// ParseFile parses the source code of a single Go source file and returns
// the corresponding ast.File node. The source code may be provided via
// the filename of the source file, or via the src parameter.
//
// If src != nil, ParseFile parses the source from src and the filename is
// only used when recording position information. The type of the argument
// for the src parameter must be string, []byte, or io.Reader.
// If src == nil, ParseFile parses the file specified by filename.
//
// The mode parameter controls the amount of source text parsed and other
// optional parser functionality. Position information is recorded in the
// file set fset.
//
// If the source couldn't be read, the returned AST is nil and the error
// indicates the specific failure. If the source was read but syntax
// errors were found, the result is a partial AST (with ast.Bad* nodes
// representing the fragments of erroneous source code). Multiple errors
// are returned via a scanner.ErrorList which is sorted by file position.
//
func ParseFile(fset *token.FileSet, filename string, src interface{}, mode Mode) (f *ast.File, err error) {
// get source
text, err := readSource(filename, src)
if err != nil {
return nil, err
}
var p parser
defer func() {
if e := recover(); e != nil {
_ = e.(bailout) // re-panics if it's not a bailout
}
// set result values
if f == nil {
// source is not a valid Go source file - satisfy
// ParseFile API and return a valid (but) empty
// *ast.File
f = &ast.File{
Name: new(ast.Ident),
Scope: ast.NewScope(nil),
}
}
p.errors.Sort()
err = p.errors.Err()
}()
// parse source
p.init(fset, filename, text, mode)
f = p.parseFile()
return
}
// poorMansImporter returns a (dummy) package object named
// by the last path component of the provided package path
// (as is the convention for packages). This is sufficient
// to resolve package identifiers without doing an actual
// import. It never returns an error.
//
func poorMansImporter(imports map[string]*ast.Object, path string) (*ast.Object, error) {
pkg := imports[path]
if pkg == nil {
// note that strings.LastIndex returns -1 if there is no "/"
pkg = ast.NewObj(ast.Pkg, path[strings.LastIndex(path, "/")+1:])
pkg.Data = ast.NewScope(nil) // required by ast.NewPackage for dot-import
imports[path] = pkg
}
return pkg, nil
}