From f42a6d1026fc2350766be9a755d124ab49e28138 Mon Sep 17 00:00:00 2001
From: hyd-dev <yd-huang@outlook.com>
Date: Thu, 27 May 2021 06:40:47 +0800
Subject: [PATCH] Skip doctests of `proc-macro` crates

---
 cargo-miri/bin.rs                                  | 7 +++++++
 test-cargo-miri/run-test.py                        | 4 ++++
 test-cargo-miri/subcrate/src/lib.rs                | 3 +++
 test-cargo-miri/test.stderr-proc-macro-doctest.ref | 1 +
 test-cargo-miri/test.stdout-empty.ref              | 0
 5 files changed, 15 insertions(+)
 create mode 100644 test-cargo-miri/test.stderr-proc-macro-doctest.ref
 create mode 100644 test-cargo-miri/test.stdout-empty.ref

diff --git a/cargo-miri/bin.rs b/cargo-miri/bin.rs
index 295acd6638a..19d235cf67d 100644
--- a/cargo-miri/bin.rs
+++ b/cargo-miri/bin.rs
@@ -903,6 +903,13 @@ fn phase_rustdoc(fst_arg: &str, mut args: env::Args) {
         show_error(format!("cross-interpreting doc-tests is not currently supported by Miri."));
     }
 
+    // Doc-tests of `proc-macro` crates (and their dependencies) are always built for the host,
+    // so we are not able to run them in Miri.
+    if ArgFlagValueIter::new("--crate-type").any(|crate_type| crate_type == "proc-macro") {
+        eprintln!("Running doc-tests of `proc-macro` crates is not currently supported by Miri.");
+        return;
+    }
+
     // For each doc-test, rustdoc starts two child processes: first the test is compiled,
     // then the produced executable is invoked. We want to reroute both of these to cargo-miri,
     // such that the first time we'll enter phase_cargo_rustc, and phase_cargo_runner second.
diff --git a/test-cargo-miri/run-test.py b/test-cargo-miri/run-test.py
index 9185c2507b6..c850e7d1459 100755
--- a/test-cargo-miri/run-test.py
+++ b/test-cargo-miri/run-test.py
@@ -140,6 +140,10 @@ def test_cargo_miri_test():
         "test.subcrate.stdout.ref", "test.stderr-proc-macro.ref",
         env={'MIRIFLAGS': "-Zmiri-disable-isolation"},
     )
+    test("`cargo miri test` (subcrate, doctests)",
+        cargo_miri("test") + ["-p", "subcrate", "--doc"],
+        "test.stdout-empty.ref", "test.stderr-proc-macro-doctest.ref",
+    )
 
 os.chdir(os.path.dirname(os.path.realpath(__file__)))
 os.environ["RUST_TEST_NOCAPTURE"] = "0" # this affects test output, so make sure it is not set
diff --git a/test-cargo-miri/subcrate/src/lib.rs b/test-cargo-miri/subcrate/src/lib.rs
index 706e368017c..07ed1acb7a0 100644
--- a/test-cargo-miri/subcrate/src/lib.rs
+++ b/test-cargo-miri/subcrate/src/lib.rs
@@ -1,2 +1,5 @@
+#[cfg(doctest)]
+use num_cpus as _;
+
 #[cfg(test)]
 compile_error!("Miri should not touch me");
diff --git a/test-cargo-miri/test.stderr-proc-macro-doctest.ref b/test-cargo-miri/test.stderr-proc-macro-doctest.ref
new file mode 100644
index 00000000000..55d0f7cf54a
--- /dev/null
+++ b/test-cargo-miri/test.stderr-proc-macro-doctest.ref
@@ -0,0 +1 @@
+Running doc-tests of `proc-macro` crates is not currently supported by Miri.
diff --git a/test-cargo-miri/test.stdout-empty.ref b/test-cargo-miri/test.stdout-empty.ref
new file mode 100644
index 00000000000..e69de29bb2d