Merge pull request rust-lang#4635 from RalfJung/rustup

Rustup

Author: RalfJung

Cargo.lock

@@ -4119,6 +4119,7 @@ name = "rustc_log"
 version = "0.0.0"
 dependencies = [
  "tracing",
+ "tracing-core",
  "tracing-subscriber",
  "tracing-tree",
 ]

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -26,13 +26,12 @@ extern crate rustc_fs_util;
 extern crate rustc_hir;
 extern crate rustc_incremental;
 extern crate rustc_index;
+extern crate rustc_log;
 extern crate rustc_metadata;
 extern crate rustc_session;
 extern crate rustc_span;
 extern crate rustc_symbol_mangling;
 extern crate rustc_target;
-#[macro_use]
-extern crate tracing;
 
 // This prevents duplicating functions and statics that are already part of the host rustc process.
 #[allow(unused_extern_crates)]
@@ -46,6 +45,7 @@ use cranelift_codegen::isa::TargetIsa;
 use cranelift_codegen::settings::{self, Configurable};
 use rustc_codegen_ssa::traits::CodegenBackend;
 use rustc_codegen_ssa::{CodegenResults, TargetConfig};
+use rustc_log::tracing::info;
 use rustc_middle::dep_graph::{WorkProduct, WorkProductId};
 use rustc_session::Session;
 use rustc_session::config::OutputFilenames;

compiler/rustc_codegen_gcc/src/back/lto.rs

@@ -30,6 +30,7 @@ use rustc_codegen_ssa::traits::*;
 use rustc_codegen_ssa::{ModuleCodegen, ModuleKind, looks_like_rust_object_file};
 use rustc_data_structures::memmap::Mmap;
 use rustc_errors::DiagCtxtHandle;
+use rustc_log::tracing::info;
 use rustc_middle::bug;
 use rustc_middle::dep_graph::WorkProduct;
 use rustc_session::config::Lto;

compiler/rustc_codegen_gcc/src/back/write.rs

@@ -5,6 +5,7 @@ use rustc_codegen_ssa::back::link::ensure_removed;
 use rustc_codegen_ssa::back::write::{BitcodeSection, CodegenContext, EmitObj, ModuleConfig};
 use rustc_codegen_ssa::{CompiledModule, ModuleCodegen};
 use rustc_fs_util::link_or_copy;
+use rustc_log::tracing::debug;
 use rustc_session::config::OutputType;
 use rustc_target::spec::SplitDebuginfo;
 

compiler/rustc_codegen_gcc/src/consts.rs

@@ -8,6 +8,7 @@ use rustc_codegen_ssa::traits::{
 use rustc_hir::attrs::Linkage;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LOCAL_CRATE;
+use rustc_log::tracing::trace;
 use rustc_middle::middle::codegen_fn_attrs::{CodegenFnAttrFlags, CodegenFnAttrs};
 use rustc_middle::mir::interpret::{
     self, ConstAllocation, ErrorHandled, Scalar as InterpScalar, read_target_uint,

compiler/rustc_codegen_gcc/src/gcc_util.rs

@@ -1,8 +1,8 @@
 #[cfg(feature = "master")]
 use gccjit::Context;
 use rustc_codegen_ssa::target_features;
+use rustc_data_structures::smallvec::{SmallVec, smallvec};
 use rustc_session::Session;
-use smallvec::{SmallVec, smallvec};
 
 fn gcc_features_by_flags(sess: &Session, features: &mut Vec<String>) {
     target_features::retpoline_features_by_flags(sess, features);

compiler/rustc_codegen_gcc/src/lib.rs

@@ -25,12 +25,6 @@
 #![deny(clippy::pattern_type_mismatch)]
 #![allow(clippy::needless_lifetimes, clippy::uninlined_format_args)]
 
