Consider the test-case added in this patch, with resulting dwarf:
...
Compilation Unit @ offset 0xc7:
Length: 0x2c (32-bit)
Version: 4
Abbrev Offset: 0x64
Pointer Size: 8
<0><d2>: Abbrev Number: 2 (DW_TAG_partial_unit)
<d3> DW_AT_language : 2 (non-ANSI C)
<d4> DW_AT_name : imported_unit.c
<1><e4>: Abbrev Number: 3 (DW_TAG_base_type)
<e5> DW_AT_byte_size : 4
<e6> DW_AT_encoding : 5 (signed)
<e7> DW_AT_name : int
<1><eb>: Abbrev Number: 4 (DW_TAG_subprogram)
<ec> DW_AT_name : main
<f1> DW_AT_type : <0xe4>
<f5> DW_AT_external : 1
<1><f6>: Abbrev Number: 0
Compilation Unit @ offset 0xf7:
Length: 0x2c (32-bit)
Version: 4
Abbrev Offset: 0x85
Pointer Size: 8
<0><102>: Abbrev Number: 2 (DW_TAG_compile_unit)
<103> DW_AT_language : 2 (non-ANSI C)
<104> DW_AT_name : <artificial>
<1><111>: Abbrev Number: 3 (DW_TAG_subprogram)
<112> DW_AT_abstract_origin: <0xeb>
<116> DW_AT_low_pc : 0x4004a7
<11e> DW_AT_high_pc : 0x4004b2
<1><126>: Abbrev Number: 0
...
When run with target board cc-with-gdb-index, we run into:
...
(gdb) break main
warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.)
<repeat>
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
Breakpoint 1 at 0x4004ab
(gdb) PASS: gdb.dwarf2/imported-unit-runto-main.exp: setting breakpoint at main
run
Starting program: /data/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.dwarf2/imported-unit-runto-main/imported-unit-runto-main
warning: (Internal error: pc 0x4004a7 in read in CU, but not in symtab.)
<repeat>
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
Breakpoint 1, warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
0x00000000004004ab in main ()
warning: (Internal error: pc 0x4004ab in read in CU, but not in symtab.)
<repeat>
(gdb) FAIL: gdb.dwarf2/imported-unit-runto-main.exp: running to main in runto
...
Looking at the .gdb_index section contents using objdump --dwarf=gdb_index, we
have:
...
CU table:
[ 0] 0x0 - 0x2d
[ 1] 0x2e - 0xa4
[ 2] 0xa5 - 0xc6
[ 3] 0xf7 - 0x126
[ 4] 0x127 - 0x2de
[ 5] 0x2df - 0x300
Address table:
00000000004004a7 00000000004004b2 4
Symbol table:
[489] main: 4 [global, function]
...
We see that both the main symbol, and main address range map to CU 4, which has
offset range 0x127 - 0x2de, while main actually is contained in CU 3 at offset
range 0xf7 - 0x126.
This is caused by this continue in write_gdbindex, which triggers for the PU:
...
/* CU of a shared file from 'dwz -m' may be unused by this main file.
It may be referenced from a local scope but in such case it does not
need to be present in .gdb_index. */
if (psymtab == NULL)
continue;
...
The continue causes the PU to be skipped in the CU table (we can see that the
PU offset range 0xc7-0xf6 is missing) but the references are not taking that
into account.
I've tried fixing this in the optimal way, by updating the references, but ran
into trouble when follow_die_offset tries to find the CU for the inter-CU
ref. Because the PU is missing from the CU table,
dwarf2_find_containing_comp_unit bisects to the wrong CU.
Fix this by not skipping the PU in the CU table.
Build and reg-tested on x86_64-linux, with native and target boards
cc-with-gdb-index, cc-with-dwz and cc-with-dwz-m.
gdb/ChangeLog:
2020-04-16 Tom de Vries <tdevries@suse.de>
PR symtab/25791
* dwarf2/index-write.c (write_gdbindex): Generate CU table entries for
CUs without psymtab.
gdb/testsuite/ChangeLog:
2020-04-16 Tom de Vries <tdevries@suse.de>
PR symtab/25791
* gdb.dwarf2/gdb-add-index.exp (add_gdb_index): Move ...
(ensure_gdb_index): and factor out and move ...
* lib/gdb.exp (add_gdb_index, ensure_gdb_index): ... here.
* gdb.dwarf2/imported-unit-runto-main.exp: New file.
+2020-04-16 Tom de Vries <tdevries@suse.de>
+
+ PR symtab/25791
+ * dwarf2/index-write.c (write_gdbindex): Generate CU table entries for
+ CUs without psymtab.
+
2020-04-16 Kevin Buettner <kevinb@redhat.com>
* python/python.c (do_start_initialization): Don't call
= dwarf2_per_objfile->all_comp_units[i];
partial_symtab *psymtab = per_cu->v.psymtab;
- /* CU of a shared file from 'dwz -m' may be unused by this main file.
- It may be referenced from a local scope but in such case it does not
- need to be present in .gdb_index. */
- if (psymtab == NULL)
- continue;
-
- if (psymtab->user == NULL)
- recursively_write_psymbols (objfile, psymtab, &symtab,
- psyms_seen, i);
+ if (psymtab != NULL)
+ {
+ if (psymtab->user == NULL)
+ recursively_write_psymbols (objfile, psymtab, &symtab,
+ psyms_seen, i);
- const auto insertpair = cu_index_htab.emplace (psymtab, i);
- gdb_assert (insertpair.second);
+ const auto insertpair = cu_index_htab.emplace (psymtab, i);
+ gdb_assert (insertpair.second);
+ }
/* The all_comp_units list contains CUs read from the objfile as well as
from the eventual dwz file. We need to place the entry in the
+2020-04-16 Tom de Vries <tdevries@suse.de>
+
+ PR symtab/25791
+ * gdb.dwarf2/gdb-add-index.exp (add_gdb_index): Move ...
