func IncDecStmt(stmt ast.Stmt, info *types.Info) ast.Stmt {
if s, ok := stmt.(*ast.IncDecStmt); ok {
t := info.TypeOf(s.X)
if iExpr, isIExpr := s.X.(*ast.IndexExpr); isIExpr {
switch u := info.TypeOf(iExpr.X).Underlying().(type) {
case *types.Array:
t = u.Elem()
case *types.Slice:
t = u.Elem()
case *types.Map:
t = u.Elem()
}
}
tok := token.ADD_ASSIGN
if s.Tok == token.DEC {
tok = token.SUB_ASSIGN
}
one := &ast.BasicLit{Kind: token.INT}
info.Types[one] = types.TypeAndValue{Type: t, Value: constant.MakeInt64(1)}
return &ast.AssignStmt{
Lhs: []ast.Expr{s.X},
Tok: tok,
Rhs: []ast.Expr{one},
}
}
return stmt
}
func (b *builder) extractString(f *ast.File, info *types.Info, fset *token.FileSet) error {
ast.Inspect(f, func(n ast.Node) bool {
switch x := n.(type) {
case *ast.CallExpr:
if len(x.Args) > 0 {
tc := info.TypeOf(x.Fun)
if tc.String() == "github.com/nicksnyder/go-i18n/i18n.TranslateFunc" {
str := x.Args[0].(*ast.BasicLit)
b.str = append(b.str, str.Value[1:len(str.Value)-1])
//fmt.Printf("got string %s\n", str.Value[1:len(str.Value)-1])
}
}
}
return true
})
return nil
}
// funcHasSingleReturnVal returns true if func called by e has a
// single return value (and false if it has multiple return values).
func funcHasSingleReturnVal(typeInfo *types.Info, e *ast.CallExpr) bool {
// quick local pass
if id, ok := e.Fun.(*ast.Ident); ok && id.Obj != nil {
if fn, ok := id.Obj.Decl.(*ast.FuncDecl); ok {
return len(fn.Type.Results.List) == 1
}
}
if typeInfo != nil {
// look up in type info
typ := typeInfo.TypeOf(e)
if _, ok := typ.(*types.Tuple); ok {
return false
}
return true
}
// conservatively return false if we don't have type info
return false
}
// NewTransformer returns a transformer based on the specified template,
// a single-file package containing "before" and "after" functions as
// described in the package documentation.
// tmplInfo is the type information for tmplFile.
//
func NewTransformer(fset *token.FileSet, tmplPkg *types.Package, tmplFile *ast.File, tmplInfo *types.Info, verbose bool) (*Transformer, error) {
// Check the template.
beforeSig := funcSig(tmplPkg, "before")
if beforeSig == nil {
return nil, fmt.Errorf("no 'before' func found in template")
}
afterSig := funcSig(tmplPkg, "after")
if afterSig == nil {
return nil, fmt.Errorf("no 'after' func found in template")
}
// TODO(adonovan): should we also check the names of the params match?
if !types.Identical(afterSig, beforeSig) {
return nil, fmt.Errorf("before %s and after %s functions have different signatures",
beforeSig, afterSig)
}
for _, imp := range tmplFile.Imports {
if imp.Name != nil && imp.Name.Name == "." {
// Dot imports are currently forbidden. We
// make the simplifying assumption that all
// imports are regular, without local renames.
// TODO(adonovan): document
return nil, fmt.Errorf("dot-import (of %s) in template", imp.Path.Value)
}
}
var beforeDecl, afterDecl *ast.FuncDecl
for _, decl := range tmplFile.Decls {
if decl, ok := decl.(*ast.FuncDecl); ok {
switch decl.Name.Name {
case "before":
beforeDecl = decl
case "after":
afterDecl = decl
}
}
}
before, err := soleExpr(beforeDecl)
if err != nil {
return nil, fmt.Errorf("before: %s", err)
}
after, err := soleExpr(afterDecl)
if err != nil {
return nil, fmt.Errorf("after: %s", err)
}
wildcards := make(map[*types.Var]bool)
for i := 0; i < beforeSig.Params().Len(); i++ {
wildcards[beforeSig.Params().At(i)] = true
}
// checkExprTypes returns an error if Tb (type of before()) is not
// safe to replace with Ta (type of after()).
//
// Only superficial checks are performed, and they may result in both
// false positives and negatives.
//
// Ideally, we would only require that the replacement be assignable
// to the context of a specific pattern occurrence, but the type
// checker doesn't record that information and it's complex to deduce.
// A Go type cannot capture all the constraints of a given expression
// context, which may include the size, constness, signedness,
// namedness or constructor of its type, and even the specific value
// of the replacement. (Consider the rule that array literal keys
// must be unique.) So we cannot hope to prove the safety of a
// transformation in general.
