Merge #92

92: Add wasm32-unknown-unknown support r=kvark a=grovesNL

This PR adds wasm32-unknown-unknown support for GLSL/ESSL compilation. Other compilers could easily be added to the Emscripten bundle, but it only includes the GLSL compiler for now.

This works by manually writing function bindings to redirect native Rust -> C++ calls to become Rust/wasm32-unknown-unknown -> C++/Emscripten calls. Rust and C++ have separate wasm memory, so we have to do some copying between both of these in order to pass arguments back and forth. There is some more information in gfx-rs/gfx#2554

There are a few parts to this PR:

- A crate to generate an Emscripten bundle from the C wrapper of SPIRV-Cross
- The generated Emscripten bundle which contains everything needed for compiling SPIR-V to GLSL/ESSL
  - This bundle could easily include MSL and HLSL compilation too, but at the moment it's not clear how best to support all combinations (other than providing one large bundle), and we ideally don't want to require Emscripten binaries to be installed as a dependency. So for now to keep it straightforward we'll just keep the bundle limited to GLSL/ESSL, unless somebody needs HLSL/MSL support in wasm.
- Some Emscripten and pointer utilities to unify access to pointers (to make Emscripten heap offsets look like pointers) so we can avoid changing the API. I think these could still be improved a lot, especially because it becomes confusing when accessing the wrong heap (Rust vs. Emscripten) but this seems to work ok for now. There is a bit of copying that could probably be made more efficient.

I've been testing this so far through an example so I can run native and wasm side-by-side to check the output of reflection/compilation:

![image](https://user-images.githubusercontent.com/2113872/53678099-aa73c780-3c77-11e9-984f-749dcb42d2ec.png)

In the future I want to expand the native test cases to improve coverage (there could still be a few calls omitted from my example) and figure out the best approach to run these tests in wasm too.

Co-authored-by: Joshua Groves <[email protected]>

.travis.yml

@@ -12,16 +12,16 @@ branches:
     - staging.tmp
 matrix:
   include:
-    - os: linux
-      language: android
-      compiler: gcc
-      env:
-        - JOB="android_gcc"
-      android:
-        components:
-          - build-tools-26.0.1
-          - android-18
-      jdk: openjdk8
+    #- os: linux
+    #  language: android
+    #  compiler: gcc
+    #  env:
+    #    - JOB="android_gcc"
+    #  android:
+    #    components:
+    #      - build-tools-26.0.1
+    #      - android-18
+    #  jdk: openjdk8
     - os: osx
       osx_image: xcode9
       compiler: clang

.travis/linux_clang.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 export CXX=clang++
 
-cargo build --verbose --all
-cargo test --verbose --all
+cargo build --verbose --all --all-features
+cargo test --verbose --all --all-features

.travis/linux_clang_coverage.sh

@@ -2,7 +2,7 @@
 export RUSTFLAGS="-C link-dead-code"
 export CXX=clang++
 
-cargo test --verbose --no-run
+cargo test --verbose --no-run --all-features
 wget https://github.com/SimonKagstrom/kcov/archive/master.tar.gz
 tar xzf master.tar.gz
 cd kcov-master

.travis/linux_gcc.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 export CXX=g++-5
 
-cargo build --verbose --all
-cargo test --verbose --all
+cargo build --verbose --all --all-features
+cargo test --verbose --all --all-features

.travis/macos_clang.sh

@@ -2,5 +2,5 @@
 export CXX=clang++
 export MACOSX_DEPLOYMENT_TARGET=10.7
 
-cargo build --verbose --all
-cargo test --verbose --all
+cargo build --verbose --all --all-features
+cargo test --verbose --all --all-features

