From 67d8ccc0e4cfd654b45a23264f55a420cf5fd863 Mon Sep 17 00:00:00 2001 From: Ken Raeburn Date: Mon, 21 May 2012 00:30:45 -0400 Subject: [PATCH] FFI: sizeof: Account for trailing padding of structs. * libguile/foreign.c (scm_sizeof): Make sure the overall size is a multiple of the alignment of the structure. * test-suite/tests/foreign.test: Test size of { double, int8 }. --- libguile/foreign.c | 5 +++-- test-suite/tests/foreign.test | 4 ++++ 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/libguile/foreign.c b/libguile/foreign.c index 5c30d5458..29cfc733d 100644 --- a/libguile/foreign.c +++ b/libguile/foreign.c @@ -1,4 +1,4 @@ -/* Copyright (C) 2010-2014 Free Software Foundation, Inc. +/* Copyright (C) 2010-2015 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License @@ -547,13 +547,14 @@ SCM_DEFINE (scm_sizeof, "sizeof", 1, 0, 0, (SCM type), { /* a struct */ size_t off = 0; + size_t align = scm_to_size_t (scm_alignof (type)); while (scm_is_pair (type)) { off = ROUND_UP (off, scm_to_size_t (scm_alignof (scm_car (type)))); off += scm_to_size_t (scm_sizeof (scm_car (type))); type = scm_cdr (type); } - return scm_from_size_t (off); + return scm_from_size_t (ROUND_UP (off, align)); } else scm_wrong_type_arg (FUNC_NAME, 1, type); diff --git a/test-suite/tests/foreign.test b/test-suite/tests/foreign.test index acdb3db05..8ba989e4d 100644 --- a/test-suite/tests/foreign.test +++ b/test-suite/tests/foreign.test @@ -342,6 +342,10 @@ (= (sizeof (list int8 double)) (+ (alignof double) (sizeof double)))) + (pass-if "sizeof { double, int8 }" + (= (sizeof (list double int8)) + (+ (alignof double) (sizeof double)))) + (pass-if "sizeof { short, int, long, pointer }" (let ((layout (list short int long '*))) (>= (sizeof layout)