Sorting the output semantically (#2254)

Generated code needs some sorting in a way that is
semantically appealing. The request[1] asks for basic
sorting like "types are declared first, then all structs,
then all consts, then all function signatures, etc.

[1] https://github.com/rust-lang/rust-bindgen/issues/1743

Signed-off-by: Amanjeev Sethi <aj@amanjeev.com>
Co-authored-by: Christian Poveda <christian.poveda@ferrous-systems.com>
Co-authored-by: Darren Kulp <darren@kulp.ch>

4 files changed, 196 insertions, 0 deletions

diff --git a/tests/expectations/tests/sorted-items.rs b/tests/expectations/tests/sorted-items.rs
new file mode 100644
index 00000000..7df7c3d7
--- /dev/null
+++ b/tests/expectations/tests/sorted-items.rs
@@ -0,0 +1,82 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+pub type number = ::std::os::raw::c_int;
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct Point {
+    pub x: number,
+    pub y: number,
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct Angle {
+    pub a: number,
+    pub b: number,
+}
+pub const NUMBER: number = 42;
+#[test]
+fn bindgen_test_layout_Point() {
+    const UNINIT: ::std::mem::MaybeUninit<Point> =
+        ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<Point>(),
+        8usize,
+        concat!("Size of: ", stringify!(Point))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<Point>(),
+        4usize,
+        concat!("Alignment of ", stringify!(Point))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).x) as usize - ptr as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(Point), "::", stringify!(x))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).y) as usize - ptr as usize },
+        4usize,
+        concat!("Offset of field: ", stringify!(Point), "::", stringify!(y))
+    );
+}
+#[test]
+fn bindgen_test_layout_Angle() {
+    const UNINIT: ::std::mem::MaybeUninit<Angle> =
+        ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<Angle>(),
+        8usize,
+        concat!("Size of: ", stringify!(Angle))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<Angle>(),
+        4usize,
+        concat!("Alignment of ", stringify!(Angle))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).a) as usize - ptr as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(Angle), "::", stringify!(a))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).b) as usize - ptr as usize },
+        4usize,
+        concat!("Offset of field: ", stringify!(Angle), "::", stringify!(b))
+    );
+}
+extern "C" {
+    pub fn foo() -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn bar(x: number) -> ::std::os::raw::c_int;
+}
+extern "C" {
+    pub fn baz(point: Point) -> ::std::os::raw::c_int;
+}
diff --git a/tests/expectations/tests/unsorted-items.rs b/tests/expectations/tests/unsorted-items.rs
new file mode 100644
index 00000000..ce0c5f3f
--- /dev/null
+++ b/tests/expectations/tests/unsorted-items.rs
@@ -0,0 +1,82 @@
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+extern "C" {
+    pub fn foo() -> ::std::os::raw::c_int;
+}
+pub type number = ::std::os::raw::c_int;
+extern "C" {
+    pub fn bar(x: number) -> ::std::os::raw::c_int;
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct Point {
+    pub x: number,
+    pub y: number,
+}
+#[test]
+fn bindgen_test_layout_Point() {
+    const UNINIT: ::std::mem::MaybeUninit<Point> =
+        ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<Point>(),
+        8usize,
+        concat!("Size of: ", stringify!(Point))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<Point>(),
+        4usize,
+        concat!("Alignment of ", stringify!(Point))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).x) as usize - ptr as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(Point), "::", stringify!(x))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).y) as usize - ptr as usize },
+        4usize,
+        concat!("Offset of field: ", stringify!(Point), "::", stringify!(y))
+    );
+}
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct Angle {
+    pub a: number,
+    pub b: number,
+}
+#[test]
+fn bindgen_test_layout_Angle() {
+    const UNINIT: ::std::mem::MaybeUninit<Angle> =
+        ::std::mem::MaybeUninit::uninit();
+    let ptr = UNINIT.as_ptr();
+    assert_eq!(
+        ::std::mem::size_of::<Angle>(),
+        8usize,
+        concat!("Size of: ", stringify!(Angle))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<Angle>(),
+        4usize,
+        concat!("Alignment of ", stringify!(Angle))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).a) as usize - ptr as usize },
+        0usize,
+        concat!("Offset of field: ", stringify!(Angle), "::", stringify!(a))
+    );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).b) as usize - ptr as usize },
+        4usize,
+        concat!("Offset of field: ", stringify!(Angle), "::", stringify!(b))
+    );
+}
+extern "C" {
+    pub fn baz(point: Point) -> ::std::os::raw::c_int;
+}
+pub const NUMBER: number = 42;
diff --git a/tests/headers/sorted-items.h b/tests/headers/sorted-items.h
new file mode 100644
index 00000000..11fc2ef4
--- /dev/null
+++ b/tests/headers/sorted-items.h
@@ -0,0 +1,17 @@
+// bindgen-flags: --sort-semantically -- --target=x86_64-unknown-linux
+
+int foo();
+typedef int number;
+int bar(number x);
+struct Point
+{
+    number x;
+    number y;
+};
+struct Angle
+{
+    number a;
+    number b;
+};
+int baz(struct Point point);
+const number NUMBER = 42;
diff --git a/tests/headers/unsorted-items.h b/tests/headers/unsorted-items.h
new file mode 100644
index 00000000..23962d18
--- /dev/null
+++ b/tests/headers/unsorted-items.h
@@ -0,0 +1,15 @@
+int foo();
+typedef int number;
+int bar(number x);
+struct Point
+{
+    number x;
+    number y;
+};
+struct Angle
+{
+    number a;
+    number b;
+};
+int baz(struct Point point);
+const number NUMBER = 42;