Auto merge of #13438 - Urgau:check-cfg-msrv-annoyance, r=ehuss

bors · bors · commit a3ba4ee28a38 · 2024-02-28T15:14:12.000Z
Silently ignore `cargo::rustc-check-cfg` to avoid MSRV annoyance when stabilizing `-Zcheck-cfg` This PR, removes the warning when trying to use `cargo::rustc-check-cfg` on stable or nightly (without the nightly-only `-Zcheck-cfg` flag) to avoid MSRV annoyance when stabilizing `-Zcheck-cfg`. See this [Zulip thread](https://rust-lang.zulipchat.com/#narrow/stream/246057-t-cargo/topic/check-cfg.20backwards.20compatible.20warnings) for more information and context. cc `@ehuss`
diff --git a/src/cargo/core/compiler/custom_build.rs b/src/cargo/core/compiler/custom_build.rs
@@ -916,10 +916,8 @@ impl BuildOutput {
                     if extra_check_cfg {
                         check_cfgs.push(value.to_string());
                     } else {
-                        warnings.push(format!(
-                            "{}{} requires -Zcheck-cfg flag",
-                            syntax_prefix, key
-                        ));
+                        // silently ignoring the instruction to try to
+                        // minimise MSRV annoyance when stabilizing -Zcheck-cfg
                     }
                 }
                 "rustc-env" => {
diff --git a/src/cargo/util/config/target.rs b/src/cargo/util/config/target.rs
@@ -208,10 +208,8 @@ fn parse_links_overrides(
                         let list = value.list(key)?;
                         output.check_cfgs.extend(list.iter().map(|v| v.0.clone()));
                     } else {
-                        gctx.shell().warn(format!(
-                            "target config `{}.{}` requires -Zcheck-cfg flag",
-                            target_key, key
-                        ))?;
+                        // silently ignoring the instruction to try to
+                        // minimise MSRV annoyance when stabilizing -Zcheck-cfg
                     }
                 }
                 "rustc-env" => {
diff --git a/tests/testsuite/check_cfg.rs b/tests/testsuite/check_cfg.rs
@@ -471,9 +471,7 @@ fn build_script_override_feature_gate() {
         .build();
 
     p.cargo("check")
-        .with_stderr_contains(
-            "warning: target config[..]rustc-check-cfg[..] requires -Zcheck-cfg flag",
-        )
+        .with_stderr_does_not_contain("warning: [..]rustc-check-cfg[..]")
         .run();
 }
 
@@ -555,7 +553,7 @@ fn build_script_feature_gate() {
         .build();
 
     p.cargo("check")
-        .with_stderr_contains("warning[..]cargo::rustc-check-cfg requires -Zcheck-cfg flag")
+        .with_stderr_does_not_contain("warning: [..]rustc-check-cfg[..]")
         .with_status(0)
         .run();
 }

Original file line number	Diff line number	Diff line change
`@@ -916,10 +916,8 @@ impl BuildOutput {`
`916`	`916`	`if extra_check_cfg {`
`917`	`917`	`check_cfgs.push(value.to_string());`
`918`	`918`	`} else {`
`919`		`- warnings.push(format!(`
`920`		`- "{}{} requires -Zcheck-cfg flag",`
`921`		`- syntax_prefix, key`
`922`		`- ));`
	`919`	`+ // silently ignoring the instruction to try to`
	`920`	`+ // minimise MSRV annoyance when stabilizing -Zcheck-cfg`
`923`	`921`	`}`
`924`	`922`	`}`
`925`	`923`	`"rustc-env" => {`
Original file line number	Diff line number	Diff line change
`@@ -208,10 +208,8 @@ fn parse_links_overrides(`
`208`	`208`	`let list = value.list(key)?;`
`209`	`209`	`output.check_cfgs.extend(list.iter().map(\|v\| v.0.clone()));`
`210`	`210`	`} else {`
`211`		`- gctx.shell().warn(format!(`
`212`		- "target config `{}.{}` requires -Zcheck-cfg flag",
`213`		`- target_key, key`
`214`		`- ))?;`
	`211`	`+ // silently ignoring the instruction to try to`
	`212`	`+ // minimise MSRV annoyance when stabilizing -Zcheck-cfg`
`215`	`213`	`}`
`216`	`214`	`}`
`217`	`215`	`"rustc-env" => {`