[PATCH] sparse type checking on function pointers

[Dave Olien <dmo@osdl.org>]

This patch fixes type checking on function arguments that are pointers
to functions.  Below is an example.

int total;

void dofunc(void (f)(int))
{
	f(5);
}

void func(int z)
{
	total += z;
}

main(void)
{
	dofunc(func);
}

without this patch, check reports the warnings:

warning: testfunc.c:16:9: incorrect type in argument 1 (different base types)
warning: testfunc.c:16:9:   expected void ( f )( ... )
warning: testfunc.c:16:9:   got void ( * )( ... )

------------------------------------------------------------------------

--- sparse_original/evaluate.c	2003-06-03 09:00:47.000000000 -0700
+++ sparse_test/evaluate.c	2003-06-10 12:08:23.000000000 -0700
@@ -431,6 +431,17 @@
 			/* Ignore ARRAY/PTR differences, as long as they point to the same type */
 			type1 = type1 == SYM_ARRAY ? SYM_PTR : type1;
 			type2 = type2 == SYM_ARRAY ? SYM_PTR : type2;
+
+			if ((type1 == SYM_PTR) && (target->ctype.base_type->type == SYM_FN)) {
+				target = target->ctype.base_type;
+				type1 = SYM_FN;
+			}
+
+			if ((type2 == SYM_PTR) && (source->ctype.base_type->type == SYM_FN)) {
+				source = source->ctype.base_type;
+				type2 = SYM_FN;
+			}
+
 			if (type1 != type2)
 				return "different base types";
 		}