Merge remote-tracking branch 'origin/master' into frewsxcv-san

12 files changed, 313 insertions, 183 deletions

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 46febf049c3..55fddb38e10 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -2,7 +2,7 @@ use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::temp_dir::MaybeTempDir;
 use rustc_fs_util::fix_windows_verbatim_for_gcc;
 use rustc_hir::def_id::CrateNum;
-use rustc_middle::middle::cstore::{EncodedMetadata, LibSource, NativeLib};
+use rustc_middle::middle::cstore::{EncodedMetadata, LibSource};
 use rustc_middle::middle::dependency_format::Linkage;
 use rustc_session::config::{self, CFGuard, CrateType, DebugInfo};
 use rustc_session::config::{OutputFilenames, OutputType, PrintRequest, SanitizerSet};
@@ -21,7 +21,10 @@ use super::archive::ArchiveBuilder;
 use super::command::Command;
 use super::linker::{self, Linker};
 use super::rpath::{self, RPathConfig};
-use crate::{looks_like_rust_object_file, CodegenResults, CrateInfo, METADATA_FILENAME};
+use crate::{
+    looks_like_rust_object_file, CodegenResults, CompiledModule, CrateInfo, NativeLib,
+    METADATA_FILENAME,
+};
 
 use cc::windows_registry;
 use tempfile::Builder as TempFileBuilder;
@@ -96,6 +99,9 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
                         path.as_ref(),
                         target_cpu,
                     );
+                    if sess.opts.debugging_opts.split_dwarf == config::SplitDwarfKind::Split {
+                        link_dwarf_object(sess, &out_filename);
+                    }
                 }
             }
             if sess.opts.json_artifact_notifications {
@@ -107,22 +113,30 @@ pub fn link_binary<'a, B: ArchiveBuilder<'a>>(
     // Remove the temporary object file and metadata if we aren't saving temps
     sess.time("link_binary_remove_temps", || {
         if !sess.opts.cg.save_temps {
+            let remove_temps_from_module = |module: &CompiledModule| {
+                if let Some(ref obj) = module.object {
+                    remove(sess, obj);
+                }
+
+                if let Some(ref obj) = module.dwarf_object {
+                    remove(sess, obj);
+                }
+            };
+
             if sess.opts.output_types.should_codegen()
                 && !preserve_objects_for_their_debuginfo(sess)
             {
-                for obj in codegen_results.modules.iter().filter_map(|m| m.object.as_ref()) {
-                    remove(sess, obj);
+                for module in &codegen_results.modules {
+                    remove_temps_from_module(module);
                 }
             }
+
             if let Some(ref metadata_module) = codegen_results.metadata_module {
-                if let Some(ref obj) = metadata_module.object {
-                    remove(sess, obj);
-                }
+                remove_temps_from_module(metadata_module);
             }
+
             if let Some(ref allocator_module) = codegen_results.allocator_module {
-                if let Some(ref obj) = allocator_module.object {
-                    remove(sess, obj);
-                }
+                remove_temps_from_module(allocator_module);
             }
         }
     });
@@ -279,12 +293,12 @@ pub fn emit_metadata(sess: &Session, metadata: &EncodedMetadata, tmpdir: &MaybeT
     out_filename
 }
 
-// Create an 'rlib'
-//
-// An rlib in its current incarnation is essentially a renamed .a file. The
-// rlib primarily contains the object file of the crate, but it also contains
-// all of the object files from native libraries. This is done by unzipping
-// native libraries and inserting all of the contents into this archive.
+/// Create an 'rlib'.
+///
+/// An rlib in its current incarnation is essentially a renamed .a file. The rlib primarily contains
+/// the object file of the crate, but it also contains all of the object files from native
+/// libraries. This is done by unzipping native libraries and inserting all of the contents into
+/// this archive.
 fn link_rlib<'a, B: ArchiveBuilder<'a>>(
     sess: &'a Session,
     codegen_results: &CodegenResults,
@@ -379,18 +393,17 @@ fn link_rlib<'a, B: ArchiveBuilder<'a>>(
     ab
 }
 
-// Create a static archive
-//
-// This is essentially the same thing as an rlib, but it also involves adding
-// all of the upstream crates' objects into the archive. This will slurp in
-// all of the native libraries of upstream dependencies as well.
-//
-// Additionally, there's no way for us to link dynamic libraries, so we warn
-// about all dynamic library dependencies that they're not linked in.
-//
-// There's no need to include metadata in a static archive, so ensure to not
-// link in the metadata object file (and also don't prepare the archive with a
-// metadata file).
+/// Create a static archive.
+///
+/// This is essentially the same thing as an rlib, but it also involves adding all of the upstream
+/// crates' objects into the archive. This will slurp in all of the native libraries of upstream
+/// dependencies as well.
+///
+/// Additionally, there's no way for us to link dynamic libraries, so we warn about all dynamic
+/// library dependencies that they're not linked in.
+///
+/// There's no need to include metadata in a static archive, so ensure to not link in the metadata
+/// object file (and also don't prepare the archive with a metadata file).
 fn link_staticlib<'a, B: ArchiveBuilder<'a>>(
     sess: &'a Session,
     codegen_results: &CodegenResults,
@@ -447,10 +460,73 @@ fn link_staticlib<'a, B: ArchiveBuilder<'a>>(
     }
 }
 
