Allow coverage tests to ignore test modes, and to enable color in coverage reports

src/bootstrap/src/core/build_steps/test.rs

@@ -1976,7 +1976,7 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
         }
 
         if builder.config.profiler_enabled(target) {
-            cmd.env("RUSTC_PROFILER_SUPPORT", "1");
+            cmd.arg("--profiler-support");
         }
 
         cmd.env("RUST_TEST_TMPDIR", builder.tempdir());

src/tools/compiletest/src/common.rs

@@ -387,6 +387,10 @@ pub struct Config {
     // Needed both to construct build_helper::git::GitConfig
     pub git_repository: String,
     pub nightly_branch: String,
+
+    /// True if the profiler runtime is enabled for this target.
+    /// Used by the "needs-profiler-support" header in test files.
+    pub profiler_support: bool,
 }
 
 impl Config {

src/tools/compiletest/src/header.rs

@@ -178,6 +178,9 @@ pub struct TestProps {
     // Whether to tell `rustc` to remap the "src base" directory to a fake
     // directory.
     pub remap_src_base: bool,
+    /// Extra flags to pass to `llvm-cov` when producing coverage reports.
+    /// Only used by the "coverage-run" test mode.
+    pub llvm_cov_flags: Vec<String>,
 }
 
 mod directives {
@@ -216,6 +219,7 @@ mod directives {
     pub const MIR_UNIT_TEST: &'static str = "unit-test";
     pub const REMAP_SRC_BASE: &'static str = "remap-src-base";
     pub const COMPARE_OUTPUT_LINES_BY_SUBSET: &'static str = "compare-output-lines-by-subset";
+    pub const LLVM_COV_FLAGS: &'static str = "llvm-cov-flags";
     // This isn't a real directive, just one that is probably mistyped often
     pub const INCORRECT_COMPILER_FLAGS: &'static str = "compiler-flags";
 }
@@ -265,6 +269,7 @@ impl TestProps {
             stderr_per_bitwidth: false,
             mir_unit_test: None,
             remap_src_base: false,
+            llvm_cov_flags: vec![],
         }
     }
 
@@ -321,16 +326,23 @@ impl TestProps {
                     |r| r,
                 );
 
-                if let Some(flags) = config.parse_name_value_directive(ln, COMPILE_FLAGS) {
-                    self.compile_flags.extend(
-                        flags
-                            .split("'")
-                            .enumerate()
-                            .flat_map(|(i, f)| {
+                fn split_flags(flags: &str) -> Vec<String> {
+                    // Individual flags can be single-quoted to preserve spaces; see
+                    // <https://github.com/rust-lang/rust/pull/115948/commits/957c5db6>.
+                    flags
+                        .split("'")
+                        .enumerate()
+                        .flat_map(
+                            |(i, f)| {
                                 if i % 2 == 1 { vec![f] } else { f.split_whitespace().collect() }
-                            })
-                            .map(|s| s.to_owned()),
-                    );
+                            },
+                        )
+                        .map(move |s| s.to_owned())
+                        .collect::<Vec<_>>()
+                }
+
+                if let Some(flags) = config.parse_name_value_directive(ln, COMPILE_FLAGS) {
+                    self.compile_flags.extend(split_flags(&flags));
                 }
                 if config.parse_name_value_directive(ln, INCORRECT_COMPILER_FLAGS).is_some() {
                     panic!("`compiler-flags` directive should be spelled `compile-flags`");
@@ -488,6 +500,10 @@ impl TestProps {
                     COMPARE_OUTPUT_LINES_BY_SUBSET,
                     &mut self.compare_output_lines_by_subset,
                 );
+
+                if let Some(flags) = config.parse_name_value_directive(ln, LLVM_COV_FLAGS) {
+                    self.llvm_cov_flags.extend(split_flags(&flags));
+                }
             });
         }
 

src/tools/compiletest/src/header/cfg.rs

@@ -1,4 +1,4 @@
-use crate::common::{CompareMode, Config, Debugger};
+use crate::common::{CompareMode, Config, Debugger, Mode};
 use crate::header::IgnoreDecision;
 use std::collections::HashSet;
 
