Use Cargo provided icu_capi headers

Use the headers provided by cargo, instead of our local checkout.
This also revealed that we had been using version 1.5, when
we wanted to use 1.4, to be in sync with upstream.

Signed-off-by: Jonathan Schwender <[email protected]>

Author: jschwe

mozjs-sys/Cargo.toml

@@ -2,7 +2,7 @@
 name = "mozjs_sys"
 description = "System crate for the Mozilla SpiderMonkey JavaScript engine."
 repository.workspace = true
-version = "0.128.13-1"
+version = "0.128.13-2"
 authors = ["Mozilla"]
 links = "mozjs"
 license.workspace = true
@@ -35,11 +35,12 @@ libz-sys = "1.1.19"
 encoding_c = "0.9.8"
 encoding_c_mem = "0.2.6"
 # unicode-bidi-ffi = { path = "./mozjs/intl/bidi/rust/unicode-bidi-ffi" }
-icu_capi = "1.4.0" # keep in sync with intl/icu_capi/Cargo.toml
+icu_capi = "=1.4.0" # keep in sync with intl/icu_capi/Cargo.toml from upstream
 
 [build-dependencies]
 bindgen.workspace = true
 cc.workspace = true
 walkdir = "2"
 flate2 = "1"
 tar = "0.4"
+cargo_metadata = "0.21"

mozjs-sys/build.rs

@@ -123,6 +123,28 @@ fn main() {
     }
 }
 
+fn get_icu_capi_include_path() -> String {
+    // Using cargo metadata is the official recommendation from the icu4x documentation.
+    // See <https://icu4x.unicode.org/2_0/cppdoc/>. In the future we should try to upstream a
+    // patch that allows us to use DEP_ syntax, like we do with libz.
+    let metadata = cargo_metadata::MetadataCommand::new().exec().unwrap();
+    let packages = metadata.packages;
+    let icu_capi_info = packages
+        .iter()
+        .find(|pkg| pkg.name.contains("icu_capi"))
+        .expect("icu_capi not found");
+    let icu_cpath = &icu_capi_info.manifest_path;
+    // Include path for icu_capi 1.5:
+    // let c_include_path = icu_cpath.parent().expect("manifest dir?").join("bindings/c");
+    // Include path for icu_capi 1.4:
+    let c_include_path = icu_cpath.parent().expect("manifest dir?").join("c/include");
+    assert!(
+        c_include_path.exists(),
+        "ICU_C C include path {c_include_path} does not exist"
+    );
+    c_include_path.to_string()
+}
+
 fn build_spidermonkey(build_dir: &Path) {
     let target = env::var("TARGET").unwrap();
     let make;
@@ -188,15 +210,19 @@ fn build_spidermonkey(build_dir: &Path) {
         cmd.env("MAKEFLAGS", makeflags);
     }
 
+    let icu_c_include_path = get_icu_capi_include_path();
+    let mut cxxflags = vec![];
+    cxxflags.push(format!("-I{}", &icu_c_include_path));
+
     if target.contains("apple") || target.contains("freebsd") || target.contains("ohos") {
-        let mut cxxflags = OsString::from("-stdlib=libc++");
-        if let Some(flags) = env::var_os("CXXFLAGS") {
-            cxxflags.push(" ");
-            cxxflags.push(flags);
-        }
-        cmd.env("CXXFLAGS", cxxflags);
+        cxxflags.push(String::from("-stdlib=libc++"));
     }
 
+    let base_cxxflags = env::var("CXXFLAGS").unwrap_or_default();
+    let mut cxxflags = cxxflags.join(" ");
+    cxxflags.push_str(&base_cxxflags);
+    cmd.env("CXXFLAGS", cxxflags);
+
     let cargo_manifest_dir = PathBuf::from(env::var_os("CARGO_MANIFEST_DIR").unwrap());
     let result = cmd
         .args(&["-R", "-f"])