-// Create a dynamic library or executable
-//
-// This will invoke the system linker/cc to create the resulting file. This
-// links to all upstream files as well.
+fn escape_stdout_stderr_string(s: &[u8]) -> String {
+    str::from_utf8(s).map(|s| s.to_owned()).unwrap_or_else(|_| {
+        let mut x = "Non-UTF-8 output: ".to_string();
+        x.extend(s.iter().flat_map(|&b| ascii::escape_default(b)).map(char::from));
+        x
+    })
+}
+
+const LLVM_DWP_EXECUTABLE: &'static str = "rust-llvm-dwp";
+
+/// Invoke `llvm-dwp` (shipped alongside rustc) to link `dwo` files from Split DWARF into a `dwp`
+/// file.
+fn link_dwarf_object<'a>(sess: &'a Session, executable_out_filename: &Path) {
+    info!("preparing dwp to {}.dwp", executable_out_filename.to_str().unwrap());
+
+    let dwp_out_filename = executable_out_filename.with_extension("dwp");
+    let mut cmd = Command::new(LLVM_DWP_EXECUTABLE);
+    cmd.arg("-e");
+    cmd.arg(executable_out_filename);
+    cmd.arg("-o");
+    cmd.arg(&dwp_out_filename);
+
+    let mut new_path = sess.host_filesearch(PathKind::All).get_tools_search_paths(false);
+    if let Some(path) = env::var_os("PATH") {
+        new_path.extend(env::split_paths(&path));
+    }
+    let new_path = env::join_paths(new_path).unwrap();
+    cmd.env("PATH", new_path);
+
+    info!("{:?}", &cmd);
+    match sess.time("run_dwp", || cmd.output()) {
+        Ok(prog) if !prog.status.success() => {
+            sess.struct_err(&format!(
+                "linking dwarf objects with `{}` failed: {}",
+                LLVM_DWP_EXECUTABLE, prog.status
+            ))
+            .note(&format!("{:?}", &cmd))
+            .note(&escape_stdout_stderr_string(&prog.stdout))
+            .note(&escape_stdout_stderr_string(&prog.stderr))
+            .emit();
+            info!("linker stderr:\n{}", escape_stdout_stderr_string(&prog.stderr));
+            info!("linker stdout:\n{}", escape_stdout_stderr_string(&prog.stdout));
+        }
+        Ok(_) => {}
+        Err(e) => {
+            let dwp_not_found = e.kind() == io::ErrorKind::NotFound;
+            let mut err = if dwp_not_found {
+                sess.struct_err(&format!("linker `{}` not found", LLVM_DWP_EXECUTABLE))
+            } else {
+                sess.struct_err(&format!("could not exec the linker `{}`", LLVM_DWP_EXECUTABLE))
+            };
+
+            err.note(&e.to_string());
+
+            if !dwp_not_found {
+                err.note(&format!("{:?}", &cmd));
+            }
+
+            err.emit();
+        }
+    }
+}
+
+/// Create a dynamic library or executable.
+///
+/// This will invoke the system linker/cc to create the resulting file. This links to all upstream
+/// files as well.
 fn link_natively<'a, B: ArchiveBuilder<'a>>(
     sess: &'a Session,
     crate_type: CrateType,
@@ -662,7 +738,7 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
                     prog.status
                 ))
                 .note(&format!("{:?}", &cmd))
-                .note(&escape_string(&output))
+                .note(&escape_stdout_stderr_string(&output))
                 .emit();
 
                 // If MSVC's `link.exe` was expected but the return code
@@ -715,8 +791,8 @@ fn link_natively<'a, B: ArchiveBuilder<'a>>(
 
                 sess.abort_if_errors();
             }
-            info!("linker stderr:\n{}", escape_string(&prog.stderr));
-            info!("linker stdout:\n{}", escape_string(&prog.stdout));
+            info!("linker stderr:\n{}", escape_stdout_stderr_string(&prog.stderr));
+            info!("linker stdout:\n{}", escape_stdout_stderr_string(&prog.stdout));
         }
         Err(e) => {
             let linker_not_found = e.kind() == io::ErrorKind::NotFound;
@@ -962,6 +1038,13 @@ fn preserve_objects_for_their_debuginfo(sess: &Session) -> bool {
         return false;
     }
 
+    // Single mode keeps debuginfo in the same object file, but in such a way that it it skipped
+    // by the linker - so it's expected that when codegen units are linked together that this
+    // debuginfo would be lost without keeping around the temps.
+    if sess.opts.debugging_opts.split_dwarf == config::SplitDwarfKind::Single {
+        return true;
+    }
+
     // If we're on OSX then the equivalent of split dwarf is turned on by
     // default. The final executable won't actually have any debug information
     // except it'll have pointers to elsewhere. Historically we've always run
@@ -1677,17 +1760,15 @@ fn linker_with_args<'a, B: ArchiveBuilder<'a>>(
     cmd.take_cmd()
 }
 
