7 files changed, 180 insertions, 0 deletions
diff --git a/tests/codegen/cffi/c-variadic-copy.rs b/tests/codegen/cffi/c-variadic-copy.rs
new file mode 100644
index 000000000..4c61c4fcf
--- /dev/null
+++ b/tests/codegen/cffi/c-variadic-copy.rs
@@ -0,0 +1,16 @@
+// Tests that `VaListImpl::clone` gets inlined into a call to `llvm.va_copy`
+
+#![crate_type = "lib"]
+#![feature(c_variadic)]
+#![no_std]
+use core::ffi::VaList;
+
+extern "C" {
+    fn foreign_c_variadic_1(_: VaList, ...);
+}
+
+pub unsafe extern "C" fn clone_variadic(ap: VaList) {
+    let mut ap2 = ap.clone();
+    // CHECK: call void @llvm.va_copy
+    foreign_c_variadic_1(ap2.as_va_list(), 42i32);
+}
diff --git a/tests/codegen/cffi/c-variadic-opt.rs b/tests/codegen/cffi/c-variadic-opt.rs
new file mode 100644
index 000000000..969dce80f
--- /dev/null
+++ b/tests/codegen/cffi/c-variadic-opt.rs
@@ -0,0 +1,30 @@
+// compile-flags: -C opt-level=3
+
+#![crate_type = "lib"]
+#![feature(c_variadic)]
+#![no_std]
+use core::ffi::VaList;
+
+extern "C" {
+    fn vprintf(fmt: *const i8, ap: VaList) -> i32;
+}
+
+// Ensure that `va_start` and `va_end` are properly injected even
+// when the "spoofed" `VaListImpl` is not used.
+#[no_mangle]
+pub unsafe extern "C" fn c_variadic_no_use(fmt: *const i8, mut ap: ...) -> i32 {
+    // CHECK: call void @llvm.va_start
+    vprintf(fmt, ap.as_va_list())
+    // CHECK: call void @llvm.va_end
+}
+
+// Check that `VaListImpl::clone` gets inlined into a direct call to `llvm.va_copy`
+#[no_mangle]
+pub unsafe extern "C" fn c_variadic_clone(fmt: *const i8, mut ap: ...) -> i32 {
+    // CHECK: call void @llvm.va_start
+    let mut ap2 = ap.clone();
+    // CHECK: call void @llvm.va_copy
+    let res = vprintf(fmt, ap2.as_va_list());
+    res
+    // CHECK: call void @llvm.va_end
+}
diff --git a/tests/codegen/cffi/c-variadic.rs b/tests/codegen/cffi/c-variadic.rs
new file mode 100644
index 000000000..cab326522
--- /dev/null
+++ b/tests/codegen/cffi/c-variadic.rs
@@ -0,0 +1,72 @@
+// ignore-wasm32-bare compiled with panic=abort by default
+// compile-flags: -C no-prepopulate-passes -Copt-level=0
+//
+
+#![crate_type = "lib"]
+#![feature(c_variadic)]
+#![feature(c_unwind)]
+#![no_std]
+use core::ffi::VaList;
+
+extern "C" {
+    fn foreign_c_variadic_0(_: i32, ...);
+    fn foreign_c_variadic_1(_: VaList, ...);
+}
+
+pub unsafe extern "C" fn use_foreign_c_variadic_0() {
+    // Ensure that we correctly call foreign C-variadic functions.
+    // CHECK: call void (i32, ...) @foreign_c_variadic_0([[PARAM:i32( signext)?]] 0)
+    foreign_c_variadic_0(0);
+    // CHECK: call void (i32, ...) @foreign_c_variadic_0([[PARAM]] 0, [[PARAM]] 42)
+    foreign_c_variadic_0(0, 42i32);
+    // CHECK: call void (i32, ...) @foreign_c_variadic_0([[PARAM]] 0, [[PARAM]] 42, [[PARAM]] 1024)
+    foreign_c_variadic_0(0, 42i32, 1024i32);
+    // CHECK: call void (i32, ...) @foreign_c_variadic_0([[PARAM]] 0, [[PARAM]] 42, [[PARAM]] 1024, [[PARAM]] 0)
+    foreign_c_variadic_0(0, 42i32, 1024i32, 0i32);
+}
+
+// Ensure that we do not remove the `va_list` passed to the foreign function when
+// removing the "spoofed" `VaListImpl` that is used by Rust defined C-variadics.
+pub unsafe extern "C" fn use_foreign_c_variadic_1_0(ap: VaList) {
+    // CHECK: call void ({{.*}}, ...) @foreign_c_variadic_1({{.*}} %ap)
+    foreign_c_variadic_1(ap);
+}
+
+pub unsafe extern "C" fn use_foreign_c_variadic_1_1(ap: VaList) {
+    // CHECK: call void ({{.*}}, ...) @foreign_c_variadic_1({{.*}} %ap, [[PARAM]] 42)
+    foreign_c_variadic_1(ap, 42i32);
+}
+pub unsafe extern "C" fn use_foreign_c_variadic_1_2(ap: VaList) {
+    // CHECK: call void ({{.*}}, ...) @foreign_c_variadic_1({{.*}} %ap, [[PARAM]] 2, [[PARAM]] 42)
+    foreign_c_variadic_1(ap, 2i32, 42i32);
+}
+
+pub unsafe extern "C" fn use_foreign_c_variadic_1_3(ap: VaList) {
+    // CHECK: call void ({{.*}}, ...) @foreign_c_variadic_1({{.*}} %ap, [[PARAM]] 2, [[PARAM]] 42, [[PARAM]] 0)
+    foreign_c_variadic_1(ap, 2i32, 42i32, 0i32);
+}
+
+// Ensure that `va_start` and `va_end` are properly injected.
