Merge #121

121: Fix show-env subcommand bug r=taiki-e a=taiki-e

This fixes the problem that the readme example does not work.
This probably fixes the remaining problem reported in #115.

cc #93
cc `@davidhewitt` 


Co-authored-by: Taiki Endo <te316e89@gmail.com>

CHANGELOG.md

@@ -10,7 +10,9 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
-## [0.1.14] - 2022-01-07
+- Fix bug in `show-env` subcommand.
+
+## [0.1.14] - 2022-01-06
 
 - Add `show-env` subcommand. ([#115](https://github.com/taiki-e/cargo-llvm-cov/pull/115), thanks @davidhewitt)
 

README.md

@@ -304,8 +304,8 @@ cargo llvm-cov --no-run --lcov
 In combination with the `show-env` subcommand, coverage can also be produced from arbitrary binaries:
 
 ```sh
-cargo llvm-cov clean --workspace # remove artifacts that may affect the coverage results
 source <(cargo llvm-cov show-env --export-prefix)
+cargo llvm-cov clean --workspace # remove artifacts that may affect the coverage results
 cargo build # build rust binaries
 # commands using binaries in target/debug/*, including `cargo test`
 # ...

src/cargo.rs

@@ -31,7 +31,11 @@ pub(crate) struct Workspace {
 }
 
 impl Workspace {
-    pub(crate) fn new(options: &ManifestOptions, target: Option<&str>) -> Result<Self> {
+    pub(crate) fn new(
+        options: &ManifestOptions,
+        target: Option<&str>,
+        show_env: bool,
+    ) -> Result<Self> {
         let cargo = env::var_os("CARGO").unwrap_or_else(|| "cargo".into());
         let rustc = rustc_path(&cargo);
         let (nightly, ref host) = rustc_version(&rustc)?;
@@ -46,9 +50,15 @@ impl Workspace {
             Some(host),
         )?;
 
-        // If we change RUSTFLAGS, all dependencies will be recompiled. Therefore,
-        // use a subdirectory of the target directory as the actual target directory.
-        let target_dir = metadata.target_directory.join("llvm-cov-target");
+        let target_dir = if let Some(path) = env::var("CARGO_LLVM_COV_TARGET_DIR")? {
+            path.into()
+        } else if show_env {
+            metadata.target_directory.clone()
+        } else {
+            // If we change RUSTFLAGS, all dependencies will be recompiled. Therefore,
+            // use a subdirectory of the target directory as the actual target directory.
+            metadata.target_directory.join("llvm-cov-target")
+        };
         let output_dir = metadata.target_directory.join("llvm-cov");
         let doctests_dir = target_dir.join("doctestbins");
 

src/clean.rs

@@ -17,7 +17,7 @@ use crate::{
 };
 
 pub(crate) fn run(mut options: CleanOptions) -> Result<()> {
-    let ws = Workspace::new(&options.manifest, None)?;
+    let ws = Workspace::new(&options.manifest, None, false)?;
     ws.config.merge_to_args(&mut None, &mut options.verbose, &mut options.color);
     term::set_coloring(&mut options.color);
 

src/context.rs

@@ -48,8 +48,9 @@ impl Context {
         package: &[String],
         doctests: bool,
         no_run: bool,
+        show_env: bool,
     ) -> Result<Self> {
-        let ws = Workspace::new(&manifest, build.target.as_deref())?;
+        let ws = Workspace::new(&manifest, build.target.as_deref(), show_env)?;
         ws.config.merge_to_args(&mut build.target, &mut build.verbose, &mut build.color);
         term::set_coloring(&mut build.color);
         term::verbose::set(build.verbose != 0);

src/main.rs

@@ -84,6 +84,7 @@ fn try_main() -> Result<()> {
                 args.package.as_ref().map(slice::from_ref).unwrap_or_default(),
                 false,
                 false,
+                false,
             )?;
 
             clean::clean_partial(cx)?;
@@ -97,12 +98,14 @@ fn try_main() -> Result<()> {
         }
 
         Some(Subcommand::ShowEnv(options)) => {
-            let cx = &context_from_args(&mut args)?;
-            set_env(cx, &mut ShowEnvWriter { target: std::io::stdout(), options });
+            let cx = &context_from_args(&mut args, true)?;
+            let writer = &mut ShowEnvWriter { target: std::io::stdout(), options };
+            set_env(cx, writer);
+            writer.set("CARGO_LLVM_COV_TARGET_DIR", cx.ws.metadata.target_directory.as_str());
         }
 
         None => {
-            let cx = &context_from_args(&mut args)?;
+            let cx = &context_from_args(&mut args, false)?;
             let tmp = term::warn(); // The following warnings should not be promoted to an error.
             if args.doctests {
                 warn!("--doctests option is unstable");
@@ -133,7 +136,7 @@ fn try_main() -> Result<()> {
     Ok(())
 }
 
-fn context_from_args(args: &mut Args) -> Result<Context> {
+fn context_from_args(args: &mut Args, show_env: bool) -> Result<Context> {
     Context::new(
         args.build(),
         args.manifest(),
@@ -143,6 +146,7 @@ fn context_from_args(args: &mut Args) -> Result<Context> {
         &args.package,
         args.doctests,
         args.no_run,
+        show_env,
     )
 }