@@ -208,6 +208,17 @@ pub(super) fn parse_cfg_name_directive<'a>(
         },
         message: "when comparing with {name}",
     }
+    // Coverage tests run the same test file in multiple modes.
+    // If a particular test should not be run in one of the modes, ignore it
+    // with "ignore-mode-coverage-map" or "ignore-mode-coverage-run".
+    condition! {
+        name: format!("mode-{}", config.mode.to_str()),
+        allowed_names: ContainsPrefixed {
+            prefix: "mode-",
+            inner: Mode::STR_VARIANTS,
+        },
+        message: "when the test mode is {name}",
+    }
 
     if prefix == "ignore" && outcome == MatchOutcome::Invalid {
         // Don't error out for ignore-tidy-* diretives, as those are not handled by compiletest.

src/tools/compiletest/src/header/needs.rs

@@ -238,7 +238,7 @@ impl CachedNeedsConditions {
             sanitizer_memtag: sanitizers.contains(&Sanitizer::Memtag),
             sanitizer_shadow_call_stack: sanitizers.contains(&Sanitizer::ShadowCallStack),
             sanitizer_safestack: sanitizers.contains(&Sanitizer::Safestack),
-            profiler_support: std::env::var_os("RUSTC_PROFILER_SUPPORT").is_some(),
+            profiler_support: config.profiler_support,
             xray: config.target_cfg().xray,
 
             // For tests using the `needs-rust-lld` directive (e.g. for `-Clink-self-contained=+linker`),

src/tools/compiletest/src/header/tests.rs

@@ -1,7 +1,8 @@
 use std::io::Read;
 use std::path::Path;
+use std::str::FromStr;
 
-use crate::common::{Config, Debugger};
+use crate::common::{Config, Debugger, Mode};
 use crate::header::{parse_normalization_string, EarlyProps, HeadersCache};
 
 fn make_test_description<R: Read>(
@@ -55,16 +56,23 @@ fn test_parse_normalization_string() {
 
 #[derive(Default)]
 struct ConfigBuilder {
+    mode: Option<String>,
     channel: Option<String>,
     host: Option<String>,
     target: Option<String>,
     stage_id: Option<String>,
     llvm_version: Option<String>,
     git_hash: bool,
     system_llvm: bool,
+    profiler_support: bool,
 }
 
 impl ConfigBuilder {
+    fn mode(&mut self, s: &str) -> &mut Self {
+        self.mode = Some(s.to_owned());
+        self
+    }
+
     fn channel(&mut self, s: &str) -> &mut Self {
         self.channel = Some(s.to_owned());
         self
@@ -100,10 +108,16 @@ impl ConfigBuilder {
         self
     }
 
+    fn profiler_support(&mut self, s: bool) -> &mut Self {
+        self.profiler_support = s;
+        self
+    }
+
     fn build(&mut self) -> Config {
         let args = &[
             "compiletest",
-            "--mode=ui",
+            "--mode",
+            self.mode.as_deref().unwrap_or("ui"),
             "--suite=ui",
             "--compile-lib-path=",
             "--run-lib-path=",
@@ -142,6 +156,9 @@ impl ConfigBuilder {
         if self.system_llvm {
             args.push("--system-llvm".to_owned());
         }
+        if self.profiler_support {
+            args.push("--profiler-support".to_owned());
+        }
 
         args.push("--rustc-path".to_string());
         // This is a subtle/fragile thing. On rust-lang CI, there is no global
@@ -340,6 +357,15 @@ fn sanitizers() {
     assert!(check_ignore(&config, "// needs-sanitizer-thread"));
 }
 
