.github/workflows/go.yml

@@ -15,7 +15,7 @@ jobs:
   build:
     strategy:
       matrix:
-        go: ['1.21', '1.22', '1.23.0-rc.2']
+        go: ['1.21', '1.22', '1.23.0-rc.1']
         os: [macos-latest, windows-latest, ubuntu-latest]
     name: build
     runs-on: ${{ matrix.os }}

pkg/analyzer/analyzer.go

@@ -36,9 +36,32 @@ func run(pass *analysis.Pass) (interface{}, error) {
 			return
 		}
 
-		assignStmt := findNestedContext(pass, body, body.List)
+		for _, stmt := range body.List {
-		if assignStmt == nil {
+			assignStmt, ok := stmt.(*ast.AssignStmt)
-			return
+			if !ok {
+				continue
+			}
+
+			t := pass.TypesInfo.TypeOf(assignStmt.Lhs[0])
+			if t == nil {
+				continue
+			}
+
+			if t.String() != "context.Context" {
+				continue
+			}
+
+			if assignStmt.Tok == token.DEFINE {
+				break
+			}
+
+			// allow assignment to non-pointer children of values defined within the loop
+			if lhs := getRootIdent(pass, assignStmt.Lhs[0]); lhs != nil {
+				if obj := pass.TypesInfo.ObjectOf(lhs); obj != nil {
+					if obj.Pos() >= body.Pos() && obj.Pos() < body.End() {
+						continue // definition is within the loop
+					}
+				}
 			}
 
 			suggestedStmt := ast.AssignStmt{
@@ -69,6 +92,8 @@ func run(pass *analysis.Pass) (interface{}, error) {
 				SuggestedFixes: fixes,
 			})
 
+			break
+		}
 	})
 
 	return nil, nil
@@ -88,85 +113,6 @@ func getBody(node ast.Node) (*ast.BlockStmt, error) {
 	return nil, errUnknown
 }
 
-func findNestedContext(pass *analysis.Pass, block *ast.BlockStmt, stmts []ast.Stmt) *ast.AssignStmt {
-	for _, stmt := range stmts {
-		// Recurse if necessary
-		if inner, ok := stmt.(*ast.BlockStmt); ok {
-			found := findNestedContext(pass, inner, inner.List)
-			if found != nil {
-				return found
-			}
-		}
-
-		if inner, ok := stmt.(*ast.IfStmt); ok {
-			found := findNestedContext(pass, inner.Body, inner.Body.List)
-			if found != nil {
-				return found
-			}
-		}
-
-		if inner, ok := stmt.(*ast.SwitchStmt); ok {
-			found := findNestedContext(pass, inner.Body, inner.Body.List)
-			if found != nil {
-				return found
-			}
-		}
-
-		if inner, ok := stmt.(*ast.CaseClause); ok {
-			found := findNestedContext(pass, block, inner.Body)
-			if found != nil {
-				return found
-			}
-		}
-
-		if inner, ok := stmt.(*ast.SelectStmt); ok {
-			found := findNestedContext(pass, inner.Body, inner.Body.List)
-			if found != nil {
-				return found
-			}
-		}
-
-		if inner, ok := stmt.(*ast.CommClause); ok {
-			found := findNestedContext(pass, block, inner.Body)
-			if found != nil {
-				return found
-			}
-		}
-
-		// Actually check for nested context
-		assignStmt, ok := stmt.(*ast.AssignStmt)
-		if !ok {
-			continue
-		}
-
-		t := pass.TypesInfo.TypeOf(assignStmt.Lhs[0])
-		if t == nil {
-			continue
-		}
-
-		if t.String() != "context.Context" {
-			continue
-		}
-
-		if assignStmt.Tok == token.DEFINE {
-			break
-		}
-
-		// allow assignment to non-pointer children of values defined within the loop
-		if lhs := getRootIdent(pass, assignStmt.Lhs[0]); lhs != nil {
-			if obj := pass.TypesInfo.ObjectOf(lhs); obj != nil {
-				if obj.Pos() >= block.Pos() && obj.Pos() < block.End() {
-					continue // definition is within the loop
-				}
-			}
-		}
-
-		return assignStmt
-	}
-
-	return nil
-}
-
 func getRootIdent(pass *analysis.Pass, node ast.Node) *ast.Ident {
 	for {
 		switch n := node.(type) {

testdata/src/example.go

@@ -25,50 +25,12 @@ func example() {
 		ctx = wrapContext(ctx) // want "nested context in loop"
 		break
 	}
-
-	// not fooled by shadowing in nested blocks
-	for {
-		err := doSomething()
-		if err != nil {
-			ctx := wrapContext(ctx)
-			ctx = wrapContext(ctx)
-		}
-
-		switch err {
-		case nil:
-			ctx := wrapContext(ctx)
-			ctx = wrapContext(ctx)
-		default:
-			ctx := wrapContext(ctx)
-			ctx = wrapContext(ctx)
-		}
-
-		{
-			ctx := wrapContext(ctx)
-			ctx = wrapContext(ctx)
-		}
-
-		select {
-		case <-ctx.Done():
-			ctx := wrapContext(ctx)
-			ctx = wrapContext(ctx)
-		default:
-		}
-
-		ctx = wrapContext(ctx) // want "nested context in loop"
-
-		break
-	}
 }
 
 func wrapContext(ctx context.Context) context.Context {
 	return context.WithoutCancel(ctx)
 }
 
-func doSomething() error {
-	return nil
-}
-
 // storing contexts in a struct isn't recommended, but local copies of a non-pointer struct should act like local copies of a context.
 func inStructs(ctx context.Context) {
 	for i := 0; i < 10; i++ {
@@ -109,74 +71,3 @@ func inStructs(ctx context.Context) {
 		rp[0].Ctx = context.WithValue(rp[0].Ctx, "other", "val")
 	}
 }
-
-func inVariousNestedBlocks(ctx context.Context) {
-	for {
-		err := doSomething()
-		if err != nil {
-			ctx = wrapContext(ctx) // want "nested context in loop"
-		}
-
-		break
-	}
-
-	for {
-		err := doSomething()
-		if err != nil {
-			if true {
-				ctx = wrapContext(ctx) // want "nested context in loop"
-			}
-		}
-
-		break
-	}
-
-	for {
-		err := doSomething()
-		switch err {
-		case nil:
-			ctx = wrapContext(ctx) // want "nested context in loop"
-		}
-
-		break
-	}
-
-	for {
-		err := doSomething()
-		switch err {
-		default:
-			ctx = wrapContext(ctx) // want "nested context in loop"
-		}
-
-		break
-	}
-
-	for {
-		ctx := wrapContext(ctx)
-
-		err := doSomething()
-		if err != nil {
-			ctx = wrapContext(ctx)
-		}
-
-		break
-	}
-
-	for {
-		{
-			ctx = wrapContext(ctx) // want "nested context in loop"
-		}
-
-		break
-	}
-
-	for {
-		select {
-		case <-ctx.Done():
-			ctx = wrapContext(ctx) // want "nested context in loop"
-		default:
-		}
-
-		break
-	}
-}