error on non-cfg attributes on assembly

Author: folkertdev

compiler/rustc_builtin_macros/messages.ftl

@@ -1,8 +1,11 @@
 builtin_macros_alloc_error_must_be_fn = alloc_error_handler must be a function
 builtin_macros_alloc_must_statics = allocators must be statics
 
+builtin_macros_asm_attribute_not_supported =
+    this attribute is not supported on assembly
+
 builtin_macros_asm_cfg =
-    attributes on assembly are unstable
+    the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
 
 builtin_macros_asm_clobber_abi = clobber_abi
 builtin_macros_asm_clobber_no_reg = asm with `clobber_abi` must specify explicit registers for outputs

compiler/rustc_builtin_macros/src/asm.rs

@@ -78,9 +78,19 @@ impl AsmAttrVec {
             attributes.push(attr);
         }
 
-        if !attributes.is_empty() && !ecx.ecfg.features.asm_cfg() {
-            let span = span_start.to(p.prev_token.span);
-            feature_err(ecx.sess, sym::asm_cfg, span, fluent::builtin_macros_asm_cfg).emit();
+        for attr in attributes.iter() {
+            match attr.name() {
+                Some(sym::cfg | sym::cfg_attr) => {
+                    if !ecx.ecfg.features.asm_cfg() {
+                        let span = span_start.to(p.prev_token.span);
+                        feature_err(ecx.sess, sym::asm_cfg, span, fluent::builtin_macros_asm_cfg)
+                            .emit();
+                    }
+                }
+                _ => {
+                    ecx.dcx().emit_err(errors::AsmAttributeNotSupported { span: attr.span() });
+                }
+            }
         }
 
         Ok(Self(attributes))

compiler/rustc_builtin_macros/src/errors.rs

@@ -795,6 +795,13 @@ pub(crate) struct AsmRequiresTemplate {
     pub(crate) span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(builtin_macros_asm_attribute_not_supported)]
+pub(crate) struct AsmAttributeNotSupported {
+    #[primary_span]
+    pub(crate) span: Span,
+}
+
 #[derive(Diagnostic)]
 #[diag(builtin_macros_asm_expected_comma)]
 pub(crate) struct AsmExpectedComma {

tests/ui/feature-gates/feature-gate-asm_cfg.rs

@@ -5,7 +5,8 @@ use std::arch::{asm, global_asm, naked_asm};
 
 global_asm!(
     "nop",
-    #[cfg(false)] //~ ERROR attributes on assembly are unstable
+    #[cfg(false)]
+    //~^ ERROR the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
     "nop"
 );
 
@@ -14,10 +15,12 @@ global_asm!(
 extern "C" fn naked() {
     naked_asm!(
         "mov rax, 5",
-        #[cfg(false)] //~ ERROR attributes on assembly are unstable
+        #[cfg(false)]
+        //~^ ERROR the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
         "mov rax, {a}",
         "ret",
-        #[cfg(false)] //~ ERROR attributes on assembly are unstable
+        #[cfg(false)]
+        //~^ ERROR the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
         a = const 10,
     )
 }
@@ -26,9 +29,20 @@ fn asm() {
     unsafe {
         asm!(
             "nop",
-            #[cfg(false)] //~ ERROR attributes on assembly are unstable
+            #[cfg(false)]
+            //~^ ERROR the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
             clobber_abi("C"),
             clobber_abi("C"), //~ ERROR `C` ABI specified multiple times
         );
     }
 }
+
+fn bad_attribute() {
+    unsafe {
+        asm!(
+            #[inline]
+            //~^ ERROR this attribute is not supported on assembly
+            "nop"
+        )
+    };
+}

tests/ui/feature-gates/feature-gate-asm_cfg.stderr

@@ -1,4 +1,4 @@
-error[E0658]: attributes on assembly are unstable
+error[E0658]: the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
   --> $DIR/feature-gate-asm_cfg.rs:8:5
    |
 LL |     #[cfg(false)]
@@ -8,8 +8,8 @@ LL |     #[cfg(false)]
    = help: add `#![feature(asm_cfg)]` 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[E0658]: attributes on assembly are unstable
-  --> $DIR/feature-gate-asm_cfg.rs:17:9
+error[E0658]: the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
+  --> $DIR/feature-gate-asm_cfg.rs:18:9
    |
 LL |         #[cfg(false)]
    |         ^^^^^^^^^^^^^
@@ -18,8 +18,8 @@ LL |         #[cfg(false)]
    = help: add `#![feature(asm_cfg)]` 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[E0658]: attributes on assembly are unstable
-  --> $DIR/feature-gate-asm_cfg.rs:20:9
+error[E0658]: the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
+  --> $DIR/feature-gate-asm_cfg.rs:22:9
    |
 LL |         #[cfg(false)]
    |         ^^^^^^^^^^^^^
@@ -28,8 +28,8 @@ LL |         #[cfg(false)]
    = help: add `#![feature(asm_cfg)]` 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[E0658]: attributes on assembly are unstable
-  --> $DIR/feature-gate-asm_cfg.rs:29:13
+error[E0658]: the `#[cfg(/* ... */)]` and `#[cfg_attr(/* ... */)]` attributes on assembly are unstable
+  --> $DIR/feature-gate-asm_cfg.rs:32:13
    |
 LL |             #[cfg(false)]
    |             ^^^^^^^^^^^^^
@@ -38,14 +38,20 @@ LL |             #[cfg(false)]
    = help: add `#![feature(asm_cfg)]` 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: this attribute is not supported on assembly
+  --> $DIR/feature-gate-asm_cfg.rs:43:13
+   |
+LL |             #[inline]
+   |             ^^^^^^^^^
+
 error: `C` ABI specified multiple times
-  --> $DIR/feature-gate-asm_cfg.rs:31:13
+  --> $DIR/feature-gate-asm_cfg.rs:35:13
    |
 LL |             clobber_abi("C"),
    |             ---------------- previously specified here
 LL |             clobber_abi("C"),
    |             ^^^^^^^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
 
 For more information about this error, try `rustc --explain E0658`.