Rollup merge of rust-lang#66905 - petrochenkov:rmplugin2, r=Centril

rustc_plugin: Remove some remaining plugin features

- Plugin arguments (`#![plugin(my_plugin(args))]`) are no longer supported.
- Registering additional plugins from command line (`-Z extra-plugins=my_plugin`) is no longer supported, `-Z crate-attr=plugin(my_plugin)` can be used instead.
- Lint `plugin_as_library` is removed as mostly useless now, when plugins exist as a compatibility feature with greatly reduced functionality.
- Plugins registering additional LLVM passes (`Registry::register_llvm_pass`) are no longer supported, `-C                   passes=my_passes` can be used instead.

r? @Centril

src/doc/rustc/src/lints/listing/warn-by-default.md

@@ -307,18 +307,6 @@ warning: path statement with no effect
   |
 ```
 
-## plugin-as-library
-
-This lint detects when compiler plugins are used as ordinary library in
-non-plugin crate. Some example code that triggers this lint:
-
-```rust,ignore
-#![feature(plugin)]
-#![plugin(macro_crate_test)]
-
-extern crate macro_crate_test;
-```
-
 ## private-in-public
 
 This lint detects private items in public interfaces not caught by the old implementation. Some

src/doc/unstable-book/src/language-features/plugin.md

@@ -21,15 +21,10 @@ the crate attribute `#![plugin(...)]`.  See the
 `rustc_driver::plugin` documentation for more about the
 mechanics of defining and loading a plugin.
 
-If present, arguments passed as `#![plugin(foo(... args ...))]` are not
-interpreted by rustc itself.  They are provided to the plugin through the
-`Registry`'s `args` method.
-
 In the vast majority of cases, a plugin should *only* be used through
 `#![plugin]` and not through an `extern crate` item.  Linking a plugin would
 pull in all of libsyntax and librustc as dependencies of your crate.  This is
-generally unwanted unless you are building another plugin.  The
-`plugin_as_library` lint checks these guidelines.
+generally unwanted unless you are building another plugin.
 
 The usual practice is to put compiler plugins in their own crate, separate from
 any `macro_rules!` macros or ordinary Rust code meant to be used by consumers

src/librustc/lint/context.rs

@@ -47,8 +47,7 @@ use rustc_error_codes::*;
 /// This is basically the subset of `Context` that we can
 /// build early in the compile pipeline.
 pub struct LintStore {
-    /// Registered lints. The bool is true if the lint was
-    /// added by a plugin.
+    /// Registered lints.
     lints: Vec<&'static Lint>,
 
     /// Constructor functions for each variety of lint pass.

src/librustc/session/config.rs

@@ -1364,8 +1364,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "enable queries of the dependency graph for regression testing"),
     no_analysis: bool = (false, parse_bool, [UNTRACKED],
         "parse and expand the source, but run no analysis"),
-    extra_plugins: Vec<String> = (Vec::new(), parse_list, [TRACKED],
-        "load extra plugins"),
     unstable_options: bool = (false, parse_bool, [UNTRACKED],
         "adds unstable command line options to rustc interface"),
     force_overflow_checks: Option<bool> = (None, parse_opt_bool, [TRACKED],

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_feature/builtin_attrs.rs

@@ -283,7 +283,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         )
     ),
     (
-        sym::plugin, CrateLevel, template!(List: "name|name(args)"),
+        sym::plugin, CrateLevel, template!(List: "name"),
         Gated(
             Stability::Deprecated(
                 "https://github.com/rust-lang/rust/pull/64675",

src/librustc_interface/passes.rs

@@ -30,7 +30,6 @@ use rustc_mir as mir;
 use rustc_parse::{parse_crate_from_file, parse_crate_from_source_str};
 use rustc_passes::{self, ast_validation, hir_stats, layout_test};
 use rustc_plugin_impl as plugin;
-use rustc_plugin_impl::registry::Registry;
 use rustc_privacy;
 use rustc_resolve::{Resolver, ResolverArenas};
 use rustc_traits;
@@ -106,8 +105,7 @@ declare_box_region_type!(
     (&mut Resolver<'_>) -> (Result<ast::Crate>, ResolverOutputs)
 );
 
-/// Runs the "early phases" of the compiler: initial `cfg` processing,
-/// loading compiler plugins (including those from `addl_plugins`),
+/// Runs the "early phases" of the compiler: initial `cfg` processing, loading compiler plugins,
 /// syntax expansion, secondary `cfg` expansion, synthesis of a test
 /// harness if one is to be provided, injection of a dependency on the
 /// standard library and prelude, and name resolution.
