llvm-cov support pt1

.gitignore

@@ -6,5 +6,6 @@ target/
 *.log
 *.profdata
 *.profraw
+*.profdata
 # Generated by IntelliJ IDEs
 .idea

CHANGELOG.md

@@ -3,12 +3,23 @@
 From 2019 onwards, all notable changes to tarpaulin will be documented in this
 file.
 
+## [Unreleased]
+### Added
+- Check if user sets -Cdebuginfo and remove it #601
+- INTERNAL Added ability to build with LLVM coverage instrumentation and detect
+compiler support. This isn't enabled so should have no effect it's just the
+start of the support work.
+
+### Changed
+- Make doctest prefix matching less specific as the naming convention changed again
+
+### Removed
+
 ## [0.18.0-alpha1] 2021-02-14
 ### Added
 - Added `--color` option matching cargo arg
 - `--follow-exec` option making exec tracing non-default
 - `--jobs` option matching the one in cargo test
-- Check if user sets -Cdebuginfo and remove it #601
 
 ### Changed
 - Check through memory map for the first entry belonging to the executable [FIX]
@@ -21,7 +32,6 @@ file.
 - Hidden file filtering only applied for folders inside project directory not
 any folder on path. Fixes #682
 - Removed unimplemented `toml` report
-- Make doctest prefix matching less specific as the naming convention changed again
 
 ### Removed
 

src/cargo.rs

@@ -15,15 +15,29 @@ use std::process::{Command, Stdio};
 use tracing::{error, trace, warn};
 use walkdir::{DirEntry, WalkDir};
 
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
+enum Channel {
+    Stable,
+    Beta,
+    Nightly,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 struct CargoVersionInfo {
     major: usize,
     minor: usize,
+    channel: Channel,
     year: usize,
     month: usize,
     day: usize,
 }
 
+impl CargoVersionInfo {
+    fn supports_llvm_cov(&self) -> bool {
+        self.minor >= 50 && self.channel == Channel::Nightly
+    }
+}
+
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Deserialize, Serialize)]
 pub struct TestBinary {
     path: PathBuf,
@@ -108,9 +122,10 @@ impl DocTestBinaryMeta {
 
 lazy_static! {
     static ref CARGO_VERSION_INFO: Option<CargoVersionInfo> = {
-        let version_info =
-            Regex::new(r"cargo (\d)\.(\d+)\.\d+\-nightly \([[:alnum:]]+ (\d{4})-(\d{2})-(\d{2})\)")
-                .unwrap();
+        let version_info = Regex::new(
+            r"cargo (\d)\.(\d+)\.\d+([\-betanightly]*) \([[:alnum:]]+ (\d{4})-(\d{2})-(\d{2})\)",
+        )
+        .unwrap();
         Command::new("cargo")
             .arg("--version")
             .output()
@@ -119,12 +134,20 @@ lazy_static! {
                 if let Some(cap) = version_info.captures(&s) {
                     let major = cap[1].parse().unwrap();
                     let minor = cap[2].parse().unwrap();
-                    let year = cap[3].parse().unwrap();
-                    let month = cap[4].parse().unwrap();
-                    let day = cap[5].parse().unwrap();
+                    // We expect a string like `cargo 1.50.0-nightly (a0f433460 2020-02-01)
+                    // the version number either has `-nightly` `-beta` or empty for stable
+                    let channel = match &cap[3] {
+                        "-nightly" => Channel::Nightly,
+                        "-beta" => Channel::Beta,
+                        _ => Channel::Stable,
+                    };
+                    let year = cap[4].parse().unwrap();
+                    let month = cap[5].parse().unwrap();
+                    let day = cap[6].parse().unwrap();
                     Some(CargoVersionInfo {
                         major,
                         minor,
+                        channel,
                         year,
                         month,
                         day,
@@ -493,6 +516,16 @@ fn clean_doctest_folder<P: AsRef<Path>>(doctest_dir: P) {
     }
 }
 