-// # Native library linking
-//
-// User-supplied library search paths (-L on the command line). These are
-// the same paths used to find Rust crates, so some of them may have been
-// added already by the previous crate linking code. This only allows them
-// to be found at compile time so it is still entirely up to outside
-// forces to make sure that library can be found at runtime.
-//
-// Also note that the native libraries linked here are only the ones located
-// in the current crate. Upstream crates with native library dependencies
-// may have their native library pulled in above.
+/// # Native library linking
+///
+/// User-supplied library search paths (-L on the command line). These are the same paths used to
+/// find Rust crates, so some of them may have been added already by the previous crate linking
+/// code. This only allows them to be found at compile time so it is still entirely up to outside
+/// forces to make sure that library can be found at runtime.
+///
+/// Also note that the native libraries linked here are only the ones located in the current crate.
+/// Upstream crates with native library dependencies may have their native library pulled in above.
 fn add_local_native_libraries(
     cmd: &mut dyn Linker,
     sess: &Session,
@@ -1727,11 +1808,10 @@ fn add_local_native_libraries(
     }
 }
 
-// # Rust Crate linking
-//
-// Rust crates are not considered at all when creating an rlib output. All
-// dependencies will be linked when producing the final output (instead of
-// the intermediate rlib version)
+/// # Rust Crate linking
+///
+/// Rust crates are not considered at all when creating an rlib output. All dependencies will be
+/// linked when producing the final output (instead of the intermediate rlib version).
 fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
     cmd: &mut dyn Linker,
     sess: &'a Session,
@@ -1996,24 +2076,21 @@ fn add_upstream_rust_crates<'a, B: ArchiveBuilder<'a>>(
     }
 }
 
-// Link in all of our upstream crates' native dependencies. Remember that
-// all of these upstream native dependencies are all non-static
-// dependencies. We've got two cases then:
-//
-// 1. The upstream crate is an rlib. In this case we *must* link in the
-// native dependency because the rlib is just an archive.
-//
-// 2. The upstream crate is a dylib. In order to use the dylib, we have to
-// have the dependency present on the system somewhere. Thus, we don't
-// gain a whole lot from not linking in the dynamic dependency to this
-// crate as well.
-//
-// The use case for this is a little subtle. In theory the native
-// dependencies of a crate are purely an implementation detail of the crate
-// itself, but the problem arises with generic and inlined functions. If a
-// generic function calls a native function, then the generic function must
-// be instantiated in the target crate, meaning that the native symbol must
-// also be resolved in the target crate.
+/// Link in all of our upstream crates' native dependencies. Remember that all of these upstream
+/// native dependencies are all non-static dependencies. We've got two cases then:
+///
+/// 1. The upstream crate is an rlib. In this case we *must* link in the native dependency because
+/// the rlib is just an archive.
+///
+/// 2. The upstream crate is a dylib. In order to use the dylib, we have to have the dependency
+/// present on the system somewhere. Thus, we don't gain a whole lot from not linking in the
+/// dynamic dependency to this crate as well.
+///
+/// The use case for this is a little subtle. In theory the native dependencies of a crate are
+/// purely an implementation detail of the crate itself, but the problem arises with generic and
+/// inlined functions. If a generic function calls a native function, then the generic function
+/// must be instantiated in the target crate, meaning that the native symbol must also be resolved
+/// in the target crate.
 fn add_upstream_native_libraries(
     cmd: &mut dyn Linker,
     sess: &Session,
diff --git a/compiler/rustc_codegen_ssa/src/back/write.rs b/compiler/rustc_codegen_ssa/src/back/write.rs
index 7f2bb7b5bcd..c84b87964b8 100644
--- a/compiler/rustc_codegen_ssa/src/back/write.rs
+++ b/compiler/rustc_codegen_ssa/src/back/write.rs
@@ -274,17 +274,20 @@ impl ModuleConfig {
     }
 }
 
-// HACK(eddyb) work around `#[derive]` producing wrong bounds for `Clone`.
-pub struct TargetMachineFactory<B: WriteBackendMethods>(
-    pub Arc<dyn Fn() -> Result<B::TargetMachine, String> + Send + Sync>,
-);
-
-impl<B: WriteBackendMethods> Clone for TargetMachineFactory<B> {
-    fn clone(&self) -> Self {
-        TargetMachineFactory(self.0.clone())
-    }
+/// Configuration passed to the function returned by the `target_machine_factory`.
+pub struct TargetMachineFactoryConfig {
+    /// Split DWARF is enabled in LLVM by checking that `TM.MCOptions.SplitDwarfFile` isn't empty,
+    /// so the path to the dwarf object has to be provided when we create the target machine.
+    /// This can be ignored by backends which do not need it for their Split DWARF support.
+    pub split_dwarf_file: Option<PathBuf>,
 }
 
+pub type TargetMachineFactoryFn<B> = Arc<
+    dyn Fn(TargetMachineFactoryConfig) -> Result<<B as WriteBackendMethods>::TargetMachine, String>
+        + Send
+        + Sync,
+>;
+
 pub type ExportedSymbols = FxHashMap<CrateNum, Arc<Vec<(String, SymbolExportLevel)>>>;
 
