From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Wed, 18 Apr 2018 14:44:23 +0000 (+0300)
Subject: Improve rustc cache
X-Git-Tag: archive/raspbian/0.35.0-2+rpi1~3^2^2^2^2^2^2^2~22^2~1^2~59^2~2
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=1be35793963d0c38210c3ce0d5be1d71a2f46695;p=cargo.git

Improve rustc cache

Even if we've failed to calculate fingerprint and thus can't persist
cache to disk, it is still valid to cache rustc output within single
process.
---

diff --git a/src/cargo/util/rustc.rs b/src/cargo/util/rustc.rs
index 883563d2f..c6de81889 100644
--- a/src/cargo/util/rustc.rs
+++ b/src/cargo/util/rustc.rs
@@ -154,19 +154,6 @@ impl Cache {
     }
 
     fn cached_output(&mut self, cmd: &ProcessBuilder) -> CargoResult<(String, String)> {
-        let calculate = || {
-            let output = cmd.exec_with_output()?;
-            let stdout = String::from_utf8(output.stdout)
-                .map_err(|_| internal("rustc didn't return utf8 output"))?;
-            let stderr = String::from_utf8(output.stderr)
-                .map_err(|_| internal("rustc didn't return utf8 output"))?;
-            Ok((stdout, stderr))
-        };
-        if self.cache_location.is_none() {
-            info!("rustc info uncached");
-            return calculate();
-        }
-
         let key = process_fingerprint(cmd);
         match self.data.outputs.entry(key) {
             Entry::Occupied(entry) => {
@@ -175,7 +162,12 @@ impl Cache {
             }
             Entry::Vacant(entry) => {
                 info!("rustc info cache miss");
-                let output = calculate()?;
+                let output = cmd.exec_with_output()?;
+                let stdout = String::from_utf8(output.stdout)
+                    .map_err(|_| internal("rustc didn't return utf8 output"))?;
+                let stderr = String::from_utf8(output.stderr)
+                    .map_err(|_| internal("rustc didn't return utf8 output"))?;
+                let output = (stdout, stderr);
                 entry.insert(output.clone());
                 self.dirty = true;
                 Ok(output)
diff --git a/tests/testsuite/rustc_info_cache.rs b/tests/testsuite/rustc_info_cache.rs
index 28d2c5dc6..b55c84a4d 100644
--- a/tests/testsuite/rustc_info_cache.rs
+++ b/tests/testsuite/rustc_info_cache.rs
@@ -20,7 +20,6 @@ fn rustc_info_cache() {
 
     let miss = "[..] rustc info cache miss[..]";
     let hit = "[..]rustc info cache hit[..]";
-    let uncached = "[..]rustc info uncached[..]";
     let update = "[..]updated rustc info cache[..]";
 
     assert_that(
@@ -50,7 +49,6 @@ fn rustc_info_cache() {
         execs()
             .with_status(0)
             .with_stderr_contains("[..]rustc info cache disabled[..]")
-            .with_stderr_contains(uncached)
             .with_stderr_does_not_contain(update),
     );