Auto merge of #53410 - djrenren:custom-test-frameworks, r=alexcrichton

Introduce Custom Test Frameworks

Introduces `#[test_case]` and `#[test_runner]` and re-implements `#[test]` and `#[bench]` in terms of them.

Details found here: https://blog.jrenner.net/rust/testing/2018/08/06/custom-test-framework-prop.html

Author: bors

src/Cargo.lock

@@ -2739,6 +2739,7 @@ name = "syntax_ext"
 version = "0.0.0"
 dependencies = [
  "fmt_macros 0.0.0",
+ "log 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc_macro 0.0.0",
  "rustc_data_structures 0.0.0",
  "rustc_errors 0.0.0",

src/doc/unstable-book/src/language-features/custom-test-frameworks.md

@@ -0,0 +1,33 @@
+# `custom_test_frameworks`
+
+The tracking issue for this feature is: [#50297]
+
+[#50297]: https://github.com/rust-lang/rust/issues/50297
+
+------------------------
+
+The `custom_test_frameworks` feature allows the use of `#[test_case]` and `#![test_runner]`.
+Any function, const, or static can be annotated with `#[test_case]` causing it to be aggregated (like `#[test]`)
+and be passed to the test runner determined by the `#![test_runner]` crate attribute.
+
+```rust
+#![feature(custom_test_frameworks)]
+#![test_runner(my_runner)]
+
+fn my_runner(tests: &[&i32]) {
+    for t in tests {
+        if **t == 0 {
+            println!("PASSED");
+        } else {
+            println!("FAILED");
+        }
+    }
+}
+
+#[test_case]
+const WILL_PASS: i32 = 0;
+
+#[test_case]
+const WILL_FAIL: i32 = 4;
+```
+

src/librustc_driver/driver.rs

@@ -828,7 +828,6 @@ where
     let (mut krate, features) = syntax::config::features(
         krate,
         &sess.parse_sess,
-        sess.opts.test,
         sess.edition(),
     );
     // these need to be set "early" so that expansion sees `quote` if enabled.

src/librustc_lint/builtin.rs

@@ -1835,43 +1835,56 @@ impl EarlyLintPass for EllipsisInclusiveRangePatterns {
 }
 
 declare_lint! {
-    UNNAMEABLE_TEST_FUNCTIONS,
+    UNNAMEABLE_TEST_ITEMS,
     Warn,
-    "detects an function that cannot be named being marked as #[test]"
+    "detects an item that cannot be named being marked as #[test_case]",
+    report_in_external_macro: true
+}
+
+pub struct UnnameableTestItems {
+    boundary: ast::NodeId, // NodeId of the item under which things are not nameable
+    items_nameable: bool,
 }
 
-pub struct UnnameableTestFunctions;
+impl UnnameableTestItems {
+    pub fn new() -> Self {
+        Self {
+            boundary: ast::DUMMY_NODE_ID,
+            items_nameable: true
+        }
+    }
+}
 
-impl LintPass for UnnameableTestFunctions {
+impl LintPass for UnnameableTestItems {
     fn get_lints(&self) -> LintArray {
-        lint_array!(UNNAMEABLE_TEST_FUNCTIONS)
+        lint_array!(UNNAMEABLE_TEST_ITEMS)
     }
 }
 
-impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnameableTestFunctions {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for UnnameableTestItems {
     fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
-        match it.node {
-            hir::ItemKind::Fn(..) => {
-                for attr in &it.attrs {
-                    if attr.name() == "test" {
-                        let parent = cx.tcx.hir.get_parent(it.id);
-                        match cx.tcx.hir.find(parent) {
-                            Some(Node::Item(hir::Item {node: hir::ItemKind::Mod(_), ..})) |
-                            None => {}
-                            _ => {
-                                cx.struct_span_lint(
-                                    UNNAMEABLE_TEST_FUNCTIONS,
-                                    attr.span,
-                                    "cannot test inner function",
-                                ).emit();
-                            }
-                        }
-                        break;
-                    }
-                }
+        if self.items_nameable {
+            if let hir::ItemKind::Mod(..) = it.node {}
+            else {
+                self.items_nameable = false;
+                self.boundary = it.id;
             }
-            _ => return,
-        };
+            return;
+        }
+
+        if let Some(attr) = attr::find_by_name(&it.attrs, "rustc_test_marker") {
+            cx.struct_span_lint(
+                UNNAMEABLE_TEST_ITEMS,
+                attr.span,
+                "cannot test inner items",
+            ).emit();
+        }
+    }
+
+    fn check_item_post(&mut self, _cx: &LateContext, it: &hir::Item) {
+        if !self.items_nameable && self.boundary == it.id {
+            self.items_nameable = true;
+        }
     }
 }
 

