Bug 1356371 - Use cbindgen for WebRender bindings generation r=kats

This commit adds some directives to help cbindgen generate correct
structs and functions, removes some old FFI code that isn't needed
anymore, and regenerates webrender_ffi_generated.h

MozReview-Commit-ID: KZSEZEN671A

--HG--
extra : rebase_source : 23a07dd11037943156983d9facc039bb7af51c95

gfx/webrender_bindings/src/bindings.rs

@@ -15,23 +15,6 @@ use euclid::{TypedPoint2D, TypedSize2D, TypedRect, TypedMatrix4D, SideOffsets2D}
 
 extern crate webrender_traits;
 
-type WrAPI = RenderApi;
-type WrAuxiliaryListsDescriptor = AuxiliaryListsDescriptor;
-type WrBorderStyle = BorderStyle;
-type WrBoxShadowClipMode = BoxShadowClipMode;
-type WrBuiltDisplayListDescriptor = BuiltDisplayListDescriptor;
-type WrEpoch = Epoch;
-type WrFontKey = FontKey;
-type WrIdNamespace = IdNamespace;
-type WrImageFormat = ImageFormat;
-type WrImageRendering = ImageRendering;
-type WrImageKey = ImageKey;
-type WrMixBlendMode = MixBlendMode;
-type WrPipelineId = PipelineId;
-type WrRenderer = Renderer;
-type WrSideOffsets2Du32 = WrSideOffsets2D<u32>;
-type WrSideOffsets2Df32 = WrSideOffsets2D<f32>;
-
 // Enables binary recording that can be used with `wrench replay`
 // Outputs a wr-record-*.bin file for each window that is shown
 // Note: wrench will panic if external images are used, they can
@@ -39,6 +22,35 @@ type WrSideOffsets2Df32 = WrSideOffsets2D<f32>;
 // by commenting out the path that adds an external image ID
 static ENABLE_RECORDING: bool = false;
 
+type WrAPI = RenderApi;
+type WrAuxiliaryListsDescriptor = AuxiliaryListsDescriptor;
+type WrBorderStyle = BorderStyle;
+type WrBoxShadowClipMode = BoxShadowClipMode;
+type WrBuiltDisplayListDescriptor = BuiltDisplayListDescriptor;
+type WrImageFormat = ImageFormat;
+type WrImageRendering = ImageRendering;
+type WrMixBlendMode = MixBlendMode;
+type WrRenderer = Renderer;
+type WrSideOffsets2Du32 = WrSideOffsets2D<u32>;
+type WrSideOffsets2Df32 = WrSideOffsets2D<f32>;
+
+/// cbindgen:field-names=[mHandle]
+/// cbindgen:struct-gen-op-lt=true
+/// cbindgen:struct-gen-op-lte=true
+type WrEpoch = Epoch;
+/// cbindgen:field-names=[mHandle]
+/// cbindgen:struct-gen-op-lt=true
+/// cbindgen:struct-gen-op-lte=true
+type WrIdNamespace = IdNamespace;
+
+/// cbindgen:field-names=[mNamespace, mHandle]
+type WrPipelineId = PipelineId;
+/// cbindgen:field-names=[mNamespace, mHandle]
+type WrImageKey = ImageKey;
+/// cbindgen:field-names=[mNamespace, mHandle]
+type WrFontKey = FontKey;
+
+/// cbindgen:field-names=[mHandle]
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct WrExternalImageId(pub u64);
@@ -54,37 +66,6 @@ impl Into<WrExternalImageId> for ExternalImageId {
     }
 }
 
-// This macro adds some checks to make sure we notice when the memory representation of
-// types change.
-macro_rules! check_ffi_type {
-    ($check_sizes_match:ident struct $TypeName:ident as ($T1:ident, $T2:ident)) => (
-        fn $check_sizes_match() {
-            #[repr(C)] struct TestType($T1, $T2);
-            let _ = mem::transmute::<$TypeName, TestType>;
-        }
-    );
-    ($check_sizes_match:ident struct $TypeName:ident as ($T:ident)) => (
-        fn $check_sizes_match() {
-            #[repr(C)] struct TestType($T);
-            let _ = mem::transmute::<$TypeName, TestType>;
-        }
-    );
-    ($check_sizes_match:ident enum $TypeName:ident as $T:ident) => (
-        fn $check_sizes_match() { let _ = mem::transmute::<$TypeName, $T>; }
-    );
-}
-
-check_ffi_type!(_pipeline_id_repr struct WrPipelineId as (u32, u32));
-check_ffi_type!(_image_key_repr struct WrImageKey as (u32, u32));
-check_ffi_type!(_font_key_repr struct WrFontKey as (u32, u32));
-check_ffi_type!(_epoch_repr struct WrEpoch as (u32));
-check_ffi_type!(_image_format_repr enum WrImageFormat as u32);
-check_ffi_type!(_border_style_repr enum WrBorderStyle as u32);
-check_ffi_type!(_image_rendering_repr enum WrImageRendering as u32);
-check_ffi_type!(_mix_blend_mode_repr enum WrMixBlendMode as u32);
-check_ffi_type!(_box_shadow_clip_mode_repr enum WrBoxShadowClipMode as u32);
-check_ffi_type!(_namespace_id_repr struct WrIdNamespace as (u32));
-
 const GL_FORMAT_BGRA_GL: gl::GLuint = gl::BGRA;
 const GL_FORMAT_BGRA_GLES: gl::GLuint = gl::BGRA_EXT;
 
