c-common.c (c_common_truthvalue_conversion): Warn if the address of a non-weak function is used as a truth value.

gcc/
	* c-common.c (c_common_truthvalue_conversion): Warn if the
	address of a non-weak function is used as a truth value.

cp/
	* cvt.c (ocp_convert): Move warning to C common code.

testsuite/
	* gcc.dg/weak/weak-3.c: Fix for new warning.

From-SVN: r72409

6 files changed, 41 insertions, 25 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index be5de23..052e74c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-10-12  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* c-common.c (c_common_truthvalue_conversion): Warn if the
+	address of a non-weak function is used as a truth value.
+
 2003-10-12  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* config/h8300/h8300.c (WORD_REG_USED): Use SP_REG instead of
diff --git a/gcc/c-common.c b/gcc/c-common.c
index b58eda1..e8ed13b 100644
--- a/gcc/c-common.c
+++ b/gcc/c-common.c
@@ -2602,6 +2602,9 @@ c_common_truthvalue_conversion (tree expr)
   if (TREE_CODE (expr) == ERROR_MARK)
     return expr;
 
+  if (TREE_CODE (expr) == FUNCTION_DECL)
+    expr = build_unary_op (ADDR_EXPR, expr, 0);
+
 #if 0 /* This appears to be wrong for C++.  */
   /* These really should return error_mark_node after 2.4 is stable.
      But not all callers handle ERROR_MARK properly.  */
@@ -2647,17 +2650,29 @@ c_common_truthvalue_conversion (tree expr)
       return real_zerop (expr) ? truthvalue_false_node : truthvalue_true_node;
 
     case ADDR_EXPR:
-      /* If we are taking the address of an external decl, it might be zero
-	 if it is weak, so we cannot optimize.  */
-      if (DECL_P (TREE_OPERAND (expr, 0))
-	  && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
-	break;
+      {
+	if (TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL
+	    && ! DECL_WEAK (TREE_OPERAND (expr, 0)))
+	  {
+	    /* Common Ada/Pascal programmer's mistake.  We always warn
+	       about this since it is so bad.  */
+	    warning ("the address of `%D', will always evaluate as `true'",
+		     TREE_OPERAND (expr, 0));
+	    return truthvalue_true_node;
+	  }
 
-      if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
-	return build (COMPOUND_EXPR, truthvalue_type_node,
-		      TREE_OPERAND (expr, 0), truthvalue_true_node);
-      else
-	return truthvalue_true_node;
+	/* If we are taking the address of an external decl, it might be
+	   zero if it is weak, so we cannot optimize.  */
+	if (DECL_P (TREE_OPERAND (expr, 0))
+	    && DECL_EXTERNAL (TREE_OPERAND (expr, 0)))
+	  break;
+
+	if (TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 0)))
+	  return build (COMPOUND_EXPR, truthvalue_type_node,
+			TREE_OPERAND (expr, 0), truthvalue_true_node);
+	else
+	  return truthvalue_true_node;
+      }
 
     case COMPLEX_EXPR:
       return build_binary_op ((TREE_SIDE_EFFECTS (TREE_OPERAND (expr, 1))
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index da318cf..9a0735b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,7 @@
+2003-10-12  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* cvt.c (ocp_convert): Move warning to C common code.
+
 2003-10-09  Jason Merrill  <jason@redhat.com>
 
 	PR c++/6392
diff --git a/gcc/cp/cvt.c b/gcc/cp/cvt.c
index 32d0d79..1479fbd 100644
--- a/gcc/cp/cvt.c
+++ b/gcc/cp/cvt.c
@@ -694,20 +694,8 @@ ocp_convert (tree type, tree expr, int convtype, int flags)
 	  return error_mark_node;
 	}
       if (code == BOOLEAN_TYPE)
-	{
-	  tree fn = NULL_TREE;
-
-	  /* Common Ada/Pascal programmer's mistake.  We always warn
-             about this since it is so bad.  */
-	  if (TREE_CODE (expr) == FUNCTION_DECL)
-	    fn = expr;
-	  else if (TREE_CODE (expr) == ADDR_EXPR 
-		   && TREE_CODE (TREE_OPERAND (expr, 0)) == FUNCTION_DECL)
-	    fn = TREE_OPERAND (expr, 0);
-	  if (fn && !DECL_WEAK (fn))
-	    warning ("the address of `%D', will always be `true'", fn);
-	  return cp_truthvalue_conversion (e);
-	}
+	return cp_truthvalue_conversion (e);
+
       return fold (convert_to_integer (type, e));
     }
   if (POINTER_TYPE_P (type) || TYPE_PTR_TO_MEMBER_P (type))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 14e13ef..84f7c92 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-10-12  Steven Bosscher  <steven@gcc.gnu.org>
+
+	* gcc.dg/weak/weak-3.c: Fix for new warning.
+
 2003-10-12  Kelley Cook  <kcook@gcc.gnu.org>
 
 	PR optimization/8750
diff --git a/gcc/testsuite/gcc.dg/weak/weak-3.c b/gcc/testsuite/gcc.dg/weak/weak-3.c
index 338d9ad..da4367a 100644
--- a/gcc/testsuite/gcc.dg/weak/weak-3.c
+++ b/gcc/testsuite/gcc.dg/weak/weak-3.c
@@ -54,7 +54,7 @@ extern void * ffoo1f (void);
 extern void * ffoox1f (void);
 void * foo1f (void)
 {
-  if (ffoo1f)
+  if (ffoo1f) /* { dg-warning "" } */
     ffoo1f ();
   return 0;
 }