1 files changed, 101 insertions, 0 deletions
diff --git a/js/src/wasm/cranelift/build.rs b/js/src/wasm/cranelift/build.rs
new file mode 100644
index 0000000000..3c963b373c
--- /dev/null
+++ b/js/src/wasm/cranelift/build.rs
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2018 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//! Build script for the Baldr <-> Cranelift bindings.
+//!
+//! This file is executed by cargo when this crate is built. It generates the
+//! `$OUT_DIR/bindings.rs` file which is then included by `src/bindings/low_level.rs`.
+
+extern crate bindgen;
+
+use std::env;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::PathBuf;
+
+fn main() {
+    // Tell Cargo to regenerate the bindings if the header file changes.
+    println!("cargo:rerun-if-changed=baldrapi.h");
+
+    let mut generator = bindgen::builder()
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks))
+        .disable_name_namespacing()
+        .size_t_is_usize(true)
+        // We whitelist the Baldr C functions and get the associated types for free.
+        .whitelist_function("env_.*")
+        .whitelist_function("global_.*")
+        .whitelist_function("table_.*")
+        .whitelist_function("funcType_.*")
+        .whitelist_function("stackmaps_.*")
+        .whitelist_type("Cranelift.*")
+        // The enum classes defined in baldrapi.h and WasmBinaryConstants are all Rust-safe.
+        .rustified_enum("BD_.*|Trap|TypeCode|TypeIdDescKind")
+        .whitelist_type("BD_.*|Trap|TypeCode|TypeIdDescKind")
+        .header("baldrapi.h")
+        .clang_args(&[
+            "-x",
+            "c++",
+            "-std=gnu++14",
+            "-fno-sized-deallocation",
+            "-fno-aligned-new",
+            "-DRUST_BINDGEN",
+        ])
+        .clang_arg("-I../..");
+
+    match env::var_os("MOZ_TOPOBJDIR") {
+        Some(path) => {
+            let path = PathBuf::from(path).join("js/src/rust/extra-bindgen-flags");
+
+            let mut extra_flags = String::new();
+            File::open(&path)
+                .expect("Failed to open extra-bindgen-flags file")
+                .read_to_string(&mut extra_flags)
+                .expect("Failed to read extra-bindgen-flags file");
+
+            let display_path = path.to_str().expect("path is utf8 encoded");
+            println!("cargo:rerun-if-changed={}", display_path);
+
+            let extra_flags: Vec<String> = extra_flags
+                .split_whitespace()
+                .map(|s| s.to_owned())
+                .collect();
+            for flag in extra_flags {
+                generator = generator.clang_arg(flag);
+            }
+        }
+        None => {
+            println!("cargo:warning=MOZ_TOPOBJDIR should be set by default, otherwise the build is not guaranted to finish.");
+        }
+    }
+
+    let command_line_opts = generator.command_line_flags();
+
+    // In case of error, bindgen prints to stderr, and the yielded error is the empty type ().
+    let bindings = generator.generate().unwrap_or_else(|_err| {
+        panic!(
+            r#"Unable to generate baldrapi.h bindings:
+- flags: {}
+"#,
+            command_line_opts.join(" "),
+        );
+    });
+
+    // Write the bindings to the $OUT_DIR/bindings.rs file.
+    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
+    bindings
+        .write_to_file(out_path.join("bindings.rs"))
+        .expect("Couldn't write bindings!");
+}