From: Richard Stallman <rms@gnu.org>
Date: Tue, 2 Mar 1993 03:07:56 +0000 (+0000)
Subject: (build_unary_op): Warn if increment `struct unknown *'.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6bc4e3d04fe7c451bc0ded9f60ef70f96a732ebf;p=gcc.git

(build_unary_op): Warn if increment `struct unknown *'.

From-SVN: r3585
---

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 68c6679cd80..6f200484280 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -3014,9 +3014,16 @@ build_unary_op (code, xarg, noconvert)
 
 	if (typecode == POINTER_TYPE)
 	  {
-	    if ((pedantic || warn_pointer_arith)
-		&& (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
-		    || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
+	    /* If pointer target is an undefined struct,
+	       we just cannot know how to do the arithmetic.  */
+	    if (TYPE_SIZE (TREE_TYPE (result_type)) == 0)
+	      error ("%s of pointer to unknown structure",
+		       ((code == PREINCREMENT_EXPR
+			 || code == POSTINCREMENT_EXPR)
+			? "increment" : "decrement"));
+	    else if ((pedantic || warn_pointer_arith)
+		     && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
+			 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
 	      pedwarn ("wrong type argument to %s",
 		       ((code == PREINCREMENT_EXPR
 			 || code == POSTINCREMENT_EXPR)