Auto merge of #25653 - dotdash:unsize_c, r=luqmana

Fixes #25581

3 files changed, 55 insertions, 0 deletions

diff --git a/src/test/run-make/issue-25581/Makefile b/src/test/run-make/issue-25581/Makefile
new file mode 100644
index 00000000000..ea6971853fe
--- /dev/null
+++ b/src/test/run-make/issue-25581/Makefile
@@ -0,0 +1,7 @@
+-include ../tools.mk
+
+all:
+	$(CC) -std=c99 test.c -c -o $(TMPDIR)/test.o
+	$(AR) rcs $(TMPDIR)/libtest.a $(TMPDIR)/test.o
+	$(RUSTC) test.rs -L $(TMPDIR)
+	$(call RUN,test) || exit 1
diff --git a/src/test/run-make/issue-25581/test.c b/src/test/run-make/issue-25581/test.c
new file mode 100644
index 00000000000..5736b173021
--- /dev/null
+++ b/src/test/run-make/issue-25581/test.c
@@ -0,0 +1,16 @@
+// ignore-license
+#include <stddef.h>
+#include <stdint.h>
+
+struct ByteSlice {
+        uint8_t *data;
+        size_t len;
+};
+
+size_t slice_len(struct ByteSlice bs) {
+        return bs.len;
+}
+
+uint8_t slice_elem(struct ByteSlice bs, size_t idx) {
+        return bs.data[idx];
+}
diff --git a/src/test/run-make/issue-25581/test.rs b/src/test/run-make/issue-25581/test.rs
new file mode 100644
index 00000000000..e2e86df59cd
--- /dev/null
+++ b/src/test/run-make/issue-25581/test.rs
@@ -0,0 +1,32 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(libc)]
+
+extern crate libc;
+
+#[link(name = "test")]
+extern {
+    fn slice_len(s: &[u8]) -> libc::size_t;
+    fn slice_elem(s: &[u8], idx: libc::size_t) -> u8;
+}
+
+fn main() {
+    let data = [1,2,3,4,5];
+
+    unsafe {
+        assert_eq!(data.len(), slice_len(&data) as usize);
+        assert_eq!(data[0], slice_elem(&data, 0));
+        assert_eq!(data[1], slice_elem(&data, 1));
+        assert_eq!(data[2], slice_elem(&data, 2));
+        assert_eq!(data[3], slice_elem(&data, 3));
+        assert_eq!(data[4], slice_elem(&data, 4));
+    }
+}