+#[test]
+fn profiler_support() {
+    let config: Config = cfg().profiler_support(false).build();
+    assert!(check_ignore(&config, "// needs-profiler-support"));
+
+    let config: Config = cfg().profiler_support(true).build();
+    assert!(!check_ignore(&config, "// needs-profiler-support"));
+}
+
 #[test]
 fn asm_support() {
     let asms = [
@@ -530,3 +556,17 @@ fn families() {
         assert!(!check_ignore(&config, &format!("// ignore-{other}")));
     }
 }
+
+#[test]
+fn ignore_mode() {
+    for &mode in Mode::STR_VARIANTS {
+        // Indicate profiler support so that "coverage-run" tests aren't skipped.
+        let config: Config = cfg().mode(mode).profiler_support(true).build();
+        let other = if mode == "coverage-run" { "coverage-map" } else { "coverage-run" };
+        assert_ne!(mode, other);
+        assert_eq!(config.mode, Mode::from_str(mode).unwrap());
+        assert_ne!(config.mode, Mode::from_str(other).unwrap());
+        assert!(check_ignore(&config, &format!("// ignore-mode-{mode}")));
+        assert!(!check_ignore(&config, &format!("// ignore-mode-{other}")));
+    }
+}

src/tools/compiletest/src/lib.rs

@@ -142,6 +142,7 @@ pub fn parse_config(args: Vec<String>) -> Config {
         .optflag("", "force-rerun", "rerun tests even if the inputs are unchanged")
         .optflag("", "only-modified", "only run tests that result been modified")
         .optflag("", "nocapture", "")
+        .optflag("", "profiler-support", "is the profiler runtime enabled for this target")
         .optflag("h", "help", "show this message")
         .reqopt("", "channel", "current Rust channel", "CHANNEL")
         .optflag("", "git-hash", "run tests which rely on commit version being compiled into the binaries")
@@ -315,6 +316,8 @@ pub fn parse_config(args: Vec<String>) -> Config {
 
         git_repository: matches.opt_str("git-repository").unwrap(),
         nightly_branch: matches.opt_str("nightly-branch").unwrap(),
+
+        profiler_support: matches.opt_present("profiler-support"),
     }
 }
 

src/tools/compiletest/src/runtest.rs

@@ -575,6 +575,8 @@ impl<'test> TestCx<'test> {
                 cmd.arg("--object");
                 cmd.arg(bin);
             }
+
+            cmd.args(&self.props.llvm_cov_flags);
         });
         if !proc_res.status.success() {
             self.fatal_proc_rec("llvm-cov show failed!", &proc_res);

tests/coverage/color.coverage

@@ -0,0 +1,13 @@
+   LL|       |// edition: 2021
+   LL|       |// ignore-mode-coverage-map
+   LL|       |// ignore-windows
+   LL|       |// llvm-cov-flags: --use-color
+   LL|       |
+   LL|       |// Verify that telling `llvm-cov` to use colored output actually works.
+   LL|       |// Ignored on Windows because we can't tell the tool to use ANSI escapes.
+   LL|       |
+   LL|      1|fn main() {
+   LL|      1|    for _i in 0..0 {}
+                      ^0         ^0
+   LL|      1|}
+

tests/coverage/color.rs

@@ -0,0 +1,11 @@
+// edition: 2021
+// ignore-mode-coverage-map
+// ignore-windows
+// llvm-cov-flags: --use-color
+
+// Verify that telling `llvm-cov` to use colored output actually works.
+// Ignored on Windows because we can't tell the tool to use ANSI escapes.
+
+fn main() {
+    for _i in 0..0 {}
+}

tests/coverage/ignore_map.coverage

@@ -0,0 +1,4 @@
+   LL|       |// ignore-mode-coverage-map
+   LL|       |
+   LL|      1|fn main() {}
+

tests/coverage/ignore_map.rs

@@ -0,0 +1,3 @@
+// ignore-mode-coverage-map
+
+fn main() {}

tests/coverage/ignore_run.cov-map

@@ -0,0 +1,8 @@
+Function name: ignore_run::main
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 03, 01, 00, 0d]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 3, 1) to (start + 0, 13)
+

tests/coverage/ignore_run.rs

@@ -0,0 +1,3 @@
+// ignore-mode-coverage-run
+
+fn main() {}