Auto merge of #148035 - bjorn3:check_skip_codegen_crate, r=madsmtm

Skip codegen_crate call in check mode

This way we don't have to spawn the coordinator thread. Some errors will no longer be emitted with this in check mode. For example the check that `-Ctarget-cpu` is passed on targets that need this.

Suggested by `@saethlin`

Author: bors

src/driver/aot.rs

@@ -671,18 +671,7 @@ pub(crate) fn run_aot(tcx: TyCtxt<'_>) -> Box<OngoingCodegen> {
     }
     .to_owned();
 
-    let cgus = if tcx.sess.opts.output_types.should_codegen() {
-        tcx.collect_and_partition_mono_items(()).codegen_units
-    } else {
-        // If only `--emit metadata` is used, we shouldn't perform any codegen.
-        // Also `tcx.collect_and_partition_mono_items` may panic in that case.
-        return Box::new(OngoingCodegen {
-            modules: vec![],
-            allocator_module: None,
-            crate_info: CrateInfo::new(tcx, target_cpu),
-            concurrency_limiter: ConcurrencyLimiter::new(0),
-        });
-    };
+    let cgus = tcx.collect_and_partition_mono_items(()).codegen_units;
 
     if tcx.dep_graph.is_fully_enabled() {
         for cgu in cgus {

src/driver/jit.rs

@@ -33,9 +33,7 @@ fn create_jit_module(tcx: TyCtxt<'_>) -> (UnwindModule<JITModule>, CodegenCx) {
 }
 
 pub(crate) fn run_jit(tcx: TyCtxt<'_>, jit_args: Vec<String>) -> ! {
-    if !tcx.sess.opts.output_types.should_codegen() {
-        tcx.dcx().fatal("JIT mode doesn't work with `cargo check`");
-    }
+    // FIXME error on check mode or crate types other than bin in CodegenBackend::init()
 
     if !tcx.crate_types().contains(&rustc_session::config::CrateType::Executable) {
         tcx.dcx().fatal("can't jit non-executable crate");