 /// Additional resources used by optimize_and_codegen (not module specific)
@@ -305,12 +308,13 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     pub regular_module_config: Arc<ModuleConfig>,
     pub metadata_module_config: Arc<ModuleConfig>,
     pub allocator_module_config: Arc<ModuleConfig>,
-    pub tm_factory: TargetMachineFactory<B>,
+    pub tm_factory: TargetMachineFactoryFn<B>,
     pub msvc_imps_needed: bool,
     pub is_pe_coff: bool,
     pub target_pointer_width: u32,
     pub target_arch: String,
     pub debuginfo: config::DebugInfo,
+    pub split_dwarf_kind: config::SplitDwarfKind,
 
     // Number of cgus excluding the allocator/metadata modules
     pub total_cgus: usize,
@@ -627,6 +631,12 @@ fn produce_final_output_artifacts(
                 }
             }
 
+            if let Some(ref path) = module.dwarf_object {
+                if !keep_numbered_objects {
+                    remove(sess, path);
+                }
+            }
+
             if let Some(ref path) = module.bytecode {
                 if !keep_numbered_bitcode {
                     remove(sess, path);
@@ -849,6 +859,7 @@ fn execute_copy_from_cache_work_item<B: ExtraBackendMethods>(
         name: module.name,
         kind: ModuleKind::Regular,
         object,
+        dwarf_object: None,
         bytecode: None,
     }))
 }
@@ -1020,13 +1031,14 @@ fn start_executing_work<B: ExtraBackendMethods>(
         regular_module_config: regular_config,
         metadata_module_config: metadata_config,
         allocator_module_config: allocator_config,
-        tm_factory: TargetMachineFactory(backend.target_machine_factory(tcx.sess, ol)),
+        tm_factory: backend.target_machine_factory(tcx.sess, ol),
         total_cgus,
         msvc_imps_needed: msvc_imps_needed(tcx),
         is_pe_coff: tcx.sess.target.is_like_windows,
         target_pointer_width: tcx.sess.target.pointer_width,
         target_arch: tcx.sess.target.arch.clone(),
         debuginfo: tcx.sess.opts.debuginfo,
+        split_dwarf_kind: tcx.sess.opts.debugging_opts.split_dwarf,
     };
 
     // This is the "main loop" of parallel work happening for parallel codegen.
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index 21138f967a2..f47d2ada61a 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -1,18 +1,3 @@
-//! Codegen the completed AST to the LLVM IR.
-//!
-//! Some functions here, such as `codegen_block` and `codegen_expr`, return a value --
-//! the result of the codegen to LLVM -- while others, such as `codegen_fn`
-//! and `mono_item`, are called only for the side effect of adding a
-//! particular definition to the LLVM IR output we're producing.
-//!
-//! Hopefully useful general knowledge about codegen:
-//!
-//! * There's no way to find out the `Ty` type of a `Value`. Doing so
-//!   would be "trying to get the eggs out of an omelette" (credit:
-//!   pcwalton). You can, instead, find out its `llvm::Type` by calling `val_ty`,
-//!   but one `llvm::Type` corresponds to many `Ty`s; for instance, `tup(int, int,
-//!   int)` and `rec(x=int, y=int, z=int)` will have the same `llvm::Type`.
-
 use crate::back::write::{
     compute_per_cgu_lto_type, start_async_codegen, submit_codegened_module_to_llvm,
     submit_post_lto_module_to_llvm, submit_pre_lto_module_to_llvm, ComputedLtoType, OngoingCodegen,
@@ -46,7 +31,6 @@ use rustc_session::cgu_reuse_tracker::CguReuse;
 use rustc_session::config::{self, EntryFnType};
 use rustc_session::utils::NativeLibKind;
 use rustc_session::Session;
-use rustc_symbol_mangling::test as symbol_names_test;
 use rustc_target::abi::{Align, LayoutOf, VariantIdx};
 
 use std::cmp;
@@ -486,8 +470,6 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
 
         ongoing_codegen.codegen_finished(tcx);
 
-        finalize_tcx(tcx);
-
         ongoing_codegen.check_for_errors(tcx.sess);
 
         return ongoing_codegen;
@@ -688,14 +670,8 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
         total_codegen_time.into_inner(),
     );
 
-    rustc_incremental::assert_module_sources::assert_module_sources(tcx);
-
-    symbol_names_test::report_symbol_names(tcx);
-
     ongoing_codegen.check_for_errors(tcx.sess);
 
-    finalize_tcx(tcx);
-
     ongoing_codegen.into_inner()
 }
 
@@ -746,18 +722,6 @@ impl<B: ExtraBackendMethods> Drop for AbortCodegenOnDrop<B> {
     }
 }
 
