try to improve control flow

workingjubilee · workingjubilee · commit 154eb954d309 · 2025-02-12T16:18:26.000-08:00
accept diffs

become more nightly-sensitive
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
@@ -122,43 +122,42 @@ fn require_c_abi_if_c_variadic(
     const UNSTABLE_EXPLAIN: &str =
         "using calling conventions other than `C` or `cdecl` for varargs functions is unstable";
 
+    // ABIs which can stably use varargs
     if !decl.c_variadic || matches!(abi, ExternAbi::C { .. } | ExternAbi::Cdecl { .. }) {
         return;
     }
 
+    // ABIs with feature-gated stability
     let extended_abi_support = tcx.features().extended_varargs_abi_support();
     let extern_system_varargs = tcx.features().extern_system_varargs();
-    let conventions = if extended_abi_support { CONVENTIONS_UNSTABLE } else { CONVENTIONS_STABLE };
+
+    // If the feature gate has been enabled, we can stop here
+    if extern_system_varargs && let ExternAbi::System { .. } = abi {
+        return;
+    };
+    if extended_abi_support && abi.supports_varargs() {
+        return;
+    };
+
+    // Looks like we need to pick an error to emit.
+    // Is there any feature which we could have enabled to make this work?
     match abi {
         ExternAbi::System { .. } => {
-            // User enabled additional ABI support for varargs and function ABI matches those ones.
-            if extern_system_varargs {
-                return;
-            } else {
-                // Using this ABI would be ok, if the feature for additional ABI support was enabled.
-                feature_err(&tcx.sess, sym::extern_system_varargs, span, UNSTABLE_EXPLAIN).emit();
-            }
+            feature_err(&tcx.sess, sym::extern_system_varargs, span, UNSTABLE_EXPLAIN)
         }
-        abi => {
-            if abi.supports_varargs() {
-                // User enabled additional ABI support for varargs and function ABI matches those ones.
-                if extended_abi_support {
-                    return;
-                } else {
-                    // Using this ABI would be ok, if the feature for additional ABI support was enabled.
-                    feature_err(
-                        &tcx.sess,
-                        sym::extended_varargs_abi_support,
-                        span,
-                        UNSTABLE_EXPLAIN,
-                    )
-                    .emit();
-                };
-            }
+        abi if abi.supports_varargs() => {
+            feature_err(&tcx.sess, sym::extended_varargs_abi_support, span, UNSTABLE_EXPLAIN)
         }
-    };
-
-    tcx.dcx().emit_err(errors::VariadicFunctionCompatibleConvention { span, conventions });
+        _ => tcx.dcx().create_err(errors::VariadicFunctionCompatibleConvention {
+            span,
+            conventions: if tcx.sess.opts.unstable_features.is_nightly_build() {
+                CONVENTIONS_UNSTABLE
+            } else {
+                CONVENTIONS_STABLE
+            },
+        }),
+    }
+    .emit();
 }
 
 pub fn provide(providers: &mut Providers) {
diff --git a/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.rs
@@ -1,18 +1,15 @@
 //@ only-x86_64
 
 fn efiapi(f: extern "efiapi" fn(usize, ...)) {
-    //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-    //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+    //~^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
     f(22, 44);
 }
 fn sysv(f: extern "sysv64" fn(usize, ...)) {
-    //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-    //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+    //~^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
     f(22, 44);
 }
 fn win(f: extern "win64" fn(usize, ...)) {
-    //~^ ERROR: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-    //~^^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
+    //~^ ERROR: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
     f(22, 44);
 }
 
