cmd/go: ignore vet typecheck failure during go test

For Go 1.10, works around a go/types bug that can't typecheck
a corner-case type cycle. Once we are confident that bugs like
this are gone from go/types then we can stop ignoring these
failures.

For #22890.

Change-Id: I38da57e01a0636323e1af4484c30871786125df3
Reviewed-on: https://go-review.googlesource.com/81500
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/cmd/vet/main.go b/src/cmd/vet/main.go
index 66f9449d7e..a10c798850 100644
--- a/src/cmd/vet/main.go
+++ b/src/cmd/vet/main.go
@@ -35,6 +35,8 @@ var (
 	tagList = []string{} // exploded version of tags flag; set in main
 
 	mustTypecheck bool
+
+	succeedOnTypecheckFailure bool // during go test, we ignore potential bugs in go/types
 )
 
 var exitCode = 0
@@ -291,6 +293,8 @@ type vetConfig struct {
 	ImportMap   map[string]string
 	PackageFile map[string]string
 
+	SucceedOnTypecheckFailure bool
+
 	imp types.Importer
 }
 
@@ -336,6 +340,7 @@ func doPackageCfg(cfgFile string) {
 	if err := json.Unmarshal(js, &vcfg); err != nil {
 		errorf("parsing vet config %s: %v", cfgFile, err)
 	}
+	succeedOnTypecheckFailure = vcfg.SucceedOnTypecheckFailure
 	stdImporter = &vcfg
 	inittypes()
 	mustTypecheck = true
@@ -427,6 +432,9 @@ func doPackage(names []string, basePkg *Package) *Package {
 	// Type check the package.
 	errs := pkg.check(fs, astFiles)
 	if errs != nil {
+		if succeedOnTypecheckFailure {
+			os.Exit(0)
+		}
 		if *verbose || mustTypecheck {
 			for _, err := range errs {
 				fmt.Fprintf(os.Stderr, "%v\n", err)