Auto merge of rust-lang#132577 - Urgau:check-cfg-report-extern-macro, r=<try>

Report the `unexpected_cfgs` lint in external macros

This PR marks the `unexpected_cfgs` lint as being reportable in external macros, as it's probably not the intention of the macro author to leave ineffective cfgs in the users code.

Fixes rust-lang#132572

try-job: aarch64-gnu-debug

Author: bors

Cargo.lock

@@ -112,9 +112,9 @@ dependencies = [
 
 [[package]]
 name = "anstream"
-version = "0.6.15"
+version = "0.6.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64e15c1ab1f89faffbf04a634d5e1962e9074f2741eef6d97f3c4e322426d526"
+checksum = "8acc5369981196006228e28809f761875c0327210a891e941f4c683b3a99529b"
 dependencies = [
  "anstyle",
  "anstyle-parse",
@@ -173,12 +173,12 @@ dependencies = [
 
 [[package]]
 name = "anstyle-wincon"
-version = "3.0.4"
+version = "3.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5bf74e1b6e971609db8ca7a9ce79fd5768ab6ae46441c572e46cf596f59e57f8"
+checksum = "2109dbce0e72be3ec00bed26e6a7479ca384ad226efdd66db8fa2e3a38c83125"
 dependencies = [
  "anstyle",
- "windows-sys 0.52.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1991,7 +1991,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4979f22fdb869068da03c9f7528f8297c6fd2606bc3a4affe42e6a823fdb8da4"
 dependencies = [
  "cfg-if",
- "windows-targets 0.52.6",
+ "windows-targets 0.48.5",
 ]
 
 [[package]]
@@ -5928,7 +5928,7 @@ version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
 dependencies = [
- "windows-sys 0.59.0",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]

compiler/rustc_lint_defs/src/builtin.rs

@@ -3184,6 +3184,7 @@ declare_lint! {
     pub UNEXPECTED_CFGS,
     Warn,
     "detects unexpected names and values in `#[cfg]` conditions",
+    report_in_external_macro
 }
 
 declare_lint! {

library/stdarch

@@ -0,0 +1,11 @@
+// Inspired by https://github.com/rust-lang/cargo/issues/14775
+
+pub fn my_lib_func() {}
+
+#[macro_export]
+macro_rules! my_lib_macro {
+    () => {
+        #[cfg(my_lib_cfg)]
+        $crate::my_lib_func()
+    };
+}

tests/ui/check-cfg/auxiliary/cfg_macro.rs

@@ -0,0 +1,12 @@
+// This test checks that we emit the `unexpected_cfgs` lint even in code
+// coming from an external macro.
+
+//@ check-pass
+//@ no-auto-check-cfg
+//@ aux-crate: cfg_macro=cfg_macro.rs
+//@ compile-flags: --check-cfg=cfg()
+
+fn main() {
+    cfg_macro::my_lib_macro!();
+    //~^ WARNING unexpected `cfg` condition name
+}

tests/ui/check-cfg/report-in-external-macros.rs

@@ -0,0 +1,14 @@
+warning: unexpected `cfg` condition name: `my_lib_cfg`
+  --> $DIR/report-in-external-macros.rs:10:5
+   |
+LL |     cfg_macro::my_lib_macro!();
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: expected names are: `clippy`, `debug_assertions`, `doc`, `doctest`, `fmt_debug`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, and `windows`
+   = help: to expect this configuration use `--check-cfg=cfg(my_lib_cfg)`
+   = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration
+   = note: `#[warn(unexpected_cfgs)]` on by default
+   = note: this warning originates in the macro `cfg_macro::my_lib_macro` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+warning: 1 warning emitted
+