Cargo.toml

@@ -2,5 +2,6 @@
 members = [
     "spirv_cross",
     "examples",
-    "bindings_generator"
+    "bindings_generator",
+    "wasm"
 ]

appveyor.yml

@@ -17,10 +17,10 @@ install:
   - git submodule update --init --recursive
 
 build_script:
-  - cargo build --verbose --all --target %TARGET%
+  - cargo build --verbose --all --target %TARGET% --all-features
 
 test_script:
-  - cargo test --verbose --all --target %TARGET%
+  - cargo test --verbose --all --target %TARGET% --all-features
 
 branches:
   only:

bindings_generator/Cargo.toml

@@ -8,4 +8,4 @@ bindgen = "0.30.0"
 
 [[bin]]
 name = "bindings_generator"
-path = "src/main.rs"
+path = "src/main.rs"

bindings_generator/src/main.rs

@@ -1,10 +1,10 @@
 extern crate bindgen;
 
 use std::env;
-use std::path::PathBuf;
 
 fn main() {
-    let out_path = PathBuf::from(env::current_dir().unwrap());
+    let out_path = env::current_dir().unwrap();
+    // For native targets, include all types and functions
     bindgen::Builder::default()
         .header(
             out_path
@@ -20,10 +20,65 @@ fn main() {
         .whitelisted_type("spirv_cross::Resource")
         .whitelisted_type("spirv_cross::MSLVertexAttr")
         .whitelisted_type("spirv_cross::MSLResourceBinding")
+        // TODO: Simplify with glob
+        .whitelisted_type("ScInternalCompilerBase")
+        .whitelisted_type("ScInternalCompilerHlsl")
+        .whitelisted_type("ScInternalCompilerMsl")
+        .whitelisted_type("ScInternalCompilerGlsl")
+        .whitelisted_type("ScInternalResult")
+        .whitelisted_type("ScEntryPoint")
+        .whitelisted_type("ScCombinedImageSampler")
+        .whitelisted_type("ScHlslRootConstant")
+        .whitelisted_type("ScHlslCompilerOptions")
+        .whitelisted_type("ScMslCompilerOptions")
+        .whitelisted_type("ScGlslCompilerOptions")
+        .whitelisted_type("ScResource")
+        .whitelisted_type("ScResourceArray")
+        .whitelisted_type("ScShaderResources")
+        .whitelisted_type("ScSpecializationConstant")
+        .whitelisted_type("ScType")
         .opaque_type("std::.*")
         .layout_tests(false)
         .generate()
         .expect("Unable to generate bindings")
-        .write_to_file(out_path.join("../spirv_cross/src/bindings.rs"))
+        .write_to_file(out_path.join("../spirv_cross/src/bindings_native.rs"))
+        .expect("Couldn't write bindings!");
+    // For wasm targets, include all types, functions will be implemented manually
+    bindgen::Builder::default()
+        .header(
+            out_path
+                .join("../spirv_cross/src/wrapper.hpp")
+                .to_str()
+                .unwrap(),
+        )
+        .clang_args(["-x", "c++", "-std=c++14"].iter())
+        .enable_cxx_namespaces()
+        .whitelisted_type("spv::.*")
+        .bitfield_enum(".*(Mask|Flags)")
+        .whitelisted_type("spirv_cross::Resource")
+        .whitelisted_type("spirv_cross::MSLVertexAttr")
+        .whitelisted_type("spirv_cross::MSLResourceBinding")
+        // TODO: Simplify with glob
+        .whitelisted_type("ScInternalCompilerBase")
+        .whitelisted_type("ScInternalCompilerHlsl")
+        .whitelisted_type("ScInternalCompilerMsl")
+        .whitelisted_type("ScInternalCompilerGlsl")
+        .whitelisted_type("ScInternalResult")
+        .whitelisted_type("ScEntryPoint")
+        .whitelisted_type("ScCombinedImageSampler")
+        .whitelisted_type("ScHlslRootConstant")
+        .whitelisted_type("ScHlslCompilerOptions")
+        .whitelisted_type("ScMslCompilerOptions")
+        .whitelisted_type("ScGlslCompilerOptions")
+        .whitelisted_type("ScResource")
+        .whitelisted_type("ScResourceArray")
+        .whitelisted_type("ScShaderResources")
+        .whitelisted_type("ScSpecializationConstant")
+        .whitelisted_type("ScType")
+        .opaque_type("std::.*")
+        .layout_tests(false)
+        .generate()
+        .expect("Unable to generate bindings")
+        .write_to_file(out_path.join("../spirv_cross/src/bindings_wasm.rs"))
         .expect("Couldn't write bindings!");
 }