+#[no_mangle]
+pub unsafe extern "C" fn c_variadic(n: i32, mut ap: ...) -> i32 {
+    // CHECK: call void @llvm.va_start
+    let mut sum = 0;
+    for _ in 0..n {
+        sum += ap.arg::<i32>();
+    }
+    sum
+    // CHECK: call void @llvm.va_end
+}
+
+// Ensure that we generate the correct `call` signature when calling a Rust
+// defined C-variadic.
+pub unsafe fn test_c_variadic_call() {
+    // CHECK: call [[RET:(signext )?i32]] (i32, ...) @c_variadic([[PARAM]] 0)
+    c_variadic(0);
+    // CHECK: call [[RET]] (i32, ...) @c_variadic([[PARAM]] 0, [[PARAM]] 42)
+    c_variadic(0, 42i32);
+    // CHECK: call [[RET]] (i32, ...) @c_variadic([[PARAM]] 0, [[PARAM]] 42, [[PARAM]] 1024)
+    c_variadic(0, 42i32, 1024i32);
+    // CHECK: call [[RET]] (i32, ...) @c_variadic([[PARAM]] 0, [[PARAM]] 42, [[PARAM]] 1024, [[PARAM]] 0)
+    c_variadic(0, 42i32, 1024i32, 0i32);
+}
diff --git a/tests/codegen/cffi/ffi-const.rs b/tests/codegen/cffi/ffi-const.rs
new file mode 100644
index 000000000..937205034
--- /dev/null
+++ b/tests/codegen/cffi/ffi-const.rs
@@ -0,0 +1,13 @@
+// compile-flags: -C no-prepopulate-passes
+#![crate_type = "lib"]
+#![feature(ffi_const)]
+
+pub fn bar() { unsafe { foo() } }
+
+extern "C" {
+    // CHECK-LABEL: declare{{.*}}void @foo()
+    // CHECK-SAME: [[ATTRS:#[0-9]+]]
+    // The attribute changed from `readnone` to `memory(none)` with LLVM 16.0.
+    // CHECK-DAG: attributes [[ATTRS]] = { {{.*}}{{readnone|memory\(none\)}}{{.*}} }
+    #[ffi_const] pub fn foo();
+}
diff --git a/tests/codegen/cffi/ffi-out-of-bounds-loads.rs b/tests/codegen/cffi/ffi-out-of-bounds-loads.rs
new file mode 100644
index 000000000..099726b2f
--- /dev/null
+++ b/tests/codegen/cffi/ffi-out-of-bounds-loads.rs
@@ -0,0 +1,25 @@
+// Regression test for #29988
+
+// compile-flags: -C no-prepopulate-passes
+// only-x86_64
+// ignore-windows
+
+#[repr(C)]
+struct S {
+    f1: i32,
+    f2: i32,
+    f3: i32,
+}
+
+extern "C" {
+    fn foo(s: S);
+}
+
+fn main() {
+    let s = S { f1: 1, f2: 2, f3: 3 };
+    unsafe {
+        // CHECK: load { i64, i32 }, {{.*}}, align 4
+        // CHECK: call void @foo({ i64, i32 } {{.*}})
+        foo(s);
+    }
+}
diff --git a/tests/codegen/cffi/ffi-pure.rs b/tests/codegen/cffi/ffi-pure.rs
new file mode 100644
index 000000000..2ed735813
--- /dev/null
+++ b/tests/codegen/cffi/ffi-pure.rs
@@ -0,0 +1,13 @@
+// compile-flags: -C no-prepopulate-passes
+#![crate_type = "lib"]
+#![feature(ffi_pure)]
+
+pub fn bar() { unsafe { foo() } }
+
+extern "C" {
+    // CHECK-LABEL: declare{{.*}}void @foo()
+    // CHECK-SAME: [[ATTRS:#[0-9]+]]
+    // The attribute changed from `readonly` to `memory(read)` with LLVM 16.0.
+    // CHECK-DAG: attributes [[ATTRS]] = { {{.*}}{{readonly|memory\(read\)}}{{.*}} }
+    #[ffi_pure] pub fn foo();
+}
diff --git a/tests/codegen/cffi/ffi-returns-twice.rs b/tests/codegen/cffi/ffi-returns-twice.rs
new file mode 100644
index 000000000..0fbe03f0b
--- /dev/null
+++ b/tests/codegen/cffi/ffi-returns-twice.rs
@@ -0,0 +1,11 @@
+// compile-flags: -C no-prepopulate-passes
+#![crate_type = "lib"]
+#![feature(ffi_returns_twice)]
+
+pub fn bar() { unsafe { foo() } }
+
+extern "C" {
+    // CHECK: declare{{( dso_local)?}} void @foo(){{.*}}[[ATTRS:#[0-9]+]]
+    // CHECK: attributes [[ATTRS]] = { {{.*}}returns_twice{{.*}} }
+    #[ffi_returns_twice] pub fn foo();
+}