gdb: Fix backtrace with disassemble-next-line on

In this commit:

  commit ec8e2b6d30
  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

@@ -1,3 +1,8 @@
+2020-01-06  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* stack.c (print_frame_info): Move disassemble_next_line code
+	inside source_print block.
+
 2020-01-06  Eli Zaretskii  <eliz@gnu.org>
 
 	* gdbsupport/gdb_wait.c: Include <signal.h> instead of

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 (set_current_sal)
     {

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2020-01-06  Andrew Burgess  <andrew.burgess@embecosm.com>
+
+	* gdb.base/backtrace.c: New file.
+	* gdb.base/backtrace.exp: New file.
+
 2020-01-05  Andrew Burgess  <andrew.burgess@embecosm.com>
 
 	* gdb.tui/list.exp: Test 'focus next' after 'list main'.

gdb/testsuite/gdb.base/backtrace.c

@@ -0,0 +1,40 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2019-2020 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/>.  */
+
+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 ();
+}

gdb/testsuite/gdb.base/backtrace.exp

@@ -0,0 +1,48 @@
+# Copyright 2019-2020 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/>.
+
+# 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 \[^\r\n\]+" ]