Merge #55

55: Various refactoring r=taiki-e a=taiki-e

Closes #50
Closes #10

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

CHANGELOG.md

@@ -10,6 +10,15 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- You can now merge the coverages generated under different test conditions by using `--no-report` and `--no-run`.
+
+  ```sh
+  cargo clean
+  cargo llvm-cov --no-report --features a
+  cargo llvm-cov --no-report --features b
+  cargo llvm-cov --no-run --lcov
+  ```
+
 - [Fix "Failed to load coverage" error when together used with trybuild.](https://github.com/taiki-e/cargo-llvm-cov/pull/49)
 
 - [Recognize rustflags and rustdocflags set by config file.](https://github.com/taiki-e/cargo-llvm-cov/pull/52)

Cargo.toml

@@ -35,7 +35,6 @@ serde = { version = "1.0.103", features = ["derive"] }
 serde_json = "1"
 shell-escape = "0.1.5"
 termcolor = "1.1"
-toml = "0.5.2"
 tracing = { version = "0.1.21", default-features = false, features = ["std"] }
 tracing-subscriber = { version = "0.2.16", default-features = false, features = ["ansi", "env-filter"] }
 walkdir = "2"
@@ -44,5 +43,7 @@ walkdir = "2"
 lazy_static = "1.4"
 
 [dev-dependencies]
+easy-ext = "0.2"
+fs-err = "2"
 once_cell = "1"
 tempfile = "3"

README.md

@@ -134,8 +134,11 @@ OPTIONS:
         --doctests
             Including doc tests (unstable)
 
+        --no-report
+            Run tests, but don't generate coverage reports
+
         --no-run
-            Compile, but don't run tests (unstable)
+            Generate coverage reports without running tests
 
