re PR middle-end/42803 (c++ compilation hang)

	PR middle-end/42803
	* varasm.c (narrowing_initializer_constant_valid_p): Add CACHE
	argument, call initializer_constant_valid_p_1 instead of
	initializer_constant_valid_p, pass CACHE to it, return NULL
	immediately if first call returns NULL.
	(initializer_constant_valid_p_1): New function.
	(initializer_constant_valid_p): Use it.

	* g++.dg/parse/limits-initializer1.C: New test.

From-SVN: r156069

gcc/ChangeLog

+2010-01-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/42803
+	* varasm.c (narrowing_initializer_constant_valid_p): Add CACHE
+	argument, call initializer_constant_valid_p_1 instead of
+	initializer_constant_valid_p, pass CACHE to it, return NULL
+	immediately if first call returns NULL.
+	(initializer_constant_valid_p_1): New function.
+	(initializer_constant_valid_p): Use it.
+
 2010-01-20  Thomas Quinot  <quinot@adacore.com>
 
 	* tree.def (PLACEHOLDER_EXPR): Fix comment.

gcc/testsuite/ChangeLog

@@ -3,6 +3,9 @@
 	* gcc.dg/cleanup-13.c: Expect DW_OP_mod to do unsigned modulo instead
 	of signed, add a few new tests.
 
+	PR middle-end/42803
+	* g++.dg/parse/limits-initializer1.C: New test.
+
 2010-01-19  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/42804

gcc/testsuite/g++.dg/parse/limits-initializer1.C

+// PR middle-end/42803
+// { dg-do compile }
+// { dg-options "-O0" }
+
+#define X2 (a + a)
+#define X4 (X2 + X2)
+#define X8 (X4 + X4)
+#define X16 (X8 + X8)
+#define X32 (X16 + X16)
+#define X64 (X32 + X32)
+#define X128 (X64 + X64)
+#define X256 (X128 + X128)
+#define X512 (X256 + X256)
+#define X1024 (X512 + X512)
+#define X2048 (X1024 + X1024)
+#define X4096 (X2048 + X2048)
+#define X8192 (X4096 + X4096)
+#define X16384 (X8192 + X8192)
+#define X32768 (X16384 + X16384)
+#define X65536 (X32768 + X32768)
+#define X131072 (X65536 + X65536)
+#define X262144 (X131072 + X131072)
+
+int
+foo (int a)
+{
+  int v = X262144;
+  return v;
+}
+
+// Emit an error to just make sure we don't waste too much time
+// in the middle-end compiling this.
+int
+bar (void)
+{
+  return x;	// { dg-error "was not declared in this scope" }
+}