Deny unreachable-pub

It's very useful when `pub` is equivalent to "this is crate's public
API", let's enforce this!

Ideally, we should enforce it for local `cargo test`, and only during
CI, but that needs rust-lang/cargo#5034.

Author: matklad

.github/workflows/ci.yaml

@@ -12,7 +12,7 @@ env:
   CARGO_NET_RETRY: 10
   CI: 1
   RUST_BACKTRACE: short
-  RUSTFLAGS: -D warnings
+  RUSTFLAGS: "-D warnings " # -W unreachable-pub"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:

.github/workflows/metrics.yaml

@@ -7,7 +7,7 @@ on:
 env:
   CARGO_INCREMENTAL: 0
   CARGO_NET_RETRY: 10
-  RUSTFLAGS: -D warnings
+  RUSTFLAGS: "-D warnings " # -W unreachable-pub"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:

.github/workflows/release.yaml

@@ -11,7 +11,7 @@ on:
 env:
   CARGO_INCREMENTAL: 0
   CARGO_NET_RETRY: 10
-  RUSTFLAGS: -D warnings
+  RUSTFLAGS: "-D warnings " # -W unreachable-pub"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:

.github/workflows/rustdoc.yaml

@@ -7,7 +7,7 @@ on:
 env:
   CARGO_INCREMENTAL: 0
   CARGO_NET_RETRY: 10
-  RUSTFLAGS: -D warnings
+  RUSTFLAGS: "-D warnings " # -W unreachable-pub"
   RUSTUP_MAX_RETRIES: 10
 
 jobs:

crates/base_db/src/input.rs

@@ -12,9 +12,7 @@ use cfg::CfgOptions;
 use rustc_hash::{FxHashMap, FxHashSet};
 use syntax::SmolStr;
 use tt::TokenExpander;
-use vfs::{file_set::FileSet, VfsPath};
-
-pub use vfs::FileId;
+use vfs::{file_set::FileSet, FileId, VfsPath};
 
 /// Files are grouped into source roots. A source root is a directory on the
 /// file systems which is watched for changes. Typically it corresponds to a

crates/base_db/src/lib.rs

@@ -14,11 +14,11 @@ pub use crate::{
     change::Change,
     input::{
         CrateData, CrateDisplayName, CrateGraph, CrateId, CrateName, Dependency, Edition, Env,
-        FileId, ProcMacroId, SourceRoot, SourceRootId,
+        ProcMacroId, SourceRoot, SourceRootId,
     },
 };
 pub use salsa;
-pub use vfs::{file_set::FileSet, VfsPath};
+pub use vfs::{file_set::FileSet, FileId, VfsPath};
 
 #[macro_export]
 macro_rules! impl_intern_key {

crates/hir_def/src/body/lower.rs

@@ -45,14 +45,14 @@ pub(crate) struct LowerCtx {
 }
 
 impl LowerCtx {
-    pub fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
+    pub(crate) fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
         LowerCtx { hygiene: Hygiene::new(db.upcast(), file_id) }
     }
-    pub fn with_hygiene(hygiene: &Hygiene) -> Self {
+    pub(crate) fn with_hygiene(hygiene: &Hygiene) -> Self {
         LowerCtx { hygiene: hygiene.clone() }
     }
 
-    pub fn lower_path(&self, ast: ast::Path) -> Option<Path> {
+    pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
         Path::from_src(ast, &self.hygiene)
     }
 }

crates/hir_def/src/lib.rs

@@ -486,12 +486,12 @@ impl AsMacroCall for InFile<&ast::MacroCall> {
 /// Helper wrapper for `AstId` with `ModPath`
 #[derive(Clone, Debug, Eq, PartialEq)]
 struct AstIdWithPath<T: ast::AstNode> {
-    pub ast_id: AstId<T>,
-    pub path: path::ModPath,
+    ast_id: AstId<T>,
+    path: path::ModPath,
 }
 
 impl<T: ast::AstNode> AstIdWithPath<T> {
-    pub fn new(file_id: HirFileId, ast_id: FileAstId<T>, path: path::ModPath) -> AstIdWithPath<T> {
+    fn new(file_id: HirFileId, ast_id: FileAstId<T>, path: path::ModPath) -> AstIdWithPath<T> {
         AstIdWithPath { ast_id: AstId::new(file_id, ast_id), path }
     }
 }

crates/hir_def/src/nameres/collector.rs

@@ -122,13 +122,13 @@ enum ImportSource {
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 struct Import {
-    pub path: ModPath,
-    pub alias: Option<ImportAlias>,
-    pub visibility: RawVisibility,
-    pub is_glob: bool,
-    pub is_prelude: bool,
-    pub is_extern_crate: bool,
-    pub is_macro_use: bool,
+    path: ModPath,
+    alias: Option<ImportAlias>,
+    visibility: RawVisibility,
+    is_glob: bool,
+    is_prelude: bool,
+    is_extern_crate: bool,
+    is_macro_use: bool,
     source: ImportSource,
 }
 

crates/hir_def/src/test_db.rs

@@ -25,7 +25,7 @@ use crate::{db::DefDatabase, ModuleDefId};
     crate::db::DefDatabaseStorage
 )]
 #[derive(Default)]
-pub struct TestDB {
+pub(crate) struct TestDB {
     storage: salsa::Storage<TestDB>,
     events: Mutex<Option<Vec<salsa::Event>>>,
 }
@@ -72,7 +72,7 @@ impl FileLoader for TestDB {
 }
 
 impl TestDB {
-    pub fn module_for_file(&self, file_id: FileId) -> crate::ModuleId {
+    pub(crate) fn module_for_file(&self, file_id: FileId) -> crate::ModuleId {
         for &krate in self.relevant_crates(file_id).iter() {
             let crate_def_map = self.crate_def_map(krate);
             for (local_id, data) in crate_def_map.modules.iter() {
@@ -84,13 +84,13 @@ impl TestDB {
         panic!("Can't find module for file")
     }
 
-    pub fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
+    pub(crate) fn log(&self, f: impl FnOnce()) -> Vec<salsa::Event> {
         *self.events.lock().unwrap() = Some(Vec::new());
         f();
         self.events.lock().unwrap().take().unwrap()
     }
 
-    pub fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
+    pub(crate) fn log_executed(&self, f: impl FnOnce()) -> Vec<String> {
         let events = self.log(f);
         events
             .into_iter()
@@ -105,7 +105,7 @@ impl TestDB {
             .collect()
     }
 
-    pub fn extract_annotations(&self) -> FxHashMap<FileId, Vec<(TextRange, String)>> {
+    pub(crate) fn extract_annotations(&self) -> FxHashMap<FileId, Vec<(TextRange, String)>> {
         let mut files = Vec::new();
         let crate_graph = self.crate_graph();
         for krate in crate_graph.iter() {
@@ -129,7 +129,7 @@ impl TestDB {
             .collect()
     }
 
-    pub fn diagnostics<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
+    pub(crate) fn diagnostics<F: FnMut(&dyn Diagnostic)>(&self, mut cb: F) {
         let crate_graph = self.crate_graph();
         for krate in crate_graph.iter() {
             let crate_def_map = self.crate_def_map(krate);
@@ -148,7 +148,7 @@ impl TestDB {
         }
     }
 
-    pub fn check_diagnostics(&self) {
+    pub(crate) fn check_diagnostics(&self) {
         let db: &TestDB = self;
         let annotations = db.extract_annotations();
         assert!(!annotations.is_empty());