Build test-macros in a build script

1 files changed, 48 insertions, 0 deletions

diff --git a/crates/proc_macro_test/build.rs b/crates/proc_macro_test/build.rs
new file mode 100644
index 000000000..4653a93dd
--- /dev/null
+++ b/crates/proc_macro_test/build.rs
@@ -0,0 +1,48 @@
+//! This will build the proc macro in `imp`, and copy the resulting dylib artifact into the
+//! `OUT_DIR`.
+//!
+//! `proc_macro_test` itself contains only a path to that artifact.
+
+use std::{
+    env, fs,
+    path::{Path, PathBuf},
+    process::Command,
+};
+
+use cargo_metadata::Message;
+
+fn main() {
+    let out_dir = env::var_os("OUT_DIR").unwrap();
+    let out_dir = Path::new(&out_dir);
+
+    let name = "proc_macro_test_impl";
+    let version = "0.0.0";
+    let output = Command::new(toolchain::cargo())
+        .current_dir("imp")
+        .args(&["build", "-p", "proc_macro_test_impl", "--message-format", "json"])
+        .output()
+        .unwrap();
+    assert!(output.status.success());
+
+    let mut artifact_path = None;
+    for message in Message::parse_stream(output.stdout.as_slice()) {
+        match message.unwrap() {
+            Message::CompilerArtifact(artifact) => {
+                if artifact.target.kind.contains(&"proc-macro".to_string()) {
+                    let repr = format!("{} {}", name, version);
+                    if artifact.package_id.repr.starts_with(&repr) {
+                        artifact_path = Some(PathBuf::from(&artifact.filenames[0]));
+                    }
+                }
+            }
+            _ => (), // Unknown message
+        }
+    }
+
+    let src_path = artifact_path.expect("no dylib for proc_macro_test_impl found");
+    let dest_path = out_dir.join(src_path.file_name().unwrap());
+    fs::copy(src_path, &dest_path).unwrap();
+
+    let info_path = out_dir.join("proc_macro_test_location.txt");
+    fs::write(info_path, dest_path.to_str().unwrap()).unwrap();
+}