cmd/compile: report mismatched version set by //go:build

Fixes #63489

Change-Id: I5e02dc5165ada7f5c292d56203dc670e96eaf2c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/534755
Auto-Submit: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Than McIntosh <thanm@google.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

diff --git a/src/cmd/compile/internal/noder/irgen.go b/src/cmd/compile/internal/noder/irgen.go
index c09a79d4f5d36108bbe94ea2aca69dbc0a674642..e77119695ba6e90dc3b8611523cdecb66a53b8ab 100644 (file)
--- a/src/cmd/compile/internal/noder/irgen.go
+++ b/src/cmd/compile/internal/noder/irgen.go
@@ -29,8 +29,12 @@ func checkFiles(m posMap, noders []*noder) (*types2.Package, *types2.Info) {
 
        // setup and syntax error reporting
        files := make([]*syntax.File, len(noders))
+       // posBaseMap maps all file pos bases back to *syntax.File
+       // for checking Go version mismatched.
+       posBaseMap := make(map[*syntax.PosBase]*syntax.File)
        for i, p := range noders {
                files[i] = p.file
+               posBaseMap[p.file.Pos().Base()] = p.file
        }
 
        // typechecking
@@ -43,17 +47,8 @@ func checkFiles(m posMap, noders []*noder) (*types2.Package, *types2.Info) {
                Context:            ctxt,
                GoVersion:          base.Flag.Lang,
                IgnoreBranchErrors: true, // parser already checked via syntax.CheckBranches mode
-               Error: func(err error) {
-                       terr := err.(types2.Error)
-                       msg := terr.Msg
-                       // if we have a version error, hint at the -lang setting
-                       if versionErrorRx.MatchString(msg) {
-                               msg = fmt.Sprintf("%s (-lang was set to %s; check go.mod)", msg, base.Flag.Lang)
-                       }
-                       base.ErrorfAt(m.makeXPos(terr.Pos), terr.Code, "%s", msg)
-               },
-               Importer: &importer,
-               Sizes:    types2.SizesFor("gc", buildcfg.GOARCH),
+               Importer:           &importer,
+               Sizes:              types2.SizesFor("gc", buildcfg.GOARCH),
        }
        if base.Flag.ErrorURL {
                conf.ErrorURL = " [go.dev/e/%s]"
@@ -69,6 +64,27 @@ func checkFiles(m posMap, noders []*noder) (*types2.Package, *types2.Info) {
                FileVersions:       make(map[*syntax.PosBase]types2.Version),
                // expand as needed
        }
+       conf.Error = func(err error) {
+               terr := err.(types2.Error)
+               msg := terr.Msg
+               if versionErrorRx.MatchString(msg) {
+                       posBase := terr.Pos.Base()
+                       for !posBase.IsFileBase() { // line directive base
+                               posBase = posBase.Pos().Base()
+                       }
+                       v := info.FileVersions[posBase]
+                       fileVersion := fmt.Sprintf("go%d.%d", v.Major, v.Minor)
+                       file := posBaseMap[posBase]
+                       if file.GoVersion == fileVersion {
+                               // If we have a version error caused by //go:build, report it.
+                               msg = fmt.Sprintf("%s (file declares //go:build %s)", msg, fileVersion)
+                       } else {
+                               // Otherwise, hint at the -lang setting.
+                               msg = fmt.Sprintf("%s (-lang was set to %s; check go.mod)", msg, base.Flag.Lang)
+                       }
+               }
+               base.ErrorfAt(m.makeXPos(terr.Pos), terr.Code, "%s", msg)
+       }
 
        pkg, err := conf.Check(base.Ctxt.Pkgpath, files, info)
        base.ExitIfErrors()

diff --git a/test/fixedbugs/issue63489a.go b/test/fixedbugs/issue63489a.go
new file mode 100644 (file)
index 0000000..b88120f
--- /dev/null
+++ b/test/fixedbugs/issue63489a.go
@@ -0,0 +1,16 @@
+// errorcheck -lang=go1.21
+
+// Copyright 2023 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.
+
+//go:build go1.4
+
+package p
+
+const c = 0o123 // ERROR "file declares //go:build go1.4"
+
+// ERROR "file declares //go:build go1.4"
+
+//line issue63489a.go:13:1
+const d = 0o124

diff --git a/test/fixedbugs/issue63489b.go b/test/fixedbugs/issue63489b.go
new file mode 100644 (file)
index 0000000..2ad590d
--- /dev/null
+++ b/test/fixedbugs/issue63489b.go
@@ -0,0 +1,11 @@
+// errorcheck -lang=go1.4
+
+// Copyright 2023 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.
+
+//go:build go1.4
+
+package p
+
+const c = 0o123 // ERROR "file declares //go:build go1.4"