[v2] New testcase for PR tui/25126 (staled source cache)
Commit Message
I'm dealing with a Fedora GDB bug that is related to PR tui/25126, and
I thought I'd write a specific testcase for it because I couldn't find
one.
The idea is to get the simple reproducer from the bug and tweak the
testcase around it. This one was a bit hard because, since we need to
modify the source file and recompile it, it involved a bit of TCL-foo
to do things. Also for this reason, I'm only enabling the test for
native boards.
I tested this with an upstream GDB and made sure everything is
passing. I also tested with a faulty GDB and made sure the test
failed.
gdb/testsuite/ChangeLog:
2020-02-10 Sergio Durigan Junior <sergiodj@redhat.com>
PR tui/25126
* gdb.base/cached-source-file.c: New file.
* gdb.base/cached-source-file.exp: New file.
Change-Id: Ib1b074342ebe8613c6d1dfde631691ebdf6d81c6
---
gdb/testsuite/gdb.base/cached-source-file.c | 43 ++++++++
gdb/testsuite/gdb.base/cached-source-file.exp | 99 +++++++++++++++++++
2 files changed, 142 insertions(+)
create mode 100644 gdb/testsuite/gdb.base/cached-source-file.c
create mode 100644 gdb/testsuite/gdb.base/cached-source-file.exp
Comments
On 2/10/20 5:02 PM, Sergio Durigan Junior wrote:
> I'm dealing with a Fedora GDB bug that is related to PR tui/25126, and
> I thought I'd write a specific testcase for it because I couldn't find
> one.
>
> The idea is to get the simple reproducer from the bug and tweak the
> testcase around it. This one was a bit hard because, since we need to
> modify the source file and recompile it, it involved a bit of TCL-foo
> to do things. Also for this reason, I'm only enabling the test for
> native boards.
>
> I tested this with an upstream GDB and made sure everything is
> passing. I also tested with a faulty GDB and made sure the test
> failed.
>
> gdb/testsuite/ChangeLog:
> 2020-02-10 Sergio Durigan Junior <sergiodj@redhat.com>
>
> PR tui/25126
> * gdb.base/cached-source-file.c: New file.
> * gdb.base/cached-source-file.exp: New file.
>
> Change-Id: Ib1b074342ebe8613c6d1dfde631691ebdf6d81c6
> ---
> gdb/testsuite/gdb.base/cached-source-file.c | 43 ++++++++
> gdb/testsuite/gdb.base/cached-source-file.exp | 99 +++++++++++++++++++
> 2 files changed, 142 insertions(+)
> create mode 100644 gdb/testsuite/gdb.base/cached-source-file.c
> create mode 100644 gdb/testsuite/gdb.base/cached-source-file.exp
>
> diff --git a/gdb/testsuite/gdb.base/cached-source-file.c b/gdb/testsuite/gdb.base/cached-source-file.c
> new file mode 100644
> index 0000000000..6f62c29799
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/cached-source-file.c
> @@ -0,0 +1,43 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + 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/>. */
> +
> +/* Test for PR tui/25126.
> +
> + The bug is about a regression that makes GDB not reload its source
> + code cache when the inferior's symbols are reloaded, which leads to
> + wrong backtraces/listings.
> +
> + This bug is reproducible even without using the TUI.
> +
> + The .exp testcase depends on the line numbers and contents from
> + this file If you change this file, make sure to double-check the
> + testcase. */
> +
> +#include <stdio.h>
> +
> +void
> +foo (void)
> +{
> + printf ("hello\n"); /* break-here */
> +}
> +
> +int
> +main ()
> +{
> + foo ();
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.base/cached-source-file.exp b/gdb/testsuite/gdb.base/cached-source-file.exp
> new file mode 100644
> index 0000000000..f6e5f081f0
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/cached-source-file.exp
> @@ -0,0 +1,99 @@
> +# Copyright (C) 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/>.
> +
> +# Test for PR tui/25126.