src/librustc_lint/lib.rs

@@ -149,7 +149,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
         MutableTransmutes: MutableTransmutes,
         UnionsWithDropFields: UnionsWithDropFields,
         UnreachablePub: UnreachablePub,
-        UnnameableTestFunctions: UnnameableTestFunctions,
+        UnnameableTestItems: UnnameableTestItems::new(),
         TypeAliasBounds: TypeAliasBounds,
         UnusedBrokenConst: UnusedBrokenConst,
         TrivialConstraints: TrivialConstraints,

src/librustc_resolve/lib.rs

@@ -1412,6 +1412,7 @@ pub struct Resolver<'a, 'b: 'a> {
     crate_loader: &'a mut CrateLoader<'b>,
     macro_names: FxHashSet<Ident>,
     macro_prelude: FxHashMap<Name, &'a NameBinding<'a>>,
+    unshadowable_attrs: FxHashMap<Name, &'a NameBinding<'a>>,
     pub all_macros: FxHashMap<Name, Def>,
     macro_map: FxHashMap<DefId, Lrc<SyntaxExtension>>,
     macro_defs: FxHashMap<Mark, DefId>,
@@ -1729,6 +1730,7 @@ impl<'a, 'crateloader: 'a> Resolver<'a, 'crateloader> {
             crate_loader,
             macro_names: FxHashSet(),
             macro_prelude: FxHashMap(),
+            unshadowable_attrs: FxHashMap(),
             all_macros: FxHashMap(),
             macro_map: FxHashMap(),
             invocations,

src/librustc_resolve/macros.rs

@@ -207,6 +207,23 @@ impl<'a, 'crateloader: 'a> base::Resolver for Resolver<'a, 'crateloader> {
         self.macro_prelude.insert(ident.name, binding);
     }
 
+    fn add_unshadowable_attr(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>) {
+        let def_id = DefId {
+            krate: BUILTIN_MACROS_CRATE,
+            index: DefIndex::from_array_index(self.macro_map.len(),
+                                              DefIndexAddressSpace::Low),
+        };
+        let kind = ext.kind();
+        self.macro_map.insert(def_id, ext);
+        let binding = self.arenas.alloc_name_binding(NameBinding {
+            kind: NameBindingKind::Def(Def::Macro(def_id, kind), false),
+            span: DUMMY_SP,
+            vis: ty::Visibility::Invisible,
+            expansion: Mark::root(),
+        });
+        self.unshadowable_attrs.insert(ident.name, binding);
+    }
+
     fn resolve_imports(&mut self) {
         ImportResolver { resolver: self }.resolve_imports()
     }
@@ -462,6 +479,12 @@ impl<'a, 'cl> Resolver<'a, 'cl> {
             return def;
         }
 
+        if kind == MacroKind::Attr {
+            if let Some(ext) = self.unshadowable_attrs.get(&path[0].name) {
+                return Ok(ext.def());
+            }
+        }
+
         let legacy_resolution = self.resolve_legacy_scope(&invocation.legacy_scope, path[0], false);
         let result = if let Some((legacy_binding, _)) = legacy_resolution {
             Ok(legacy_binding.def())

src/libsyntax/ast.rs

@@ -1587,7 +1587,7 @@ impl TyKind {
         if let TyKind::ImplicitSelf = *self { true } else { false }
     }
 