-fn finalize_tcx(tcx: TyCtxt<'_>) {
-    tcx.sess.time("assert_dep_graph", || rustc_incremental::assert_dep_graph(tcx));
-    tcx.sess.time("serialize_dep_graph", || rustc_incremental::save_dep_graph(tcx));
-
-    // We assume that no queries are run past here. If there are new queries
-    // after this point, they'll show up as "<unknown>" in self-profiling data.
-    {
-        let _prof_timer = tcx.prof.generic_activity("self_profile_alloc_query_strings");
-        tcx.alloc_self_profile_query_strings();
-    }
-}
-
 impl CrateInfo {
     pub fn new(tcx: TyCtxt<'_>) -> CrateInfo {
         let mut info = CrateInfo {
@@ -766,7 +730,7 @@ impl CrateInfo {
             profiler_runtime: None,
             is_no_builtins: Default::default(),
             native_libraries: Default::default(),
-            used_libraries: tcx.native_libraries(LOCAL_CRATE),
+            used_libraries: tcx.native_libraries(LOCAL_CRATE).iter().map(Into::into).collect(),
             link_args: tcx.link_args(LOCAL_CRATE),
             crate_name: Default::default(),
             used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
@@ -787,7 +751,8 @@ impl CrateInfo {
         info.missing_lang_items.reserve(n_crates);
 
         for &cnum in crates.iter() {
-            info.native_libraries.insert(cnum, tcx.native_libraries(cnum));
+            info.native_libraries
+                .insert(cnum, tcx.native_libraries(cnum).iter().map(Into::into).collect());
             info.crate_name.insert(cnum, tcx.crate_name(cnum).to_string());
             info.used_crate_source.insert(cnum, tcx.used_crate_source(cnum));
             if tcx.is_panic_runtime(cnum) {
diff --git a/compiler/rustc_codegen_ssa/src/lib.rs b/compiler/rustc_codegen_ssa/src/lib.rs
index 8ec1eed4404..e27eac3f69b 100644
--- a/compiler/rustc_codegen_ssa/src/lib.rs
+++ b/compiler/rustc_codegen_ssa/src/lib.rs
@@ -21,15 +21,17 @@ extern crate tracing;
 #[macro_use]
 extern crate rustc_middle;
 
+use rustc_ast as ast;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::Lrc;
 use rustc_hir::def_id::CrateNum;
 use rustc_hir::LangItem;
 use rustc_middle::dep_graph::WorkProduct;
-use rustc_middle::middle::cstore::{CrateSource, LibSource, NativeLib};
+use rustc_middle::middle::cstore::{self, CrateSource, LibSource};
 use rustc_middle::middle::dependency_format::Dependencies;
 use rustc_middle::ty::query::Providers;
 use rustc_session::config::{OutputFilenames, OutputType, RUST_CGU_EXT};
+use rustc_session::utils::NativeLibKind;
 use rustc_span::symbol::Symbol;
 use std::path::{Path, PathBuf};
 
@@ -64,13 +66,15 @@ impl<M> ModuleCodegen<M> {
     pub fn into_compiled_module(
         self,
         emit_obj: bool,
+        emit_dwarf_obj: bool,
         emit_bc: bool,
         outputs: &OutputFilenames,
     ) -> CompiledModule {
         let object = emit_obj.then(|| outputs.temp_path(OutputType::Object, Some(&self.name)));
+        let dwarf_object = emit_dwarf_obj.then(|| outputs.temp_path_dwo(Some(&self.name)));
         let bytecode = emit_bc.then(|| outputs.temp_path(OutputType::Bitcode, Some(&self.name)));
 
-        CompiledModule { name: self.name.clone(), kind: self.kind, object, bytecode }
+        CompiledModule { name: self.name.clone(), kind: self.kind, object, dwarf_object, bytecode }
     }
 }
 
@@ -79,6 +83,7 @@ pub struct CompiledModule {
     pub name: String,
     pub kind: ModuleKind,
     pub object: Option<PathBuf>,
+    pub dwarf_object: Option<PathBuf>,
     pub bytecode: Option<PathBuf>,
 }
 
@@ -102,6 +107,19 @@ bitflags::bitflags! {
     }
 }
 
+#[derive(Clone, Debug, Encodable, Decodable, HashStable)]
+pub struct NativeLib {
+    pub kind: NativeLibKind,
+    pub name: Option<Symbol>,
+    pub cfg: Option<ast::MetaItem>,
+}
+
+impl From<&cstore::NativeLib> for NativeLib {
+    fn from(lib: &cstore::NativeLib) -> Self {
+        NativeLib { kind: lib.kind, name: lib.name, cfg: lib.cfg.clone() }
+    }
+}
+
 /// Misc info we load from metadata to persist beyond the tcx.
 ///
 /// Note: though `CrateNum` is only meaningful within the same tcx, information within `CrateInfo`
@@ -116,9 +134,9 @@ pub struct CrateInfo {
     pub compiler_builtins: Option<CrateNum>,
     pub profiler_runtime: Option<CrateNum>,
     pub is_no_builtins: FxHashSet<CrateNum>,
-    pub native_libraries: FxHashMap<CrateNum, Lrc<Vec<NativeLib>>>,
+    pub native_libraries: FxHashMap<CrateNum, Vec<NativeLib>>,
     pub crate_name: FxHashMap<CrateNum, String>,
-    pub used_libraries: Lrc<Vec<NativeLib>>,
+    pub used_libraries: Vec<NativeLib>,
     pub link_args: Lrc<Vec<String>>,
     pub used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
     pub used_crates_static: Vec<(CrateNum, LibSource)>,
diff --git a/compiler/rustc_codegen_ssa/src/mir/analyze.rs b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
index 44bb0deeae9..57e49ba8d1a 100644
--- a/compiler/rustc_codegen_ssa/src/mir/analyze.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/analyze.rs
@@ -112,12 +112,12 @@ impl<Bx: BuilderMethods<'a, 'tcx>> LocalAnalyzer<'mir, 'a, 'tcx, Bx> {
             };
 
