Rollup merge of rust-lang#137502 - compiler-errors:global-asm-aint-mir-body, r=oli-obk

Don't include global asm in `mir_keys`, fix error body synthesis

r? oli-obk

Fixes rust-lang#137470
Fixes rust-lang#137471
Fixes rust-lang#137472
Fixes rust-lang#137473

try-job: aarch64-apple

Author: jhpratt

compiler/rustc_mir_build/src/builder/mod.rs

@@ -612,7 +612,8 @@ fn construct_error(tcx: TyCtxt<'_>, def_id: LocalDefId, guar: ErrorGuaranteed) -
         | DefKind::AssocConst
         | DefKind::AnonConst
         | DefKind::InlineConst
-        | DefKind::Static { .. } => (vec![], tcx.type_of(def_id).instantiate_identity(), None),
+        | DefKind::Static { .. }
+        | DefKind::GlobalAsm => (vec![], tcx.type_of(def_id).instantiate_identity(), None),
         DefKind::Ctor(..) | DefKind::Fn | DefKind::AssocFn => {
             let sig = tcx.liberate_late_bound_regions(
                 def_id.to_def_id(),

compiler/rustc_mir_transform/src/lib.rs

@@ -316,6 +316,10 @@ fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> {
     // All body-owners have MIR associated with them.
     let mut set: FxIndexSet<_> = tcx.hir_body_owners().collect();
 
+    // Remove the fake bodies for `global_asm!`, since they're not useful
+    // to be emitted (`--emit=mir`) or encoded (in metadata).
+    set.retain(|&def_id| !matches!(tcx.def_kind(def_id), DefKind::GlobalAsm));
+
     // Coroutine-closures (e.g. async closures) have an additional by-move MIR
     // body that isn't in the HIR.
     for body_owner in tcx.hir_body_owners() {

tests/ui/asm/global-asm-isnt-really-a-mir-body.rs

@@ -0,0 +1,23 @@
+//@ revisions: emit_mir instrument cfi
+
+// Make sure we don't try to emit MIR for it.
+//@[emit_mir] compile-flags: --emit=mir
+
+// Make sure we don't try to instrument it.
+//@[instrument] compile-flags: -Cinstrument-coverage -Zno-profiler-runtime
+//@[instrument] only-linux
+
+// Make sure we don't try to CFI encode it.
+//@[cfi] compile-flags: -Zsanitizer=cfi -Ccodegen-units=1 -Clto -Clink-dead-code=true
+//@[cfi] needs-sanitizer-cfi
+//@[cfi] no-prefer-dynamic
+
+//@ build-pass
+
+use std::arch::global_asm;
+
+fn foo() {}
+
+global_asm!("/* {} */", sym foo);
+
+fn main() {}

tests/ui/asm/global-asm-with-error.rs

@@ -0,0 +1,9 @@
+// Ensure that we don't ICE when constructing the fake MIR body for a global
+// asm when the body has errors. See #137470.
+
+use std::arch::global_asm;
+
+global_asm!("/* {} */", sym a);
+//~^ ERROR cannot find value `a` in this scope
+
+fn main() {}

tests/ui/asm/global-asm-with-error.stderr

@@ -0,0 +1,9 @@
+error[E0425]: cannot find value `a` in this scope
+  --> $DIR/global-asm-with-error.rs:6:29
+   |
+LL | global_asm!("/* {} */", sym a);
+   |                             ^ not found in this scope
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0425`.