(convert_arguments): Don't warn for -Wconversion about signedness of an arg...

(convert_arguments): Don't warn for -Wconversion
about signedness of an arg that's extended from narrower unsigned type.

From-SVN: r4857

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 00de4cb..33b20c6 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -2079,6 +2079,13 @@ convert_arguments (typelist, values, name, fundecl)
                        /* Change in signedness doesn't matter
                           if an enum value is unaffected.  */
                        ;
+                     /* If the value is extended from a narrower
+                        unsigned type, it doesn't matter whether we
+                        pass it as signed or unsigned; the value
+                        certainly is the same either way.  */
+                     else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
+                              && TREE_UNSIGNED (TREE_TYPE (val)))
+                       ;
                      else if (TREE_UNSIGNED (type))
                        warn_for_assignment ("%s as unsigned due to prototype", (char *) 0, name, parmnum + 1);
                      else