-    crate fn is_unit(&self) -> bool {
+    pub fn is_unit(&self) -> bool {
         if let TyKind::Tup(ref tys) = *self { tys.is_empty() } else { false }
     }
 }

src/libsyntax/config.rs

@@ -21,18 +21,16 @@ use ptr::P;
 
 /// A folder that strips out items that do not belong in the current configuration.
 pub struct StripUnconfigured<'a> {
-    pub should_test: bool,
     pub sess: &'a ParseSess,
     pub features: Option<&'a Features>,
 }
 
 // `cfg_attr`-process the crate's attributes and compute the crate's features.
-pub fn features(mut krate: ast::Crate, sess: &ParseSess, should_test: bool, edition: Edition)
+pub fn features(mut krate: ast::Crate, sess: &ParseSess, edition: Edition)
                 -> (ast::Crate, Features) {
     let features;
     {
         let mut strip_unconfigured = StripUnconfigured {
-            should_test,
             sess,
             features: None,
         };
@@ -118,11 +116,6 @@ impl<'a> StripUnconfigured<'a> {
     // Determine if a node with the given attributes should be included in this configuration.
     pub fn in_cfg(&mut self, attrs: &[ast::Attribute]) -> bool {
         attrs.iter().all(|attr| {
-            // When not compiling with --test we should not compile the #[test] functions
-            if !self.should_test && is_test_or_bench(attr) {
-                return false;
-            }
-
             let mis = if !is_cfg(attr) {
                 return true;
             } else if let Some(mis) = attr.meta_item_list() {
@@ -249,7 +242,7 @@ impl<'a> StripUnconfigured<'a> {
         //
         // NB: This is intentionally not part of the fold_expr() function
         //     in order for fold_opt_expr() to be able to avoid this check
-        if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(a) || is_test_or_bench(a)) {
+        if let Some(attr) = expr.attrs().iter().find(|a| is_cfg(a)) {
             let msg = "removing an expression is not supported in this position";
             self.sess.span_diagnostic.span_err(attr.span, msg);
         }
@@ -352,7 +345,3 @@ impl<'a> fold::Folder for StripUnconfigured<'a> {
 fn is_cfg(attr: &ast::Attribute) -> bool {
     attr.check_name("cfg")
 }
-
-pub fn is_test_or_bench(attr: &ast::Attribute) -> bool {
-    attr.check_name("test") || attr.check_name("bench")
-}

src/libsyntax/ext/base.rs

@@ -721,6 +721,7 @@ pub trait Resolver {
     fn visit_ast_fragment_with_placeholders(&mut self, mark: Mark, fragment: &AstFragment,
                                             derives: &[Mark]);
     fn add_builtin(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>);
+    fn add_unshadowable_attr(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>);
 
     fn resolve_imports(&mut self);
     // Resolves attribute and derive legacy macros from `#![plugin(..)]`.
@@ -729,6 +730,7 @@ pub trait Resolver {
 
     fn resolve_macro_invocation(&mut self, invoc: &Invocation, scope: Mark, force: bool)
                                 -> Result<Option<Lrc<SyntaxExtension>>, Determinacy>;
+
     fn resolve_macro_path(&mut self, path: &ast::Path, kind: MacroKind, scope: Mark,
                           derives_in_scope: &[ast::Path], force: bool)
                           -> Result<Lrc<SyntaxExtension>, Determinacy>;
@@ -759,6 +761,7 @@ impl Resolver for DummyResolver {
     fn visit_ast_fragment_with_placeholders(&mut self, _invoc: Mark, _fragment: &AstFragment,
                                             _derives: &[Mark]) {}
     fn add_builtin(&mut self, _ident: ast::Ident, _ext: Lrc<SyntaxExtension>) {}
+    fn add_unshadowable_attr(&mut self, _ident: ast::Ident, _ext: Lrc<SyntaxExtension>) {}
 
     fn resolve_imports(&mut self) {}
     fn find_legacy_attr_invoc(&mut self, _attrs: &mut Vec<Attribute>, _allow_derive: bool)