compiletest: Remove the libtest-based executor and its dependency

src/bootstrap/src/core/build_steps/tool.rs

@@ -462,7 +462,7 @@ macro_rules! bootstrap_tool {
     }
 }
 
-pub(crate) const COMPILETEST_ALLOW_FEATURES: &str = "test,internal_output_capture";
+pub(crate) const COMPILETEST_ALLOW_FEATURES: &str = "internal_output_capture";
 
 bootstrap_tool!(
     // This is marked as an external tool because it includes dependencies

src/tools/compiletest/src/common.rs

@@ -413,14 +413,6 @@ pub struct Config {
     /// cross-compilation scenarios that do not otherwise want/need to `-Zbuild-std`. Used in e.g.
     /// ABI tests.
     pub minicore_path: Utf8PathBuf,
-
-    /// If true, disable the "new" executor, and use the older libtest-based
-    /// executor to run tests instead. This is a temporary fallback, to make
-    /// manual comparative testing easier if bugs are found in the new executor.
-    ///
-    /// FIXME(Zalathar): Eventually remove this flag and remove the libtest
-    /// dependency.
-    pub no_new_executor: bool,
 }
 
 impl Config {

src/tools/compiletest/src/executor.rs

@@ -12,7 +12,6 @@ use crate::common::{Config, TestPaths};
 
 mod deadline;
 mod json;
-pub(crate) mod libtest;
 
 pub(crate) fn run_tests(config: &Config, tests: Vec<CollectedTest>) -> bool {
     let tests_len = tests.len();

src/tools/compiletest/src/lib.rs

@@ -1,11 +1,10 @@
 #![crate_name = "compiletest"]
-// Needed by the libtest-based test executor.
-#![feature(test)]
 // Needed by the "new" test executor that does not depend on libtest.
+// FIXME(Zalathar): We should be able to get rid of `internal_output_capture`,
+// by having `runtest` manually capture all of its println-like output instead.
+// That would result in compiletest being written entirely in stable Rust!
 #![feature(internal_output_capture)]
 
-extern crate test;
-
 #[cfg(test)]
 mod tests;
 
@@ -448,8 +447,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
         diff_command: matches.opt_str("compiletest-diff-tool"),
 
         minicore_path: opt_path(matches, "minicore-path"),
-
-        no_new_executor: matches.opt_present("no-new-executor"),
     }
 }
 
@@ -576,12 +573,10 @@ pub fn run_tests(config: Arc<Config>) {
     // Delegate to the executor to filter and run the big list of test structures
     // created during test discovery. When the executor decides to run a test,
     // it will return control to the rest of compiletest by calling `runtest::run`.
-    let res = if !config.no_new_executor {
-        Ok(executor::run_tests(&config, tests))
-    } else {
-        // FIXME(Zalathar): Eventually remove the libtest executor entirely.
-        crate::executor::libtest::execute_tests(&config, tests)
-    };
+    // FIXME(Zalathar): Once we're confident that we won't need to revert the
+    // removal of the libtest-based executor, remove this Result and other
+    // remnants of the old executor.
+    let res: io::Result<bool> = Ok(executor::run_tests(&config, tests));
 
     // Check the outcome reported by libtest.
     match res {