*highpc = max (*highpc, high);
@@ -10378,7 +10393,7 @@
CORE_ADDR current_low, current_high;
if (dwarf2_get_pc_bounds (die, ¤t_low, ¤t_high, cu, NULL)
- != PC_BOUNDS_NOT_PRESENT)
+ >= PC_BOUNDS_RANGES)
{
best_low = current_low;
best_high = current_high;
--- /dev/null 2016-05-30 15:04:01.916990766 +0200
+++ gdb-7.6.1/gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.exp 2016-05-30 15:19:22.236042134 +0200
@@ -0,0 +1,32 @@
+# Copyright 2016 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+standard_testfile .S main.c
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} \
+ [list $srcfile2 $srcfile] {nodebug}] } {
+ return -1
+}
+
+runto_main
+
+# FAILing GDB did print: No symbol "testvar" in current context.
+gdb_test "p testvar" { = -?[0-9]+}
--- /dev/null 2016-05-30 15:04:01.916990766 +0200
+++ gdb-7.6.1/gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.S 2016-05-30 15:17:42.580173290 +0200
@@ -0,0 +1,89 @@
+ .section .debug_info
+.Lcu1_begin:
+ .4byte .Lcu1_end - .Lcu1_start
+.Lcu1_start:
+ .2byte 4 /* Version */
+ .4byte .Labbrev1_begin /* Abbrevs */
+ .byte 4 /* Pointer size */
+ .uleb128 2 /* Abbrev (DW_TAG_compile_unit) */
+ .4byte main_label
+ .4byte main_label+0x10000
+.Llabel1:
+ .uleb128 3 /* Abbrev (DW_TAG_base_type) */
+ .sleb128 4
+ .sleb128 0x5
+ .ascii "integer\0"
+ .uleb128 4 /* Abbrev (DW_TAG_subprogram) */
+ .ascii "main\0"
+ .byte 1
+ .4byte main_label
+ .4byte main_label+0x10000
+ .uleb128 5 /* Abbrev (DW_TAG_lexical_block) */
+ .uleb128 6 /* Abbrev (DW_TAG_variable) */
+ .ascii "testvar\0"
+ .4byte .Llabel1 - .Lcu1_begin
+ .byte 1
+ .uleb128 .Lexpr_end3 - .Lexpr_start2/* expression */
+.Lexpr_start2:
+ .byte 0x03 /* DW_OP_addr */
+ .4byte main
+.Lexpr_end3:
+ .byte 0x0 /* Terminate children */
+ .byte 0x0 /* Terminate children */
+ .byte 0x0 /* Terminate children */
+.Lcu1_end:
+ .section .debug_abbrev
+.Labbrev1_begin:
+ .uleb128 2 /* Abbrev start */
+ .uleb128 0x11 /* DW_TAG_compile_unit */
+ .byte 1 /* has_children */
+ .uleb128 0x11 /* DW_AT_low_pc */
+ .uleb128 0x01 /* DW_FORM_addr */
+ .uleb128 0x12 /* DW_AT_high_pc */
+ .uleb128 0x01 /* DW_FORM_addr */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .uleb128 3 /* Abbrev start */
+ .uleb128 0x24 /* DW_TAG_base_type */
+ .byte 0 /* has_children */
+ .uleb128 0x0b /* DW_AT_byte_size */
+ .uleb128 0x0d /* DW_FORM_sdata */
+ .uleb128 0x3e /* DW_AT_encoding */
+ .uleb128 0x0d /* DW_FORM_sdata */
+ .uleb128 0x03 /* DW_AT_name */
+ .uleb128 0x08 /* DW_FORM_string */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .uleb128 4 /* Abbrev start */
+ .uleb128 0x2e /* DW_TAG_subprogram */
+ .byte 1 /* has_children */
+ .uleb128 0x03 /* DW_AT_name */
+ .uleb128 0x08 /* DW_FORM_string */
+ .uleb128 0x3f /* DW_AT_external */
+ .uleb128 0x0c /* DW_FORM_flag */
+ .uleb128 0x11 /* DW_AT_low_pc */
+ .uleb128 0x01 /* DW_FORM_addr */
+ .uleb128 0x12 /* DW_AT_high_pc */
+ .uleb128 0x01 /* DW_FORM_addr */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .uleb128 5 /* Abbrev start */
+ .uleb128 0x0b /* DW_TAG_lexical_block */
+ .byte 1 /* has_children */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .uleb128 6 /* Abbrev start */
+ .uleb128 0x34 /* DW_TAG_variable */
+ .byte 0 /* has_children */
+ .uleb128 0x03 /* DW_AT_name */
+ .uleb128 0x08 /* DW_FORM_string */
+ .uleb128 0x49 /* DW_AT_type */
+ .uleb128 0x13 /* DW_FORM_ref4 */
+ .uleb128 0x3f /* DW_AT_external */
+ .uleb128 0x0c /* DW_FORM_flag */
+ .uleb128 0x02 /* DW_AT_location */
+ .uleb128 0x09 /* SPECIAL_expr */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
+ .byte 0x0 /* Terminator */
diff -dup -rup gdb-7.6.1/gdb/testsuite/gdb.dwarf2/main.c gdb-7.6.1-orig/gdb/testsuite/gdb.dwarf2/main.c
--- gdb-7.6.1/gdb/testsuite/gdb.dwarf2/main.c 2013-01-01 07:41:22.000000000 +0100
+++ gdb-7.6.1-orig/gdb/testsuite/gdb.dwarf2/main.c 2017-03-08 22:20:21.085438961 +0100
@@ -20,5 +20,6 @@
int
main()
{
+ asm ("main_label: .globl main_label");
return 0;
}