Merge #9192

9192: internal: Build test-macros in a build script r=jonas-schievink a=jonas-schievink

This build the test-proc-macros in `proc_macro_test` in a build script, and copies the artifact to `OUT_DIR`. This should make it available throughout all of rust-analyzer at no cost other than depending on `proc_macro_test`, fixing https://github.com/rust-analyzer/rust-analyzer/issues/9067.

This hopefully will let us later write inline tests that utilize proc macros, which makes my life fixing proc macro bugs easier.

Opening this as a sort of RFC, because I'm not totally sure this approach is the best.

Co-authored-by: Jonas Schievink <[email protected]>

2 files changed, 8 insertions, 32 deletions

diff --git a/crates/proc_macro_srv/src/dylib.rs b/crates/proc_macro_srv/src/dylib.rs
index cccc53220..5133e7c50 100644
--- a/crates/proc_macro_srv/src/dylib.rs
+++ b/crates/proc_macro_srv/src/dylib.rs
@@ -188,7 +188,9 @@ impl Expander {
 /// Copy the dylib to temp directory to prevent locking in Windows
 #[cfg(windows)]
 fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
-    use std::{ffi::OsString, time::SystemTime};
+    use std::collections::hash_map::RandomState;
+    use std::ffi::OsString;
+    use std::hash::{BuildHasher, Hasher};
 
     let mut to = std::env::temp_dir();
 
@@ -199,10 +201,11 @@ fn ensure_file_with_lock_free_access(path: &Path) -> io::Result<PathBuf> {
         )
     })?;
 
-    // generate a time deps unique number
-    let t = SystemTime::now().duration_since(std::time::UNIX_EPOCH).expect("Time went backwards");
+    // Generate a unique number by abusing `HashMap`'s hasher.
+    // Maybe this will also "inspire" a libs team member to finally put `rand` in libstd.
+    let t = RandomState::new().build_hasher().finish();
 
-    let mut unique_name = OsString::from(t.as_millis().to_string());
+    let mut unique_name = OsString::from(t.to_string());
     unique_name.push(file_name);
 
     to.push(unique_name);
diff --git a/crates/proc_macro_srv/src/tests/utils.rs b/crates/proc_macro_srv/src/tests/utils.rs
index 2e950c113..2c093aa0a 100644
--- a/crates/proc_macro_srv/src/tests/utils.rs
+++ b/crates/proc_macro_srv/src/tests/utils.rs
@@ -7,35 +7,8 @@ use proc_macro_api::ListMacrosTask;
 use std::str::FromStr;
 
 pub mod fixtures {
-    use cargo_metadata::Message;
-    use std::path::PathBuf;
-    use std::process::Command;
-
-    // Use current project metadata to get the proc-macro dylib path
     pub fn proc_macro_test_dylib_path() -> std::path::PathBuf {
-        let name = "proc_macro_test";
-        let version = "0.0.0";
-        let command = Command::new(toolchain::cargo())
-            .args(&["check", "--tests", "--message-format", "json"])
-            .output()
-            .unwrap()
-            .stdout;
-
-        for message in Message::parse_stream(command.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) {
-                            return PathBuf::from(&artifact.filenames[0]);
-                        }
-                    }
-                }
-                _ => (), // Unknown message
-            }
-        }
-
-        panic!("No proc-macro dylib for {} found!", name);
+        proc_macro_test::PROC_MACRO_TEST_LOCATION.into()
     }
 }