// reduceScope is called for one-shot queries that need only a single
// typed package. It attempts to guess the query package from pos and
// reduce the analysis scope (set of loaded packages) to just that one
// plus (the exported parts of) its dependencies. It leaves its
// arguments unchanged on failure.
//
// TODO(adonovan): this is a real mess... but it's fast.
//
func reduceScope(pos string, conf *loader.Config) {
fqpos, err := fastQueryPos(pos)
if err != nil {
return // bad query
}
// TODO(adonovan): fix: this gives the wrong results for files
// in non-importable packages such as tests and ad-hoc packages
// specified as a list of files (incl. the oracle's tests).
_, importPath, err := guessImportPath(fqpos.fset.File(fqpos.start).Name(), conf.Build)
if err != nil {
return // can't find GOPATH dir
}
if importPath == "" {
return
}
// Check that it's possible to load the queried package.
// (e.g. oracle tests contain different 'package' decls in same dir.)
// Keep consistent with logic in loader/util.go!
cfg2 := *conf.Build
cfg2.CgoEnabled = false
bp, err := cfg2.Import(importPath, "", 0)
if err != nil {
return // no files for package
}
// Check that the queried file appears in the package:
// it might be a '// +build ignore' from an ad-hoc main
// package, e.g. $GOROOT/src/net/http/triv.go.
if !pkgContainsFile(bp, fqpos.fset.File(fqpos.start).Name()) {
return // not found
}
conf.TypeCheckFuncBodies = func(p string) bool { return p == importPath }
// Ignore packages specified on command line.
conf.CreatePkgs = nil
conf.ImportPkgs = nil
// Instead load just the one containing the query position
// (and possibly its corresponding tests/production code).
// TODO(adonovan): set 'augment' based on which file list
// contains
_ = conf.ImportWithTests(importPath) // ignore error
}