[driver breaking] Rename rustc_trans to rustc_codegen_llvm and allow runtime switching between trans backends

src/doc/rustc-ux-guidelines.md

@@ -70,7 +70,7 @@ for details on how to format and write long error codes.
   [librustc_passes](https://github.com/rust-lang/rust/blob/master/src/librustc_passes/diagnostics.rs),
   [librustc_privacy](https://github.com/rust-lang/rust/blob/master/src/librustc_privacy/diagnostics.rs),
   [librustc_resolve](https://github.com/rust-lang/rust/blob/master/src/librustc_resolve/diagnostics.rs),
-  [librustc_trans](https://github.com/rust-lang/rust/blob/master/src/librustc_trans/diagnostics.rs),
+  [librustc_codegen_llvm](https://github.com/rust-lang/rust/blob/master/src/librustc_codegen_llvm/diagnostics.rs),
   [librustc_plugin](https://github.com/rust-lang/rust/blob/master/src/librustc_plugin/diagnostics.rs),
   [librustc_typeck](https://github.com/rust-lang/rust/blob/master/src/librustc_typeck/diagnostics.rs).
 * Explanations have full markdown support. Use it, especially to highlight

src/libcore/intrinsics.rs

@@ -10,7 +10,7 @@
 
 //! rustc compiler intrinsics.
 //!
-//! The corresponding definitions are in librustc_trans/intrinsic.rs.
+//! The corresponding definitions are in librustc_codegen_llvm/intrinsic.rs.
 //!
 //! # Volatiles
 //!

src/librustc/Cargo.toml

@@ -32,21 +32,21 @@ syntax_pos = { path = "../libsyntax_pos" }
 # rlib/dylib pair but all crates.io crates tend to just be rlibs. This means
 # we've got a problem for dependency graphs that look like:
 #
-#           foo - rustc_trans
-#         /                  \
-#   rustc                     ---- rustc_driver
+#           foo - rustc_codegen_llvm
+#         /                         \
+#   rustc                        ----- rustc_driver
 #         \                     /
 #           foo - rustc_metadata
 #
-# Here the crate `foo` is linked into the `rustc_trans` and the
+# Here the crate `foo` is linked into the `rustc_codegen_llvm` and the
 # `rustc_metadata` dylibs, meaning we've got duplicate copies! When we then
 # go to link `rustc_driver` the compiler notices this and gives us a compiler
 # error.
 #
 # To work around this problem we just add these crates.io dependencies to the
 # `rustc` crate which is a shared dependency above. That way the crate `foo`
 # shows up in the dylib for the `rustc` crate, deduplicating it and allowing
-# crates like `rustc_trans` to use `foo` *through* the `rustc` crate.
+# crates like `rustc_codegen_llvm` to use `foo` *through* the `rustc` crate.
 #
 # tl;dr; this is not needed to get `rustc` to compile, but if you remove it then
 #        later crate stop compiling. If you can remove this and everything

src/librustc/README.md

@@ -26,7 +26,7 @@ The crates of rustc
 ===================
 
 Rustc consists of a number of crates, including `syntax`,
-`rustc`, `rustc_back`, `rustc_trans`, `rustc_driver`, and
+`rustc`, `rustc_back`, `rustc_codegen_llvm`, `rustc_driver`, and
 many more. The source for each crate can be found in a directory
 like `src/libXXX`, where `XXX` is the crate name.
 
@@ -38,23 +38,23 @@ incremental improves that may change.)
 The dependency structure of these crates is roughly a diamond:
 
 ```
-                  rustc_driver
-                /      |       \
-              /        |         \
-            /          |           \
-          /            v             \
-rustc_trans    rustc_borrowck   ...  rustc_metadata
-          \            |            /
-            \          |          /
-              \        |        /
-                \      v      /
-                    rustc
-                       |
-                       v
-                    syntax
-                    /    \
-                  /       \
-           syntax_pos  syntax_ext
+                         rustc_driver
+                       /      |       \
+                     /        |         \
+                   /          |           \
+                 /            v             \
+rustc_codegen_llvm    rustc_borrowck   ...  rustc_metadata
+                 \            |            /
+                   \          |          /
+                     \        |        /
+                       \      v      /
+                            rustc
+                              |
+                              v
+                           syntax
+                           /    \
+                         /       \
+                    syntax_pos  syntax_ext
 ```                    
 
 The `rustc_driver` crate, at the top of this lattice, is effectively

src/librustc/session/config.rs

@@ -936,6 +936,8 @@ options! {CodegenOptions, CodegenSetter, basic_codegen_options,
 options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
          build_debugging_options, "Z", "debugging",
          DB_OPTIONS, db_type_desc, dbsetters,
+    trans: Option<String> = (None, parse_opt_string, [TRACKED],
+        "the backend to use"),
     verbose: bool = (false, parse_bool, [UNTRACKED],
         "in general, enable more debug printouts"),
     span_free_formats: bool = (false, parse_bool, [UNTRACKED],

src/librustc/util/common.rs

@@ -84,7 +84,7 @@ pub fn profq_msg(msg: ProfileQueriesMsg) {
             // Do nothing.
             //
             // FIXME(matthewhammer): Multi-threaded translation phase triggers the panic below.
-            // From backtrace: rustc_trans::back::write::spawn_work::{{closure}}.
+            // From backtrace: rustc_codegen_llvm::back::write::spawn_work::{{closure}}.
             //
             // panic!("no channel on which to send profq_msg: {:?}", msg)
         }

src/librustc_trans/Cargo.toml → src/librustc_codegen_llvm/Cargo.toml

@@ -1,10 +1,10 @@
 [package]
 authors = ["The Rust Project Developers"]
-name = "rustc_trans"
+name = "rustc_codegen_llvm"
 version = "0.0.0"
 
