From f1b52b34f201456d8a0e9da907e3e5619fa24ac7 Mon Sep 17 00:00:00 2001
From: John VanEnk <jvanenk@fastly.com>
Date: Fri, 10 Jan 2020 17:42:30 -0800
Subject: [PATCH] Add a test that demonstrates an incorrect return value when
 calling into rust with non-c-like-enums.

---
 .../arguments-non-c-like-enum/Makefile        |  7 ++++
 .../arguments-non-c-like-enum/nonclike.rs     | 18 +++++++++
 .../arguments-non-c-like-enum/test.c          | 40 +++++++++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 src/test/run-make-fulldeps/arguments-non-c-like-enum/Makefile
 create mode 100644 src/test/run-make-fulldeps/arguments-non-c-like-enum/nonclike.rs
 create mode 100644 src/test/run-make-fulldeps/arguments-non-c-like-enum/test.c

diff --git a/src/test/run-make-fulldeps/arguments-non-c-like-enum/Makefile b/src/test/run-make-fulldeps/arguments-non-c-like-enum/Makefile
new file mode 100644
index 00000000000..5b5d620efe6
--- /dev/null
+++ b/src/test/run-make-fulldeps/arguments-non-c-like-enum/Makefile
@@ -0,0 +1,7 @@
+-include ../tools.mk
+
+all:
+	$(RUSTC) --crate-type=staticlib nonclike.rs
+	$(CC) test.c $(call STATICLIB,nonclike) $(call OUT_EXE,test) \
+		$(EXTRACFLAGS) $(EXTRACXXFLAGS)
+	$(call RUN,test)
diff --git a/src/test/run-make-fulldeps/arguments-non-c-like-enum/nonclike.rs b/src/test/run-make-fulldeps/arguments-non-c-like-enum/nonclike.rs
new file mode 100644
index 00000000000..563f907608b
--- /dev/null
+++ b/src/test/run-make-fulldeps/arguments-non-c-like-enum/nonclike.rs
@@ -0,0 +1,18 @@
+#![crate_type = "lib"]
+#![crate_name = "nonclike"]
+
+#[repr(C,u8)]
+pub enum T {
+    A(u64),
+    B,
+}
+
+#[no_mangle]
+pub extern "C" fn t_add(a: T, b: T) -> u64 {
+    match (a,b) {
+        (T::A(a), T::A(b)) => a + b,
+        (T::A(a), T::B) => a,
+        (T::B, T::A(b)) => b,
+        _ => 0,
+    }
+}
diff --git a/src/test/run-make-fulldeps/arguments-non-c-like-enum/test.c b/src/test/run-make-fulldeps/arguments-non-c-like-enum/test.c
new file mode 100644
index 00000000000..f622471e7d1
--- /dev/null
+++ b/src/test/run-make-fulldeps/arguments-non-c-like-enum/test.c
@@ -0,0 +1,40 @@
+#include <stdint.h>
+#include <assert.h>
+
+#include <stdio.h>
+
+/* This is the code generated by cbindgen 0.12.1 for the `enum T` type
+ * in nonclike.rs . */
+enum T_Tag {
+  A,
+  B,
+};
+typedef uint8_t T_Tag;
+
+typedef struct {
+  uint64_t _0;
+} A_Body;
+
+typedef struct {
+  T_Tag tag;
+  union {
+    A_Body a;
+  };
+} T;
+
+/* This symbol is defined by the Rust staticlib built from
+ * nonclike.rs. */
+extern uint64_t t_add(T a, T b);
+
+int main(int argc, char *argv[]) {
+  (void)argc; (void)argv;
+
+  T x = { .tag = A, .a = { ._0 = 1 } };
+  T y = { .tag = A, .a = { ._0 = 10 } };
+
+  uint64_t r = t_add(x, y);
+
+  assert(11 == r);
+
+  return 0;
+}