@@ -570,6 +551,9 @@ impl ExternalImageHandler for WrExternalImageHandler {
     }
 }
 
+/// cbindgen:field-names=[mHandle]
+/// cbindgen:struct-gen-op-lt=true
+/// cbindgen:struct-gen-op-lte=true
 #[repr(C)]
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub struct WrWindowId(u64);
@@ -752,7 +736,7 @@ pub extern "C" fn wr_renderer_current_epoch(renderer: &mut WrRenderer,
     return false;
 }
 
-/// wr-binding:destructor_safe // This is used by the binding generator
+/// cbindgen:function-postfix=WR_DESTRUCTOR_SAFE_FUNC
 #[no_mangle]
 pub unsafe extern "C" fn wr_renderer_delete(renderer: *mut WrRenderer) {
     Box::from_raw(renderer);
@@ -785,7 +769,7 @@ pub unsafe extern "C" fn wr_rendered_epochs_next(pipeline_epochs: &mut WrRendere
     return false;
 }
 
-/// wr-binding:destructor_safe // This is used by the binding generator
+/// cbindgen:function-postfix=WR_DESTRUCTOR_SAFE_FUNC
 #[no_mangle]
 pub unsafe extern "C" fn wr_rendered_epochs_delete(pipeline_epochs: *mut WrRenderedEpochs) {
     Box::from_raw(pipeline_epochs);
@@ -1001,7 +985,7 @@ pub extern "C" fn wr_api_generate_frame(api: &mut WrAPI) {
     api.generate_frame(None);
 }
 
-/// wr-binding:destructor_safe // This is used by the binding generator
+/// cbindgen:function-postfix=WR_DESTRUCTOR_SAFE_FUNC
 #[no_mangle]
 pub extern "C" fn wr_api_send_external_event(api: &mut WrAPI, evt: usize) {
     assert!(unsafe { !is_in_render_thread() });

gfx/webrender_bindings/webrender_ffi.h

@@ -9,60 +9,9 @@
 
 #include "mozilla/gfx/Types.h"
 #include "nsTArray.h"
-#include "mozilla/gfx/Point.h"
-// ---
-#define WR_DECL_FFI_1(WrType, t1)                 \
-struct WrType {                                   \
-  t1 mHandle;                                     \
-  bool operator==(const WrType& rhs) const {      \
-    return mHandle == rhs.mHandle;                \
-  }                                               \
-  bool operator!=(const WrType& rhs) const {      \
-    return mHandle != rhs.mHandle;                \
-  }                                               \
-  bool operator<(const WrType& rhs) const {       \
-    return mHandle < rhs.mHandle;                 \
-  }                                               \
-  bool operator<=(const WrType& rhs) const {      \
-    return mHandle <= rhs.mHandle;                \
-  }                                               \
-};                                                \
-// ---
-
-// ---
-#define WR_DECL_FFI_2(WrType, t1, t2)             \
-struct WrType {                                   \
-  t1 mNamespace;                                  \
-  t2 mHandle;                                     \
-  bool operator==(const WrType& rhs) const {      \
-    return mNamespace == rhs.mNamespace           \
-        && mHandle == rhs.mHandle;                \
-  }                                               \
-  bool operator!=(const WrType& rhs) const {      \
-    return mNamespace != rhs.mNamespace           \
-        || mHandle != rhs.mHandle;                \
-  }                                               \
-};                                                \
-// ---
-
 
 extern "C" {
 
-// If you modify any of the declarations below, make sure to update the
-// serialization code in WebRenderMessageUtils.h and the rust bindings.
-
-WR_DECL_FFI_1(WrEpoch, uint32_t)
-WR_DECL_FFI_1(WrIdNamespace, uint32_t)
-WR_DECL_FFI_1(WrWindowId, uint64_t)
-WR_DECL_FFI_1(WrExternalImageId, uint64_t)
-
-WR_DECL_FFI_2(WrPipelineId, uint32_t, uint32_t)
-WR_DECL_FFI_2(WrImageKey, uint32_t, uint32_t)
-WR_DECL_FFI_2(WrFontKey, uint32_t, uint32_t)
-
-#undef WR_DECL_FFI_1
-#undef WR_DECL_FFI_2
-
 // ----
 // Functions invoked from Rust code
 // ----
@@ -91,12 +40,6 @@ void* get_proc_address_from_glcontext(void* glcontext_ptr, const char* procname)
 #  define WR_DESTRUCTOR_SAFE_FUNC {}
 #endif
 
-// Structs defined in Rust, but opaque to C++ code.
-struct WrRenderedEpochs;
-struct WrRenderer;
-struct WrState;
-struct WrAPI;
-
 #include "webrender_ffi_generated.h"
 
 #undef WR_FUNC