go/types: propagate *ast.LabeledStmt in blockBranches properly

Fixes #70974

Change-Id: I330c0ae53dcbcdb173ab514ee94f2ca53944df09
GitHub-Last-Rev: 7c2b740da6d6e94ac8787f04ad8942f3776ac56c
GitHub-Pull-Request: golang/go#70976
Reviewed-on: https://go-review.googlesource.com/c/go/+/638257
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Commit-Queue: Alan Donovan <adonovan@google.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

diff --git a/src/cmd/compile/internal/types2/labels.go b/src/cmd/compile/internal/types2/labels.go
index e44b7c7f70f3cd00ba2f306b68550c55f8329b15..6a6f64b4b8a7b2f430d98993d06e866b69dab7ad 100644 (file)
--- a/src/cmd/compile/internal/types2/labels.go
+++ b/src/cmd/compile/internal/types2/labels.go
@@ -112,8 +112,8 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *syntax.Lab
                return varDeclPos.IsKnown() && slices.Contains(badJumps, jmp)
        }
 
-       var stmtBranches func(syntax.Stmt)
-       stmtBranches = func(s syntax.Stmt) {
+       var stmtBranches func(*syntax.LabeledStmt, syntax.Stmt)
+       stmtBranches = func(lstmt *syntax.LabeledStmt, s syntax.Stmt) {
                switch s := s.(type) {
                case *syntax.DeclStmt:
                        for _, d := range s.DeclList {
@@ -163,7 +163,7 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *syntax.Lab
                                fwdJumps = fwdJumps[:i]
                                lstmt = s
                        }
-                       stmtBranches(s.Stmt)
+                       stmtBranches(lstmt, s.Stmt)
 
                case *syntax.BranchStmt:
                        if s.Label == nil {
@@ -232,9 +232,9 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *syntax.Lab
                        fwdJumps = append(fwdJumps, check.blockBranches(all, b, lstmt, s.List)...)
 
                case *syntax.IfStmt:
-                       stmtBranches(s.Then)
+                       stmtBranches(lstmt, s.Then)
                        if s.Else != nil {
-                               stmtBranches(s.Else)
+                               stmtBranches(lstmt, s.Else)
                        }
 
                case *syntax.SwitchStmt:
@@ -250,12 +250,12 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *syntax.Lab
                        }
 
                case *syntax.ForStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
                }
        }
 
        for _, s := range list {
-               stmtBranches(s)
+               stmtBranches(nil, s)
        }
 
        return fwdJumps

diff --git a/src/go/types/labels.go b/src/go/types/labels.go
index 97b753581aedd98026b15f4fa2944fe2c624c357..7b6324880af6c035eb0cd80a989991c460a390b0 100644 (file)
--- a/src/go/types/labels.go
+++ b/src/go/types/labels.go
@@ -119,8 +119,8 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *ast.Labele
                fwdJumps = append(fwdJumps, check.blockBranches(all, b, lstmt, list)...)
        }
 
-       var stmtBranches func(ast.Stmt)
-       stmtBranches = func(s ast.Stmt) {
+       var stmtBranches func(*ast.LabeledStmt, ast.Stmt)
+       stmtBranches = func(lstmt *ast.LabeledStmt, s ast.Stmt) {
                switch s := s.(type) {
                case *ast.DeclStmt:
                        if d, _ := s.Decl.(*ast.GenDecl); d != nil && d.Tok == token.VAR {
@@ -168,7 +168,7 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *ast.Labele
                                fwdJumps = fwdJumps[:i]
                                lstmt = s
                        }
-                       stmtBranches(s.Stmt)
+                       stmtBranches(lstmt, s.Stmt)
 
                case *ast.BranchStmt:
                        if s.Label == nil {
@@ -235,36 +235,36 @@ func (check *Checker) blockBranches(all *Scope, parent *block, lstmt *ast.Labele
                        blockBranches(lstmt, s.List)
 
                case *ast.IfStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
                        if s.Else != nil {
-                               stmtBranches(s.Else)
+                               stmtBranches(lstmt, s.Else)
                        }
 
                case *ast.CaseClause:
                        blockBranches(nil, s.Body)
 
                case *ast.SwitchStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
 
                case *ast.TypeSwitchStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
 
                case *ast.CommClause:
                        blockBranches(nil, s.Body)
 
                case *ast.SelectStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
 
                case *ast.ForStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
 
                case *ast.RangeStmt:
-                       stmtBranches(s.Body)
+                       stmtBranches(lstmt, s.Body)
                }
        }
 
        for _, s := range list {
-               stmtBranches(s)
+               stmtBranches(nil, s)
        }
 
        return fwdJumps

diff --git a/src/internal/types/testdata/check/doubled_labels.go b/src/internal/types/testdata/check/doubled_labels.go
new file mode 100644 (file)
index 0000000..f3de270
--- /dev/null
+++ b/src/internal/types/testdata/check/doubled_labels.go
@@ -0,0 +1,26 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func _() {
+outer:
+inner:
+       for {
+               continue inner
+               break inner
+       }
+       goto outer
+}
+
+func _() {
+outer:
+inner:
+       for {
+               continue inner
+               continue outer /* ERROR "invalid continue label outer" */
+               break outer    /* ERROR "invalid break label outer" */
+       }
+       goto outer
+}

diff --git a/src/internal/types/testdata/check/issue70974.go b/src/internal/types/testdata/check/issue70974.go
new file mode 100644 (file)
index 0000000..59b1165
--- /dev/null
+++ b/src/internal/types/testdata/check/issue70974.go
@@ -0,0 +1,27 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+func _() {
+outer:
+       for {
+               break outer
+       }
+
+       for {
+               break outer /* ERROR "invalid break label outer" */
+       }
+}
+
+func _() {
+outer:
+       for {
+               continue outer
+       }
+
+       for {
+               continue outer /* ERROR "invalid continue label outer" */
+       }
+}