[pph] add tests and -fpph-check (issue5820069)

[crowl at google dot com (Lawrence Crowl)]

This patch mostly adds several test cases reduced from full-scale attempts to
use PPH.

  c?anonymous* -- problems handling anonymous/tagless types
  c?features* -- problems with benign macro redefinitions
  x?tmpldfltparm* -- inappropriately merging default template arguments

It also add an option -fpph-check to refine our check for headers compatible
with PPH.  It implies -fprimary-system-header-okay and checks for the main
source file missing a guard.  Generating a pph file implies the same check.

Tested on x64.


Index: gcc/c-family/ChangeLog.pph

2012-03-15   Lawrence Crowl  <crowl@google.com>

	* c.opt (-fpph-check): New.
	* c-opts.c (c_common_handle_option): Add OPT_fpph_check.
	(case OPT__output_pph_): Also imply -fpph-check.
	* c-common.h (bool pph_check_main_missing_guard): New.
	* c-common.c (bool pph_check_main_missing_guard): New.
	(const char *pph_out_file): Explicitly initialize to NULL.

Index: gcc/testsuite/ChangeLog.pph

2012-03-15   Lawrence Crowl  <crowl@google.com>

	* g++.dg/pph/c0anonymous.h: New.
	* g++.dg/pph/c1anonymous1.h: New.
	* g++.dg/pph/c1anonymous2.h: New.
	* g++.dg/pph/c5features1.h: New.
	* g++.dg/pph/c5features2.h: New.
	* g++.dg/pph/c7features.cc: New.
	* g++.dg/pph/d8dupguard.cc: Add xfail-if comment.
	* g++.dg/pph/x0tmpldfltparm.h: New.
	* g++.dg/pph/x1tmpldfltparm.cc: New.
	* g++.dg/pph/y9overload.cc: Add xfail-if comment.

Index: gcc/cp/ChangeLog.pph

2012-03-15   Lawrence Crowl  <crowl@google.com>

	* pph.h (pph_check_main_guarded): New.
	* pph-core.c (pph_check_main_guarded): New.
	* pph-out.c (pph_writer_finish): Factor out guard check into
	pph_check_main_guarded.
	* parser.c (c_parse_file): Add guard check for non-pph compiles.


Index: gcc/c-family/c.opt
===================================================================
--- gcc/c-family/c.opt	(revision 185442)
+++ gcc/c-family/c.opt	(working copy)
@@ -981,6 +981,10 @@ fplan9-extensions
 C ObjC Var(flag_plan9_extensions)
 Enable Plan 9 language extensions
 
+fpph-check
+C++
+-fpph-check	Check a header for minimal compatibility with PPH.
+
 fpph-debug=
 C++ Joined RejectNegative UInteger Var(flag_pph_debug)
 -fpph-debug=N   Enable debugging output at level N from PPH support
Index: gcc/c-family/c-opts.c
===================================================================
--- gcc/c-family/c-opts.c	(revision 185442)
+++ gcc/c-family/c-opts.c	(working copy)
@@ -404,6 +404,7 @@ c_common_handle_option (size_t scode, co
     case OPT__output_pph_:
       pph_out_file = arg;
       cpp_opts->primary_system_header_okay = true;
+      pph_check_main_missing_guard = true;
       break;
 
     case OPT_A:
@@ -814,6 +815,11 @@ c_common_handle_option (size_t scode, co
       set_struct_debug_option (&global_options, loc, arg);
       break;
 
+    case OPT_fpph_check:
+      cpp_opts->primary_system_header_okay = true;
+      pph_check_main_missing_guard = true;
+      break;
+
     case OPT_fpph_hdr_:
       add_pph_header_map (arg);
       break;
Index: gcc/c-family/c-common.c
===================================================================
--- gcc/c-family/c-common.c	(revision 185442)
+++ gcc/c-family/c-common.c	(working copy)
@@ -194,7 +194,11 @@ const char *pch_file;
 /* The file name to which we should write a preparsed header, or
    NULL if no header will be written in this compile.  */
 
-const char *pph_out_file;
+const char *pph_out_file = NULL;
+
+/* Whether or not we should check for a guard on the main input file.  */
+
+bool pph_check_main_missing_guard = false;
 
 /* Nonzero if an ISO standard was selected.  It rejects macros in the
    user's namespace.  */
Index: gcc/c-family/c-common.h
===================================================================
--- gcc/c-family/c-common.h	(revision 185442)
+++ gcc/c-family/c-common.h	(working copy)
@@ -585,6 +585,10 @@ extern const char *pch_file;
 
 extern const char *pph_out_file;
 
