func emitTraceExpr(f *Function, event TraceEvent, syntax ast.Expr) Value {
t := &Trace{
Event: event,
Start: syntax.Pos(),
End: syntax.End(),
Breakpoint: false,
syntax: syntax,
}
return emitTraceCommon(f, t)
}
func extractText(ctx *Context, t ast.Expr) (string, error) {
pos := ctx.Fset.Position(t.Pos())
end := ctx.Fset.Position(t.End())
read, err := ioutil.ReadFile(pos.Filename)
if err != nil {
return "", err
}
return string(read[pos.Offset:end.Offset]), nil
}
func hasType(pkg *grinder.Package, fn *ast.FuncDecl, edit *grinder.EditBuffer, x, v ast.Expr) bool {
// Does x (by itself) default to v's type?
// Find the scope in which x appears.
xScope := pkg.Info.Scopes[fn.Type]
ast.Inspect(fn.Body, func(z ast.Node) bool {
if z == nil {
return false
}
if x.Pos() < z.Pos() || z.End() <= x.Pos() {
return false
}
scope := pkg.Info.Scopes[z]
if scope != nil {
xScope = scope
}
return true
})
xs := edit.TextAt(x.Pos(), x.End())
xt, err := types.Eval(pkg.FileSet, pkg.Types, xScope.Pos(), xs)
if err != nil {
return false
}
vt := pkg.Info.Types[v]
if types.Identical(xt.Type, vt.Type) {
return true
}
// Might be untyped.
vb, ok1 := vt.Type.(*types.Basic)
xb, ok2 := xt.Type.(*types.Basic)
if ok1 && ok2 {
switch xb.Kind() {
case types.UntypedInt:
return vb.Kind() == types.Int
case types.UntypedBool:
return vb.Kind() == types.Bool
case types.UntypedRune:
return vb.Kind() == types.Rune
case types.UntypedFloat:
return vb.Kind() == types.Float64
case types.UntypedComplex:
return vb.Kind() == types.Complex128
case types.UntypedString:
return vb.Kind() == types.String
}
}
return false
}
// checkExprOrType checks that x is an expression or a type
// (and not a raw type such as [...]T).
//
func (p *parser) checkExprOrType(x ast.Expr) ast.Expr {
switch t := unparen(x).(type) {
case *ast.ParenExpr:
panic("unreachable")
case *ast.UnaryExpr:
if t.Op == token.RANGE {
// the range operator is only allowed at the top of a for statement
p.errorExpected(x.Pos(), "expression")
x = &ast.BadExpr{x.Pos(), x.End()}
}
case *ast.ArrayType:
if len, isEllipsis := t.Len.(*ast.Ellipsis); isEllipsis {
p.error(len.Pos(), "expected array length, found '...'")
x = &ast.BadExpr{x.Pos(), x.End()}
}
}
// all other nodes are expressions or types
return x
}
// checkExpr checks that x is an expression (and not a type).
func (p *parser) checkExpr(x ast.Expr) ast.Expr {
switch t := unparen(x).(type) {
case *ast.BadExpr:
case *ast.Ident:
case *ast.BasicLit:
case *ast.FuncLit:
case *ast.CompositeLit:
case *ast.ParenExpr:
panic("unreachable")
case *ast.SelectorExpr:
case *ast.IndexExpr:
case *ast.SliceExpr:
case *ast.TypeAssertExpr:
if t.Type == nil {
// the form X.(type) is only allowed in type switch expressions
p.errorExpected(x.Pos(), "expression")
x = &ast.BadExpr{x.Pos(), x.End()}
}
case *ast.CallExpr:
case *ast.StarExpr:
case *ast.UnaryExpr:
if t.Op == token.RANGE {
// the range operator is only allowed at the top of a for statement
p.errorExpected(x.Pos(), "expression")
x = &ast.BadExpr{x.Pos(), x.End()}
}
case *ast.BinaryExpr:
default:
// all other nodes are not proper expressions
p.errorExpected(x.Pos(), "expression")
x = &ast.BadExpr{x.Pos(), x.End()}
}
return x
}
// reflectFixSwitch rewrites *n (if n is an *ast.Stmt) corresponding
// to a type switch.
func reflectFixSwitch(n interface{}) bool {
ptr, ok := n.(*ast.Stmt)
if !ok {
return false
}
n = *ptr
ts, ok := n.(*ast.TypeSwitchStmt)
if !ok {
return false
}
// Are any switch cases referring to reflect types?
// (That is, is this an old reflect type switch?)
for _, cas := range ts.Body.List {
for _, typ := range cas.(*ast.CaseClause).List {
if reflectType(typ) != "" {
goto haveReflect
}
}
}
return false
haveReflect:
// Now we know it's an old reflect type switch. Prepare the new version,
// but don't replace or edit the original until we're sure of success.
// Figure out the initializer statement, if any, and the receiver for the Kind call.
var init ast.Stmt
var rcvr ast.Expr
init = ts.Init
switch n := ts.Assign.(type) {
default:
warn(ts.Pos(), "unexpected form in type switch")
return false
case *ast.AssignStmt:
as := n
ta := as.Rhs[0].(*ast.TypeAssertExpr)
x := isIdent(as.Lhs[0])
z := isIdent(ta.X)
if isBlank(x) || x != nil && z != nil && x.Name == z.Name && !assignsTo(x, ts.Body.List) {
// Can drop the variable creation.
rcvr = ta.X
} else {
// Need to use initialization statement.
if init != nil {
warn(ts.Pos(), "cannot rewrite reflect type switch with initializing statement")
return false
}
init = &ast.AssignStmt{
Lhs: []ast.Expr{as.Lhs[0]},
TokPos: as.TokPos,
Tok: token.DEFINE,
Rhs: []ast.Expr{ta.X},
}
rcvr = as.Lhs[0]
}
case *ast.ExprStmt:
rcvr = n.X.(*ast.TypeAssertExpr).X
}
// Prepare rewritten type switch (see large comment above for form).
