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mirror of https://github.com/golang/go synced 2024-09-30 16:08:36 -06:00
Change-Id: I8d63575f2053eda2d7f0a63f3ff862bf0de88d31
Reviewed-on: https://go-review.googlesource.com/10807
Reviewed-by: Alan Donovan <adonovan@google.com>
This commit is contained in:
Robert Griesemer 2015-06-08 14:37:01 -07:00
parent ac303766f5
commit a6d2a4254e

View File

@ -19,8 +19,8 @@ var imports = make(map[string]*types.Package)
var (
errorType *types.Interface
stringerType *types.Interface
formatterType *types.Interface
stringerType *types.Interface // possibly nil
formatterType *types.Interface // possibly nil
)
func init() {
@ -37,13 +37,12 @@ func init() {
// importType returns the type denoted by the qualified identifier
// path.name, and adds the respective package to the imports map
// as a side effect.
// as a side effect. In case of an error, importType returns nil.
func importType(path, name string) types.Type {
pkg, err := types.DefaultImport(imports, path)
if err != nil {
// This can happen if fmt hasn't been compiled yet.
// Since nothing uses formatterType anyway, don't complain.
//warnf("import failed: %v", err)
// This can happen if the package at path hasn't been compiled yet.
warnf("import failed: %v", err)
return nil
}
if obj, ok := pkg.Scope().Lookup(name).(*types.TypeName); ok {
@ -136,16 +135,13 @@ func (f *File) matchArgTypeInternal(t printfArgType, typ types.Type, arg ast.Exp
}
}
// If the type implements fmt.Formatter, we have nothing to check.
// But (see issue 6259) that's not easy to verify, so instead we see
// if its method set contains a Format function. We could do better,
// even now, but we don't need to be 100% accurate. Wait for 6259 to
// be fixed instead. TODO.
if f.hasMethod(typ, "Format") {
// formatterTyp may be nil - be conservative and check for Format method in that case.
if formatterType != nil && types.Implements(typ, formatterType) || f.hasMethod(typ, "Format") {
return true
}
// If we can use a string, might arg (dynamically) implement the Stringer or Error interface?
if t&argString != 0 {
if types.AssertableTo(errorType, typ) || types.AssertableTo(stringerType, typ) {
if types.AssertableTo(errorType, typ) || stringerType != nil && types.AssertableTo(stringerType, typ) {
return true
}
}
@ -319,7 +315,9 @@ func (f *File) isErrorMethodCall(call *ast.CallExpr) bool {
if typ != nil {
// We know it's called "Error", so just check the function signature
// (stringerType has exactly one method, String).
return types.Identical(f.pkg.types[call.Fun].Type, stringerType.Method(0).Type())
if stringerType != nil && stringerType.NumMethods() == 1 {
return types.Identical(f.pkg.types[call.Fun].Type, stringerType.Method(0).Type())
}
}
// Without types, we can still check by hand.
// Is it a selector expression? Otherwise it's a function call, not a method call.