         --no-fail-fast
             Run all tests regardless of failure
@@ -232,6 +235,15 @@ With lcov report (if `--output-path` is not specified, the report will be printe
 cargo llvm-cov --lcov --output-path lcov.info
 ```
 
+You can merge the coverages generated under different test conditions by using `--no-report` and `--no-run`.
+
+```sh
+cargo clean
+cargo llvm-cov --no-report --features a
+cargo llvm-cov --no-report --features b
+cargo llvm-cov --no-run --lcov
+```
+
 ### Continuous Integration
 
 Here is an example of GitHub Actions workflow that uploads coverage to [Codecov].

src/cargo.rs

@@ -1,40 +1,68 @@
-use std::env;
+use std::{
+    env,
+    ffi::{OsStr, OsString},
+};
 
 use anyhow::{format_err, Result};
+use camino::Utf8Path;
 use serde::Deserialize;
 
 use crate::{
     cli::{Args, Coloring},
-    context::EnvironmentVariables,
+    context::Env,
+    process::ProcessBuilder,
 };
 
-fn ver(key: &str) -> Result<Option<String>> {
-    match env::var(key) {
-        Ok(v) if v.is_empty() => Ok(None),
-        Ok(v) => Ok(Some(v)),
-        Err(env::VarError::NotPresent) => Ok(None),
-        Err(e) => Err(e.into()),
-    }
+#[derive(Debug)]
+pub(crate) struct Cargo {
+    path: OsString,
+    pub(crate) nightly: bool,
 }
 
-// =============================================================================
-// Cargo manifest
-// https://doc.rust-lang.org/nightly/cargo/reference/manifest.html
+impl Cargo {
+    pub(crate) fn new(env: &Env, workspace_root: &Utf8Path) -> Result<Self> {
+        let mut path = env.cargo();
+        let version = cmd!(path, "version").dir(workspace_root).read()?;
+        let nightly = version.contains("-nightly") || version.contains("-dev");
+        if !nightly {
+            path = OsStr::new("cargo");
+        }
 
-#[derive(Debug, Deserialize)]
-pub(crate) struct Manifest {
-    pub(crate) package: Option<Package>,
+        Ok(Self { path: path.into(), nightly })
+    }
+
+    pub(crate) fn process(&self) -> ProcessBuilder {
+        let mut cmd = cmd!(&self.path);
+        if !self.nightly {
+            cmd.arg("+nightly");
+        }
+        cmd
+    }
 }
 
-// https://doc.rust-lang.org/nightly/cargo/reference/manifest.html#the-package-section
-#[derive(Debug, Deserialize)]
-pub(crate) struct Package {
-    pub(crate) name: String,
+pub(crate) fn config(cargo: &Cargo, workspace_root: &Utf8Path) -> Result<Config> {
+    let s = cargo
+        .process()
+        .args(&["-Z", "unstable-options", "config", "get", "--format", "json"])
+        .env("RUSTC_BOOTSTRAP", "1")
+        .dir(workspace_root)
+        .stderr_capture()
+        .read()?;
+    let mut config: Config = serde_json::from_str(&s)?;
+    config.apply_env()?;
+    Ok(config)
+}
+
+pub(crate) fn locate_project() -> Result<String> {
+    cmd!("cargo", "locate-project", "--message-format", "plain").read()
 }
 
 // =============================================================================
 // Cargo configuration
-// https://doc.rust-lang.org/nightly/cargo/reference/config.html
+//
+// Refs:
+// - https://doc.rust-lang.org/nightly/cargo/reference/config.html
+// - https://github.com/rust-lang/cargo/issues/9301
 
 #[derive(Debug, Default, Deserialize)]
 pub(crate) struct Config {
@@ -46,7 +74,7 @@ pub(crate) struct Config {
 
 impl Config {
     // Apply configuration environment variables
-    pub(crate) fn apply_env(&mut self) -> Result<()> {
+    fn apply_env(&mut self) -> Result<()> {
         // Environment variables are prefer over config values.
         // https://doc.rust-lang.org/nightly/cargo/reference/config.html#environment-variables
         if let Some(rustc) = ver("CARGO_BUILD_RUSTC")? {
@@ -58,6 +86,9 @@ impl Config {
         if let Some(rustdocflags) = ver("CARGO_BUILD_RUSTDOCFLAGS")? {
             self.build.rustdocflags = Some(StringOrArray::String(rustdocflags));
         }
+        if let Some(target) = ver("CARGO_BUILD_TARGET")? {
+            self.build.target = Some(target);
+        }
         if let Some(verbose) = ver("CARGO_TERM_VERBOSE")? {
             self.term.verbose = Some(verbose.parse()?);
         }
@@ -68,7 +99,7 @@ impl Config {
         Ok(())
     }
 
-    pub(crate) fn merge_to(self, args: &mut Args, env: &mut EnvironmentVariables) {
+    pub(crate) fn merge_to(self, args: &mut Args, env: &mut Env) {
         // RUSTFLAGS environment variable is prefer over build.rustflags config value.
         // https://doc.rust-lang.org/nightly/cargo/reference/config.html#buildrustflags
         if env.rustflags.is_none() {
@@ -89,6 +120,9 @@ impl Config {
                 env.rustc = Some(rustc.into());
             }
         }
+        if args.target.is_none() {
+            args.target = self.build.target;
+        }
         if args.verbose == 0 && self.term.verbose.unwrap_or(false) {
             args.verbose = 1;
         }
@@ -107,6 +141,8 @@ struct Build {