sw := &ast.SwitchStmt{
Switch: ts.Switch,
Init: init,
Tag: &ast.CallExpr{
Fun: &ast.SelectorExpr{
X: rcvr,
Sel: &ast.Ident{
NamePos: rcvr.End(),
Name: "Kind",
Obj: nil,
},
},
Lparen: rcvr.End(),
Rparen: rcvr.End(),
},
Body: &ast.BlockStmt{
Lbrace: ts.Body.Lbrace,
List: nil, // to be filled in
Rbrace: ts.Body.Rbrace,
},
}
// Translate cases.
for _, tcas := range ts.Body.List {
tcas := tcas.(*ast.CaseClause)
cas := &ast.CaseClause{
Case: tcas.Case,
Colon: tcas.Colon,
Body: tcas.Body,
}
for _, t := range tcas.List {
if isTopName(t, "nil") {
cas.List = append(cas.List, newPkgDot(t.Pos(), "reflect", "Invalid"))
continue
}
typ := reflectType(t)
if typ == "" {
warn(t.Pos(), "cannot rewrite reflect type switch case with non-reflect type %s", gofmt(t))
cas.List = append(cas.List, t)
continue
}
for _, k := range reflectKind[typ] {
cas.List = append(cas.List, newPkgDot(t.Pos(), "reflect", k))
}
}
sw.Body.List = append(sw.Body.List, cas)
}
// Everything worked. Rewrite AST.
*ptr = sw
return true
}
func extractExpressionAsFunc(
astFile *ast.File,
fileSet *token.FileSet,
expr ast.Expr,
parent ast.Node,
extractedFuncName string) {
params := varIdentsUsedIn([]ast.Node{expr})
util.MapStringAstIdentRemoveKeys(params, namesOf(globalVarIdents(astFile)))
newExpr := CopyNode(callExprWith(extractedFuncName, params)).(ast.Expr)
RecalcPoses(newExpr, expr.Pos(), nil, 0)
switch typedNode := parent.(type) {
case *ast.AssignStmt:
for i, rhs := range typedNode.Rhs {
if rhs == expr {
typedNode.Rhs[i] = newExpr
}
}
for i, lhs := range typedNode.Lhs {
if lhs == expr {
typedNode.Lhs[i] = newExpr
}
}
case *ast.CallExpr:
for i, arg := range typedNode.Args {
if arg == expr {
typedNode.Args[i] = newExpr
}
}
case *ast.ExprStmt:
typedNode.X = newExpr
case *ast.ReturnStmt:
for i, result := range typedNode.Results {
if result == expr {
typedNode.Results[i] = newExpr
}
}
case *ast.IfStmt:
if typedNode.Cond == expr {
typedNode.Cond = newExpr
}
case *ast.CaseClause:
for i, caseExpr := range typedNode.List {
if caseExpr == expr {
typedNode.List[i] = newExpr
}
}
case *ast.SwitchStmt:
if typedNode.Tag == expr {
typedNode.Tag = newExpr
}
case *ast.ForStmt:
if typedNode.Cond == expr {
typedNode.Cond = newExpr
}
case *ast.RangeStmt:
if typedNode.Key == expr {
typedNode.Key = newExpr
} else if typedNode.Value == expr {
typedNode.Value = newExpr
} else if typedNode.X == expr {
typedNode.X = newExpr
}
case *ast.SendStmt:
if typedNode.Chan == expr {
typedNode.Chan = newExpr
} else if typedNode.Value == expr {
typedNode.Value = newExpr
}
case *ast.IncDecStmt:
if typedNode.X == expr {
typedNode.X = newExpr
}
case *ast.ValueSpec:
for i, value := range typedNode.Values {
if value == expr {
typedNode.Values[i] = newExpr
}
}
default:
panic(fmt.Sprintf("Type %v not supported yet", reflect.TypeOf(parent)))
}
areaRemoved := areaRemoved(fileSet, expr.Pos(), expr.End())
lineLengths := lineLengthsFrom(fileSet)
lineNum, numLinesToCut, newLineLength := replacementModifications(fileSet, expr.Pos(), expr.End(), newExpr.End(), lineLengths, areaRemoved)
shiftPosesAfterPos(astFile, newExpr, expr.End(), newExpr.End()-expr.End())
singleExprStmtFuncDeclWith := CopyNode(singleExprStmtFuncDeclWith(extractedFuncName, fieldsFrom(params), expr)).(*ast.FuncDecl)
var moveOffset token.Pos
RecalcPoses(singleExprStmtFuncDeclWith, astFile.End()+2, &moveOffset, 0)
astFile.Decls = append(astFile.Decls, singleExprStmtFuncDeclWith)
areaToBeAppended := insertionModifications(astFile, singleExprStmtFuncDeclWith, areaRemoved)
lineLengths = append(
lineLengths[:lineNum+1],
lineLengths[lineNum+1+numLinesToCut:]...)
lineLengths[lineNum] = newLineLength
lineLengths = append(lineLengths, areaToBeAppended...)
newFileSet := token.NewFileSet()
newFileSet.AddFile(fileSet.File(1).Name(), 1, int(astFile.End()))
success := newFileSet.File(1).SetLines(ConvertLineLengthsToLineOffsets(lineLengths))
if !success {
panic("Could not SetLines on File.")
}
*fileSet = *newFileSet
moveComments(astFile, moveOffset /*, needs a range to restict which comments to move*/)
}
func getTypeString(expr ast.Expr, source []byte) string {
return string(source[expr.Pos()-1 : expr.End()-1])
}