+/* Whether or not we should check for a guard on the main input file.  */
+
+extern bool pph_check_main_missing_guard;
+
 /* Return true if we have any map from INCLUDE to PPH file.  */
 
 extern bool
Index: gcc/testsuite/g++.dg/pph/c1anonymous1.h
===================================================================
--- gcc/testsuite/g++.dg/pph/c1anonymous1.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c1anonymous1.h	(revision 0)
@@ -0,0 +1,11 @@
+// {    xfail-if "ANONYMOUS MERGING" { "*-*-*" } { "-fpph-map=pph.map" } }
+// { dg-bogus "c0anonymous.h:4:16: error: 'anon_t' has a previous declaration here" "" { xfail *-*-* } 0 }
+
+#ifndef	C1ANONYMOUS
+#define	C1ANONYMOUS
+
+#include "c0anonymous.h"
+
+enum { first, second }; // { dg-bogus "'anon_t' referred to as enum" "" { xfail *-*-* } }
+
+#endif
Index: gcc/testsuite/g++.dg/pph/c1anonymous2.h
===================================================================
--- gcc/testsuite/g++.dg/pph/c1anonymous2.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c1anonymous2.h	(revision 0)
@@ -0,0 +1,14 @@
+// {    xfail-if "ANONYMOUS MERGING" { "*-*-*" } { "-fpph-map=pph.map" } }
+// { dg-bogus "c0anonymous.h:4:16: error: 'struct anon_t' has a previous declaration as 'struct anon_t'" "" { xfail *-*-* } 0 }
+
+#ifndef C1ANONYMOUS2_H
+#define C1ANONYMOUS2_H
+
+#include "c0anonymous.h"
+
+typedef struct { // { dg-bogus "conflicting declaration 'struct<anonymous>'" "" { xfail *-*-* } }
+
+    char *field;
+} anon2_t; // { dg-bogus "invalid type in declaration before ';' token" "" { xfail *-*-* } }
+
+#endif
Index: gcc/testsuite/g++.dg/pph/c5features1.h
===================================================================
--- gcc/testsuite/g++.dg/pph/c5features1.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c5features1.h	(revision 0)
@@ -0,0 +1,4 @@
+#ifndef C5FEATURES1_H
+#define C5FEATURES1_H
+#include <features.h>
+#endif
Index: gcc/testsuite/g++.dg/pph/c0anonymous.h
===================================================================
--- gcc/testsuite/g++.dg/pph/c0anonymous.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c0anonymous.h	(revision 0)
@@ -0,0 +1,6 @@
+#ifndef C0ANONYMOUS_H
+#define C0ANONYMOUS_H
+
+typedef struct { int field; } anon_t;
+
+#endif
Index: gcc/testsuite/g++.dg/pph/x0tmpldfltparm.h
===================================================================
--- gcc/testsuite/g++.dg/pph/x0tmpldfltparm.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/x0tmpldfltparm.h	(revision 0)
@@ -0,0 +1,17 @@
+#ifndef X0TMPLDFLTPARM_H
+#define X0TMPLDFLTPARM_H
+
+template< typename T >
+struct auxillary
+{
+};
+
+template< typename T, typename U = auxillary< T > >
+struct primary
+{
+};
+
+typedef primary< int > handlei;
+typedef primary< long > handlel;
+
+#endif
Index: gcc/testsuite/g++.dg/pph/c5features2.h
===================================================================
--- gcc/testsuite/g++.dg/pph/c5features2.h	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c5features2.h	(revision 0)
@@ -0,0 +1,4 @@
+#ifndef C5FEATURES2_H
+#define C5FEATURES2_H
+#include <features.h>
+#endif
Index: gcc/testsuite/g++.dg/pph/x1tmpldfltparm.cc
===================================================================
--- gcc/testsuite/g++.dg/pph/x1tmpldfltparm.cc	(revision 0)
+++ gcc/testsuite/g++.dg/pph/x1tmpldfltparm.cc	(revision 0)
@@ -0,0 +1,7 @@
+// { dg-xfail-if "DEFAULT TEMPLATE ARG MERGING" { "*-*-*" } { "-fpph-map=pph.map" } }
+// { dg-bogus "Trying to merge distinct trees from the same PPH image x0tmpldfltparm.pph" "" { xfail *-*-* } 0 }
+
+#include "x0tmpldfltparm.h"
+
+handlei x;
+handlel y;
Index: gcc/testsuite/g++.dg/pph/c7features.cc
===================================================================
--- gcc/testsuite/g++.dg/pph/c7features.cc	(revision 0)
+++ gcc/testsuite/g++.dg/pph/c7features.cc	(revision 0)
@@ -0,0 +1,7 @@
+// {    xfail-if "UNKNOWN" { "*-*-*" } { "-fpph-map=pph.map" } }
+// { dg-bogus "warning: .__STDC_IEC_559_COMPLEX__. redefined" "" { xfail *-*-* } 0 }
+// { dg-bogus "warning: .__STDC_ISO_10646__. redefined" "" { xfail *-*-* } 0 }
+// { dg-bogus "warning: .__STDC_IEC_559__. redefined" "" { xfail *-*-* } 0 }
+
+#include "c5features1.h"
+#include "c5features2.h"
Index: gcc/testsuite/g++.dg/pph/y9overload.cc
===================================================================
--- gcc/testsuite/g++.dg/pph/y9overload.cc	(revision 185442)
+++ gcc/testsuite/g++.dg/pph/y9overload.cc	(working copy)
@@ -1,3 +1,5 @@
+// {    xfail-if "UNWANTED ERROR DETECTION" { "*-*-*" } { "-fpph-map=pph.map" } }
+
 #include "x0overload1.h"
 #include "x0overload2.h"
 #include "x1overload3.h"
Index: gcc/testsuite/g++.dg/pph/d8dupguard.cc
===================================================================
--- gcc/testsuite/g++.dg/pph/d8dupguard.cc	(revision 185442)
+++ gcc/testsuite/g++.dg/pph/d8dupguard.cc	(working copy)
@@ -1,3 +1,5 @@
+// {    xfail-if "LOW ERROR DETECTION" { "*-*-*" } { "-fpph-map=pph.map" } }
+
 #include "c0dupguard1.h"
 #include "c0dupguard2.h" // { dg-error "fails macro validation" "" { xfail *-*-* } }
 int foo() { return x; }
Index: gcc/cp/pph-core.c
===================================================================
--- gcc/cp/pph-core.c	(revision 185442)
+++ gcc/cp/pph-core.c	(working copy)
@@ -1547,6 +1547,19 @@ pph_streamer_finish (void)
 }
 
