Revert "Conditionally mark the test cfg as a well known cfg (#15007)" (#15132)

This reverts #15007,
as it causes confusions and needs more time to figure out a proper
solution.

See

* #15131
*
<https://rust-lang.zulipchat.com/#narrow/channel/246057-t-cargo/topic/.60test.60.20well.20known.20cfg.20error>
* <https://github.com/rust-lang/cargo/pull/15007#discussion_r1938322212>

src/cargo/core/compiler/mod.rs

@@ -1391,26 +1391,17 @@ fn check_cfg_args(unit: &Unit) -> Vec<OsString> {
     }
     arg_feature.push("))");
 
-    // In addition to the package features, we also conditionaly include the `test` cfg
+    // In addition to the package features, we also include the `test` cfg (since
-    // based on the unit target "test" field (ie `lib.test = false`, `[[bin]] test = false` and
+    // compiler-team#785, as to be able to someday apply yt conditionaly), as well
-    // others).
+    // the `docsrs` cfg from the docs.rs service.
     //
-    // We also include `docsrs` here (in Cargo) instead of rustc, since there is a much closer
+    // We include `docsrs` here (in Cargo) instead of rustc, since there is a much closer
     // relationship between Cargo and docs.rs than rustc and docs.rs. In particular, all
     // users of docs.rs use Cargo, but not all users of rustc (like Rust-for-Linux) use docs.rs.
-    let arg_extra = if unit.target.tested()
-        // Benchmarks default to `test = false` but most of them still use the test crate
-        // and the `#[test]` attribute, so for now always mark `test` as well known for them.
-        || unit.target.is_bench()
-    {
-        OsString::from("cfg(docsrs,test)")
-    } else {
-        OsString::from("cfg(docsrs)")
-    };
 
     vec![
         OsString::from("--check-cfg"),
-        arg_extra,
+        OsString::from("cfg(docsrs,test)"),
         OsString::from("--check-cfg"),
         arg_feature,
     ]

src/doc/src/reference/cargo-targets.md

@@ -216,10 +216,7 @@ the target name.
 ### The `test` field
 
 The `test` field indicates whether or not the target is tested by default by
-[`cargo test`], and whenever the target is expected to have tests. Warnings
+[`cargo test`]. The default is `true` for lib, bins, and tests.
-may be reported when tests are unexpected (i.e., `test = false`).
-
-The default is `true` for lib, bins, and tests.
 
 > **Note**: Examples are built by [`cargo test`] by default to ensure they
 > continue to compile, but they are not *tested* by default. Setting `test =