-// These crates are pulled from the sysroot because they are part of
-// rustc's public API, so we need to ensure version compatibility.
-extern crate smallvec;
-#[macro_use]
-extern crate tracing;
-
 // The rustc crates we need
 extern crate rustc_abi;
 extern crate rustc_apfloat;
@@ -44,6 +38,7 @@ extern crate rustc_hir;
 extern crate rustc_index;
 #[cfg(feature = "master")]
 extern crate rustc_interface;
+extern crate rustc_log;
 extern crate rustc_macros;
 extern crate rustc_middle;
 extern crate rustc_session;

compiler/rustc_data_structures/src/lib.rs

@@ -44,6 +44,8 @@ use std::fmt;
 pub use atomic_ref::AtomicRef;
 pub use ena::{snapshot_vec, undo_log, unify};
 pub use rustc_index::static_assert_size;
+// Re-export some data-structure crates which are part of our public API.
+pub use {either, indexmap, smallvec, thin_vec};
 
 pub mod aligned;
 pub mod base_n;

compiler/rustc_lint/messages.ftl

@@ -325,6 +325,9 @@ lint_impl_trait_overcaptures = `{$self_ty}` will capture more lifetimes than pos
 lint_impl_trait_redundant_captures = all possible in-scope parameters are already captured, so `use<...>` syntax is redundant
     .suggestion = remove the `use<...>` syntax
 
+lint_implicit_sysroot_crate_import = dangerous use of `extern crate {$name}` which is not guaranteed to exist exactly once in the sysroot
+    .help = try using a cargo dependency or using a re-export of the dependency provided by a rustc_* crate
+
 lint_implicit_unsafe_autorefs = implicit autoref creates a reference to the dereference of a raw pointer
     .note = creating a reference requires the pointer target to be valid and imposes aliasing requirements
     .raw_ptr = this raw pointer has type `{$raw_ptr_ty}`

compiler/rustc_lint/src/internal.rs

@@ -12,10 +12,10 @@ use tracing::debug;
 use {rustc_ast as ast, rustc_hir as hir};
 
 use crate::lints::{
-    BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, LintPassByHand,
-    NonGlobImportTypeIrInherent, QueryInstability, QueryUntracked, SpanUseEqCtxtDiag,
-    SymbolInternStringLiteralDiag, TyQualified, TykindDiag, TykindKind, TypeIrDirectUse,
-    TypeIrInherentUsage, TypeIrTraitUsage, UntranslatableDiag,
+    BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, ImplicitSysrootCrateImportDiag,
+    LintPassByHand, NonGlobImportTypeIrInherent, QueryInstability, QueryUntracked,
+    SpanUseEqCtxtDiag, SymbolInternStringLiteralDiag, TyQualified, TykindDiag, TykindKind,
+    TypeIrDirectUse, TypeIrInherentUsage, TypeIrTraitUsage, UntranslatableDiag,
 };
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 
@@ -745,3 +745,40 @@ impl<'tcx> LateLintPass<'tcx> for SymbolInternStringLiteral {
         }
     }
 }
+
+declare_tool_lint! {
+    /// The `implicit_sysroot_crate_import` detects use of `extern crate` to import non-sysroot crates
+    /// (e.g. crates.io deps) from the sysroot, which is dangerous because these crates are not guaranteed
+    /// to exist exactly once, and so may be missing entirely or appear multiple times resulting in ambiguity.
+    pub rustc::IMPLICIT_SYSROOT_CRATE_IMPORT,
+    Allow,
+    "Forbid uses of non-sysroot crates in `extern crate`",
+    report_in_external_macro: true
+}
+
+declare_lint_pass!(ImplicitSysrootCrateImport => [IMPLICIT_SYSROOT_CRATE_IMPORT]);
+
+impl EarlyLintPass for ImplicitSysrootCrateImport {
+    fn check_item(&mut self, cx: &EarlyContext<'_>, item: &ast::Item) {
+        fn is_whitelisted(crate_name: &str) -> bool {
+            // Whitelist of allowed crates.
+            crate_name.starts_with("rustc_")
+                || matches!(
+                    crate_name,
+                    "test" | "self" | "core" | "alloc" | "std" | "proc_macro" | "tikv_jemalloc_sys"
+                )
+        }
+
+        if let ast::ItemKind::ExternCrate(original_name, imported_name) = &item.kind {
+            let name = original_name.as_ref().unwrap_or(&imported_name.name).as_str();
+            let externs = &cx.builder.sess().opts.externs;
+            if externs.get(name).is_none() && !is_whitelisted(name) {
+                cx.emit_span_lint(
+                    IMPLICIT_SYSROOT_CRATE_IMPORT,
+                    item.span,
+                    ImplicitSysrootCrateImportDiag { name },
+                );
+            }
+        }
+    }
+}