added --no-run option for rustdoc

src/librustdoc/config.rs

@@ -121,6 +121,8 @@ crate struct Options {
     /// For example, using ignore-foo to ignore running the doctest on any target that
     /// contains "foo" as a substring
     crate enable_per_target_ignores: bool,
+    /// Do not run doctests, compile them if should_test is active.
+    crate no_run: bool,
 
     /// The path to a rustc-like binary to build tests with. If not set, we
     /// default to loading from `$sysroot/bin/rustc`.
@@ -198,6 +200,7 @@ impl fmt::Debug for Options {
             .field("runtool_args", &self.runtool_args)
             .field("enable-per-target-ignores", &self.enable_per_target_ignores)
             .field("run_check", &self.run_check)
+            .field("no_run", &self.no_run)
             .finish()
     }
 }
@@ -626,6 +629,7 @@ impl Options {
         let document_hidden = matches.opt_present("document-hidden-items");
         let run_check = matches.opt_present("check");
         let generate_redirect_map = matches.opt_present("generate-redirect-map");
+        let no_run = matches.opt_present("no-run");
 
         let (lint_opts, describe_lints, lint_cap) = get_cmd_lint_options(matches, error_format);
 
@@ -662,6 +666,7 @@ impl Options {
             enable_per_target_ignores,
             test_builder,
             run_check,
+            no_run,
             render_options: RenderOptions {
                 output,
                 external_html,

src/librustdoc/doctest.rs

@@ -940,13 +940,14 @@ impl Tester for Collector {
                 let report_unused_externs = |uext| {
                     unused_externs.lock().unwrap().push(uext);
                 };
+                let no_run = config.no_run || options.no_run;
                 let res = run_test(
                     &test,
                     &cratename,
                     line,
                     options,
                     config.should_panic,
-                    config.no_run,
+                    no_run,
                     config.test_harness,
                     runtool,
                     runtool_args,

src/librustdoc/lib.rs

@@ -536,6 +536,7 @@ fn opts() -> Vec<RustcOptGroup> {
                 "[unversioned-shared-resources,toolchain-shared-resources,invocation-specific]",
             )
         }),
+        unstable("no-run", |o| o.optflag("", "no-run", "Compile doctests without running them")),
     ]
 }