[PATCH v2] gdb/testsuite: fix gdb.base/dlmopen-ns-ids.exp racy test

Guinevere Larsen
2025-04-10T13:06:27Z

The recently included gdb.base/dlmopen-ns-ids.exp test can sometimes
fail the call to get_integer_valueof when trying to check the namespace
ID of the fourth dlopened SO, for apparently no reason.

What's happening is that the call to get_first_so_ns doesn't necessarily
consume the GDB prompt, and so get_integer_valueof will see the prompt
immediately and not find the value the test is looking for.

To fix this, the test was changed so that we consume all of the output
of the command "info sharedlibrary", but only set the namespace ID for
the first occurence of the SO we're looking for. The command now also
gets the solib name as a parameter, to reduce the amount of output.

Co-Authored-By: tdevries@suse.de
---
gdb/testsuite/gdb.base/dlmopen-ns-ids.exp | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/gdb/testsuite/gdb.base/dlmopen-ns-ids.exp b/gdb/testsuite/gdb.base/dlmopen-ns-ids.exp
index 03b7a527af5..3ddc07e7773 100644
--- a/gdb/testsuite/gdb.base/dlmopen-ns-ids.exp
+++ b/gdb/testsuite/gdb.base/dlmopen-ns-ids.exp
@@ -24,7 +24,8 @@ require allow_dlmopen_tests
standard_testfile -main.c -lib.c

set srcfile_lib $srcfile2
-set binfile_lib [standard_output_file dlmopen-lib.so]
+set so_name dlmopen-lib.so
+set binfile_lib [standard_output_file $so_name]

if { [build_executable "build shlib" $binfile_lib $srcfile_lib \
[list debug shlib]] == -1 } {
@@ -41,18 +42,19 @@ if { [build_executable "failed to build" $testfile $srcfile \
# for the so
proc get_first_so_ns {} {
set ns -1
- gdb_test_multiple "info sharedlibrary" "get SO namespace" -lbl {
- -re "From\\s+To\\s+\(NS\\s+\)?Syms\\s+Read\\s+Shared Object Library\r\n" {
+ set lib_regexp [string_to_regexp ${::binfile_lib}]
+ gdb_test_multiple "info sharedlibrary $::so_name" "get SO namespace" -lbl {
+ -re "\r\nFrom\\s+To\\s+\(NS\\s+\)?Syms\\s+Read\\s+Shared Object Library(?=\r\n)" {
exp_continue
}
- -re "^$::hex\\s+$::hex\\s+\\\[\\\[($::decimal)\\\]\\\]\\s+\[^\r\n]+$::binfile_lib.*" {
- set ns $expect_out(1,string)
- }
- -re "^$::gdb_prompt $" {
- }
- -re "^\[^\r\n\]+\r\n" {
+ -re "\r\n$::hex\\s+$::hex\\s+\\\[\\\[($::decimal)\\\]\\\]\\s+\[^\r\n]+${lib_regexp}(?=\r\n)" {
+ if {$ns == -1} {
+ set ns $expect_out(1,string)
+ }
exp_continue
}
+ -re -wrap "" {
+ }
}
return $ns
}

base-commit: d1458933830456e54223d9fc61f0d9b3a19256f5
--
2.49.0