github.com/graybobo/golang.org-package-offline-cache@v0.0.0-20200626051047-6608995c132f/x/tools/oracle/definition14.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build !go1.5
     6  
     7  package oracle
     8  
     9  import (
    10  	"fmt"
    11  	"go/ast"
    12  	"go/token"
    13  
    14  	"golang.org/x/tools/go/loader"
    15  	"golang.org/x/tools/go/types"
    16  	"golang.org/x/tools/oracle/serial"
    17  )
    18  
    19  // definition reports the location of the definition of an identifier.
    20  //
    21  // TODO(adonovan): opt: for intra-file references, the parser's
    22  // resolution might be enough; we should start with that.
    23  //
    24  func definition(q *Query) error {
    25  	lconf := loader.Config{Build: q.Build}
    26  	allowErrors(&lconf)
    27  
    28  	if _, err := importQueryPackage(q.Pos, &lconf); err != nil {
    29  		return err
    30  	}
    31  
    32  	// Load/parse/type-check the program.
    33  	lprog, err := lconf.Load()
    34  	if err != nil {
    35  		return err
    36  	}
    37  	q.Fset = lprog.Fset
    38  
    39  	qpos, err := parseQueryPos(lprog, q.Pos, false)
    40  	if err != nil {
    41  		return err
    42  	}
    43  
    44  	id, _ := qpos.path[0].(*ast.Ident)
    45  	if id == nil {
    46  		return fmt.Errorf("no identifier here")
    47  	}
    48  
    49  	obj := qpos.info.ObjectOf(id)
    50  	if obj == nil {
    51  		// Happens for y in "switch y := x.(type)",
    52  		// and the package declaration,
    53  		// but I think that's all.
    54  		return fmt.Errorf("no object for identifier")
    55  	}
    56  
    57  	q.result = &definitionResult{qpos, obj}
    58  	return nil
    59  }
    60  
    61  type definitionResult struct {
    62  	qpos *queryPos
    63  	obj  types.Object // object it denotes
    64  }
    65  
    66  func (r *definitionResult) display(printf printfFunc) {
    67  	printf(r.obj, "defined here as %s", r.qpos.objectString(r.obj))
    68  }
    69  
    70  func (r *definitionResult) toSerial(res *serial.Result, fset *token.FileSet) {
    71  	definition := &serial.Definition{
    72  		Desc: r.obj.String(),
    73  	}
    74  	if pos := r.obj.Pos(); pos != token.NoPos { // Package objects have no Pos()
    75  		definition.ObjPos = fset.Position(pos).String()
    76  	}
    77  	res.Definition = definition
    78  }