re PR lto/41669 (Infinite recursion trying to build gcc)

2009-10-15  Richard Guenther  <rguenther@suse.de>

	PR lto/41669
	* gimple.c (gimple_get_alias_set): Avoid recursing on
	invalid type topology.

	* gcc.dg/lto/20091015-1_0.c: New testcase.
	* gcc.dg/lto/20091015-1_1.c: Likewise.
	* gcc.dg/lto/20091015-1_2.c: Likewise.
	* gcc.dg/lto/20091015-1_a.h: Likewise.
	* gcc.dg/lto/20091015-1_b.h: Likewise.

From-SVN: r152850

gcc/ChangeLog

+2009-10-15  Richard Guenther  <rguenther@suse.de>
+
+	PR lto/41669
+	* gimple.c (gimple_get_alias_set): Avoid recursing on
+	invalid type topology.
+
 2009-10-15  Andrew Pinski  <andrew_pinski@playstation.sony.com>
 
 	* config/spu/spu.c (get_branch_target): Use extract_asm_operands.

gcc/gimple.c

@@ -4111,6 +4111,7 @@ gimple_signed_type (tree type)
 alias_set_type
 gimple_get_alias_set (tree t)
 {
+  static bool recursing_p;
   tree u;
 
   /* Permit type-punning when accessing a union, provided the access
@@ -4152,6 +4153,12 @@ gimple_get_alias_set (tree t)
     {
       tree t1;
 
+      /* ???  We can end up creating cycles with TYPE_MAIN_VARIANT
+	 and TYPE_CANONICAL.  Avoid recursing endlessly between
+	 this langhook and get_alias_set.  */
+      if (recursing_p)
+	return -1;
+
       /* Unfortunately, there is no canonical form of a pointer type.
 	 In particular, if we have `typedef int I', then `int *', and
 	 `I *' are different types.  So, we have to pick a canonical
@@ -4176,7 +4183,13 @@ gimple_get_alias_set (tree t)
 	 C++ committee.  */
       t1 = build_type_no_quals (t);
       if (t1 != t)
-	return get_alias_set (t1);
+	{
+	  alias_set_type set;
+	  recursing_p = true;
+	  set = get_alias_set (t1);
+	  recursing_p = false;
+	  return set;
+	}
     }
 
   return -1;

gcc/testsuite/ChangeLog

+2009-10-15  Richard Guenther  <rguenther@suse.de>
+
+	PR lto/41669
+	* gcc.dg/lto/20091015-1_0.c: New testcase.
+	* gcc.dg/lto/20091015-1_1.c: Likewise.
+	* gcc.dg/lto/20091015-1_2.c: Likewise.
+	* gcc.dg/lto/20091015-1_a.h: Likewise.
+	* gcc.dg/lto/20091015-1_b.h: Likewise.
+
 2009-10-15  Steve Ellcey  <sje@cup.hp.com>
 
 	* gcc.dg/torture/pr41555.c: Add -std=c99 option.

gcc/testsuite/gcc.dg/lto/20091015-1_0.c

+/* { dg-lto-do link } */
+/* { dg-lto-options {{-fPIC -shared -O2 -flto} {-fPIC -shared -O2 -fwhopr}} } */
+
+#include "20091015-1_b.h"
+void diagnostic_initialize (FILE **stream) { *stream = stderr; }

gcc/testsuite/gcc.dg/lto/20091015-1_1.c

+#include "20091015-1_a.h"
+#include "20091015-1_b.h"
+void ggc_print_common_statistics (FILE *stream) {
+}

gcc/testsuite/gcc.dg/lto/20091015-1_2.c

+#include "20091015-1_a.h"
+#include "20091015-1_b.h"
+void debug_optab_libfuncs (void) {
+foo (stderr,       4         );
+}

gcc/testsuite/gcc.dg/lto/20091015-1_a.h

+struct _IO_FILE { int _flags;
+};

gcc/testsuite/gcc.dg/lto/20091015-1_b.h

+typedef struct _IO_FILE FILE;
+extern struct _IO_FILE *stderr;