Skip build process for prebuilt libraries

Libraries were built ahead-of-time for the following platforms:
- x86_64-pc-windows-msvc
- x86_64-unknown-linux-gnu
- x86_64-apple-darwin
- aarch64-linux-android
- armv7-linux-androideabi

Libraries are built from source for the following platform(s):
- i686-pc-windows-msvc

.cargo/config.toml

@@ -0,0 +1,64 @@
+[target.x86_64-pc-windows-msvc.glslang]
+rustc-link-search = ["build/windows"]
+rustc-link-lib = [
+    "HLSL.glsltospirv",
+    "OGLCompiler.glsltospirv",
+    "OSDependent.glsltospirv",
+    "SPIRV.glsltospirv",
+    "SPVRemapper.glsltospirv",
+    "glslang.glsltospirv"
+]
+
+[target.x86_64-unknown-linux-gnu.glslang]
+rustc-link-search = ["build/linux"]
+rustc-link-lib = [
+    "HLSL.glsltospirv",
+    "OGLCompiler.glsltospirv",
+    "OSDependent.glsltospirv",
+    "SPIRV.glsltospirv",
+    "SPVRemapper.glsltospirv",
+    "glslang.glsltospirv",
+    # linux and macOS-specific libraries
+    "SPIRV-Tools-opt.glsltospirv",
+    "SPIRV-Tools.glsltospirv"
+]
+
+[target.x86_64-apple-darwin.glslang]
+rustc-link-search = ["build/osx"]
+rustc-link-lib = [
+    "HLSL.glsltospirv",
+    "OGLCompiler.glsltospirv",
+    "OSDependent.glsltospirv",
+    "SPIRV.glsltospirv",
+    "SPVRemapper.glsltospirv",
+    "glslang.glsltospirv",
+    # linux and macOS-specific libraries
+    "SPIRV-Tools-opt.glsltospirv",
+    "SPIRV-Tools.glsltospirv"
+]
+
+[target.aarch64-linux-android.glslang]
+rustc-link-search = ["build/android-arm64-v8a"]
+rustc-link-lib = [
+    "HLSL.glsltospirv",
+    "OGLCompiler.glsltospirv",
+    "OSDependent.glsltospirv",
+    "SPIRV.glsltospirv",
+    "SPVRemapper.glsltospirv",
+    "glslang.glsltospirv",
+    # android-specific libraries
+    "c++_shared"
+]
+
+[target.armv7-linux-androideabi.glslang]
+rustc-link-search = ["build/android-armeabi-v7a"]
+rustc-link-lib = [
+    "HLSL.glsltospirv",
+    "OGLCompiler.glsltospirv",
+    "OSDependent.glsltospirv",
+    "SPIRV.glsltospirv",
+    "SPVRemapper.glsltospirv",
+    "glslang.glsltospirv",
+    # android-specific libraries
+    "c++_shared"
+]

Cargo.toml

@@ -1,13 +1,14 @@
 [package]
 name = "bevy-glsl-to-spirv"
 version = "0.2.2"
-authors = ["Pierre Krieger <[email protected]>", "The vulkano contributors", "Carter Anderson <[email protected]>", "Nicholas Rishel <[email protected]>"]
+authors = ["Pierre Krieger <[email protected]>", "The vulkano contributors", "Carter Anderson <[email protected]>", "Nicholas Rishel <[email protected]>", "Martin Krisnanto Putra <[email protected]>"]
 description = "Deprecated. This crate is a temporary measure until native rust shader compilation like https://github.com/gfx-rs/naga lands."
 repository = "https://github.com/cart/glsl-to-spirv"
 license = "MIT/Apache-2.0"
 build = "build/build.rs"
 categories = ["rendering::graphics-api"]
 edition = "2018"
+links = "glslang"
 
 [build-dependencies]
 cmake = "0.1.45"

build/build.rs

@@ -15,28 +15,10 @@ const COMMON_FILES: &[&str] = &[
 ];
 
 fn main() {
-    let target = env::var("TARGET").unwrap();
-    let mut bin_dir = PathBuf::from(&env::var("CARGO_MANIFEST_DIR").unwrap());
-    bin_dir.push("build");
-
-    if target.contains("x86_64-pc-windows-msvc") {
-        bin_dir.push("windows");
-    } else if target.contains("i686-pc-windows-msvc") {
-        bin_dir = build_windows_i686();
-    } else if target.contains("x86_64-unknown-linux-gnu") {
-        bin_dir.push("linux");
-    } else if target.contains("x86_64-apple-darwin") {
-        bin_dir.push("osx");
-    } else if target.contains("android") {
-        if target.contains("aarch64") {
-            bin_dir.push("android-arm64-v8a");
-        } else if target.contains("armv7") {
-            bin_dir.push("android-armeabi-v7a");
-        } else {
-            panic!("Missing Android target support {}", target);
-        }
-    } else {
-        panic!("Missing target support {}", target);
+    let target: &str = &env::var("TARGET").unwrap();
+    let bin_dir = match target {
+        "i686-pc-windows-msvc" => build_libraries(),
+        _ => panic!("Missing target support {}", target),
     };
 
     // Link order matters, make sure dependents are linked before their dependencies.
@@ -56,7 +38,8 @@ fn main() {
     }
 }
 
-fn build_windows_i686() -> PathBuf {
+/// Build target libraries and returns the path they're in
+pub fn build_libraries() -> PathBuf {
     // Prepare directories
     let cargo_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
     let source_dir = cargo_dir.join("glslang");
@@ -71,6 +54,12 @@ fn build_windows_i686() -> PathBuf {
         return library_dir;
     }
 
+    // Check glslang folder is initialized
+    let cmakelists = source_dir.join("CMakeLists.txt");
+    if !cmakelists.exists() {
+        panic!("Please make sure the glslang submodule is initialized");
+    }
+
     // Set up "install" subdirectory
     match std::fs::create_dir_all(&install_dir) {
         Ok(_) => {}
@@ -92,7 +81,7 @@ fn build_windows_i686() -> PathBuf {
             library_dir.join(file).with_extension("glsltospirv.lib"),
         ) {
             Ok(_) => {}
-            Err(err) => panic!("Error copying glslang libaries: {}", err),
+            Err(err) => panic!("Error renaming glslang libaries: {}", err),
         }
     });