Tests: Add a --use-core --impl-debug case

This demonstrates the [...] abbreviation of large arrays in contrast to
the std variety. (Long (>32) arrays currently don't have a dedicated
test, but are piggy-backed on the derive-debug-bitfield and
derive-debug-function-pointer tests).

Note that the single occurrence of the `std` namespace in the
expectation is valid: No --ctypes-prefix was set, and ::std::os::raw is
the default value that needs to be overridden in most practical
--use-core applications.

Author: chrysn

tests/expectations/tests/derive-debug-bitfield-core.rs

@@ -0,0 +1,189 @@
+/* automatically generated by rust-bindgen */
+
+#![allow(
+    dead_code,
+    non_snake_case,
+    non_camel_case_types,
+    non_upper_case_globals
+)]
+
+#[repr(C)]
+#[derive(Copy, Clone, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct __BindgenBitfieldUnit<Storage, Align>
+where
+    Storage: AsRef<[u8]> + AsMut<[u8]>,
+{
+    storage: Storage,
+    align: [Align; 0],
+}
+
+impl<Storage, Align> __BindgenBitfieldUnit<Storage, Align>
+where
+    Storage: AsRef<[u8]> + AsMut<[u8]>,
+{
+    #[inline]
+    pub fn new(storage: Storage) -> Self {
+        Self { storage, align: [] }
+    }
+
+    #[inline]
+    pub fn get_bit(&self, index: usize) -> bool {
+        debug_assert!(index / 8 < self.storage.as_ref().len());
+
+        let byte_index = index / 8;
+        let byte = self.storage.as_ref()[byte_index];
+
+        let bit_index = if cfg!(target_endian = "big") {
+            7 - (index % 8)
+        } else {
+            index % 8
+        };
+
+        let mask = 1 << bit_index;
+
+        byte & mask == mask
+    }
+
+    #[inline]
+    pub fn set_bit(&mut self, index: usize, val: bool) {
+        debug_assert!(index / 8 < self.storage.as_ref().len());
+
+        let byte_index = index / 8;
+        let byte = &mut self.storage.as_mut()[byte_index];
+
+        let bit_index = if cfg!(target_endian = "big") {
+            7 - (index % 8)
+        } else {
+            index % 8
+        };
+
+        let mask = 1 << bit_index;
+        if val {
+            *byte |= mask;
+        } else {
+            *byte &= !mask;
+        }
+    }
+
+    #[inline]
+    pub fn get(&self, bit_offset: usize, bit_width: u8) -> u64 {
+        debug_assert!(bit_width <= 64);
+        debug_assert!(bit_offset / 8 < self.storage.as_ref().len());
+        debug_assert!((bit_offset + (bit_width as usize)) / 8 <= self.storage.as_ref().len());
+
+        let mut val = 0;
+
+        for i in 0..(bit_width as usize) {
+            if self.get_bit(i + bit_offset) {
+                let index = if cfg!(target_endian = "big") {
+                    bit_width as usize - 1 - i
+                } else {
+                    i
+                };
+                val |= 1 << index;
+            }
+        }
+
+        val
+    }
+
+    #[inline]
+    pub fn set(&mut self, bit_offset: usize, bit_width: u8, val: u64) {
+        debug_assert!(bit_width <= 64);
+        debug_assert!(bit_offset / 8 < self.storage.as_ref().len());
+        debug_assert!((bit_offset + (bit_width as usize)) / 8 <= self.storage.as_ref().len());
+
+        for i in 0..(bit_width as usize) {
+            let mask = 1 << i;
+            let val_bit_is_set = val & mask == mask;
+            let index = if cfg!(target_endian = "big") {
+                bit_width as usize - 1 - i
+            } else {
+                i
+            };
+            self.set_bit(index + bit_offset, val_bit_is_set);
+        }
+    }
+}
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct C {
+    pub _bitfield_1: __BindgenBitfieldUnit<[u8; 1usize], u8>,
+    pub large_array: [::std::os::raw::c_int; 50usize],
+}
+#[test]
+fn bindgen_test_layout_C() {
+    assert_eq!(
+        ::core::mem::size_of::<C>(),
+        204usize,
+        concat!("Size of: ", stringify!(C))
+    );
+    assert_eq!(
+        ::core::mem::align_of::<C>(),
+        4usize,
+        concat!("Alignment of ", stringify!(C))
+    );
+    assert_eq!(
+        unsafe { &(*(::core::ptr::null::<C>())).large_array as *const _ as usize },
+        4usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(C),
+            "::",
+            stringify!(large_array)
+        )
+    );
+}
+impl Default for C {
+    fn default() -> Self {
+        unsafe { ::core::mem::zeroed() }
+    }
+}
+impl ::core::fmt::Debug for C {
+    fn fmt(&self, f: &mut ::core::fmt::Formatter) -> ::core::fmt::Result {
+        write!(
+            f,
+            "C {{ a : {:?}, b : {:?}, large_array: [...] }}",
+            self.a(),
+            self.b()
+        )
+    }
+}
+impl C {
+    #[inline]
+    pub fn a(&self) -> bool {
+        unsafe { ::core::mem::transmute(self._bitfield_1.get(0usize, 1u8) as u8) }
+    }
+    #[inline]
+    pub fn set_a(&mut self, val: bool) {
+        unsafe {
+            let val: u8 = ::core::mem::transmute(val);
+            self._bitfield_1.set(0usize, 1u8, val as u64)
+        }
+    }
+    #[inline]
+    pub fn b(&self) -> bool {
+        unsafe { ::core::mem::transmute(self._bitfield_1.get(1usize, 7u8) as u8) }
+    }
+    #[inline]
+    pub fn set_b(&mut self, val: bool) {
+        unsafe {
+            let val: u8 = ::core::mem::transmute(val);
+            self._bitfield_1.set(1usize, 7u8, val as u64)
+        }
+    }
+    #[inline]
+    pub fn new_bitfield_1(a: bool, b: bool) -> __BindgenBitfieldUnit<[u8; 1usize], u8> {
+        let mut __bindgen_bitfield_unit: __BindgenBitfieldUnit<[u8; 1usize], u8> =
+            Default::default();
+        __bindgen_bitfield_unit.set(0usize, 1u8, {
+            let a: u8 = unsafe { ::core::mem::transmute(a) };
+            a as u64
+        });
+        __bindgen_bitfield_unit.set(1usize, 7u8, {
+            let b: u8 = unsafe { ::core::mem::transmute(b) };
+            b as u64
+        });
+        __bindgen_bitfield_unit
+    }
+}

tests/headers/derive-debug-bitfield-core.hpp

@@ -0,0 +1,7 @@
+// bindgen-flags: --impl-debug --use-core
+
+class C {
+  bool a: 1;
+  bool b: 7;
+  int large_array[50];
+};