Golang File.Pos方法代码示例

// findQueryPos searches fset for filename and translates the
// specified file-relative byte offsets into token.Pos form.  It
// returns an error if the file was not found or the offsets were out
// of bounds.
//
func findQueryPos(fset *token.FileSet, filename string, startOffset, endOffset int) (start, end token.Pos, err error) {
	var file *token.File
	fset.Iterate(func(f *token.File) bool {
		if sameFile(filename, f.Name()) {
			// (f.Name() is absolute)
			file = f
			return false // done
		}
		return true // continue
	})
	if file == nil {
		err = fmt.Errorf("couldn't find file containing position")
		return
	}

	// Range check [start..end], inclusive of both end-points.

	if 0 <= startOffset && startOffset <= file.Size() {
		start = file.Pos(int(startOffset))
	} else {
		err = fmt.Errorf("start position is beyond end of file")
		return
	}

	if 0 <= endOffset && endOffset <= file.Size() {
		end = file.Pos(int(endOffset))
	} else {
		err = fmt.Errorf("end position is beyond end of file")
		return
	}

	return
}

// parseQueryPos parses a string of the form "file:pos" or
// file:start,end" where pos, start, end match #%d and represent byte
// offsets, and returns the extent to which it refers.
//
// (Numbers without a '#' prefix are reserved for future use,
// e.g. to indicate line/column positions.)
//
func parseQueryPos(fset *token.FileSet, queryPos string) (start, end token.Pos, err error) {
	if queryPos == "" {
		err = fmt.Errorf("no source position specified (-pos flag)")
		return
	}

	colon := strings.LastIndex(queryPos, ":")
	if colon < 0 {
		err = fmt.Errorf("invalid source position -pos=%q", queryPos)
		return
	}
	filename, offset := queryPos[:colon], queryPos[colon+1:]
	startOffset := -1
	endOffset := -1
	if hyphen := strings.Index(offset, ","); hyphen < 0 {
		// e.g. "foo.go:#123"
		startOffset = parseOctothorpDecimal(offset)
		endOffset = startOffset
	} else {
		// e.g. "foo.go:#123,#456"
		startOffset = parseOctothorpDecimal(offset[:hyphen])
		endOffset = parseOctothorpDecimal(offset[hyphen+1:])
	}
	if startOffset < 0 || endOffset < 0 {
		err = fmt.Errorf("invalid -pos offset %q", offset)
		return
	}

	var file *token.File
	fset.Iterate(func(f *token.File) bool {
		if sameFile(filename, f.Name()) {
			// (f.Name() is absolute)
			file = f
			return false // done
		}
		return true // continue
	})
	if file == nil {
		err = fmt.Errorf("couldn't find file containing position -pos=%q", queryPos)
		return
	}

	// Range check [start..end], inclusive of both end-points.

	if 0 <= startOffset && startOffset <= file.Size() {
		start = file.Pos(int(startOffset))
	} else {
		err = fmt.Errorf("start position is beyond end of file -pos=%q", queryPos)
		return
	}

	if 0 <= endOffset && endOffset <= file.Size() {
		end = file.Pos(int(endOffset))
	} else {
		err = fmt.Errorf("end position is beyond end of file -pos=%q", queryPos)
		return
	}

	return
}

// fileOffsetToPos translates the specified file-relative byte offsets
// into token.Pos form.  It returns an error if the file was not found
// or the offsets were out of bounds.
//
func fileOffsetToPos(file *token.File, startOffset, endOffset int) (start, end token.Pos, err error) {
	// Range check [start..end], inclusive of both end-points.

	if 0 <= startOffset && startOffset <= file.Size() {
		start = file.Pos(int(startOffset))
	} else {
		err = fmt.Errorf("start position is beyond end of file")
		return
	}

	if 0 <= endOffset && endOffset <= file.Size() {
		end = file.Pos(int(endOffset))
	} else {
		err = fmt.Errorf("end position is beyond end of file")
		return
	}

	return
}

func (d *debugInfo) getCompileUnit(file *token.File) *debug.CompileUnitDescriptor {
	if d.cu == nil {
		d.cu = make(map[*token.File]*debug.CompileUnitDescriptor)
	}
	cu := d.cu[file]
	if cu == nil {
		var path string
		if file != nil {
			path = d.Fset.File(file.Pos(0)).Name()
		}
		cu = &debug.CompileUnitDescriptor{
			Language: debug.DW_LANG_Go,
			Path:     debug.FileDescriptor(path),
			Producer: "llgo",
			Runtime:  LLGORuntimeVersion,
		}
		d.cu[file] = cu
	}
	return cu
}