> +#
> +# The bug is about a regression that makes GDB not reload its source
> +# code cache when the inferior's symbols are reloaded, which leads to
> +# wrong backtraces/listings.
> +#
> +# This bug is reproducible even without using the TUI.
> +
> +standard_testfile
> +
> +# Only run on native boards.
> +if { [use_gdb_stub] || [target_info gdb_protocol] == "extended-remote" } {
> + return -1
> +}
> +
> +# Because we need to modify the source file later, it's better if we
> +# just copy it to our output directory (instead of messing with the
> +# user's source directory).
> +set newsrc [standard_output_file $testfile].c
> +file copy -force -- $srcdir/$subdir/$srcfile $newsrc
> +set srcfile $newsrc
> +
> +if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
> + return -1
> +}
> +
> +# Get the line number for the line with the "break-here" marker.
> +set bp_line [gdb_get_line_number "break-here" $srcfile]
> +
> +gdb_assert { [runto "$srcfile:$bp_line"] } \
> + "run to $srcfile:$bp_line"
> +
> +# Do a "list" and check that the printed line matches the line of the
> +# original source file.
> +gdb_test_no_output "set listsize 1"
> +gdb_test "list" "$bp_line\[ \t\]+printf \\(\"hello\\\\n\"\\); /\\* break-here \\*/" \
> + "check the first version of the source file"
> +
> +# Modify the original source file, and add an extra line into it.
> +# This only works locally because of the TCL commands.
> +set bkpsrc [standard_output_file $testfile].c.bkp
> +set bkpsrcfd [open $bkpsrc w]
> +set srcfd [open $srcfile r]
> +
> +while { [gets $srcfd line] != -1 } {
> + if { [string first "break-here" $line] != -1 } {
> + # Put a "printf" line before the "break-here" line.
> + puts $bkpsrcfd " printf (\"foo\\n\"); /* new-marker */"
> + }
> + puts $bkpsrcfd $line
> +}
> +
> +close $bkpsrcfd
> +close $srcfd
> +file rename -force -- $bkpsrc $srcfile
> +# Here, we have to wait 1 second because of the way GDB keeps track to
> +# check whether the binary has changed or not. GDB uses stat(2) and
> +# currently checks 'st_mtime', whose precision is measured in
> +# seconds. Since the whole file-copying/rename operation can take
> +# less than 1 second, GDB can mistakenly assume that the binary is
> +# still the same if we don't wait here.
> +sleep 1
> +
> +# Recompile the modified source. We use "gdb_compile" here instead of
> +# "prepare_for_testing" because we don't want to call "clean_restart".
> +if { [gdb_compile "${srcfile}" "${binfile}" executable {debug}] != "" } {
> + return -1
> +}
> +
> +# Rerun the program. This should not only force GDB to reload the
> +# source cache, but also to break at BP_LINE again, which now has
> +# different contents.
> +gdb_test_multiple "run" "rerun program" {
> + -re {The program being debugged has been started already\.\r\nStart it from the beginning\? \(y or n\) $} {
> + set binregex [string_to_regexp $binfile]
> + gdb_test "y" "\\`$binregex\\' has changed; re-reading symbols\.\r\nStarting program: ${binregex}.*" \
> + "rerun program"
> + }
> +}
> +
> +# Again, perform the listing and check that the line indeed has
> +# changed for GDB.
> +gdb_test "list" "${bp_line}\[ \t\]+printf \\(\"foo\\\\n\"\\); /\\\* new-marker \\\*/.*" \
> + "verify that the source code is properly reloaded"
>
Thanks. I have no further comments on this one.
* Sergio Durigan Junior <sergiodj@redhat.com> [2020-02-10 15:02:20 -0500]:
> I'm dealing with a Fedora GDB bug that is related to PR tui/25126, and
> I thought I'd write a specific testcase for it because I couldn't find
> one.
>
> The idea is to get the simple reproducer from the bug and tweak the
> testcase around it. This one was a bit hard because, since we need to
> modify the source file and recompile it, it involved a bit of TCL-foo
> to do things. Also for this reason, I'm only enabling the test for
> native boards.
>
> I tested this with an upstream GDB and made sure everything is
> passing. I also tested with a faulty GDB and made sure the test
> failed.
>
> gdb/testsuite/ChangeLog:
> 2020-02-10 Sergio Durigan Junior <sergiodj@redhat.com>
>
> PR tui/25126
> * gdb.base/cached-source-file.c: New file.
> * gdb.base/cached-source-file.exp: New file.
>
> Change-Id: Ib1b074342ebe8613c6d1dfde631691ebdf6d81c6
> ---
> gdb/testsuite/gdb.base/cached-source-file.c | 43 ++++++++
> gdb/testsuite/gdb.base/cached-source-file.exp | 99 +++++++++++++++++++
> 2 files changed, 142 insertions(+)
> create mode 100644 gdb/testsuite/gdb.base/cached-source-file.c
> create mode 100644 gdb/testsuite/gdb.base/cached-source-file.exp
>
> diff --git a/gdb/testsuite/gdb.base/cached-source-file.c b/gdb/testsuite/gdb.base/cached-source-file.c
> new file mode 100644
> index 0000000000..6f62c29799
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/cached-source-file.c
> @@ -0,0 +1,43 @@
> +/* This testcase is part of GDB, the GNU debugger.
> +
> + 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/>. */
> +
> +/* Test for PR tui/25126.
> +
> + The bug is about a regression that makes GDB not reload its source
> + code cache when the inferior's symbols are reloaded, which leads to
> + wrong backtraces/listings.
> +
> + This bug is reproducible even without using the TUI.
> +
> + The .exp testcase depends on the line numbers and contents from
> + this file If you change this file, make sure to double-check the
> + testcase. */
> +
> +#include <stdio.h>
> +
> +void
> +foo (void)
> +{
> + printf ("hello\n"); /* break-here */
> +}
> +
> +int
> +main ()
> +{
> + foo ();
> + return 0;
> +}
> diff --git a/gdb/testsuite/gdb.base/cached-source-file.exp b/gdb/testsuite/gdb.base/cached-source-file.exp
> new file mode 100644
> index 0000000000..f6e5f081f0
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/cached-source-file.exp
> @@ -0,0 +1,99 @@
> +# Copyright (C) 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/>.
> +
> +# Test for PR tui/25126.
> +#
> +# The bug is about a regression that makes GDB not reload its source
> +# code cache when the inferior's symbols are reloaded, which leads to
> +# wrong backtraces/listings.
> +#
> +# This bug is reproducible even without using the TUI.
> +
> +standard_testfile
> +
> +# Only run on native boards.
> +if { [use_gdb_stub] || [target_info gdb_protocol] == "extended-remote" } {
> + return -1
> +}
> +
> +# Because we need to modify the source file later, it's better if we
> +# just copy it to our output directory (instead of messing with the
> +# user's source directory).
> +set newsrc [standard_output_file $testfile].c
> +file copy -force -- $srcdir/$subdir/$srcfile $newsrc
> +set srcfile $newsrc
> +
> +if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
> + return -1
> +}
> +
> +# Get the line number for the line with the "break-here" marker.
> +set bp_line [gdb_get_line_number "break-here" $srcfile]
> +
> +gdb_assert { [runto "$srcfile:$bp_line"] } \
> + "run to $srcfile:$bp_line"
> +
> +# Do a "list" and check that the printed line matches the line of the
> +# original source file.
> +gdb_test_no_output "set listsize 1"
> +gdb_test "list" "$bp_line\[ \t\]+printf \\(\"hello\\\\n\"\\); /\\* break-here \\*/" \
> + "check the first version of the source file"
> +
> +# Modify the original source file, and add an extra line into it.
> +# This only works locally because of the TCL commands.
> +set bkpsrc [standard_output_file $testfile].c.bkp
> +set bkpsrcfd [open $bkpsrc w]
> +set srcfd [open $srcfile r]
> +
> +while { [gets $srcfd line] != -1 } {
> + if { [string first "break-here" $line] != -1 } {
> + # Put a "printf" line before the "break-here" line.
> + puts $bkpsrcfd " printf (\"foo\\n\"); /* new-marker */"
> + }
> + puts $bkpsrcfd $line
> +}
> +
> +close $bkpsrcfd
> +close $srcfd
> +file rename -force -- $bkpsrc $srcfile
> +# Here, we have to wait 1 second because of the way GDB keeps track to
> +# check whether the binary has changed or not. GDB uses stat(2) and
> +# currently checks 'st_mtime', whose precision is measured in
> +# seconds. Since the whole file-copying/rename operation can take
> +# less than 1 second, GDB can mistakenly assume that the binary is
> +# still the same if we don't wait here.
Maybe rewrite this comment as:
We have to wait 1 second because of the way GDB checks whether the
binary has changed or not. GDB uses stat(2) and currently checks
'st_mtime', whose precision is measured in seconds. Since the copy,
rename, and rebuild can take less than 1 second, GDB might mistakenly
assume that the binary is unchanged.
Otherwise this looks good to me and can be applied.
Thanks,
Andrew
> +sleep 1
> +
> +# Recompile the modified source. We use "gdb_compile" here instead of
> +# "prepare_for_testing" because we don't want to call "clean_restart".
> +if { [gdb_compile "${srcfile}" "${binfile}" executable {debug}] != "" } {
> + return -1
> +}
> +
> +# Rerun the program. This should not only force GDB to reload the
> +# source cache, but also to break at BP_LINE again, which now has
> +# different contents.
> +gdb_test_multiple "run" "rerun program" {
> + -re {The program being debugged has been started already\.\r\nStart it from the beginning\? \(y or n\) $} {
> + set binregex [string_to_regexp $binfile]
> + gdb_test "y" "\\`$binregex\\' has changed; re-reading symbols\.\r\nStarting program: ${binregex}.*" \
> + "rerun program"
> + }
> +}
> +
> +# Again, perform the listing and check that the line indeed has
> +# changed for GDB.
> +gdb_test "list" "${bp_line}\[ \t\]+printf \\(\"foo\\\\n\"\\); /\\\* new-marker \\\*/.*" \
> + "verify that the source code is properly reloaded"
> --
> 2.21.0
>
On Tuesday, February 11 2020, Andrew Burgess wrote:
> * Sergio Durigan Junior <sergiodj@redhat.com> [2020-02-10 15:02:20 -0500]:
[...]
>> +close $bkpsrcfd
>> +close $srcfd
>> +file rename -force -- $bkpsrc $srcfile
>> +# Here, we have to wait 1 second because of the way GDB keeps track to
>> +# check whether the binary has changed or not. GDB uses stat(2) and
>> +# currently checks 'st_mtime', whose precision is measured in
>> +# seconds. Since the whole file-copying/rename operation can take
>> +# less than 1 second, GDB can mistakenly assume that the binary is
>> +# still the same if we don't wait here.
>
> Maybe rewrite this comment as:
>
> We have to wait 1 second because of the way GDB checks whether the
> binary has changed or not. GDB uses stat(2) and currently checks
> 'st_mtime', whose precision is measured in seconds. Since the copy,
> rename, and rebuild can take less than 1 second, GDB might mistakenly
> assume that the binary is unchanged.
>
> Otherwise this looks good to me and can be applied.
Thanks, I adopted your version of the text and pushed the patch.
f6be87130b5b327075a09c05e78532816f186995
Thank you and Luis for the reviews.
new file mode 100644
@@ -0,0 +1,43 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ 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/>. */
+
+/* Test for PR tui/25126.
+
+ The bug is about a regression that makes GDB not reload its source
+ code cache when the inferior's symbols are reloaded, which leads to
+ wrong backtraces/listings.
