Rollup merge of #77795 - bjorn3:codegen_backend_interface_refactor, r=oli-obk

Codegen backend interface refactor

This moves several things away from the codegen backend to rustc_interface. There are a few behavioral changes where previously the incremental cache (incorrectly) wouldn't get finalized, but now it does. See the individual commit messages.

1 files changed, 26 insertions, 32 deletions

diff --git a/src/test/run-make-fulldeps/hotplug_codegen_backend/the_backend.rs b/src/test/run-make-fulldeps/hotplug_codegen_backend/the_backend.rs
index dd49ca67c67..0e1bef6f68d 100644
--- a/src/test/run-make-fulldeps/hotplug_codegen_backend/the_backend.rs
+++ b/src/test/run-make-fulldeps/hotplug_codegen_backend/the_backend.rs
@@ -3,7 +3,6 @@
 extern crate rustc_codegen_ssa;
 extern crate rustc_errors;
 extern crate rustc_middle;
-#[macro_use]
 extern crate rustc_data_structures;
 extern crate rustc_driver;
 extern crate rustc_hir;
@@ -12,17 +11,19 @@ extern crate rustc_span;
 extern crate rustc_symbol_mangling;
 extern crate rustc_target;
 
+use rustc_codegen_ssa::back::linker::LinkerInfo;
 use rustc_codegen_ssa::traits::CodegenBackend;
-use rustc_data_structures::owning_ref::OwningRef;
+use rustc_codegen_ssa::{CodegenResults, CrateInfo};
+use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::sync::MetadataRef;
 use rustc_errors::ErrorReported;
 use rustc_middle::dep_graph::DepGraph;
+use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_middle::middle::cstore::{EncodedMetadata, MetadataLoader, MetadataLoaderDyn};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::OutputFilenames;
 use rustc_session::Session;
-use rustc_span::symbol::Symbol;
 use rustc_target::spec::Target;
 use std::any::Any;
 use std::path::Path;
@@ -31,14 +32,11 @@ pub struct NoLlvmMetadataLoader;
 
 impl MetadataLoader for NoLlvmMetadataLoader {
     fn get_rlib_metadata(&self, _: &Target, filename: &Path) -> Result<MetadataRef, String> {
-        let buf =
-            std::fs::read(filename).map_err(|e| format!("metadata file open err: {:?}", e))?;
-        let buf: OwningRef<Vec<u8>, [u8]> = OwningRef::new(buf);
-        Ok(rustc_erase_owner!(buf.map_owner_box()))
+        unreachable!("some_crate.rs shouldn't depend on any external crates");
     }
 
     fn get_dylib_metadata(&self, target: &Target, filename: &Path) -> Result<MetadataRef, String> {
-        self.get_rlib_metadata(target, filename)
+        unreachable!("some_crate.rs shouldn't depend on any external crates");
     }
 }
 
@@ -49,53 +47,49 @@ impl CodegenBackend for TheBackend {
         Box::new(NoLlvmMetadataLoader)
     }
 
-    fn provide(&self, providers: &mut Providers) {
-        rustc_symbol_mangling::provide(providers);
-
-        providers.supported_target_features = |tcx, _cnum| {
-            Default::default() // Just a dummy
-        };
-        providers.is_reachable_non_generic = |_tcx, _defid| true;
-        providers.exported_symbols = |_tcx, _crate| &[];
-    }
-
-    fn provide_extern(&self, providers: &mut Providers) {
-        providers.is_reachable_non_generic = |_tcx, _defid| true;
-    }
+    fn provide(&self, providers: &mut Providers) {}
+    fn provide_extern(&self, providers: &mut Providers) {}
 
     fn codegen_crate<'a, 'tcx>(
         &self,
         tcx: TyCtxt<'tcx>,
-        _metadata: EncodedMetadata,
+        metadata: EncodedMetadata,
         _need_metadata_module: bool,
     ) -> Box<dyn Any> {
         use rustc_hir::def_id::LOCAL_CRATE;
 
-        Box::new(tcx.crate_name(LOCAL_CRATE) as Symbol)
+        Box::new(CodegenResults {
+            crate_name: tcx.crate_name(LOCAL_CRATE),
+            modules: vec![],
+            allocator_module: None,
+            metadata_module: None,
+            metadata,
+            windows_subsystem: None,
+            linker_info: LinkerInfo::new(tcx),
+            crate_info: CrateInfo::new(tcx),
+        })
     }
 
     fn join_codegen(
         &self,
         ongoing_codegen: Box<dyn Any>,
         _sess: &Session,
-        _dep_graph: &DepGraph,
-    ) -> Result<Box<dyn Any>, ErrorReported> {
-        let crate_name = ongoing_codegen
-            .downcast::<Symbol>()
-            .expect("in join_codegen: ongoing_codegen is not a Symbol");
-        Ok(crate_name)
+    ) -> Result<(CodegenResults, FxHashMap<WorkProductId, WorkProduct>), ErrorReported> {
+        let codegen_results = ongoing_codegen
+            .downcast::<CodegenResults>()
+            .expect("in join_codegen: ongoing_codegen is not a CodegenResults");
+        Ok((*codegen_results, FxHashMap::default()))
     }
 
     fn link(
         &self,
         sess: &Session,
-        codegen_results: Box<dyn Any>,
+        codegen_results: CodegenResults,
         outputs: &OutputFilenames,
     ) -> Result<(), ErrorReported> {
         use rustc_session::{config::CrateType, output::out_filename};
         use std::io::Write;
-        let crate_name =
-            codegen_results.downcast::<Symbol>().expect("in link: codegen_results is not a Symbol");
+        let crate_name = codegen_results.crate_name;
         for &crate_type in sess.opts.crate_types.iter() {
             if crate_type != CrateType::Rlib {
                 sess.fatal(&format!("Crate type is {:?}", crate_type));