Stabilize target-applies-to-host feature.

Details: rust-lang#9453, rust-lang#9322

src/cargo/util/config/target.rs

@@ -67,18 +67,10 @@ pub(super) fn load_target_cfgs(config: &Config) -> CargoResult<Vec<(String, Targ
 
 /// Returns true if the `[target]` table should be applied to host targets.
 pub(super) fn get_target_applies_to_host(config: &Config) -> CargoResult<bool> {
-    if config.cli_unstable().target_applies_to_host {
-        if let Ok(target_applies_to_host) = config.get::<bool>("target-applies-to-host") {
-            Ok(target_applies_to_host)
-        } else {
-            Ok(!config.cli_unstable().host_config)
-        }
-    } else if config.cli_unstable().host_config {
-        anyhow::bail!(
-            "the -Zhost-config flag requires the -Ztarget-applies-to-host flag to be set"
-        );
+    if let Ok(target_applies_to_host) = config.get::<bool>("target-applies-to-host") {
+        Ok(target_applies_to_host)
     } else {
-        Ok(true)
+        Ok(!config.cli_unstable().host_config)
     }
 }
 

tests/testsuite/build_script.rs

@@ -402,10 +402,7 @@ fn custom_build_env_var_rustc_linker_host_target() {
 
     // no crate type set => linker never called => build succeeds if and
     // only if build.rs succeeds, despite linker binary not existing.
-    p.cargo("build -Z target-applies-to-host --target")
-        .arg(&target)
-        .masquerade_as_nightly_cargo()
-        .run();
+    p.cargo("build --target").arg(&target).run();
 }
 
 #[cargo_test]
@@ -437,10 +434,9 @@ fn custom_build_env_var_rustc_linker_host_target_env() {
 
     // no crate type set => linker never called => build succeeds if and
     // only if build.rs succeeds, despite linker binary not existing.
-    p.cargo("build -Z target-applies-to-host --target")
+    p.cargo("build --target")
         .env("CARGO_TARGET_APPLIES_TO_HOST", "false")
         .arg(&target)
-        .masquerade_as_nightly_cargo()
         .run();
 }
 
@@ -462,16 +458,10 @@ fn custom_build_invalid_host_config_feature_flag() {
         .file("src/lib.rs", "")
         .build();
 
-    // build.rs should fail due to -Zhost-config being set without -Ztarget-applies-to-host
+    // build.rs should not fail due to -Zhost-config being set
     p.cargo("build -Z host-config --target")
         .arg(&target)
         .masquerade_as_nightly_cargo()
-        .with_status(101)
-        .with_stderr_contains(
-            "\
-error: the -Zhost-config flag requires the -Ztarget-applies-to-host flag to be set
-",
-        )
         .run();
 }
 
@@ -496,7 +486,7 @@ fn custom_build_linker_host_target_with_bad_host_config() {
         .build();
 
     // build.rs should fail due to bad host linker being set
-    p.cargo("build -Z target-applies-to-host -Z host-config --verbose --target")
+    p.cargo("build -Z host-config --verbose --target")
             .arg(&target)
             .masquerade_as_nightly_cargo()
             .with_status(101)
@@ -531,7 +521,7 @@ fn custom_build_linker_bad_host() {
         .build();
 
     // build.rs should fail due to bad host linker being set
-    p.cargo("build -Z target-applies-to-host -Z host-config --verbose --target")
+    p.cargo("build -Z host-config --verbose --target")
             .arg(&target)
             .masquerade_as_nightly_cargo()
             .with_status(101)
@@ -568,7 +558,7 @@ fn custom_build_linker_bad_host_with_arch() {
         .build();
 
     // build.rs should fail due to bad host linker being set
-    p.cargo("build -Z target-applies-to-host -Z host-config --verbose --target")
+    p.cargo("build -Z host-config --verbose --target")
             .arg(&target)
             .masquerade_as_nightly_cargo()
             .with_status(101)
@@ -614,7 +604,7 @@ fn custom_build_env_var_rustc_linker_cross_arch_host() {
 
     // build.rs should be built fine since cross target != host target.
     // assertion should succeed since it's still passed the target linker
-    p.cargo("build -Z target-applies-to-host -Z host-config --verbose --target")
+    p.cargo("build -Z host-config --verbose --target")
         .arg(&target)
         .masquerade_as_nightly_cargo()
         .run();
@@ -644,7 +634,7 @@ fn custom_build_linker_bad_cross_arch_host() {
         .build();
 
     // build.rs should fail due to bad host linker being set
-    p.cargo("build -Z target-applies-to-host -Z host-config --verbose --target")
+    p.cargo("build -Z host-config --verbose --target")
             .arg(&target)
             .masquerade_as_nightly_cargo()
             .with_status(101)