             // Allow uses of projections that are ZSTs or from scalar fields.
-            let is_consume = match context {
+            let is_consume = matches!(
+                context,
                 PlaceContext::NonMutatingUse(
                     NonMutatingUseContext::Copy | NonMutatingUseContext::Move,
-                ) => true,
-                _ => false,
-            };
+                )
+            );
             if is_consume {
                 let base_ty =
                     mir::Place::ty_from(place_ref.local, proj_base, self.fx.mir, cx.tcx());
diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index e59832a8eed..ecac05fd955 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -522,7 +522,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         mut bx: Bx,
         terminator: &mir::Terminator<'tcx>,
         func: &mir::Operand<'tcx>,
-        args: &Vec<mir::Operand<'tcx>>,
+        args: &[mir::Operand<'tcx>],
         destination: &Option<(mir::Place<'tcx>, mir::BasicBlock)>,
         cleanup: Option<mir::BasicBlock>,
         fn_span: Span,
@@ -1395,6 +1395,25 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         dst: PlaceRef<'tcx, Bx::Value>,
     ) {
         let src = self.codegen_operand(bx, src);
+
+        // Special-case transmutes between scalars as simple bitcasts.
+        match (&src.layout.abi, &dst.layout.abi) {
+            (abi::Abi::Scalar(src_scalar), abi::Abi::Scalar(dst_scalar)) => {
+                // HACK(eddyb) LLVM doesn't like `bitcast`s between pointers and non-pointers.
+                if (src_scalar.value == abi::Pointer) == (dst_scalar.value == abi::Pointer) {
+                    assert_eq!(src.layout.size, dst.layout.size);
+
+                    // NOTE(eddyb) the `from_immediate` and `to_immediate_scalar`
+                    // conversions allow handling `bool`s the same as `u8`s.
+                    let src = bx.from_immediate(src.immediate());
+                    let src_as_dst = bx.bitcast(src, bx.backend_type(dst.layout));
+                    Immediate(bx.to_immediate_scalar(src_as_dst, dst_scalar)).store(bx, dst);
+                    return;
+                }
+            }
+            _ => {}
+        }
+
         let llty = bx.backend_type(src.layout);
         let cast_ptr = bx.pointercast(dst.llval, bx.type_ptr_to(llty));
         let align = src.layout.align.abi.min(dst.align);
diff --git a/compiler/rustc_codegen_ssa/src/mir/constant.rs b/compiler/rustc_codegen_ssa/src/mir/constant.rs
index c8001b8daf0..3a85c268e0e 100644
--- a/compiler/rustc_codegen_ssa/src/mir/constant.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/constant.rs
@@ -11,7 +11,7 @@ use super::FunctionCx;
 
 impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     pub fn eval_mir_constant_to_operand(
-        &mut self,
+        &self,
         bx: &mut Bx,
         constant: &mir::Constant<'tcx>,
     ) -> Result<OperandRef<'tcx, Bx::Value>, ErrorHandled> {
@@ -21,7 +21,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     }
 
     pub fn eval_mir_constant(
-        &mut self,
+        &self,
         constant: &mir::Constant<'tcx>,
     ) -> Result<ConstValue<'tcx>, ErrorHandled> {
         match self.monomorphize(constant.literal).val {
diff --git a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs
index c4191a4e23d..f1eae605da0 100644
--- a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs
@@ -8,7 +8,7 @@ use rustc_span::symbol::{kw, Symbol};
 use rustc_span::{BytePos, Span};
 use rustc_target::abi::{LayoutOf, Size};
 
-use super::operand::OperandValue;
+use super::operand::{OperandRef, OperandValue};
 use super::place::PlaceRef;
 use super::{FunctionCx, LocalRef};
 
@@ -116,6 +116,24 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
         span
     }
 
+    fn spill_operand_to_stack(
+        operand: &OperandRef<'tcx, Bx::Value>,
+        name: Option<String>,
+        bx: &mut Bx,
+    ) -> PlaceRef<'tcx, Bx::Value> {
+        // "Spill" the value onto the stack, for debuginfo,
+        // without forcing non-debuginfo uses of the local
+        // to also load from the stack every single time.
+        // FIXME(#68817) use `llvm.dbg.value` instead,
+        // at least for the cases which LLVM handles correctly.
+        let spill_slot = PlaceRef::alloca(bx, operand.layout);
+        if let Some(name) = name {
+            bx.set_var_name(spill_slot.llval, &(name + ".dbg.spill"));
+        }
+        operand.val.store(bx, spill_slot);
+        spill_slot
+    }
+
     /// Apply debuginfo and/or name, after creating the `alloca` for a local,
     /// or initializing the local with an operand (whichever applies).
     pub fn debug_introduce_local(&self, bx: &mut Bx, local: mir::Local) {
@@ -152,7 +170,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 // (after #67586 gets fixed).
                 None
             } else {
-                let name = kw::Invalid;
+                let name = kw::Empty;
                 let decl = &self.mir.local_decls[local];
                 let dbg_var = if full_debug_info {
                     self.adjusted_span_and_dbg_scope(decl.source_info).map(
@@ -186,7 +204,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             None
         } else {
             Some(match whole_local_var.or(fallback_var) {
-                Some(var) if var.name != kw::Invalid => var.name.to_string(),
+                Some(var) if var.name != kw::Empty => var.name.to_string(),
                 _ => format!("{:?}", local),
             })
         };
@@ -226,17 +244,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     return;
                 }
 
