// ParseQueryPos parses the source query position pos.
// If needExact, it must identify a single AST subtree;
// this is appropriate for queries that allow fairly arbitrary syntax,
// e.g. "describe".
//
func ParseQueryPos(iprog *loader.Program, posFlag string, needExact bool) (*QueryPos, error) {
filename, startOffset, endOffset, err := parsePosFlag(posFlag)
if err != nil {
return nil, err
}
start, end, err := findQueryPos(iprog.Fset, filename, startOffset, endOffset)
if err != nil {
return nil, err
}
info, path, exact := iprog.PathEnclosingInterval(start, end)
if path == nil {
return nil, fmt.Errorf("no syntax here")
}
if needExact && !exact {
return nil, fmt.Errorf("ambiguous selection within %s", astutil.NodeDescription(path[0]))
}
return &QueryPos{iprog.Fset, start, end, path, exact, info}, nil
}
func findFromObjectsInFile(iprog *loader.Program, spec *spec) ([]types.Object, error) {
var fromObjects []types.Object
for _, info := range iprog.AllPackages {
// restrict to specified filename
// NB: under certain proprietary build systems, a given
// filename may appear in multiple packages.
for _, f := range info.Files {
thisFile := iprog.Fset.File(f.Pos())
if !sameFile(thisFile.Name(), spec.filename) {
continue
}
// This package contains the query file.
if spec.offset != 0 {
// Search for a specific ident by file/offset.
id := identAtOffset(iprog.Fset, f, spec.offset)
if id == nil {
// can't happen?
return nil, fmt.Errorf("identifier not found")
}
obj := info.Uses[id]
if obj == nil {
obj = info.Defs[id]
if obj == nil {
// Ident without Object.
// Package clause?
pos := thisFile.Pos(spec.offset)
_, path, _ := iprog.PathEnclosingInterval(pos, pos)
if len(path) == 2 { // [Ident File]
// TODO(adonovan): support this case.
return nil, fmt.Errorf("cannot rename %q: renaming package clauses is not yet supported",
path[1].(*ast.File).Name.Name)
}
// Implicit y in "switch y := x.(type) {"?
if obj := typeSwitchVar(&info.Info, path); obj != nil {
return []types.Object{obj}, nil
}
// Probably a type error.
return nil, fmt.Errorf("cannot find object for %q", id.Name)
}
}
if obj.Pkg() == nil {
return nil, fmt.Errorf("cannot rename predeclared identifiers (%s)", obj)
}
fromObjects = append(fromObjects, obj)
} else {
// do a package-wide query
objects, err := findObjects(info, spec)
if err != nil {
return nil, err
}
// filter results: only objects defined in thisFile
var filtered []types.Object
for _, obj := range objects {
if iprog.Fset.File(obj.Pos()) == thisFile {
filtered = append(filtered, obj)
}
}
if len(filtered) == 0 {
return nil, fmt.Errorf("no object %q declared in file %s",
spec.fromName, spec.filename)
} else if len(filtered) > 1 {
return nil, ambiguityError(iprog.Fset, filtered)
}
fromObjects = append(fromObjects, filtered[0])
}
break
}
}
if len(fromObjects) == 0 {
// can't happen?
return nil, fmt.Errorf("file %s was not part of the loaded program", spec.filename)
}
return fromObjects, nil
}