PR c++/77804 - Internal compiler error on incorrect initialization of new-d array

gcc/cp/ChangeLog:

	PR c++/77804
	* init.c (warn_placement_new_too_small): Avoid assuming an array type
	has a constant size.

gcc/testsuite/ChangeLog:

	PR c++/77804
	* g++.dg/warn/Wplacement-new-size-4.C: New test.

From-SVN: r240754

gcc/cp/ChangeLog

+2016-10-04  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/77804
+	* init.c (warn_placement_new_too_small): Avoid assuming an array type
+	has a constant size.
+
 2016-10-04  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/77791

gcc/cp/init.c

@@ -2504,7 +2504,7 @@ warn_placement_new_too_small (tree type, tree nelts, tree size, tree oper)
 	      && warn_placement_new < 2)
 	    return;
 	}
-	  
+
       /* The size of the buffer can only be adjusted down but not up.  */
       gcc_checking_assert (0 <= adjust);
 
@@ -2526,8 +2526,13 @@ warn_placement_new_too_small (tree type, tree nelts, tree size, tree oper)
       else if (nelts && CONSTANT_CLASS_P (nelts))
 	  bytes_need = tree_to_uhwi (nelts)
 	    * tree_to_uhwi (TYPE_SIZE_UNIT (type));
-      else
+      else if (tree_fits_uhwi_p (TYPE_SIZE_UNIT (type)))
 	bytes_need = tree_to_uhwi (TYPE_SIZE_UNIT (type));
+      else
+	{
+	  /* The type is a VLA.  */
+	  return;
+	}
 
       if (bytes_avail < bytes_need)
 	{

gcc/testsuite/ChangeLog

+2016-10-04  Martin Sebor  <msebor@redhat.com>
+
+	PR c++/77804
+	* g++.dg/warn/Wplacement-new-size-4.C: New test.
+
 2016-10-04  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/77791

gcc/testsuite/g++.dg/warn/Wplacement-new-size-4.C

+// PR c++/77804 - Internal compiler error on incorrect initialization of
+// new-d array
+// { dg-do compile }
+// { dg-additional-options "-Wplacement-new -Wvla -Wno-error=vla" }
+
+void* operator new[] (__SIZE_TYPE__ n, void *p) { return p; }
+
+int main()
+{
+    char buf[256];
+    unsigned n = 10;
+    int* p = new (buf) (int[n]);  // { dg-warning "non-constant array new length must be specified without parentheses around the type-id" }
+    //  { dg-warning "ISO C\\+\\+ forbids variable length array" "vla warning" { target *-*-* } .-1 }
+}