-                // "Spill" the value onto the stack, for debuginfo,
-                // without forcing non-debuginfo uses of the local
-                // to also load from the stack every single time.
-                // FIXME(#68817) use `llvm.dbg.value` instead,
-                // at least for the cases which LLVM handles correctly.
-                let spill_slot = PlaceRef::alloca(bx, operand.layout);
-                if let Some(name) = name {
-                    bx.set_var_name(spill_slot.llval, &(name + ".dbg.spill"));
-                }
-                operand.val.store(bx, spill_slot);
-                spill_slot
+                Self::spill_operand_to_stack(operand, name, bx)
             }
 
             LocalRef::Place(place) => *place,
@@ -308,6 +316,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
     /// Partition all `VarDebugInfo` in `self.mir`, by their base `Local`.
     pub fn compute_per_local_var_debug_info(
         &self,
+        bx: &mut Bx,
     ) -> Option<IndexVec<mir::Local, Vec<PerLocalVarDebugInfo<'tcx, Bx::DIVariable>>>> {
         let full_debug_info = self.cx.sess().opts.debuginfo == DebugInfo::Full;
 
@@ -322,31 +331,63 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             } else {
                 None
             };
+
             let dbg_var = dbg_scope_and_span.map(|(dbg_scope, _, span)| {
-                let place = var.place;
-                let var_ty = self.monomorphized_place_ty(place.as_ref());
-                let var_kind = if self.mir.local_kind(place.local) == mir::LocalKind::Arg
-                    && place.projection.is_empty()
-                    && var.source_info.scope == mir::OUTERMOST_SOURCE_SCOPE
-                {
-                    let arg_index = place.local.index() - 1;
-
-                    // FIXME(eddyb) shouldn't `ArgumentVariable` indices be
-                    // offset in closures to account for the hidden environment?
-                    // Also, is this `+ 1` needed at all?
-                    VariableKind::ArgumentVariable(arg_index + 1)
-                } else {
-                    VariableKind::LocalVariable
+                let (var_ty, var_kind) = match var.value {
+                    mir::VarDebugInfoContents::Place(place) => {
+                        let var_ty = self.monomorphized_place_ty(place.as_ref());
+                        let var_kind = if self.mir.local_kind(place.local) == mir::LocalKind::Arg
+                            && place.projection.is_empty()
+                            && var.source_info.scope == mir::OUTERMOST_SOURCE_SCOPE
+                        {
+                            let arg_index = place.local.index() - 1;
+
+                            // FIXME(eddyb) shouldn't `ArgumentVariable` indices be
+                            // offset in closures to account for the hidden environment?
+                            // Also, is this `+ 1` needed at all?
+                            VariableKind::ArgumentVariable(arg_index + 1)
+                        } else {
+                            VariableKind::LocalVariable
+                        };
+                        (var_ty, var_kind)
+                    }
+                    mir::VarDebugInfoContents::Const(c) => {
+                        let ty = self.monomorphize(c.literal.ty);
+                        (ty, VariableKind::LocalVariable)
+                    }
                 };
+
                 self.cx.create_dbg_var(var.name, var_ty, dbg_scope, var_kind, span)
             });
 
-            per_local[var.place.local].push(PerLocalVarDebugInfo {
-                name: var.name,
-                source_info: var.source_info,
-                dbg_var,
-                projection: var.place.projection,
-            });
+            match var.value {
+                mir::VarDebugInfoContents::Place(place) => {
+                    per_local[place.local].push(PerLocalVarDebugInfo {
+                        name: var.name,
+                        source_info: var.source_info,
+                        dbg_var,
+                        projection: place.projection,
+                    });
+                }
+                mir::VarDebugInfoContents::Const(c) => {
+                    if let Some(dbg_var) = dbg_var {
+                        let dbg_loc = match self.dbg_loc(var.source_info) {
+                            Some(dbg_loc) => dbg_loc,
+                            None => continue,
+                        };
+
+                        if let Ok(operand) = self.eval_mir_constant_to_operand(bx, &c) {
+                            let base = Self::spill_operand_to_stack(
+                                &operand,
+                                Some(var.name.to_string()),
+                                bx,
+                            );
+
+                            bx.dbg_var_addr(dbg_var, dbg_loc, base.llval, Size::ZERO, &[]);
+                        }
+                    }
+                }
+            }
         }
         Some(per_local)
     }
diff --git a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
index 72a64a8c510..80e3ed75b85 100644
--- a/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/intrinsic.rs
@@ -83,9 +83,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 return;
             }
 
