Classify function calls as functions when shadowed by types

crates/hir/src/source_analyzer.rs

@@ -224,14 +224,18 @@ impl SourceAnalyzer {
     ) -> Option<PathResolution> {
         if let Some(path_expr) = path.syntax().parent().and_then(ast::PathExpr::cast) {
             let expr_id = self.expr_id(db, &path_expr.into())?;
-            if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_expr(expr_id) {
+            let infer = self.infer.as_ref()?;
+            if let Some(assoc) = infer.assoc_resolutions_for_expr(expr_id) {
                 return Some(PathResolution::AssocItem(assoc.into()));
             }
             if let Some(VariantId::EnumVariantId(variant)) =
-                self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
+                infer.variant_resolution_for_expr(expr_id)
             {
                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
             }
+            if let Some(func) = infer[expr_id].as_fn_def() {
+                return Some(PathResolution::Def(ModuleDef::Function(func.into())));
+            }
         }
 
         if let Some(path_pat) = path.syntax().parent().and_then(ast::PathPat::cast) {

crates/hir_ty/src/diagnostics/unsafe_check.rs

@@ -12,8 +12,7 @@ use hir_def::{
 use hir_expand::diagnostics::DiagnosticSink;
 
 use crate::{
-    db::HirDatabase, diagnostics::MissingUnsafe, lower::CallableDefId, ApplicationTy,
-    InferenceResult, Ty, TypeCtor,
+    db::HirDatabase, diagnostics::MissingUnsafe, ApplicationTy, InferenceResult, Ty, TypeCtor,
 };
 
 pub(super) struct UnsafeValidator<'a, 'b: 'a> {
@@ -87,13 +86,8 @@ fn walk_unsafe(
 ) {
     let expr = &body.exprs[current];
     match expr {
-        Expr::Call { callee, .. } => {
-            let ty = &infer[*callee];
-            if let &Ty::Apply(ApplicationTy {
-                ctor: TypeCtor::FnDef(CallableDefId::FunctionId(func)),
-                ..
-            }) = ty
-            {
+        &Expr::Call { callee, .. } => {
+            if let Some(func) = infer[callee].as_fn_def() {
                 if db.function_data(func).is_unsafe {
                     unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
                 }

crates/hir_ty/src/lib.rs

@@ -29,8 +29,8 @@ use base_db::{salsa, CrateId};
 use hir_def::{
     expr::ExprId,
     type_ref::{Mutability, Rawness},
-    AdtId, AssocContainerId, DefWithBodyId, GenericDefId, HasModule, LifetimeParamId, Lookup,
-    TraitId, TypeAliasId, TypeParamId,
+    AdtId, AssocContainerId, DefWithBodyId, FunctionId, GenericDefId, HasModule, LifetimeParamId,
+    Lookup, TraitId, TypeAliasId, TypeParamId,
 };
 use itertools::Itertools;
 
@@ -43,10 +43,9 @@ use crate::{
 
 pub use autoderef::autoderef;
 pub use infer::{InferTy, InferenceResult};
-pub use lower::CallableDefId;
 pub use lower::{
-    associated_type_shorthand_candidates, callable_item_sig, ImplTraitLoweringMode, TyDefId,
-    TyLoweringContext, ValueTyDefId,
+    associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
+    TyDefId, TyLoweringContext, ValueTyDefId,
 };
 pub use traits::{InEnvironment, Obligation, ProjectionPredicate, TraitEnvironment};
 
@@ -824,6 +823,16 @@ impl Ty {
         }
     }
 
+    pub fn as_fn_def(&self) -> Option<FunctionId> {
+        match self {
+            &Ty::Apply(ApplicationTy {
+                ctor: TypeCtor::FnDef(CallableDefId::FunctionId(func)),
+                ..
+            }) => Some(func),
+            _ => None,
+        }
+    }
+
     pub fn callable_sig(&self, db: &dyn HirDatabase) -> Option<FnSig> {
         match self {
             Ty::Apply(a_ty) => match a_ty.ctor {

crates/ide/src/syntax_highlighting/test_data/highlighting.html

@@ -108,6 +108,10 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="brace">}</span>
 <span class="brace">}</span>
 
+<span class="keyword">fn</span> <span class="function declaration">str</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span>
+    <span class="function">str</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span>
+<span class="brace">}</span>
+
 <span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable unsafe">STATIC_MUT</span><span class="colon">:</span> <span class="builtin_type">i32</span> <span class="operator">=</span> <span class="numeric_literal">0</span><span class="semicolon">;</span>
 
 <span class="keyword">fn</span> <span class="function declaration">foo</span><span class="angle">&lt;</span><span class="lifetime declaration">'a</span><span class="comma">,</span> <span class="type_param declaration">T</span><span class="angle">&gt;</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="operator">-&gt;</span> <span class="type_param">T</span> <span class="brace">{</span>

crates/ide/src/syntax_highlighting/tests.rs

@@ -81,6 +81,10 @@ impl FooCopy {
     }
 }
 
+fn str() {
+    str();
+}
+
 static mut STATIC_MUT: i32 = 0;
 
 fn foo<'a, T>() -> T {