compiletest: introduce skip-trans

src/test/run-pass/compiletest-skip-trans.rs

+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Test that with the `skip-trans` option the test isn't executed.
+
+// skip-trans
+
+fn main() {
+    unreachable!();
+}

src/tools/compiletest/src/header.rs

@@ -228,6 +228,8 @@ pub struct TestProps {
     pub check_test_line_numbers_match: bool,
     // The test must be compiled and run successfully. Only used in UI tests for now.
     pub run_pass: bool,
+    // Skip any codegen step and running the executable. Only for run-pass.
+    pub skip_trans: bool,
     // Do not pass `-Z ui-testing` to UI tests
     pub disable_ui_testing_normalization: bool,
     // customized normalization rules
@@ -260,6 +262,7 @@ pub fn new() -> Self {
             compile_pass: false,
             check_test_line_numbers_match: false,
             run_pass: false,
+            skip_trans: false,
             disable_ui_testing_normalization: false,
             normalize_stdout: vec![],
             normalize_stderr: vec![],
@@ -381,6 +384,10 @@ fn load_from(&mut self,
                     config.parse_compile_pass(ln) || self.run_pass;
             }
 
+                        if !self.skip_trans {
+                            self.skip_trans = config.parse_skip_trans(ln);
+                        }
+
             if !self.disable_ui_testing_normalization {
                 self.disable_ui_testing_normalization =
                     config.parse_disable_ui_testing_normalization(ln);
@@ -524,6 +531,10 @@ fn parse_run_pass(&self, line: &str) -> bool {
         self.parse_name_directive(line, "run-pass")
     }
 
+    fn parse_skip_trans(&self, line: &str) -> bool {
+        self.parse_name_directive(line, "skip-trans")
+    }
+
     fn parse_env(&self, line: &str, name: &str) -> Option<(String, String)> {
         self.parse_name_value_directive(line, name).map(|nv| {
             // nv is either FOO or FOO=BAR

src/tools/compiletest/src/runtest.rs

@@ -343,9 +343,11 @@ fn run_rpass_test(&self) {
             "run-pass tests with expected warnings should be moved to ui/"
         );
 
-        let proc_res = self.exec_compiled_test();
-        if !proc_res.status.success() {
-            self.fatal_proc_rec("test run failed!", &proc_res);
+        if !self.props.skip_trans {
+            let proc_res = self.exec_compiled_test();
+            if !proc_res.status.success() {
+                self.fatal_proc_rec("test run failed!", &proc_res);
+            }
         }
     }
 
@@ -1697,6 +1699,11 @@ fn make_compile_args(&self, input_file: &Path, output_file: TargetLocation) -> C
             }
         }
 
+        if self.props.skip_trans {
+            assert!(!self.props.compile_flags.iter().any(|s| s.starts_with("--emit")));
+            rustc.args(&["--emit", "metadata"]);
+        }
+
         if !is_rustdoc {
             if self.config.target == "wasm32-unknown-unknown" {
                 // rustc.arg("-g"); // get any backtrace at all on errors