 
+/* Return true when the main source file is guarded against preprocessor
+   multiple inclusions.  */
+
+bool pph_check_main_guarded (void)
+{
+  const char *offending_file = cpp_main_missing_guard (parse_in);
+  if (offending_file == NULL)
+    return true;
+  error ("header lacks guard for PPH");
+  return false;
+}
+
+
 /* Finalize PPH support.  */
 
 void
Index: gcc/cp/pph.h
===================================================================
--- gcc/cp/pph.h	(revision 185442)
+++ gcc/cp/pph.h	(working copy)
@@ -144,6 +144,7 @@ extern FILE *pph_logfile;
 extern void pph_init (void);
 extern void pph_loaded (void);
 extern void pph_finish (void);
+extern bool pph_check_main_guarded (void);
 extern void pph_dump_location (FILE *file, location_t loc);
 extern void pph_dump_tree_name (FILE *file, tree t, int flags);
 extern void pph_dump_vec_tree (FILE *file, VEC(tree,gc) *v);
Index: gcc/cp/pph-out.c
===================================================================
--- gcc/cp/pph-out.c	(revision 185442)
+++ gcc/cp/pph-out.c	(working copy)
@@ -2750,16 +2750,11 @@ pph_flush_buffers (pph_stream *stream)
 void
 pph_writer_finish (void)
 {
-  const char *offending_file;
-
   if (pph_out_stream == NULL)
     return;
 
-  offending_file = cpp_main_missing_guard (parse_in);
-  if (offending_file == NULL)
+  if (!pph_check_main_missing_guard || pph_check_main_guarded ())
     pph_write_file (pph_out_stream);
-  else
-    error ("header lacks guard for PPH: %s", offending_file);
 
   pph_stream_close (pph_out_stream);
   pph_out_stream = NULL;
Index: gcc/cp/parser.c
===================================================================
--- gcc/cp/parser.c	(revision 185442)
+++ gcc/cp/parser.c	(working copy)
@@ -27509,6 +27509,8 @@ c_parse_file (void)
 
   if (pph_enabled_p ())
     pph_finish ();
+  else if (pph_check_main_missing_guard)
+    pph_check_main_guarded ();
 }
 
 #include "gt-cp-parser.h"

--
This patch is available for review at http://codereview.appspot.com/5820069