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[patch] PR 15231: import bare DW_TAG_lexical_block
- From: Jan Kratochvil <jan dot kratochvil at redhat dot com>
- To: gdb-patches at sourceware dot org
- Cc: Joel Brobecker <brobecker at adacore dot com>
- Date: Sat, 14 May 2016 21:30:03 +0200
- Subject: [patch] PR 15231: import bare DW_TAG_lexical_block
- Authentication-results: sourceware.org; auth=none
Hi,
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.
I agree that my dwarf2_get_pc_bounds() extension is ugly.
No regression on Fedora Rawhide.
OK for check-in?
Thanks,
Jan
gdb/ChangeLog
2016-05-14 Jan Kratochvil <jan.kratochvil@redhat.com>
PR c++/15231
* dwarf2read.c (read_lexical_block_scope): Import DIEs from bare
DW_TAG_lexical_block.
(dwarf2_get_pc_bounds): Return more info in *LOWPC.
gdb/testsuite/ChangeLog
2016-05-14 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.
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index f526619..9ec595a 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -11534,7 +11534,18 @@ read_lexical_block_scope (struct die_info *die, struct dwarf2_cu *cu)
be nasty. Might be easier to properly extend generic blocks to
describe ranges. */
if (!dwarf2_get_pc_bounds (die, &lowpc, &highpc, cu, NULL))
- return;
+ {
+ if (lowpc == 1)
+ {
+ /* DW_TAG_lexical_block has no attributes, process its child 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 && child_die->tag;
+ child_die = sibling_die (child_die))
+ process_die (child_die, cu);
+ }
+ return;
+ }
lowpc = gdbarch_adjust_dwarf2_addr (gdbarch, lowpc + baseaddr);
highpc = gdbarch_adjust_dwarf2_addr (gdbarch, highpc + baseaddr);
@@ -12020,7 +12031,10 @@ dwarf2_ranges_read (unsigned offset, CORE_ADDR *low_return,
/* Get low and high pc attributes from a die. Return 1 if the attributes
are present and valid, otherwise, return 0. Return -1 if the range is
- discontinuous, i.e. derived from DW_AT_ranges information. */
+ discontinuous, i.e. derived from DW_AT_ranges information.
+ If the function returns 0 then *LOWPC is set to 1 if none of the
+ range specifying attribute was present; otherwise *LOW is set to 0 as
+ the attribute values were not valid. */
static int
dwarf2_get_pc_bounds (struct die_info *die, CORE_ADDR *lowpc,
@@ -12033,6 +12047,7 @@ dwarf2_get_pc_bounds (struct die_info *die, CORE_ADDR *lowpc,
CORE_ADDR high = 0;
int ret = 0;
+ *lowpc = 0;
attr_high = dwarf2_attr (die, DW_AT_high_pc, cu);
if (attr_high)
{
@@ -12072,6 +12087,12 @@ dwarf2_get_pc_bounds (struct die_info *die, CORE_ADDR *lowpc,
/* Found discontinuous range of addresses. */
ret = -1;
}
+ else
+ {
+ /* None of the attributes is present. */
+ *lowpc = 1;
+ return 0;
+ }
}
/* read_partial_die has also the strict LOW < HIGH requirement. */
diff --git a/gdb/testsuite/gdb.ada/out_of_line_in_inlined.exp b/gdb/testsuite/gdb.ada/out_of_line_in_inlined.exp
index 1ebd89f..8a3a4b1 100644
--- a/gdb/testsuite/gdb.ada/out_of_line_in_inlined.exp
+++ b/gdb/testsuite/gdb.ada/out_of_line_in_inlined.exp
@@ -23,20 +23,14 @@ if {[gdb_compile_ada "${srcfile}" "${binfile}" executable {debug optimize=-O2}]
clean_restart ${testfile}
-# GCC currently is missing a DW_AT_origin attribute in one of the
-# lexical blocks, preventing GDB from creating a symbol for the
-# subprogram we want to break on.
-setup_xfail "*-*-*"
gdb_test "break foo_o224_021.child1.child2" \
"Breakpoint \[0-9\]+ at.*: file .*foo_o224_021.adb, line \[0-9\]+."
gdb_run_cmd
-setup_xfail "*-*-*"
gdb_test "" \
"Breakpoint $decimal, foo_o224_021\\.child1\\.child2 \\(s=\\.\\.\\.\\).*"
set opt_addr_in "($hex in)?"
-setup_xfail "*-*-*"
gdb_test "bt" \
[multi_line "#0 +$opt_addr_in +foo_o224_021\\.child1\\.child2 \\(s=\\.\\.\\.\\).*" \
"#1 +$opt_addr_in +foo_o224_021\\.child1 \\(\\).*" \
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.exp b/gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.exp
new file mode 100644
index 0000000..3f9411e
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-lexical-block-bare.exp
@@ -0,0 +1,70 @@
+# 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
+
+# Make some DWARF for the test.
+set asm_file [standard_output_file $srcfile]
+Dwarf::assemble $asm_file {
+ cu {} {
+ compile_unit {
+ {low_pc [gdb_target_symbol main] DW_FORM_addr}
+ {high_pc [gdb_target_symbol main]+0x10000 DW_FORM_addr}
+ } {
+ declare_labels integer_label
+
+ integer_label: DW_TAG_base_type {
+ {DW_AT_byte_size 4 DW_FORM_sdata}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name integer}
+ }
+
+ DW_TAG_subprogram {
+ {name main}
+ {DW_AT_external 1 flag}
+ {low_pc [gdb_target_symbol main] DW_FORM_addr}
+ {high_pc [gdb_target_symbol main]+0x10000 DW_FORM_addr}
+ } {
+ DW_TAG_lexical_block {
+ } {
+ DW_TAG_variable {
+ {DW_AT_name testvar}
+ {DW_AT_type :$integer_label}
+ {DW_AT_external 1 flag}
+ {DW_AT_location {
+ DW_OP_addr [gdb_target_symbol main]
+ } SPECIAL_expr}
+ }
+ }
+ }
+ }
+ }
+}
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} \
+ [list $srcfile2 $asm_file] {nodebug}] } {
+ return -1
+}
+
+runto_main
+
+# FAILing GDB did print: No symbol "testvar" in current context.
+gdb_test "p testvar" { = -?[0-9]+}