Tb := tmplInfo.TypeOf(before)
Ta := tmplInfo.TypeOf(after)
if types.AssignableTo(Tb, Ta) {
// safe: replacement is assignable to pattern.
} else if tuple, ok := Tb.(*types.Tuple); ok && tuple.Len() == 0 {
// safe: pattern has void type (must appear in an ExprStmt).
} else {
return nil, fmt.Errorf("%s is not a safe replacement for %s", Ta, Tb)
}
tr := &Transformer{
fset: fset,
verbose: verbose,
wildcards: wildcards,
allowWildcards: true,
seenInfos: make(map[*types.Info]bool),
importedObjs: make(map[types.Object]*ast.SelectorExpr),
before: before,
after: after,
}
// Combine type info from the template and input packages, and
// type info for the synthesized ASTs too. This saves us
// having to book-keep where each ast.Node originated as we
// construct the resulting hybrid AST.
tr.info = &types.Info{
Types: make(map[ast.Expr]types.TypeAndValue),
Defs: make(map[*ast.Ident]types.Object),
Uses: make(map[*ast.Ident]types.Object),
Selections: make(map[*ast.SelectorExpr]*types.Selection),
}
mergeTypeInfo(tr.info, tmplInfo)
// Compute set of imported objects required by after().
// TODO(adonovan): reject dot-imports in pattern
ast.Inspect(after, func(n ast.Node) bool {
if n, ok := n.(*ast.SelectorExpr); ok {
if _, ok := tr.info.Selections[n]; !ok {
// qualified ident
obj := tr.info.Uses[n.Sel]
tr.importedObjs[obj] = n
return false // prune
}
}
return true // recur
})
return tr, nil
}
func Assign(stmt ast.Stmt, info *types.Info, pkg *types.Package) ast.Stmt {
if s, ok := stmt.(*ast.AssignStmt); ok && s.Tok != token.ASSIGN && s.Tok != token.DEFINE {
var op token.Token
switch s.Tok {
case token.ADD_ASSIGN:
op = token.ADD
case token.SUB_ASSIGN:
op = token.SUB
case token.MUL_ASSIGN:
op = token.MUL
case token.QUO_ASSIGN:
op = token.QUO
case token.REM_ASSIGN:
op = token.REM
case token.AND_ASSIGN:
op = token.AND
case token.OR_ASSIGN:
op = token.OR
case token.XOR_ASSIGN:
op = token.XOR
case token.SHL_ASSIGN:
op = token.SHL
case token.SHR_ASSIGN:
op = token.SHR
case token.AND_NOT_ASSIGN:
op = token.AND_NOT
default:
panic(s.Tok)
}
var list []ast.Stmt
var viaTmpVars func(expr ast.Expr, name string) ast.Expr
viaTmpVars = func(expr ast.Expr, name string) ast.Expr {
switch e := astutil.RemoveParens(expr).(type) {
case *ast.IndexExpr:
return astutil.SetType(info, info.TypeOf(e), &ast.IndexExpr{
X: viaTmpVars(e.X, "_slice"),
Index: viaTmpVars(e.Index, "_index"),
})
case *ast.SelectorExpr:
sel, ok := info.Selections[e]
if !ok {
// qualified identifier
return e
}
newSel := &ast.SelectorExpr{
X: viaTmpVars(e.X, "_struct"),
Sel: e.Sel,
}
info.Selections[newSel] = sel
return astutil.SetType(info, info.TypeOf(e), newSel)
case *ast.StarExpr:
return astutil.SetType(info, info.TypeOf(e), &ast.StarExpr{
X: viaTmpVars(e.X, "_ptr"),
})
case *ast.Ident, *ast.BasicLit:
return e
default:
tmpVar := astutil.NewIdent(name, info.TypeOf(e), info, pkg)
list = append(list, &ast.AssignStmt{
Lhs: []ast.Expr{tmpVar},
Tok: token.DEFINE,
Rhs: []ast.Expr{e},
})
return tmpVar
}
}
lhs := viaTmpVars(s.Lhs[0], "_val")
list = append(list, &ast.AssignStmt{
Lhs: []ast.Expr{lhs},
Tok: token.ASSIGN,
Rhs: []ast.Expr{
astutil.SetType(info, info.TypeOf(s.Lhs[0]), &ast.BinaryExpr{
X: lhs,
Op: op,
Y: astutil.SetType(info, info.TypeOf(s.Rhs[0]), &ast.ParenExpr{
X: s.Rhs[0],
}),
}),
},
})
return &ast.BlockStmt{
List: list,
}
}
return stmt
}