rustc_plugin: Remove support for plugins adding LLVM passes

src/librustc/session/mod.rs

@@ -76,7 +76,6 @@ pub struct Session {
     /// (sub)diagnostics that have been set once, but should not be set again,
     /// in order to avoid redundantly verbose output (Issue #24690, #44953).
     pub one_time_diagnostics: Lock<FxHashSet<(DiagnosticMessageId, Option<Span>, String)>>,
-    pub plugin_llvm_passes: OneThread<RefCell<Vec<String>>>,
     pub crate_types: Once<Vec<config::CrateType>>,
     /// The `crate_disambiguator` is constructed out of all the `-C metadata`
     /// arguments passed to the compiler. Its value together with the crate-name
@@ -1149,7 +1148,6 @@ fn build_session_(
         local_crate_source_file,
         working_dir,
         one_time_diagnostics: Default::default(),
-        plugin_llvm_passes: OneThread::new(RefCell::new(Vec::new())),
         crate_types: Once::new(),
         crate_disambiguator: Once::new(),
         features: Once::new(),

src/librustc_codegen_llvm/back/write.rs

@@ -365,20 +365,6 @@ pub(crate) unsafe fn optimize(cgcx: &CodegenContext<LlvmCodegenBackend>,
 
             add_sanitizer_passes(config, &mut extra_passes);
 
-            for pass_name in &cgcx.plugin_passes {
-                if let Some(pass) = find_pass(pass_name) {
-                    extra_passes.push(pass);
-                } else {
-                    diag_handler.err(&format!("a plugin asked for LLVM pass \
-                                               `{}` but LLVM does not \
-                                               recognize it", pass_name));
-                }
-
-                if pass_name == "name-anon-globals" {
-                    have_name_anon_globals_pass = true;
-                }
-            }
-
             // Some options cause LLVM bitcode to be emitted, which uses ThinLTOBuffers, so we need
             // to make sure we run LLVM's NameAnonGlobals pass when emitting bitcode; otherwise
             // we'll get errors in LLVM.

src/librustc_codegen_ssa/back/write.rs

@@ -231,8 +231,6 @@ pub struct CodegenContext<B: WriteBackendMethods> {
     pub total_cgus: usize,
     // Handler to use for diagnostics produced during codegen.
     pub diag_emitter: SharedEmitter,
-    // LLVM passes added by plugins.
-    pub plugin_passes: Vec<String>,
     // LLVM optimizations for which we want to print remarks.
     pub remark: Passes,
     // Worker thread number
@@ -1028,7 +1026,6 @@ fn start_executing_work<B: ExtraBackendMethods>(
         time_passes: sess.time_extended(),
         prof: sess.prof.clone(),
         exported_symbols,
-        plugin_passes: sess.plugin_llvm_passes.borrow().clone(),
         remark: sess.opts.cg.remark.clone(),
         worker: 0,
         incr_comp_session_dir: sess.incr_comp_session_dir_opt().map(|r| r.clone()),

src/librustc_interface/passes.rs

@@ -208,27 +208,22 @@ pub fn register_plugins<'a>(
         middle::recursion_limit::update_limits(sess, &krate);
     });
 
-    let registrars = time(sess, "plugin loading", || {
-        plugin::load::load_plugins(sess, metadata_loader, &krate)
-    });
-
     let mut lint_store = rustc_lint::new_lint_store(
         sess.opts.debugging_opts.no_interleave_lints,
         sess.unstable_options(),
     );
+    register_lints(&sess, &mut lint_store);
 
-    (register_lints)(&sess, &mut lint_store);
-
-    let mut registry = Registry::new(sess, &mut lint_store, krate.span);
-
+    let registrars = time(sess, "plugin loading", || {
+        plugin::load::load_plugins(sess, metadata_loader, &krate)
+    });
     time(sess, "plugin registration", || {
+        let mut registry = Registry::new(sess, &mut lint_store, krate.span);
         for registrar in registrars {
             registrar(&mut registry);
         }
     });
 
-    *sess.plugin_llvm_passes.borrow_mut() = registry.llvm_passes;
-
     Ok((krate, Lrc::new(lint_store)))
 }
 

src/librustc_plugin_impl/registry.rs

@@ -4,8 +4,6 @@ use rustc::lint::LintStore;
 use rustc::session::Session;
 use syntax_pos::Span;
 
-use std::borrow::ToOwned;
-
 /// Structure used to register plugins.
 ///
 /// A plugin registrar function takes an `&mut Registry` and should call
@@ -24,9 +22,6 @@ pub struct Registry<'a> {
 
     #[doc(hidden)]
     pub krate_span: Span,
-
-    #[doc(hidden)]
-    pub llvm_passes: Vec<String>,
 }
 
 impl<'a> Registry<'a> {
@@ -36,16 +31,6 @@ impl<'a> Registry<'a> {
             sess,
             lint_store,
             krate_span,
-            llvm_passes: vec![],
         }
     }
-
-    /// Register an LLVM pass.
-    ///
-    /// Registration with LLVM itself is handled through static C++ objects with
-    /// constructors. This method simply adds a name to the list of passes to
-    /// execute.
-    pub fn register_llvm_pass(&mut self, name: &str) {
-        self.llvm_passes.push(name.to_owned());
-    }
 }

src/test/ui-fulldeps/auxiliary/llvm-pass-plugin.rs

@@ -1,19 +0,0 @@
-// force-host
-
-#![feature(plugin_registrar)]
-#![feature(rustc_private)]
-
-extern crate rustc;
-extern crate rustc_driver;
-
-use rustc_driver::plugin::Registry;
-
-#[plugin_registrar]
-pub fn plugin_registrar(reg: &mut Registry) {
-    // This pass is built in to LLVM.
-    //
-    // Normally, we would name a pass that was registered through
-    // C++ static object constructors in the same .so file as the
-    // plugin registrar.
-    reg.register_llvm_pass("gvn");
-}

src/test/ui-fulldeps/llvm-pass-plugin.rs

@@ -1,8 +0,0 @@
-// run-pass
-// aux-build:llvm-pass-plugin.rs
-// ignore-stage1
-
-#![feature(plugin)]
-#![plugin(llvm_pass_plugin)] //~ WARNING compiler plugins are deprecated
-
-pub fn main() { }

src/test/ui-fulldeps/llvm-pass-plugin.stderr

@@ -1,8 +0,0 @@
-warning: use of deprecated attribute `plugin`: compiler plugins are deprecated. See https://github.com/rust-lang/rust/pull/64675
-  --> $DIR/llvm-pass-plugin.rs:6:1
-   |
-LL | #![plugin(llvm_pass_plugin)]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: may be removed in a future compiler version
-   |
-   = note: `#[warn(deprecated)]` on by default
-