Rollup merge of #108949 - Urgau:check-cfg-target-json, r=oli-obk

Honor current target when checking conditional compilation values

This is fixed by simply using the currently registered target in the current session. We need to use it because of target json that are not by design included in the rustc list of targets.

Fixes https://github.com/rust-lang/rust/issues/108941

5 files changed, 51 insertions, 4 deletions

diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index e5d2fb2ea28..043892410ce 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -110,7 +110,7 @@ pub fn create_session(
     add_configuration(&mut cfg, &mut sess, &*codegen_backend);
 
     let mut check_cfg = config::to_crate_check_config(check_cfg);
-    check_cfg.fill_well_known();
+    check_cfg.fill_well_known(&sess.target);
 
     sess.parse_sess.config = cfg;
     sess.parse_sess.check_config = check_cfg;
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index d4e4ace889b..485c3f55462 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1137,7 +1137,7 @@ impl CrateCheckConfig {
     }
 
     /// Fills a `CrateCheckConfig` with well-known configuration values.
-    fn fill_well_known_values(&mut self) {
+    fn fill_well_known_values(&mut self, current_target: &Target) {
         if !self.well_known_values {
             return;
         }
@@ -1229,6 +1229,7 @@ impl CrateCheckConfig {
             for target in TARGETS
                 .iter()
                 .map(|target| Target::expect_builtin(&TargetTriple::from_triple(target)))
+                .chain(iter::once(current_target.clone()))
             {
                 values_target_os.insert(Symbol::intern(&target.options.os));
                 values_target_family
@@ -1243,9 +1244,9 @@ impl CrateCheckConfig {
         }
     }
 
-    pub fn fill_well_known(&mut self) {
+    pub fn fill_well_known(&mut self, current_target: &Target) {
         self.fill_well_known_names();
-        self.fill_well_known_values();
+        self.fill_well_known_values(current_target);
     }
 }
 
diff --git a/tests/ui/check-cfg/my-awesome-platform.json b/tests/ui/check-cfg/my-awesome-platform.json
new file mode 100644
index 00000000000..5e9ab8f1a2d
--- /dev/null
+++ b/tests/ui/check-cfg/my-awesome-platform.json
@@ -0,0 +1,12 @@
+{
+    "llvm-target": "x86_64-unknown-none-gnu",
+    "data-layout": "e-m:e-i64:64-f80:128-n8:16:32:64-S128",
+    "arch": "x86_64",
+    "target-endian": "little",
+    "target-pointer-width": "64",
+    "target-c-int-width": "32",
+    "os": "ericos",
+    "linker-flavor": "ld.lld",
+    "linker": "rust-lld",
+    "executables": true
+}
diff --git a/tests/ui/check-cfg/values-target-json.rs b/tests/ui/check-cfg/values-target-json.rs
new file mode 100644
index 00000000000..2ef5a44592b
--- /dev/null
+++ b/tests/ui/check-cfg/values-target-json.rs
@@ -0,0 +1,21 @@
+// This test checks that we don't lint values defined by a custom target (target json)
+//
+// check-pass
+// needs-llvm-components: x86
+// compile-flags: --crate-type=lib --check-cfg=values() --target={{src-base}}/check-cfg/my-awesome-platform.json -Z unstable-options
+
+#![feature(lang_items, no_core, auto_traits)]
+#![no_core]
+
+#[lang = "sized"]
+trait Sized {}
+
+#[cfg(target_os = "linuz")]
+//~^ WARNING unexpected `cfg` condition value
+fn target_os_linux_misspell() {}
+
+#[cfg(target_os = "linux")]
+fn target_os_linux() {}
+
+#[cfg(target_os = "ericos")]
+fn target_os_ericos() {}
diff --git a/tests/ui/check-cfg/values-target-json.stderr b/tests/ui/check-cfg/values-target-json.stderr
new file mode 100644
index 00000000000..b58d2970773
--- /dev/null
+++ b/tests/ui/check-cfg/values-target-json.stderr
@@ -0,0 +1,13 @@
+warning: unexpected `cfg` condition value
+  --> $DIR/values-target-json.rs:13:7
+   |
+LL | #[cfg(target_os = "linuz")]
+   |       ^^^^^^^^^^^^-------
+   |                   |
+   |                   help: did you mean: `"linux"`
+   |
+   = note: expected values for `target_os` are: aix, android, cuda, dragonfly, emscripten, ericos, espidf, freebsd, fuchsia, haiku, hermit, horizon, illumos, ios, l4re, linux, macos, netbsd, none, nto, openbsd, psp, redox, solaris, solid_asp3, tvos, uefi, unknown, vita, vxworks, wasi, watchos, windows, xous
+   = note: `#[warn(unexpected_cfgs)]` on by default
+
+warning: 1 warning emitted
+