@@ -209,33 +207,22 @@ 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,
-            Some(sess.opts.debugging_opts.extra_plugins.clone()),
-        )
-    });
-
     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 = plugin::Registry { lint_store: &mut lint_store };
         for registrar in registrars {
-            registry.args_hidden = Some(registrar.args);
-            (registrar.fun)(&mut registry);
+            registrar(&mut registry);
         }
     });
 
-    *sess.plugin_llvm_passes.borrow_mut() = registry.llvm_passes;
-
     Ok((krate, Lrc::new(lint_store)))
 }
 

src/librustc_interface/tests.rs

@@ -650,10 +650,6 @@ fn test_debugging_options_tracking_hash() {
     opts.debugging_opts.continue_parse_after_error = true;
     assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());
 
-    opts = reference.clone();
-    opts.debugging_opts.extra_plugins = vec![String::from("plugin1"), String::from("plugin2")];
-    assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());
-
     opts = reference.clone();
     opts.debugging_opts.force_overflow_checks = Some(true);
     assert!(reference.dep_tracking_hash() != opts.dep_tracking_hash());

src/librustc_lint/builtin.rs

@@ -24,7 +24,7 @@
 use std::fmt::Write;
 
 use rustc::hir::def::{Res, DefKind};
-use rustc::hir::def_id::{DefId, LOCAL_CRATE};
+use rustc::hir::def_id::DefId;
 use rustc::ty::{self, Ty, TyCtxt, layout::VariantIdx};
 use rustc::{lint, util};
 use rustc::lint::FutureIncompatibleInfo;
@@ -800,45 +800,6 @@ impl EarlyLintPass for UnusedDocComment {
     }
 }
 
-declare_lint! {
-    PLUGIN_AS_LIBRARY,
-    Warn,
-    "compiler plugin used as ordinary library in non-plugin crate"
-}
-
-declare_lint_pass!(PluginAsLibrary => [PLUGIN_AS_LIBRARY]);
-
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for PluginAsLibrary {
-    fn check_item(&mut self, cx: &LateContext<'_, '_>, it: &hir::Item) {
-        if cx.tcx.plugin_registrar_fn(LOCAL_CRATE).is_some() {
-            // We're compiling a plugin; it's fine to link other plugins.
-            return;
-        }
-
-        match it.kind {
-            hir::ItemKind::ExternCrate(..) => (),
-            _ => return,
-        };
-
-        let def_id = cx.tcx.hir().local_def_id(it.hir_id);
-        let prfn = match cx.tcx.extern_mod_stmt_cnum(def_id) {
-            Some(cnum) => cx.tcx.plugin_registrar_fn(cnum),
-            None => {
-                // Probably means we aren't linking the crate for some reason.
-                //
-                // Not sure if / when this could happen.
-                return;
-            }
-        };
-
-        if prfn.is_some() {
-            cx.span_lint(PLUGIN_AS_LIBRARY,
-                         it.span,
-                         "compiler plugin used as an ordinary library");
-        }
-    }
-}
-
 declare_lint! {
     NO_MANGLE_CONST_ITEMS,
     Deny,
@@ -1268,7 +1229,6 @@ declare_lint_pass!(
         MISSING_DEBUG_IMPLEMENTATIONS,
         ANONYMOUS_PARAMETERS,
         UNUSED_DOC_COMMENTS,
-        PLUGIN_AS_LIBRARY,
         NO_MANGLE_CONST_ITEMS,
         NO_MANGLE_GENERIC_ITEMS,
         MUTABLE_TRANSMUTES,

src/librustc_lint/lib.rs

@@ -157,8 +157,6 @@ macro_rules! late_lint_mod_passes {
             // Depends on types used in type definitions
             MissingCopyImplementations: MissingCopyImplementations,
 
-            PluginAsLibrary: PluginAsLibrary,
-
             // Depends on referenced function signatures in expressions
             MutableTransmutes: MutableTransmutes,
 
@@ -350,6 +348,7 @@ fn register_builtins(store: &mut lint::LintStore, no_interleave_lints: bool) {
         "converted into hard error, see https://github.com/rust-lang/rust/issues/35896");
     store.register_removed("nested_impl_trait",
         "converted into hard error, see https://github.com/rust-lang/rust/issues/59014");
+    store.register_removed("plugin_as_library", "plugins have been deprecated and retired");
 }
 
 fn register_internals(store: &mut lint::LintStore) {

src/librustc_plugin_impl/lib.rs

@@ -10,10 +10,16 @@
 
 #![feature(nll)]
 
-#![recursion_limit="256"]
+use rustc::lint::LintStore;
 
-pub use registry::Registry;
-
-pub mod registry;
-pub mod load;
 pub mod build;
+pub mod load;
+
+/// Structure used to register plugins.
+///
+/// A plugin registrar function takes an `&mut Registry` and should call
+/// methods to register its plugins.
+pub struct Registry<'a> {
+    /// The `LintStore` allows plugins to register new lints.
+    pub lint_store: &'a mut LintStore,
+}