cmd/compile/internal/syntax: return correct start pos for KeyValueExprs

Fixes #67866.

Change-Id: Id9d345aab87e493b8ed94319c5acaa1900362648
Reviewed-on: https://go-review.googlesource.com/c/go/+/591695
Reviewed-by: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/cmd/compile/internal/syntax/issues_test.go b/src/cmd/compile/internal/syntax/issues_test.go
new file mode 100644 (file)
index 0000000..d72890c
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/issues_test.go
@@ -0,0 +1,51 @@
+// Copyright 2024 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.
+
+// This file holds test cases for individual issues
+// for which there is (currently) no better location.
+
+package syntax
+
+import (
+       "strings"
+       "testing"
+)
+
+func TestIssue67866(t *testing.T) {
+       var tests = []string{
+               "package p; var _ = T{@0: 0}",
+               "package p; var _ = T{@1 + 2: 0}",
+               "package p; var _ = T{@x[i]: 0}",
+               "package p; var _ = T{@f(1, 2, 3): 0}",
+               "package p; var _ = T{@a + f(b) + <-ch: 0}",
+       }
+
+       for _, src := range tests {
+               // identify column position of @ and remove it from src
+               i := strings.Index(src, "@")
+               if i < 0 {
+                       t.Errorf("%s: invalid test case (missing @)", src)
+                       continue
+               }
+               src = src[:i] + src[i+1:]
+               want := colbase + uint(i)
+
+               f, err := Parse(nil, strings.NewReader(src), nil, nil, 0)
+               if err != nil {
+                       t.Errorf("%s: %v", src, err)
+                       continue
+               }
+
+               // locate KeyValueExpr
+               Inspect(f, func(n Node) bool {
+                       _, ok := n.(*KeyValueExpr)
+                       if ok {
+                               if got := StartPos(n).Col(); got != want {
+                                       t.Errorf("%s: got col = %d, want %d", src, got, want)
+                               }
+                       }
+                       return !ok
+               })
+       }
+}

diff --git a/src/cmd/compile/internal/syntax/positions.go b/src/cmd/compile/internal/syntax/positions.go
index 93596559a02328a3a23296c15ffa2983630a20a1..419855f70ffe71f13ba31a1c32cc171f04d8a0b1 100644 (file)
--- a/src/cmd/compile/internal/syntax/positions.go
+++ b/src/cmd/compile/internal/syntax/positions.go
@@ -36,7 +36,8 @@ func StartPos(n Node) Pos {
                                continue
                        }
                        return n.Pos()
-               // case *KeyValueExpr:
+               case *KeyValueExpr:
+                       m = n.Key
                // case *FuncLit:
                // case *ParenExpr:
                case *SelectorExpr: