gdb: Fix backtrace with disassemble-next-line on

Message ID 20191226215415.14589-1-andrew.burgess@embecosm.com
State New, archived
Headers

Commit Message

Andrew Burgess Dec. 26, 2019, 9:54 p.m. UTC
  I think this should be applied to the v9 branch too.

--

In this commit:

  commit ec8e2b6d3051f0b4b2a8eee9917898e95046c62f
  Date:   Fri Jun 14 23:43:00 2019 +0100

      gdb: Don't allow annotations to influence what else GDB prints

A change was accidentally made that moved a call to do_gdb_disassembly
out of an if block guarded by 'if (source_print && sal.symtab)'.  The
result was that if a user has 'set disassemble-next-line on' then the
backtrace would now include some disassembly of a few instructions in
each frame.

This change was not intentional, but was not spotted by any tests.

This commit restores the old behaviour and adds a test to ensure this
doesn't break again in the future.

gdb/ChangeLog:

	* stack.c (print_frame_info): Move disassemble_next_line code
	inside source_print block.

gdb/testsuite/ChangeLog:

	* gdb.base/backtrace.c: New file.
	* gdb.base/backtrace.exp: New file.

Change-Id: I47c52a202fa74be138382646b695827940178689
---
 gdb/ChangeLog                        |  5 ++++
 gdb/stack.c                          | 10 ++++----
 gdb/testsuite/ChangeLog              |  5 ++++
 gdb/testsuite/gdb.base/backtrace.c   | 40 ++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.base/backtrace.exp | 48 ++++++++++++++++++++++++++++++++++++
 5 files changed, 103 insertions(+), 5 deletions(-)
 create mode 100644 gdb/testsuite/gdb.base/backtrace.c
 create mode 100644 gdb/testsuite/gdb.base/backtrace.exp
  

Comments

Tom Tromey Jan. 6, 2020, 4:13 p.m. UTC | #1
>>>>> "Andrew" == Andrew Burgess <andrew.burgess@embecosm.com> writes:

Andrew> gdb/ChangeLog:

Andrew> 	* stack.c (print_frame_info): Move disassemble_next_line code
Andrew> 	inside source_print block.

Andrew> gdb/testsuite/ChangeLog:

Andrew> 	* gdb.base/backtrace.c: New file.
Andrew> 	* gdb.base/backtrace.exp: New file.

This looks good to me.

Tom
  

Patch

diff --git a/gdb/stack.c b/gdb/stack.c
index 22820524871..fed482486e9 100644
--- a/gdb/stack.c
+++ b/gdb/stack.c
@@ -1153,12 +1153,12 @@  print_frame_info (const frame_print_options &fp_opts,
 
 	  print_source_lines (sal.symtab, sal.line, sal.line + 1, 0);
 	}
-    }
 
-  /* If disassemble-next-line is set to on and there is line debug
-     messages, output assembly codes for next line.  */
-  if (disassemble_next_line == AUTO_BOOLEAN_TRUE)
-    do_gdb_disassembly (get_frame_arch (frame), -1, sal.pc, sal.end);
+      /* If disassemble-next-line is set to on and there is line debug
+	 messages, output assembly codes for next line.  */
+      if (disassemble_next_line == AUTO_BOOLEAN_TRUE)
+	do_gdb_disassembly (get_frame_arch (frame), -1, sal.pc, sal.end);
+    }
 
   if (set_current_sal)
     {
diff --git a/gdb/testsuite/gdb.base/backtrace.c b/gdb/testsuite/gdb.base/backtrace.c
new file mode 100644
index 00000000000..e6262e8d513
--- /dev/null
+++ b/gdb/testsuite/gdb.base/backtrace.c
@@ -0,0 +1,40 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2019 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/>.  */
+
+int __attribute__((noinline,noclone))
+baz ()
+{
+  return 0;	/* Break here.  */
+}
+
+int __attribute__((noinline,noclone))
+bar ()
+{
+  return baz ();
+}
+
+int __attribute__((noinline,noclone))
+foo ()
+{
+  return bar ();
+}
+
+int
+main ()
+{
+  return foo ();
+}
diff --git a/gdb/testsuite/gdb.base/backtrace.exp b/gdb/testsuite/gdb.base/backtrace.exp
new file mode 100644
index 00000000000..05214c2389a
--- /dev/null
+++ b/gdb/testsuite/gdb.base/backtrace.exp
@@ -0,0 +1,48 @@ 
+# Copyright 2019 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/>.
+
+# A place for miscellaneous tests related to backtrace.
+
+standard_testfile
+
+if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } {
+    return -1
+}
+
+if ![runto_main] then {
+    fail "can't run to main"
+    return 0
+}
+
+# Run to the breakpoint at return.
+gdb_breakpoint [gdb_get_line_number "Break here."]
+gdb_continue_to_breakpoint "Break here."
+
+# Backtrace with the default options.
+gdb_test "bt" \
+    [multi_line \
+	 "#0\[ \t\]*baz \\(\\) at \[^\r\n\]+" \
+	 "#1\[ \t\]*$hex in bar \\(\\) at \[^\r\n\]+" \
+	 "#2\[ \t\]*$hex in foo \\(\\) at \[^\r\n\]+" \
+	 "#3\[ \t\]*$hex in main \\(\\) at \[^\r\n\]+" ]
+
+# Backtrace with 'set disassemble-next-line on'.  This shouldn't make
+# any difference to the backtrace.
+gdb_test "with disassemble-next-line on -- bt" \
+    [multi_line \
+	 "#0\[ \t\]*baz \\(\\) at \[^\r\n\]+" \
+	 "#1\[ \t\]*$hex in bar \\(\\) at \[^\r\n\]+" \
+	 "#2\[ \t\]*$hex in foo \\(\\) at \[^\r\n\]+" \
+	 "#3\[ \t\]*$hex in main \\(\\) at \[^\r\n\]+" ]