Move selftest::test_diagnostic_context to its own header

It's useful to not rely on global_dc in selftests, so this patch
moves class selftest::test_diagnostic_context from
diagnostic-show-locus.c to a new header and source file.

gcc/ChangeLog:
	* Makefile.in (OBJS-libcommon): Add selftest-diagnostic.o.
	* diagnostic-show-locus.c: Include "selftest-diagnostic.h".
	(class selftest::test_diagnostic_context): Move to...
	* selftest-diagnostic.c: New file.
	* selftest-diagnostic.h: New file.

From-SVN: r254354

gcc/ChangeLog

+2017-11-02  David Malcolm  <dmalcolm@redhat.com>
+
+	* Makefile.in (OBJS-libcommon): Add selftest-diagnostic.o.
+	* diagnostic-show-locus.c: Include "selftest-diagnostic.h".
+	(class selftest::test_diagnostic_context): Move to...
+	* selftest-diagnostic.c: New file.
+	* selftest-diagnostic.h: New file.
+
 2017-11-02  James Bowman  <james.bowman@ftdichip.com>
 
 	* config/ft32/ft32.c (ft32_addr_space_legitimate_address_p): increase

gcc/Makefile.in

@@ -1591,7 +1591,7 @@ OBJS-libcommon = diagnostic.o diagnostic-color.o diagnostic-show-locus.o \
 	pretty-print.o intl.o \
 	sbitmap.o \
 	vec.o input.o version.o hash-table.o ggc-none.o memory-block.o \
-	selftest.o
+	selftest.o selftest-diagnostic.o
 
 # Objects in libcommon-target.a, used by drivers and by the core
 # compiler and containing target-dependent code.

gcc/diagnostic-show-locus.c

@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "diagnostic-color.h"
 #include "gcc-rich-location.h"
 #include "selftest.h"
+#include "selftest-diagnostic.h"
 
 #ifdef HAVE_TERMIOS_H
 # include <termios.h>
@@ -1987,34 +1988,6 @@ namespace selftest {
 
 /* Selftests for diagnostic_show_locus.  */
 
-/* Convenience subclass of diagnostic_context for testing
-   diagnostic_show_locus.  */
-
-class test_diagnostic_context : public diagnostic_context
-{
- public:
-  test_diagnostic_context ()
-  {
-    diagnostic_initialize (this, 0);
-    show_caret = true;
-    show_column = true;
-    start_span = start_span_cb;
-  }
-  ~test_diagnostic_context ()
-  {
-    diagnostic_finish (this);
-  }
-
-  /* Implementation of diagnostic_start_span_fn, hiding the
-     real filename (to avoid printing the names of tempfiles).  */
-  static void
-  start_span_cb (diagnostic_context *context, expanded_location exploc)
-  {
-    exploc.file = "FILENAME";
-    default_diagnostic_start_span_fn (context, exploc);
-  }
-};
-
 /* Verify that diagnostic_show_locus works sanely on UNKNOWN_LOCATION.  */
 
 static void

gcc/selftest-diagnostic.c

+/* Selftest support for diagnostics.
+   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC 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, or (at your option) any later
+version.
+
+GCC 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 GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "diagnostic.h"
+#include "selftest.h"
+#include "selftest-diagnostic.h"
+
+/* The selftest code should entirely disappear in a production
+   configuration, hence we guard all of it with #if CHECKING_P.  */
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Implementation of class selftest::test_diagnostic_context.  */
+
+test_diagnostic_context::test_diagnostic_context ()
+{
+  diagnostic_initialize (this, 0);
+  show_caret = true;
+  show_column = true;
+  start_span = start_span_cb;
+}
+
+test_diagnostic_context::~test_diagnostic_context ()
+{
+  diagnostic_finish (this);
+}
+
+/* Implementation of diagnostic_start_span_fn, hiding the
+   real filename (to avoid printing the names of tempfiles).  */
+
+void
+test_diagnostic_context::start_span_cb (diagnostic_context *context,
+					expanded_location exploc)
+{
+  exploc.file = "FILENAME";
+  default_diagnostic_start_span_fn (context, exploc);
+}
+
+} // namespace selftest
+
+#endif /* #if CHECKING_P */

gcc/selftest-diagnostic.h

+/* Selftest support for diagnostics.
+   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC 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, or (at your option) any later
+version.
+
+GCC 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 GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_SELFTEST_DIAGNOSTIC_H
+#define GCC_SELFTEST_DIAGNOSTIC_H
+
+/* The selftest code should entirely disappear in a production
+   configuration, hence we guard all of it with #if CHECKING_P.  */
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Convenience subclass of diagnostic_context for testing
+   the diagnostic subsystem.  */
+
+class test_diagnostic_context : public diagnostic_context
+{
+ public:
+  test_diagnostic_context ();
+  ~test_diagnostic_context ();
+
+  /* Implementation of diagnostic_start_span_fn, hiding the
+     real filename (to avoid printing the names of tempfiles).  */
+  static void
+  start_span_cb (diagnostic_context *context, expanded_location exploc);
+};
+
+} // namespace selftest
+
+#endif /* #if CHECKING_P */
+
+#endif /* GCC_SELFTEST_DIAGNOSTIC_H */