     rustflags: Option<StringOrArray>,
     // https://doc.rust-lang.org/nightly/cargo/reference/config.html#buildrustdocflags
     rustdocflags: Option<StringOrArray>,
+    // https://doc.rust-lang.org/nightly/cargo/reference/config.html#buildtarget
+    target: Option<String>,
 }
 
 // https://doc.rust-lang.org/nightly/cargo/reference/config.html#term
@@ -133,3 +169,12 @@ impl StringOrArray {
         }
     }
 }
+
+fn ver(key: &str) -> Result<Option<String>> {
+    match env::var(key) {
+        Ok(v) if v.is_empty() => Ok(None),
+        Ok(v) => Ok(Some(v)),
+        Err(env::VarError::NotPresent) => Ok(None),
+        Err(e) => Err(e.into()),
+    }
+}

src/cli.rs

@@ -1,35 +1,10 @@
-use std::{env, ffi::OsString};
-
-use anyhow::{format_err, Result};
+use anyhow::Result;
 use camino::Utf8PathBuf;
 use clap::{AppSettings, Clap};
 use serde::Deserialize;
 
-// Clap panics if you pass a non-utf8 value to an argument that expects a utf8
-// value.
-//
-// clap 3.0.0-beta.2:
-//      thread 'main' panicked at 'unexpected invalid UTF-8 code point', $CARGO/clap-3.0.0-beta.2/src/parse/matches/arg_matches.rs:220:28
-//
-// clap 2.33.3:
-//      thread 'main' panicked at 'unexpected invalid UTF-8 code point', $CARGO/clap-2.33.3/src/args/arg_matches.rs:217:28
-//
-// Even if you store a value as OsString and pass to cargo as is, you will get
-// the same panic on cargo side. e.g., `cargo check --manifest-path $'fo\x80o'`
-fn handle_args(args: impl IntoIterator<Item = impl Into<OsString>>) -> Result<Vec<String>> {
-    // Adapted from https://github.com/rust-lang/rust/blob/3bc9dd0dd293ab82945e35888ed6d7ab802761ef/compiler/rustc_driver/src/lib.rs#L1365-L1375.
-    args.into_iter()
-        .enumerate()
-        .map(|(i, arg)| {
-            arg.into()
-                .into_string()
-                .map_err(|arg| format_err!("argument {} is not valid Unicode: {:?}", i, arg))
-        })
-        .collect()
-}
-
 pub(crate) fn from_args() -> Result<Args> {
-    let Opts::LlvmCov(args) = Opts::parse_from(handle_args(env::args_os())?);
+    let Opts::LlvmCov(args) = Opts::parse();
     Ok(args)
 }
 
@@ -44,6 +19,7 @@ const MAX_TERM_WIDTH: usize = 100;
     bin_name = "cargo",
     max_term_width = MAX_TERM_WIDTH,
     setting = AppSettings::DeriveDisplayOrder,
+    setting = AppSettings::StrictUtf8,
     setting = AppSettings::UnifiedHelpMessage,
 )]
 enum Opts {
@@ -57,6 +33,7 @@ enum Opts {
     about = ABOUT,
     max_term_width = MAX_TERM_WIDTH,
     setting = AppSettings::DeriveDisplayOrder,
+    setting = AppSettings::StrictUtf8,
     setting = AppSettings::UnifiedHelpMessage,
 )]
 pub(crate) struct Args {
@@ -128,16 +105,22 @@ pub(crate) struct Args {
     // For debugging (unstable)
     #[clap(long, hidden = true)]
     pub(crate) disable_default_ignore_filename_regex: bool,
+    // For debugging (unstable)
+    #[clap(long, hidden = true)]
+    pub(crate) hide_instantiations: bool,
 
     // https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/instrument-coverage.html#including-doc-tests
     /// Including doc tests (unstable)
     #[clap(long)]
     pub(crate) doctests: bool,
+    /// Run tests, but don't generate coverage reports
+    #[clap(long, conflicts_with_all = &["no-run"])]
+    pub(crate) no_report: bool,
 
     // =========================================================================
     // `cargo test` options
     // https://doc.rust-lang.org/nightly/cargo/commands/cargo-test.html
-    /// Compile, but don't run tests (unstable)
+    /// Generate coverage reports without running tests
     #[clap(long)]
     pub(crate) no_run: bool,
     /// Run all tests regardless of failure
@@ -217,7 +200,9 @@ impl Args {
 pub(crate) enum Subcommand {
     // internal (unstable)
     #[clap(
+        max_term_width = MAX_TERM_WIDTH,
         setting = AppSettings::DeriveDisplayOrder,
+        setting = AppSettings::StrictUtf8,
         setting = AppSettings::UnifiedHelpMessage,
         setting = AppSettings::Hidden,
     )]
@@ -250,12 +235,12 @@ mod tests {
 
     use anyhow::Result;
     use clap::IntoApp;
+    use fs_err as fs;
     use tempfile::Builder;
 
     use super::{Args, MAX_TERM_WIDTH};
-    use crate::fs;
 
-    // See handle_args function for more.
+    // https://github.com/clap-rs/clap/issues/751
     #[cfg(unix)]
     #[test]
     fn non_utf8_arg() {
@@ -266,17 +251,7 @@ mod tests {
         use super::Opts;
 
         // `cargo llvm-cov -- $'fo\x80o'`
-        let res = panic::catch_unwind(|| {
-            drop(Opts::try_parse_from(&[
-                "cargo".as_ref(),
-                "llvm-cov".as_ref(),
-                "--".as_ref(),
-                OsStr::from_bytes(&[b'f', b'o', 0x80, b'o']),
-            ]));
-        });
-        assert!(res.is_err());
-
-        super::handle_args(&[
+        Opts::try_parse_from(&[
             "cargo".as_ref(),
             "llvm-cov".as_ref(),
             "--".as_ref(),