examples/Cargo.toml

@@ -2,6 +2,7 @@
 name = "examples"
 version = "0.1.0"
 authors = ["Joshua Groves <[email protected]>"]
+edition = "2018"
 
 [dependencies]
 spirv_cross = { path = "../spirv_cross" }

examples/src/lib.rs

@@ -1,3 +1,4 @@
+#[allow(clippy::cast_ptr_alignment)]
 pub fn words_from_bytes(buf: &[u8]) -> &[u32] {
     unsafe {
         std::slice::from_raw_parts(

spirv_cross/Cargo.toml

@@ -9,6 +9,20 @@ repository = "https://github.com/grovesNL/spirv_cross"
 readme = "../README.md"
 keywords = ["spirv", "cross"]
 build = "build.rs"
+edition = "2018"
 
-[build-dependencies]
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[features]
+default = []
+glsl = []
+hlsl = []
+msl = []
+
+[target.'cfg(not(target_arch = "wasm32"))'.build-dependencies]
 cc = "1.0.4"
+
+[target.wasm32-unknown-unknown.dependencies]
+wasm-bindgen = "0.2.33"
+js-sys = "0.3.10"

spirv_cross/build.rs

@@ -1,6 +1,12 @@
-extern crate cc;
-
 fn main() {
+    // Prevent building SPIRV-Cross on wasm32 target
+    let target_arch = std::env::var("CARGO_CFG_TARGET_ARCH");
+    if let Ok(arch) = target_arch {
+        if "wasm32" == arch {
+            return; 
+        }
+    }
+
     let target_os = std::env::var("CARGO_CFG_TARGET_OS");
     let is_macos = target_os.is_ok() && target_os.unwrap() == "macos";
 
@@ -22,9 +28,16 @@ fn main() {
         .file("src/vendor/SPIRV-Cross/spirv_cross.cpp")
         .file("src/vendor/SPIRV-Cross/spirv_cross_parsed_ir.cpp")
         .file("src/vendor/SPIRV-Cross/spirv_parser.cpp")
-        .file("src/vendor/SPIRV-Cross/spirv_cross_util.cpp")
-        .file("src/vendor/SPIRV-Cross/spirv_glsl.cpp")
-        .file("src/vendor/SPIRV-Cross/spirv_hlsl.cpp")
-        .file("src/vendor/SPIRV-Cross/spirv_msl.cpp")
-        .compile("spirv-cross-rust-wrapper");
+        .file("src/vendor/SPIRV-Cross/spirv_cross_util.cpp");
+
+    #[cfg(feature = "glsl")]
+    build.file("src/vendor/SPIRV-Cross/spirv_glsl.cpp");
+
+    #[cfg(feature = "hlsl")]
+    build.file("src/vendor/SPIRV-Cross/spirv_hlsl.cpp");
+
+    #[cfg(feature = "msl")]
+    build.file("src/vendor/SPIRV-Cross/spirv_msl.cpp");
+
+    build.compile("spirv-cross-rust-wrapper");
 }

spirv_cross/src/bindings.rs → spirv_cross/src/bindings_native.rs

@@ -1843,7 +1843,10 @@ pub mod root {
         pub fn sc_internal_compiler_set_scalar_constant(compiler:
                                                             *const root::ScInternalCompilerBase,
                                                         id: u32,
-                                                        constant: u64)
+                                                        constant_high_bits:
+                                                            u32,
+                                                        constant_low_bits:
+                                                            u32)
          -> root::ScInternalResult;
     }
     extern "C" {