diff --git a/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr b/tests/ui/c-variadic/feature-gate-extended_varargs_abi_support.stderr
@@ -8,14 +8,8 @@ LL | fn efiapi(f: extern "efiapi" fn(usize, ...)) {
    = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-  --> $DIR/feature-gate-extended_varargs_abi_support.rs:3:14
-   |
-LL | fn efiapi(f: extern "efiapi" fn(usize, ...)) {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
-
 error[E0658]: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
-  --> $DIR/feature-gate-extended_varargs_abi_support.rs:8:12
+  --> $DIR/feature-gate-extended_varargs_abi_support.rs:7:12
    |
 LL | fn sysv(f: extern "sysv64" fn(usize, ...)) {
    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -24,14 +18,8 @@ LL | fn sysv(f: extern "sysv64" fn(usize, ...)) {
    = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-  --> $DIR/feature-gate-extended_varargs_abi_support.rs:8:12
-   |
-LL | fn sysv(f: extern "sysv64" fn(usize, ...)) {
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
-
 error[E0658]: using calling conventions other than `C` or `cdecl` for varargs functions is unstable
-  --> $DIR/feature-gate-extended_varargs_abi_support.rs:13:11
+  --> $DIR/feature-gate-extended_varargs_abi_support.rs:11:11
    |
 LL | fn win(f: extern "win64" fn(usize, ...)) {
    |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -40,13 +28,6 @@ LL | fn win(f: extern "win64" fn(usize, ...)) {
    = help: add `#![feature(extended_varargs_abi_support)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-  --> $DIR/feature-gate-extended_varargs_abi_support.rs:13:11
-   |
-LL | fn win(f: extern "win64" fn(usize, ...)) {
-   |           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
-
-error: aborting due to 6 previous errors
+error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0045, E0658.
-For more information about an error, try `rustc --explain E0045`.
+For more information about this error, try `rustc --explain E0658`.
diff --git a/tests/ui/c-variadic/variadic-ffi-1.stderr b/tests/ui/c-variadic/variadic-ffi-1.stderr
@@ -1,4 +1,4 @@
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
+error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
   --> $DIR/variadic-ffi-1.rs:9:5
    |
 LL |     fn printf(_: *const u8, ...);
diff --git a/tests/ui/feature-gates/feature-gate-extern_system_varargs.rs b/tests/ui/feature-gates/feature-gate-extern_system_varargs.rs
@@ -1,6 +1,5 @@
 fn system(f: extern "system" fn(usize, ...)) {
     //~^  ERROR using calling conventions other than `C` or `cdecl` for varargs functions is unstable
-    //~| ERROR C-variadic function must have a compatible calling convention, like `C` or `cdecl`
 
     f(22, 44);
 }
diff --git a/tests/ui/feature-gates/feature-gate-extern_system_varargs.stderr b/tests/ui/feature-gates/feature-gate-extern_system_varargs.stderr
@@ -8,13 +8,6 @@ LL | fn system(f: extern "system" fn(usize, ...)) {
    = help: add `#![feature(extern_system_varargs)]` to the crate attributes to enable
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
-  --> $DIR/feature-gate-extern_system_varargs.rs:1:14
-   |
-LL | fn system(f: extern "system" fn(usize, ...)) {
-   |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ C-variadic function must have a compatible calling convention
-
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
-Some errors have detailed explanations: E0045, E0658.
-For more information about an error, try `rustc --explain E0045`.
+For more information about this error, try `rustc --explain E0658`.

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		-error[E0045]: C-variadic function must have a compatible calling convention, like `C` or `cdecl`
	`1`	+error[E0045]: C-variadic function must have a compatible calling convention, like `C`, `cdecl`, `system`, `aapcs`, `win64`, `sysv64` or `efiapi`
`2`	`2`	`--> $DIR/variadic-ffi-1.rs:9:5`
`3`	`3`	`\|`
`4`	`4`	`LL \| fn printf(_: *const u8, ...);`
Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,5 @@`
`1`	`1`	`fn system(f: extern "system" fn(usize, ...)) {`
`2`	`2`	//~^ ERROR using calling conventions other than `C` or `cdecl` for varargs functions is unstable
`3`		- //~\| ERROR C-variadic function must have a compatible calling convention, like `C` or `cdecl`
`4`	`3`
`5`	`4`	`f(22, 44);`
`6`	`5`	`}`