Make a copy of string AST value to a null terminated temporary

gcc/d/ChangeLog

@@ -1,3 +1,8 @@
+2018-05-28  Iain Buclaw  <ibuclaw@gdcproject.org>
+
+	* expr.cc (ExprVisitor::visit(StringExp)): Copy string literal from
+	the frontend to a null terminated string.
+
 2018-05-21  Iain Buclaw  <ibuclaw@gdcproject.org>
 
 	* expr.cc (ExprVisitor::binary_op): Don't do complex conversions if

gcc/d/expr.cc

@@ -2595,14 +2595,12 @@ class ExprVisitor : public Visitor
 				   build_float_cst (cimagl (e->value), tnext));
   }
 
-  /* Build a string literal.  */
+  /* Build a string literal, all strings are null terminated except for
+     static arrays.  */
 
   void visit (StringExp *e)
   {
     Type *tb = e->type->toBasetype ();
-
-    /* All strings are null terminated except static arrays.  */
-    const char *string = (const char *)(e->len ? e->string : "");
     tree type = build_ctype (e->type);
 
     if (tb->ty == Tsarray)
@@ -2624,10 +2622,15 @@ class ExprVisitor : public Visitor
       }
     else
       {
-	/* Array type string length includes the null terminator.  */
-	dinteger_t length = (e->len * e->sz) + 1;
-	tree value = build_string (length, string);
-	TREE_TYPE (value) = make_array_type (tb->nextOf (), length);
+	/* Copy the string contents to a null terminated string.  */
+	dinteger_t length = (e->len * e->sz);
+	char *string = XALLOCAVEC (char, length + 1);
+	memcpy (string, e->string, length);
+	string[length] = '\0';
+
+	/* String value and type includes the null terminator.  */
+	tree value = build_string (length + 1, string);
+	TREE_TYPE (value) = make_array_type (tb->nextOf (), length + 1);
 	value = build_address (value);
 
 	if (tb->ty == Tarray)