+fn handle_llvm_flags(value: &mut String, config: &Config) {
+    if (config.engine == TraceEngine::Auto || config.engine == TraceEngine::Llvm)
+        && supports_llvm_coverage()
+    {
+        value.push_str("-Z instrument-coverage ");
+    } else if config.engine == TraceEngine::Llvm {
+        error!("unable to utilise llvm coverage, due to compiler support. Falling back to Ptrace");
+    }
+}
+
 pub fn rustdoc_flags(config: &Config) -> String {
     const RUSTDOC: &str = "RUSTDOCFLAGS";
     let common_opts = " -C link-dead-code -C debuginfo=2 --cfg=tarpaulin ";
@@ -506,18 +539,20 @@ pub fn rustdoc_flags(config: &Config) -> String {
             value.push_str(vtemp.as_ref());
         }
     }
+    handle_llvm_flags(&mut value, config);
     value
 }
 
 pub fn rust_flags(config: &Config) -> String {
     const RUSTFLAGS: &str = "RUSTFLAGS";
     let mut value = " -C link-dead-code -C debuginfo=2 ".to_string();
     if !config.avoid_cfg_tarpaulin {
-        value = format!("{}--cfg=tarpaulin ", value);
+        value.push_str("--cfg=tarpaulin ");
     }
     if config.release {
-        value = format!("{}-C debug-assertions=off ", value);
+        value.push_str("-C debug-assertions=off ");
     }
+    handle_llvm_flags(&mut value, config);
     if let Ok(vtemp) = env::var(RUSTFLAGS) {
         lazy_static! {
             static ref DEBUG_INFO: Regex = Regex::new(r#"\-C\s*debuginfo=\d"#).unwrap();
@@ -538,3 +573,49 @@ fn setup_environment(cmd: &mut Command, config: &Config) {
     trace!("Setting RUSTDOCFLAGS='{}'", value);
     cmd.env(rustdoc, value);
 }
+
+fn supports_llvm_coverage() -> bool {
+    if let Some(version) = CARGO_VERSION_INFO.as_ref() {
+        version.supports_llvm_cov()
+    } else {
+        false
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn llvm_cov_compatible_version() {
+        let version = CargoVersionInfo {
+            major: 1,
+            minor: 50,
+            channel: Channel::Nightly,
+            year: 2020,
+            month: 12,
+            day: 22,
+        };
+        assert!(version.supports_llvm_cov());
+    }
+
+    #[test]
+    fn llvm_cov_incompatible_version() {
+        let mut version = CargoVersionInfo {
+            major: 1,
+            minor: 48,
+            channel: Channel::Stable,
+            year: 2020,
+            month: 10,
+            day: 14,
+        };
+        assert!(!version.supports_llvm_cov());
+        version.channel = Channel::Beta;
+        assert!(!version.supports_llvm_cov());
+        version.minor = 50;
+        assert!(!version.supports_llvm_cov());
+        version.minor = 58;
+        version.channel = Channel::Stable;
+        assert!(!version.supports_llvm_cov());
+    }
+}

src/config/mod.rs

@@ -165,6 +165,8 @@ pub struct Config {
     pub follow_exec: bool,
     /// Number of jobs used for building the tests
     pub jobs: Option<usize>,
+    /// Engine to use to collect coverage
+    pub engine: TraceEngine,
 }
 
 fn default_test_timeout() -> Duration {
@@ -227,6 +229,7 @@ impl Default for Config {
             avoid_cfg_tarpaulin: false,
             jobs: None,
             color: Color::Auto,
+            engine: TraceEngine::Ptrace,
         }
     }
 }
@@ -300,6 +303,7 @@ impl<'a> From<&'a ArgMatches<'a>> for ConfigWrapper {
             profile: get_profile(args),
             metadata: RefCell::new(None),
             avoid_cfg_tarpaulin: args.is_present("avoid-cfg-tarpaulin"),
+            engine: TraceEngine::Ptrace,
         };
         if args.is_present("ignore-config") {
             Self(vec![args_config])

src/config/types.rs

@@ -12,6 +12,15 @@ arg_enum! {
     }
 }
 
+arg_enum! {
+    #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
+    pub enum TraceEngine {
+        Auto,
+        Ptrace,
+        Llvm,
+    }
+}
+
 arg_enum! {
     #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Ord, PartialOrd, Deserialize, Serialize)]
     pub enum Mode {

src/lib.rs

@@ -329,6 +329,10 @@ fn execute_test(test: &TestBinary, ignored: bool, config: &Config) -> Result<(),
         envars
             .push(CString::new(format!("CARGO_MANIFEST_DIR={}", s.display())).unwrap_or_default());
     }
+    if config.engine == TraceEngine::Llvm || config.engine == TraceEngine::Auto {
+        // Used for llvm coverage to avoid report naming clashes
+        envars.push(CString::new("LLVM_PROFILE_FILE=default_%p.profraw").unwrap_or_default());
+    }
 
     execute(exec_path, &argv, envars.as_slice())
 }