Run Hermes CMake from cargo

Summary:
Use the `cmake` crate instead of relying on an existing build of Hermes.
The crate puts the libraries in a given destination path, whence they
can be linked by `build.rs` directives.

It also handles the use of `--release` and sets the optimization and
debug flags automatically.

We have to `rerun-if-changed` in the relevant directories,
but we can't include the entire `hermes` directory because that would
capture all the other `juno` crates as well.

Reviewed By: tmikov

Differential Revision: D33714180

fbshipit-source-id: c68deea1fa652d46abda14185240e0db6b186127

Author: avp

unsupported/juno/Cargo.lock

@@ -12,4 +12,4 @@ libc = "0.2"
 thiserror = "1.0"
 
 [build-dependencies]
-toml = "=0.5.7"
+cmake = "0.1"

unsupported/juno/crates/hermes/Cargo.toml

@@ -5,32 +5,39 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-use std::{env, fs};
-use toml::Value;
-
 fn main() {
-    let hermes_build = match env::var("HERMES_BUILD") {
-        Ok(dir) => dir,
-        Err(_) => {
-            let file =
-                fs::read_to_string(format!("{}/../../.hermes.toml", env!("CARGO_MANIFEST_DIR")))
-                    .expect("Must provide either HERMES_BUILD env variable or .hermes.toml file");
-            let value = file.parse::<Value>().unwrap();
-            value["hermes_build"].as_str().unwrap().to_owned()
-        }
-    };
+    println!("cargo:rerun-if-changed=../../../../include");
+    println!("cargo:rerun-if-changed=../../../../lib");
+    println!("cargo:rerun-if-changed=../../../../external");
+    println!("cargo:rerun-if-changed=../../../../cmake");
+    println!("cargo:rerun-if-changed=../../../../CMakeLists.txt");
+
+    // Build sourceMap library because it depends on everything we depend on here
+    // via the hermesParser library.
+    let dst = cmake::Config::new("../../../../")
+        .build_target("hermesSourceMap")
+        .build();
 
-    println!("cargo:rustc-link-search={}/lib/Parser", hermes_build);
+    println!("cargo:rustc-link-search={}/build/lib/Parser", dst.display());
+    println!(
+        "cargo:rustc-link-search={}/build/lib/Platform/Unicode",
+        dst.display()
+    );
+    println!(
+        "cargo:rustc-link-search={}/build/lib/SourceMap",
+        dst.display()
+    );
+    println!(
+        "cargo:rustc-link-search={}/build/lib/Support",
+        dst.display()
+    );
     println!(
-        "cargo:rustc-link-search={}/lib/Platform/Unicode",
-        hermes_build
+        "cargo:rustc-link-search={}/build/external/dtoa",
+        dst.display()
     );
-    println!("cargo:rustc-link-search={}/lib/SourceMap", hermes_build);
-    println!("cargo:rustc-link-search={}/lib/Support", hermes_build);
-    println!("cargo:rustc-link-search={}/external/dtoa", hermes_build);
     println!(
-        "cargo:rustc-link-search={}/external/llvh/lib/Support",
-        hermes_build
+        "cargo:rustc-link-search={}/build/external/llvh/lib/Support",
+        dst.display()
     );
 
     println!("cargo:rustc-link-lib=hermesSourceMap");

unsupported/juno/crates/hermes/build.rs

@@ -13,4 +13,4 @@ thiserror = "1.0"
 url = "2.2.2"
 
 [build-dependencies]
-toml = "=0.5.7"
+cmake = "0.1"

unsupported/juno/crates/juno_support/Cargo.toml

@@ -5,24 +5,23 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-use std::{env, fs};
-use toml::Value;
-
 fn main() {
-    let hermes_build = match env::var("HERMES_BUILD") {
-        Ok(dir) => dir,
-        Err(_) => {
-            let file =
-                fs::read_to_string(format!("{}/../../.hermes.toml", env!("CARGO_MANIFEST_DIR")))
-                    .expect("Must provide either HERMES_BUILD env variable or .hermes.toml file");
-            let value = file.parse::<Value>().unwrap();
-            value["hermes_build"].as_str().unwrap().to_owned()
-        }
-    };
-
-    println!("cargo:rustc-link-search={}/lib/Support", hermes_build);
-    println!("cargo:rustc-link-search={}/external/dtoa", hermes_build);
-
+    println!("cargo:rerun-if-changed=../../../../include");
+    println!("cargo:rerun-if-changed=../../../../lib");
+    println!("cargo:rerun-if-changed=../../../../external");
+    println!("cargo:rerun-if-changed=../../../../cmake");
+    println!("cargo:rerun-if-changed=../../../../CMakeLists.txt");
+    let dst = cmake::Config::new("../../../../")
+        .build_target("hermesSupport")
+        .build();
+    println!(
+        "cargo:rustc-link-search={}/build/lib/Support",
+        dst.display()
+    );
     println!("cargo:rustc-link-lib=hermesSupport");
+    println!(
+        "cargo:rustc-link-search={}/build/external/dtoa",
+        dst.display()
+    );
     println!("cargo:rustc-link-lib=dtoa");
 }