mirror of
https://github.com/golang/go.git
synced 2025-12-08 06:10:04 +00:00
e87f2a1b70
R=go1.11 Also: Minor updates to syntax.Parse doc string. Change-Id: I649965be9670a2f1c3de2cdb350634ed21e36ad9 Reviewed-on: https://go-review.googlesource.com/85663 Reviewed-by: Matthew Dempsky <mdempsky@google.com>
93 lines
2.7 KiB
Go
93 lines
2.7 KiB
Go
// Copyright 2016 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.
|
|
|
|
package syntax
|
|
|
|
import (
|
|
"cmd/internal/src"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
)
|
|
|
|
// Mode describes the parser mode.
|
|
type Mode uint
|
|
|
|
// Modes supported by the parser.
|
|
const (
|
|
CheckBranches Mode = 1 << iota // check correct use of labels, break, continue, and goto statements
|
|
)
|
|
|
|
// Error describes a syntax error. Error implements the error interface.
|
|
type Error struct {
|
|
Pos src.Pos
|
|
Msg string
|
|
}
|
|
|
|
func (err Error) Error() string {
|
|
return fmt.Sprintf("%s: %s", err.Pos, err.Msg)
|
|
}
|
|
|
|
var _ error = Error{} // verify that Error implements error
|
|
|
|
// An ErrorHandler is called for each error encountered reading a .go file.
|
|
type ErrorHandler func(err error)
|
|
|
|
// A Pragma value is a set of flags that augment a function or
|
|
// type declaration. Callers may assign meaning to the flags as
|
|
// appropriate.
|
|
type Pragma uint16
|
|
|
|
// A PragmaHandler is used to process //go: directives as
|
|
// they're scanned. The returned Pragma value will be unioned into the
|
|
// next FuncDecl node.
|
|
type PragmaHandler func(pos src.Pos, text string) Pragma
|
|
|
|
// A FilenameHandler is used to process each filename encountered
|
|
// in //line directives. The returned value is used as the absolute filename.
|
|
type FilenameHandler func(name string) string
|
|
|
|
// Parse parses a single Go source file from src and returns the corresponding
|
|
// syntax tree. If there are errors, Parse will return the first error found,
|
|
// and a possibly partially constructed syntax tree, or nil if no correct package
|
|
// clause was found. The base argument is only used for position information.
|
|
//
|
|
// If errh != nil, it is called with each error encountered, and Parse will
|
|
// process as much source as possible. If errh is nil, Parse will terminate
|
|
// immediately upon encountering an error.
|
|
//
|
|
// If pragh != nil, it is called with each pragma encountered.
|
|
//
|
|
// If fileh != nil, it is called to process each filename
|
|
// encountered in //line directives.
|
|
//
|
|
func Parse(base *src.PosBase, src io.Reader, errh ErrorHandler, pragh PragmaHandler, fileh FilenameHandler, mode Mode) (_ *File, first error) {
|
|
defer func() {
|
|
if p := recover(); p != nil {
|
|
if err, ok := p.(Error); ok {
|
|
first = err
|
|
return
|
|
}
|
|
panic(p)
|
|
}
|
|
}()
|
|
|
|
var p parser
|
|
p.init(base, src, errh, pragh, fileh, mode)
|
|
p.next()
|
|
return p.fileOrNil(), p.first
|
|
}
|
|
|
|
// ParseFile behaves like Parse but it reads the source from the named file.
|
|
func ParseFile(filename string, errh ErrorHandler, pragh PragmaHandler, mode Mode) (*File, error) {
|
|
f, err := os.Open(filename)
|
|
if err != nil {
|
|
if errh != nil {
|
|
errh(err)
|
|
}
|
|
return nil, err
|
|
}
|
|
defer f.Close()
|
|
return Parse(src.NewFileBase(filename, filename), f, errh, pragh, nil, mode)
|
|
}
|