Add __sizeof_ptr__ that looks at a pointer expression and

returns the size of the underlying object.

This is different from "sizeof(*expr)" for arrays, where
the array would degenerate to a pointer to one member, and
thus "sizeof(*expr)" gives the size of one entry in the
array.

Why do this? It's useful for things like

   #define memset(a,b,c) ({ \
        (void) __builtin_warning(__sizeof_ptr__(a) > 1, __sizeof_ptr__(a) != (c), "check memset size"); \
        memset(a, b, c); })

where we really want to check the size of the object we're
doing the "memset()" on, but the regular sizeof() just doesn't
cut it.

1 files changed, 1 insertions, 0 deletions

diff --git a/inline.c b/inline.c
index 2bac3c6..1dced4d 100644
--- a/inline.c
+++ b/inline.c
@@ -135,6 +135,7 @@ static struct expression * copy_expression(struct expression *expr)
 	/* Cast/sizeof/__alignof__ */
 	case EXPR_CAST:
 	case EXPR_SIZEOF: 
+	case EXPR_PTRSIZEOF:
 	case EXPR_ALIGNOF: {
 		struct expression *cast = copy_expression(expr->cast_expression);
 		if (cast == expr->cast_expression)