-            sym::unreachable => {
-                return;
-            }
             sym::va_start => bx.va_start(args[0].immediate()),
             sym::va_end => bx.va_end(args[0].immediate()),
             sym::size_of_val => {
@@ -106,8 +103,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     bx.const_usize(bx.layout_of(tp_ty).align.abi.bytes())
                 }
             }
-            sym::size_of
-            | sym::pref_align_of
+            sym::pref_align_of
             | sym::min_align_of
             | sym::needs_drop
             | sym::type_id
@@ -119,10 +115,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     .unwrap();
                 OperandRef::from_const(bx, value, ret_ty).immediate_or_packed_pair(bx)
             }
-            // Effectively no-op
-            sym::forget => {
-                return;
-            }
             sym::offset => {
                 let ptr = args[0].immediate();
                 let offset = args[1].immediate();
@@ -218,9 +210,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             sym::add_with_overflow
             | sym::sub_with_overflow
             | sym::mul_with_overflow
-            | sym::wrapping_add
-            | sym::wrapping_sub
-            | sym::wrapping_mul
             | sym::unchecked_div
             | sym::unchecked_rem
             | sym::unchecked_shl
@@ -254,9 +243,6 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
                             return;
                         }
-                        sym::wrapping_add => bx.add(args[0].immediate(), args[1].immediate()),
-                        sym::wrapping_sub => bx.sub(args[0].immediate(), args[1].immediate()),
-                        sym::wrapping_mul => bx.mul(args[0].immediate(), args[1].immediate()),
                         sym::exact_div => {
                             if signed {
                                 bx.exactsdiv(args[0].immediate(), args[1].immediate())
@@ -538,8 +524,19 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                         };
 
                         let ty = substs.type_at(0);
-                        if int_type_width_signed(ty, bx.tcx()).is_some() {
-                            bx.atomic_rmw(atom_op, args[0].immediate(), args[1].immediate(), order)
+                        if int_type_width_signed(ty, bx.tcx()).is_some()
+                            || (ty.is_unsafe_ptr() && op == "xchg")
+                        {
+                            let mut ptr = args[0].immediate();
+                            let mut val = args[1].immediate();
+                            if ty.is_unsafe_ptr() {
+                                // Some platforms do not support atomic operations on pointers,
+                                // so we cast to integer first.
+                                let ptr_llty = bx.type_ptr_to(bx.type_isize());
+                                ptr = bx.pointercast(ptr, ptr_llty);
+                                val = bx.ptrtoint(val, bx.type_isize());
+                            }
+                            bx.atomic_rmw(atom_op, ptr, val, order)
                         } else {
                             return invalid_monomorphization(ty);
                         }
diff --git a/compiler/rustc_codegen_ssa/src/mir/mod.rs b/compiler/rustc_codegen_ssa/src/mir/mod.rs
index 640f805d5e8..285140060be 100644
--- a/compiler/rustc_codegen_ssa/src/mir/mod.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/mod.rs
@@ -186,7 +186,7 @@ pub fn codegen_mir<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         caller_location: None,
     };
 
-    fx.per_local_var_debug_info = fx.compute_per_local_var_debug_info();
+    fx.per_local_var_debug_info = fx.compute_per_local_var_debug_info(&mut bx);
 
     for const_ in &mir.required_consts {
         if let Err(err) = fx.eval_mir_constant(const_) {
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index 2ad470c2693..e3a6cabd600 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -489,6 +489,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
 
             mir::Rvalue::Discriminant(ref place) => {
                 let discr_ty = rvalue.ty(self.mir, bx.tcx());
+                let discr_ty = self.monomorphize(discr_ty);
                 let discr = self
                     .codegen_place(&mut bx, place.as_ref())
                     .codegen_get_discr(&mut bx, discr_ty);
diff --git a/compiler/rustc_codegen_ssa/src/traits/backend.rs b/compiler/rustc_codegen_ssa/src/traits/backend.rs
index b9c555c2eb0..f28db2fe84b 100644
--- a/compiler/rustc_codegen_ssa/src/traits/backend.rs
+++ b/compiler/rustc_codegen_ssa/src/traits/backend.rs
@@ -1,5 +1,6 @@
 use super::write::WriteBackendMethods;
 use super::CodegenObject;
+use crate::back::write::TargetMachineFactoryFn;
 use crate::{CodegenResults, ModuleCodegen};
 
 use rustc_ast::expand::allocator::AllocatorKind;
@@ -21,7 +22,6 @@ use rustc_target::spec::Target;
 pub use rustc_data_structures::sync::MetadataRef;
 
 use std::any::Any;
-use std::sync::Arc;
 
 pub trait BackendTypes {
     type Value: CodegenObject;
@@ -123,7 +123,7 @@ pub trait ExtraBackendMethods: CodegenBackend + WriteBackendMethods + Sized + Se
         &self,
         sess: &Session,
         opt_level: config::OptLevel,
-    ) -> Arc<dyn Fn() -> Result<Self::TargetMachine, String> + Send + Sync>;
+    ) -> TargetMachineFactoryFn<Self>;
     fn target_cpu<'b>(&self, sess: &'b Session) -> &'b str;
     fn tune_cpu<'b>(&self, sess: &'b Session) -> Option<&'b str>;
 }