 [lib]
-name = "rustc_trans"
+name = "rustc_codegen_llvm"
 path = "lib.rs"
 crate-type = ["dylib"]
 test = false

src/librustc_trans/intrinsic.rs → src/librustc_codegen_llvm/intrinsic.rs

@@ -85,7 +85,7 @@ fn get_simple_intrinsic(ccx: &CrateContext, name: &str) -> Option<ValueRef> {
 
 /// Remember to add all intrinsics here, in librustc_typeck/check/mod.rs,
 /// and in libcore/intrinsics.rs; if you need access to any llvm intrinsics,
-/// add them to librustc_trans/trans/context.rs
+/// add them to librustc_codegen_llvm/trans/context.rs
 pub fn trans_intrinsic_call<'a, 'tcx>(bcx: &Builder<'a, 'tcx>,
                                       callee_ty: Ty<'tcx>,
                                       fn_ty: &FnType,

src/librustc_trans/lib.rs → src/librustc_codegen_llvm/lib.rs

@@ -329,7 +329,7 @@ pub struct CrateInfo {
     used_crates_dynamic: Vec<(CrateNum, LibSource)>,
 }
 
-__build_diagnostic_array! { librustc_trans, DIAGNOSTICS }
+__build_diagnostic_array! { librustc_codegen_llvm, DIAGNOSTICS }
 
 pub fn provide_local(providers: &mut Providers) {
     back::symbol_names::provide(providers);

src/librustc_trans/llvm_util.rs → src/librustc_codegen_llvm/llvm_util.rs

@@ -126,7 +126,7 @@ pub fn print(req: PrintRequest, sess: &Session) {
         match req {
             PrintRequest::TargetCPUs => llvm::LLVMRustPrintTargetCPUs(tm),
             PrintRequest::TargetFeatures => llvm::LLVMRustPrintTargetFeatures(tm),
-            _ => bug!("rustc_trans can't handle print request: {:?}", req),
+            _ => bug!("rustc_codegen_llvm can't handle print request: {:?}", req),
         }
     }
 }

src/librustc_driver/Cargo.toml

@@ -30,7 +30,7 @@ rustc_plugin = { path = "../librustc_plugin" }
 rustc_privacy = { path = "../librustc_privacy" }
 rustc_resolve = { path = "../librustc_resolve" }
 rustc_save_analysis = { path = "../librustc_save_analysis" }
-rustc_trans = { path = "../librustc_trans", optional = true }
+rustc_codegen_llvm = { path = "../librustc_codegen_llvm", optional = true }
 rustc_trans_utils = { path = "../librustc_trans_utils" }
 rustc_typeck = { path = "../librustc_typeck" }
 serialize = { path = "../libserialize" }
@@ -41,4 +41,4 @@ syntax_pos = { path = "../libsyntax_pos" }
 ar = "0.3.0"
 
 [features]
-llvm = ["rustc_trans"]
+llvm = ["rustc_codegen_llvm"]

src/librustc_driver/driver.rs

@@ -32,7 +32,6 @@ use rustc_incremental;
 use rustc_resolve::{MakeGlobMap, Resolver};
 use rustc_metadata::creader::CrateLoader;
 use rustc_metadata::cstore::{self, CStore};
-use rustc_trans as trans;
 use rustc_trans_utils::trans_crate::TransCrate;
 use rustc_typeck as typeck;
 use rustc_privacy;
@@ -41,7 +40,6 @@ use rustc_plugin as plugin;
 use rustc_passes::{self, ast_validation, no_asm, loops, consts, static_recursion, hir_stats};
 use rustc_const_eval::{self, check_match};
 use super::Compilation;
-use ::DefaultTransCrate;
 
 use serialize::json;
 
@@ -67,7 +65,7 @@ use derive_registrar;
 
 use profile;
 
-pub fn compile_input(sess: &Session,
+pub fn compile_input<Trans: TransCrate>(sess: &Session,
                      cstore: &CStore,
                      input: &Input,
                      outdir: &Option<PathBuf>,
@@ -207,7 +205,7 @@ pub fn compile_input(sess: &Session,
             None
         };
 
-        phase_3_run_analysis_passes(sess,
+        phase_3_run_analysis_passes::<Trans, _, _>(sess,
                                     cstore,
                                     hir_map,
                                     analysis,
@@ -244,7 +242,7 @@ pub fn compile_input(sess: &Session,
                 tcx.print_debug_stats();
             }
 
-            let trans = phase_4_translate_to_llvm::<DefaultTransCrate>(tcx, rx);
+            let trans = phase_4_translate_to_llvm::<Trans>(tcx, rx);
 
             if log_enabled!(::log::LogLevel::Info) {
                 println!("Post-trans");
@@ -267,18 +265,19 @@ pub fn compile_input(sess: &Session,
     }
 
     let (phase5_result, trans) =
-        phase_5_run_llvm_passes::<DefaultTransCrate>(sess, &dep_graph, trans);
+        phase_5_run_llvm_passes::<Trans>(sess, &dep_graph, trans);
 
-    controller_entry_point!(after_llvm,
-                            sess,
-                            CompileState::state_after_llvm(input, sess, outdir, output, &trans),
-                            phase5_result);
     phase5_result?;
 
+    if !sess.opts.output_types.keys().any(|&i| i == OutputType::Exe ||
+                                               i == OutputType::Metadata) {
+        return Ok(());
+    }
+
     // Run the linker on any artifacts that resulted from the LLVM run.
     // This should produce either a finished executable or library.
     time(sess.time_passes(), "linking", || {
-        DefaultTransCrate::link_binary(sess, &trans, &outputs)
+        Trans::link_binary(sess, &trans, &outputs)
     });
 
     // Now that we won't touch anything in the incremental compilation directory
@@ -338,7 +337,6 @@ pub struct CompileController<'a> {
     pub after_expand: PhaseController<'a>,
     pub after_hir_lowering: PhaseController<'a>,
     pub after_analysis: PhaseController<'a>,
-    pub after_llvm: PhaseController<'a>,
     pub compilation_done: PhaseController<'a>,
 
     // FIXME we probably want to group the below options together and offer a
@@ -357,7 +355,6 @@ impl<'a> CompileController<'a> {
             after_expand: PhaseController::basic(),
             after_hir_lowering: PhaseController::basic(),
             after_analysis: PhaseController::basic(),
-            after_llvm: PhaseController::basic(),
             compilation_done: PhaseController::basic(),
             make_glob_map: MakeGlobMap::No,
             keep_ast: false,
@@ -405,7 +402,6 @@ pub struct CompileState<'a, 'tcx: 'a> {
     pub resolutions: Option<&'a Resolutions>,
     pub analysis: Option<&'a ty::CrateAnalysis>,
     pub tcx: Option<TyCtxt<'a, 'tcx, 'tcx>>,
-    pub trans: Option<&'a trans::CrateTranslation>,
 }
 
 impl<'a, 'tcx> CompileState<'a, 'tcx> {
@@ -431,7 +427,6 @@ impl<'a, 'tcx> CompileState<'a, 'tcx> {
             resolutions: None,
             analysis: None,
             tcx: None,
-            trans: None,
         }
     }
 
@@ -521,19 +516,6 @@ impl<'a, 'tcx> CompileState<'a, 'tcx> {
         }
     }
 
-    fn state_after_llvm(input: &'a Input,
-                        session: &'tcx Session,
-                        out_dir: &'a Option<PathBuf>,
-                        out_file: &'a Option<PathBuf>,
-                        trans: &'a trans::CrateTranslation)
-                        -> Self {
-        CompileState {
-            trans: Some(trans),
-            out_file: out_file.as_ref().map(|s| &**s),
-            ..CompileState::empty(input, session, out_dir)
-        }
-    }
-
     fn state_when_compilation_done(input: &'a Input,
                                    session: &'tcx Session,
                                    out_dir: &'a Option<PathBuf>,
@@ -910,7 +892,7 @@ pub fn phase_2_configure_and_expand<F>(sess: &Session,
 /// Run the resolution, typechecking, region checking and other
 /// miscellaneous analysis passes on the crate. Return various
 /// structures carrying the results of the analysis.
-pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
+pub fn phase_3_run_analysis_passes<'tcx, Trans: TransCrate, F, R>(sess: &'tcx Session,
                                                cstore: &'tcx CrateStore,
                                                hir_map: hir_map::Map<'tcx>,
                                                mut analysis: ty::CrateAnalysis,
@@ -966,7 +948,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
     mir::provide(&mut local_providers);
     reachable::provide(&mut local_providers);
     rustc_privacy::provide(&mut local_providers);
-    DefaultTransCrate::provide_local(&mut local_providers);
+    Trans::provide_local(&mut local_providers);
     typeck::provide(&mut local_providers);
     ty::provide(&mut local_providers);
     traits::provide(&mut local_providers);
@@ -979,7 +961,7 @@ pub fn phase_3_run_analysis_passes<'tcx, F, R>(sess: &'tcx Session,
 
     let mut extern_providers = ty::maps::Providers::default();
     cstore::provide(&mut extern_providers);
-    DefaultTransCrate::provide_extern(&mut extern_providers);
+    Trans::provide_extern(&mut extern_providers);
     ty::provide_extern(&mut extern_providers);
     traits::provide_extern(&mut extern_providers);
     // FIXME(eddyb) get rid of this once we replace const_eval with miri.