+ (ensure_gdb_index): and factor out and move ...
+ * lib/gdb.exp (add_gdb_index, ensure_gdb_index): ... here.
+ * gdb.dwarf2/imported-unit-runto-main.exp: New file.
+
2020-04-16 Tom de Vries <tdevries@suse.de>
* gdb.base/maint-expand-symbols-header-file.exp: Set language before
return -1
}
-# Add a .gdb_index section to PROGRAM.
-# PROGRAM is assumed to be the output of standard_output_file.
-# Returns the 0 if there is a failure, otherwise 1.
-
-proc add_gdb_index { program } {
- global srcdir GDB env BUILD_DATA_DIRECTORY
- set contrib_dir "$srcdir/../contrib"
- set env(GDB) "$GDB --data-directory=$BUILD_DATA_DIRECTORY"
- set result [catch "exec $contrib_dir/gdb-add-index.sh $program" output]
- if { $result != 0 } {
- verbose -log "result is $result"
- verbose -log "output is $output"
- return 0
- }
-
- return 1
-}
-
-# Build a copy of the program with an index (.gdb_index/.debug_names).
-# But only if the toolchain didn't already create one: gdb doesn't support
-# building an index from a program already using one.
-
-set test "check if index present"
-gdb_test_multiple "mt print objfiles ${testfile}" $test {
- -re "gdb_index.*${gdb_prompt} $" {
- set binfile_with_index $binfile
- }
- -re "debug_names.*${gdb_prompt} $" {
- set binfile_with_index $binfile
- }
- -re "Psymtabs.*${gdb_prompt} $" {
- if { [add_gdb_index $binfile] != "1" } {
- return -1
- }
- set binfile_with_index $binfile
- }
+if { [ensure_gdb_index $binfile] == -1 } {
+ return -1
}
# Ok, we have a copy of $binfile with an index.
# Restart gdb and verify the index was used.
-clean_restart ${binfile_with_index}
+clean_restart ${binfile}
gdb_test "mt print objfiles ${testfile}" \
"(gdb_index|debug_names).*" \
"index used"
--- /dev/null
+# Copyright 2020 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 main.c .S
+
+set executable ${testfile}
+set asm_file [standard_output_file ${srcfile2}]
+
+# We need to know the size of integer types in order to write some of the
+# debugging info we'd like to generate.
+if [prepare_for_testing "failed to prepare" ${testfile} ${srcfile}] {
+ return -1
+}
+
+# Create the DWARF.
+Dwarf::assemble $asm_file {
+ declare_labels cu_label main_label int_label
+ declare_labels aaa_label
+ set int_size [get_sizeof "int" 4]
+
+ global srcdir subdir srcfile
+
+ extern main
+
+ set main_range [function_range main ${srcdir}/${subdir}/${srcfile}]
+ set main_start [lindex $main_range 0]
+ set main_length [lindex $main_range 1]
+
+ cu {} {
+ cu_label: partial_unit {
+ {language @DW_LANG_C}
+ {name "imported_unit.c"}
+ } {
+ int_label: base_type {
+ {byte_size $int_size sdata}
+ {encoding @DW_ATE_signed}
+ {name int}
+ }
+
+ main_label: subprogram {
+ {name main}
+ {type :$int_label}
+ {external 1 flag}
+ }
+ }
+ }
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_C}
+ {name "<artificial>"}
+ } {
+ subprogram {
+ {abstract_origin %$main_label}
+ {low_pc $main_start addr}
+ {high_pc "$main_start + $main_length" addr}
+ }
+ }
+ }
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+}
+
+if { [ensure_gdb_index $binfile] == -1 } {
+ return -1
+}
+
+clean_restart ${binfile}
+
+runto main message
}
}
+# Add a .gdb_index section to PROGRAM.
+# PROGRAM is assumed to be the output of standard_output_file.
+# Returns the 0 if there is a failure, otherwise 1.
+
+proc add_gdb_index { program } {
+ global srcdir GDB env BUILD_DATA_DIRECTORY
+ set contrib_dir "$srcdir/../contrib"
+ set env(GDB) "$GDB --data-directory=$BUILD_DATA_DIRECTORY"
+ set result [catch "exec $contrib_dir/gdb-add-index.sh $program" output]
+ if { $result != 0 } {
+ verbose -log "result is $result"
+ verbose -log "output is $output"
+ return 0
+ }
+
+ return 1
+}
+
+# Add a .gdb_index section to PROGRAM, unless it alread has an index
+# (.gdb_index/.debug_names). Gdb doesn't support building an index from a
+# program already using one. Return 1 if a .gdb_index was added, return 0
+# if it already contained an index, and -1 if an error occurred.
+
+proc ensure_gdb_index { binfile } {
+ set testfile [file tail $binfile]
+ set test "check if index present"
+ gdb_test_multiple "mt print objfiles ${testfile}" $test {
+ -re -wrap "gdb_index.*" {
+ return 0
+ }
+ -re -wrap "debug_names.*" {
+ return 0
+ }
+ -re -wrap "Psymtabs.*" {
+ if { [add_gdb_index $binfile] != "1" } {
+ return -1
+ }
+ return 1
+ }
+ }
+ return -1
+}
+
# Always load compatibility stuff.
load_lib future.exp
projects / binutils-gdb.git / commitdiff