tests/testsuite/check_cfg.rs

@@ -317,193 +317,6 @@ fn well_known_names_values_doctest() {
         .run();
 }
 
-#[cargo_test(nightly, reason = "warning currently only on nightly")]
-fn test_false_lib() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2018"
-
-                [lib]
-                test = false
-            "#,
-        )
-        .file("src/lib.rs", "#[cfg(test)] mod tests {}")
-        .build();
-
-    p.cargo("check -v")
-        .with_stderr_does_not_contain(x!("rustc" => "cfg" of "docsrs,test"))
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs"))
-        .with_stderr_data(str![[r#"
-...
-[WARNING] unexpected `cfg` condition name: `test`
-...
-
-[WARNING] `foo` (lib) generated 1 warning
-[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-
-"#]])
-        .run();
-
-    p.cargo("clean").run();
-    p.cargo("test -v")
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs"))
-        .with_stderr_data(str![[r#"
-...
-[WARNING] unexpected `cfg` condition name: `test`
-...
-
-[WARNING] `foo` (lib) generated 1 warning
-[FINISHED] `test` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-[DOCTEST] foo
-[RUNNING] [..]
-
-"#]])
-        .run();
-
-    p.cargo("clean").run();
-    p.cargo("test --lib -v")
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs"))
-        .with_stderr_data(str![[r#"
-...
-[WARNING] unexpected `cfg` condition name: `test`
- --> src/lib.rs:1:7
-...
-
-[WARNING] `foo` (lib test) generated 1 warning
-[FINISHED] `test` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-[RUNNING] `[ROOT]/foo/target/debug/deps/foo-[HASH][EXE]`
-
-"#]])
-        .run();
-}
-
-#[cargo_test(nightly, reason = "warning currently only on nightly")]
-fn test_false_bins() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2018"
-
-                [[bin]]
-                name = "daemon"
-                test = false
-                path = "src/deamon.rs"
-            "#,
-        )
-        .file("src/main.rs", "fn main() {}\n#[cfg(test)] mod tests {}")
-        .file("src/deamon.rs", "fn main() {}\n#[cfg(test)] mod tests {}")
-        .build();
-
-    p.cargo("check -v")
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs,test")) // for foo
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs")) // for deamon
-        .with_stderr_data(str![[r#"
-...
-[WARNING] unexpected `cfg` condition name: `test`
-...
-
-[WARNING] `foo` (bin "daemon") generated 1 warning
-[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-
-"#]])
-        .run();
-}
-
-#[cargo_test(nightly, reason = "warning currently only on nightly")]
-fn test_false_examples() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.1.0"
-                edition = "2018"
-
-                [lib]
-                test = false
-
-                [[example]]
-                name = "daemon"
-                test = false
-                path = "src/deamon.rs"
-            "#,
-        )
-        .file("src/lib.rs", "#[cfg(test)] mod tests {}")
-        .file("src/deamon.rs", "fn main() {}\n#[cfg(test)] mod tests {}")
-        .build();
-
-    p.cargo("check --examples -v")
-        .with_stderr_does_not_contain(x!("rustc" => "cfg" of "docsrs,test"))
-        .with_stderr_contains(x!("rustc" => "cfg" of "docsrs"))
-        .with_stderr_data(str![[r#"
-...
-[WARNING] unexpected `cfg` condition name: `test`
-...
-
-[WARNING] `foo` (lib) generated 1 warning
-...
-[WARNING] unexpected `cfg` condition name: `test`
-...
-
-[WARNING] `foo` (example "daemon") generated 1 warning
-[FINISHED] `dev` profile [unoptimized + debuginfo] target(s) in [ELAPSED]s
-
-"#]])
-        .run();
-}
-
-#[cargo_test(
-    nightly,
-    reason = "bench is nightly & warning currently only on nightly"
-)]
-fn test_false_benches() {
-    let p = project()
-        .file(
-            "Cargo.toml",
-            r#"
-                [package]
-                name = "foo"
-                version = "0.0.0"
-                edition = "2018"
-
-                [[bench]]
-                name = "ben1"
-                test = false
-                path = "benches/ben1.rs"
-            "#,
-        )
-        .file("src/lib.rs", "")
-        .file(
-            "benches/ben1.rs",
-            r#"
-            #![feature(test)]
-            extern crate test;
-            #[bench] fn run1(_ben: &mut test::Bencher) { }
-            "#,
-        )
-        .build();
-
-    // Benches always require the `test` cfg, there should be no warning.
-    p.cargo("bench --bench ben1")
-        .with_stderr_data(str![[r#"
-[COMPILING] foo v0.0.0 ([ROOT]/foo)
-[FINISHED] `bench` profile [optimized] target(s) in [ELAPSED]s
-[RUNNING] benches/ben1.rs (target/release/deps/ben1-[HASH][EXE])
-
-"#]])
-        .run();
-}
-
 #[cargo_test]
 fn features_doc() {
     let p = project()

tests/testsuite/test.rs

@@ -4191,19 +4191,7 @@ fn test_hint_workspace_virtual() {
         .file("a/src/lib.rs", "#[test] fn t1() {}")
         .file("b/Cargo.toml", &basic_manifest("b", "0.1.0"))
         .file("b/src/lib.rs", "#[test] fn t1() {assert!(false)}")
-        .file(
+        .file("c/Cargo.toml", &basic_manifest("c", "0.1.0"))
-            "c/Cargo.toml",
-            r#"
-                [package]
-                name = "c"
-                version = "0.1.0"
-                edition = "2015"
-
-                [[example]]
-                name = "ex1"
-                test = true
-            "#,
-        )
         .file(
             "c/src/lib.rs",
             r#"
@@ -4287,17 +4275,14 @@ fn test_hint_workspace_virtual() {
 [ERROR] test failed, to rerun pass `-p c --bin c`
 [RUNNING] tests/t1.rs (target/debug/deps/t1-[HASH][EXE])
 [ERROR] test failed, to rerun pass `-p c --test t1`
-[RUNNING] unittests examples/ex1.rs (target/debug/examples/ex1-[HASH][EXE])
-[ERROR] test failed, to rerun pass `-p c --example ex1`
 [DOCTEST] a
 [DOCTEST] b
 [DOCTEST] c
 [ERROR] doctest failed, to rerun pass `-p c --doc`
-[ERROR] 5 targets failed:
+[ERROR] 4 targets failed:
     `-p b --lib`
     `-p c --bin c`
     `-p c --test t1`
-    `-p c --example ex1`
     `-p c --doc`
 
 "#]])