[RFA] py-value.exp: Use different names for C/C++ .o files.

[Doug Evans <dje@google.com>]

Hi.

Awhile ago I submitted this patch:

http://sourceware.org/ml/gdb-patches/2012-05/msg00553.html

Jan requested I do things differently:

http://sourceware.org/ml/gdb-patches/2012-05/msg00568.html

This patch implements this request for py-value.exp.
Namely different .o files are used for C and C++ so that the
C++ compilation doesn't clobber the .dwo file of the C compilation.

Also, I noticed that the C++ test wasn't checking skip_cplus_tests.
Adding that made the code more like my original patch, but this
new patch still makes it easier to reproduce results by hand.

While I was at it I renamed py-value.cc which is used by py-value-cc.exp.
It's confusing to have py-value.cc *not* used by py-value.exp.

Regression tested on amd64-linux, with/without Fission.

Ok to check in?

2013-08-01  Doug Evans  <dje@google.com>

	* gdb.python/py-value-cc.cc: Renamed from py-value.cc.
	* gdb.python/py-value-cc.exp: Update.
	* gdb.python/py-value.exp: Use different names for .o files for
	C and C++.  Only perform C++ tests if !skip_cplus_tests.

Index: testsuite/gdb.python/py-value-cc.cc
===================================================================
RCS file: testsuite/gdb.python/py-value-cc.cc
diff -N testsuite/gdb.python/py-value-cc.cc
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.python/py-value-cc.cc	1 Aug 2013 20:57:32 -0000
@@ -0,0 +1,39 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2012-2013 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/>.  */
+
+class A {
+};
+
+typedef int *int_ptr;
+
+int
+func (const A &a)
+{
+  int val = 10;
+  int &int_ref = val;
+  int_ptr ptr = &val;
+  int_ptr &int_ptr_ref = ptr;
+
+  return 0; /* Break here.  */
+}
+
+int
+main ()
+{
+  A obj;
+  return func (obj);
+}
Index: testsuite/gdb.python/py-value-cc.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.python/py-value-cc.exp,v
retrieving revision 1.4
diff -u -p -r1.4 py-value-cc.exp
--- testsuite/gdb.python/py-value-cc.exp	1 Jan 2013 06:41:26 -0000	1.4
+++ testsuite/gdb.python/py-value-cc.exp	1 Aug 2013 20:57:32 -0000
@@ -18,7 +18,7 @@
 
 if { [skip_cplus_tests] } { continue }
 
-standard_testfile py-value.cc
+standard_testfile .cc
 
 if {[prepare_for_testing $testfile.exp $testfile $srcfile {debug c++}]} {
     return -1
Index: testsuite/gdb.python/py-value.cc
===================================================================
RCS file: testsuite/gdb.python/py-value.cc
diff -N testsuite/gdb.python/py-value.cc
--- testsuite/gdb.python/py-value.cc	1 Jan 2013 06:41:26 -0000	1.2
+++ /dev/null	1 Jan 1970 00:00:00 -0000
@@ -1,39 +0,0 @@
-/* This testcase is part of GDB, the GNU debugger.
-
-   Copyright 2012-2013 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/>.  */
-
-class A {
-};
-
-typedef int *int_ptr;
-
-int
-func (const A &a)
-{
-  int val = 10;
-  int &int_ref = val;
-  int_ptr ptr = &val;
-  int_ptr &int_ptr_ref = ptr;
-
-  return 0; /* Break here.  */
-}
-
-int
-main ()
-{
-  A obj;
-  return func (obj);
-}
Index: testsuite/gdb.python/py-value.exp
===================================================================
RCS file: /cvs/src/src/gdb/testsuite/gdb.python/py-value.exp,v
retrieving revision 1.33
diff -u -p -r1.33 py-value.exp
--- testsuite/gdb.python/py-value.exp	1 Jan 2013 06:41:26 -0000	1.33
+++ testsuite/gdb.python/py-value.exp	1 Aug 2013 20:57:32 -0000
@@ -21,13 +21,26 @@ load_lib gdb-python.exp
 standard_testfile
 
 # Build inferior to language specification.
+# LANG is one of "c" or "c++".
 proc build_inferior {exefile lang} {
   global srcdir subdir srcfile testfile hex
 
-  if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${exefile}" executable "debug $lang"] != "" } {
+  # Use different names for .o files based on the language.
+  # For Fission, the debug info goes in foo.dwo and we don't want,
+  # for example, a C++ compile to clobber the dwo of a C compile.
+  # ref: http://gcc.gnu.org/wiki/DebugFission
+  switch ${lang} {
+      "c" { set filename ${testfile}.o }
+      "c++" { set filename ${testfile}-cxx.o }
+  }
+  set objfile [standard_output_file $filename]
+
+  if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${objfile}" object "debug $lang"] != ""
+       || [gdb_compile "${objfile}" "${exefile}" executable "debug $lang"] != "" } {
       untested "Couldn't compile ${srcfile} in $lang mode"
       return -1
   }
+  return 0
 }
 
 proc test_value_creation {} {
@@ -463,9 +476,10 @@ proc test_value_hash {} {
     gdb_test "python print (one.__hash__() == hash(one))" "True" "Test inbuilt hash"
 }
 
-# Build C and C++ versions of executable
-build_inferior "${binfile}" "c"
-build_inferior "${binfile}-cxx" "c++"
+# Build C version of executable.  C++ is built later.
+if { [build_inferior "${binfile}" "c"] < 0 } {
+    return -1
+}
 
 # Start with a fresh gdb.
 clean_restart ${binfile}
@@ -494,5 +508,12 @@ test_lazy_strings
 test_value_after_death
 
 # Test either C or C++ values. 
+
 test_subscript_regression "${binfile}" "c"
-test_subscript_regression "${binfile}-cxx" "c++"
+
+if ![skip_cplus_tests] {
+    if { [build_inferior "${binfile}-cxx" "c++"] < 0 } {
+	return -1
+    }
+    test_subscript_regression "${binfile}-cxx" "c++"
+}