+
+ This bug is reproducible even without using the TUI.
+
+ The .exp testcase depends on the line numbers and contents from
+ this file If you change this file, make sure to double-check the
+ testcase. */
+
+#include <stdio.h>
+
+void
+foo (void)
+{
+ printf ("hello\n"); /* break-here */
+}
+
+int
+main ()
+{
+ foo ();
+ return 0;
+}
new file mode 100644
@@ -0,0 +1,99 @@
+# Copyright (C) 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/>.
+
+# Test for PR tui/25126.
+#
+# The bug is about a regression that makes GDB not reload its source
+# code cache when the inferior's symbols are reloaded, which leads to
+# wrong backtraces/listings.
+#
+# This bug is reproducible even without using the TUI.
+
+standard_testfile
+
+# Only run on native boards.
+if { [use_gdb_stub] || [target_info gdb_protocol] == "extended-remote" } {
+ return -1
+}
+
+# Because we need to modify the source file later, it's better if we
+# just copy it to our output directory (instead of messing with the
+# user's source directory).
+set newsrc [standard_output_file $testfile].c
+file copy -force -- $srcdir/$subdir/$srcfile $newsrc
+set srcfile $newsrc
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
+ return -1
+}
+
+# Get the line number for the line with the "break-here" marker.
+set bp_line [gdb_get_line_number "break-here" $srcfile]
+
+gdb_assert { [runto "$srcfile:$bp_line"] } \
+ "run to $srcfile:$bp_line"
+
+# Do a "list" and check that the printed line matches the line of the
+# original source file.
+gdb_test_no_output "set listsize 1"
+gdb_test "list" "$bp_line\[ \t\]+printf \\(\"hello\\\\n\"\\); /\\* break-here \\*/" \
+ "check the first version of the source file"
+
+# Modify the original source file, and add an extra line into it.
+# This only works locally because of the TCL commands.
+set bkpsrc [standard_output_file $testfile].c.bkp
+set bkpsrcfd [open $bkpsrc w]
+set srcfd [open $srcfile r]
+
+while { [gets $srcfd line] != -1 } {
+ if { [string first "break-here" $line] != -1 } {
+ # Put a "printf" line before the "break-here" line.
+ puts $bkpsrcfd " printf (\"foo\\n\"); /* new-marker */"
+ }
+ puts $bkpsrcfd $line
+}
+
+close $bkpsrcfd
+close $srcfd
+file rename -force -- $bkpsrc $srcfile
+# Here, we have to wait 1 second because of the way GDB keeps track to
+# check whether the binary has changed or not. GDB uses stat(2) and
+# currently checks 'st_mtime', whose precision is measured in
+# seconds. Since the whole file-copying/rename operation can take
+# less than 1 second, GDB can mistakenly assume that the binary is
+# still the same if we don't wait here.
+sleep 1
+
+# Recompile the modified source. We use "gdb_compile" here instead of
+# "prepare_for_testing" because we don't want to call "clean_restart".
+if { [gdb_compile "${srcfile}" "${binfile}" executable {debug}] != "" } {
+ return -1
+}
+
+# Rerun the program. This should not only force GDB to reload the
+# source cache, but also to break at BP_LINE again, which now has
+# different contents.
+gdb_test_multiple "run" "rerun program" {
+ -re {The program being debugged has been started already\.\r\nStart it from the beginning\? \(y or n\) $} {
+ set binregex [string_to_regexp $binfile]
+ gdb_test "y" "\\`$binregex\\' has changed; re-reading symbols\.\r\nStarting program: ${binregex}.*" \
+ "rerun program"
+ }
+}
+
+# Again, perform the listing and check that the line indeed has
+# changed for GDB.
+gdb_test "list" "${bp_line}\[ \t\]+printf \\(\"foo\\\\n\"\\); /\\\* new-marker \\\*/.*" \
+ "verify that the source code is properly reloaded"