factors: Fix derive macro in rust-analyzer

Rust analyzer doesn't like `include!`s that reach outside of a crate's own OUT_DIR: rust-lang/rust-analyzer#17040 Fix this by requiring any crate that wants expanded output (in tests) to have a build script that sets a magic env var. Signed-off-by: Lann Martin <[email protected]>
lann · Jul 10, 2024 · f7c8914 · f7c8914
1 parent 5d9c9f8
commit f7c8914
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Showing 6 changed files with 32 additions and 17 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/crates/factor-variables/build.rs b/crates/factor-variables/build.rs
@@ -0,0 +1,6 @@
+fn main() {
+    println!("cargo::rerun-if-changed=build.rs");
+    // Enable spin-factors-derive to emit expanded macro output.
+    let out_dir = std::env::var("OUT_DIR").unwrap();
+    println!("cargo:rustc-env=SPIN_FACTORS_DERIVE_EXPAND_DIR={out_dir}");
+}
diff --git a/crates/factor-variables/tests/factor.rs → crates/factor-variables/tests/factor_test.rs b/crates/factor-variables/tests/factor.rs → crates/factor-variables/tests/factor_test.rs
diff --git a/crates/factors-derive/Cargo.toml b/crates/factors-derive/Cargo.toml
@@ -11,7 +11,7 @@ proc-macro = true
 expander = ["dep:expander"]
 
 [dependencies]
-expander = { version = "2.1.0", optional = true }
+expander = { version = "2.2.1", optional = true }
 proc-macro2 = "1.0.79"
 quote = "1.0.35"
 syn = "2.0.52"

diff --git a/crates/factors-derive/src/lib.rs b/crates/factors-derive/src/lib.rs
@@ -8,9 +8,13 @@ pub fn derive_factors(input: proc_macro::TokenStream) -> proc_macro::TokenStream
     let expanded = expand_factors(&input).unwrap_or_else(|err| err.into_compile_error());
 
     #[cfg(feature = "expander")]
-    let expanded = expander::Expander::new("factors")
-        .write_to_out_dir(expanded)
-        .unwrap();
+    let expanded = if let Some(dest_dir) = std::env::var_os("SPIN_FACTORS_DERIVE_EXPAND_DIR") {
+        expander::Expander::new("factors")
+            .write_to(expanded, std::path::Path::new(&dest_dir))
+            .unwrap()
+    } else {
+        expanded
+    };
 
     expanded.into()
 }

diff --git a/crates/factors-test/Cargo.toml b/crates/factors-test/Cargo.toml
@@ -7,6 +7,7 @@ edition = { workspace = true }
 [dependencies]
 spin-app = { path = "../app" }
 spin-factors = { path = "../factors" }
+spin-factors-derive = { path = "../factors-derive", features = ["expander"] }
 spin-loader = { path = "../loader" }
 tempfile = "3.10.1"
 toml = "0.8.14"