diff options
author | Rob Findley <rfindley@google.com> | 2020-09-11 14:23:34 -0400 |
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committer | Rob Findley <rfindley@google.com> | 2020-09-11 14:23:34 -0400 |
commit | f8b1c17aced24a1618c6984794be9770c5d260be (patch) | |
tree | 45af8d39b5c3d9f43d439ebec0a2ba42b49efe70 /src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go | |
parent | e5d91ab096a9ff9673311f1a7f3f860a7f9c2062 (diff) | |
parent | 07c1788357cfe6a4ee5f6f6a54d4fe9f579fa844 (diff) | |
download | go-dev.types.tar.gz go-dev.types.zip |
[dev.types] all: merge master into dev.typesdev.types
Change-Id: Ia6964cb4e09153c15cc9c5b441373d1b3cb8f757
Diffstat (limited to 'src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go')
-rw-r--r-- | src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go | 343 |
1 files changed, 325 insertions, 18 deletions
diff --git a/src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go b/src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go index 26586810c7..01f6e829f7 100644 --- a/src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go +++ b/src/cmd/vendor/golang.org/x/tools/internal/analysisinternal/analysis.go @@ -14,6 +14,12 @@ import ( "strings" "golang.org/x/tools/go/ast/astutil" + "golang.org/x/tools/internal/lsp/fuzzy" +) + +var ( + GetTypeErrors func(p interface{}) []types.Error + SetTypeErrors func(p interface{}, errors []types.Error) ) func TypeErrorEndPos(fset *token.FileSet, src []byte, start token.Pos) token.Pos { @@ -45,32 +51,34 @@ func ZeroValue(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.T default: panic("unknown basic type") } - case *types.Chan, *types.Interface, *types.Map, *types.Pointer, *types.Signature, *types.Slice: + case *types.Chan, *types.Interface, *types.Map, *types.Pointer, *types.Signature, *types.Slice, *types.Array: return ast.NewIdent("nil") case *types.Struct: - texpr := typeExpr(fset, f, pkg, typ) // typ because we want the name here. + texpr := TypeExpr(fset, f, pkg, typ) // typ because we want the name here. if texpr == nil { return nil } return &ast.CompositeLit{ Type: texpr, } - case *types.Array: - texpr := typeExpr(fset, f, pkg, u.Elem()) - if texpr == nil { - return nil - } - return &ast.CompositeLit{ - Type: &ast.ArrayType{ - Elt: texpr, - Len: &ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%v", u.Len())}, - }, - } } return nil } -func typeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Type) ast.Expr { +// IsZeroValue checks whether the given expression is a 'zero value' (as determined by output of +// analysisinternal.ZeroValue) +func IsZeroValue(expr ast.Expr) bool { + switch e := expr.(type) { + case *ast.BasicLit: + return e.Value == "0" || e.Value == `""` + case *ast.Ident: + return e.Name == "nil" || e.Name == "false" + default: + return false + } +} + +func TypeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Type) ast.Expr { switch t := typ.(type) { case *types.Basic: switch t.Kind() { @@ -79,7 +87,96 @@ func typeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Ty default: return ast.NewIdent(t.Name()) } + case *types.Pointer: + x := TypeExpr(fset, f, pkg, t.Elem()) + if x == nil { + return nil + } + return &ast.UnaryExpr{ + Op: token.MUL, + X: x, + } + case *types.Array: + elt := TypeExpr(fset, f, pkg, t.Elem()) + if elt == nil { + return nil + } + return &ast.ArrayType{ + Len: &ast.BasicLit{ + Kind: token.INT, + Value: fmt.Sprintf("%d", t.Len()), + }, + Elt: elt, + } + case *types.Slice: + elt := TypeExpr(fset, f, pkg, t.Elem()) + if elt == nil { + return nil + } + return &ast.ArrayType{ + Elt: elt, + } + case *types.Map: + key := TypeExpr(fset, f, pkg, t.Key()) + value := TypeExpr(fset, f, pkg, t.Elem()) + if key == nil || value == nil { + return nil + } + return &ast.MapType{ + Key: key, + Value: value, + } + case *types.Chan: + dir := ast.ChanDir(t.Dir()) + if t.Dir() == types.SendRecv { + dir = ast.SEND | ast.RECV + } + value := TypeExpr(fset, f, pkg, t.Elem()) + if value == nil { + return nil + } + return &ast.ChanType{ + Dir: dir, + Value: value, + } + case *types.Signature: + var params []*ast.Field + for i := 0; i < t.Params().Len(); i++ { + p := TypeExpr(fset, f, pkg, t.Params().At(i).Type()) + if p == nil { + return nil + } + params = append(params, &ast.Field{ + Type: p, + Names: []*ast.Ident{ + { + Name: t.Params().At(i).Name(), + }, + }, + }) + } + var returns []*ast.Field + for i := 0; i < t.Results().Len(); i++ { + r := TypeExpr(fset, f, pkg, t.Results().At(i).Type()) + if r == nil { + return nil + } + returns = append(returns, &ast.Field{ + Type: r, + }) + } + return &ast.FuncType{ + Params: &ast.FieldList{ + List: params, + }, + Results: &ast.FieldList{ + List: returns, + }, + } case *types.Named: + if t.Obj().Pkg() == nil { + return ast.NewIdent(t.Obj().Name()) + } if t.Obj().Pkg() == pkg { return ast.NewIdent(t.Obj().Name()) } @@ -101,14 +198,15 @@ func typeExpr(fset *token.FileSet, f *ast.File, pkg *types.Package, typ types.Ty X: ast.NewIdent(pkgName), Sel: ast.NewIdent(t.Obj().Name()), } + case *types.Struct: + return ast.NewIdent(t.String()) + case *types.Interface: + return ast.NewIdent(t.String()) default: - return nil // TODO: anonymous structs, but who does that + return nil } } -var GetTypeErrors = func(p interface{}) []types.Error { return nil } -var SetTypeErrors = func(p interface{}, errors []types.Error) {} - type TypeErrorPass string const ( @@ -116,3 +214,212 @@ const ( NoResultValues TypeErrorPass = "noresultvalues" UndeclaredName TypeErrorPass = "undeclaredname" ) + +// StmtToInsertVarBefore returns the ast.Stmt before which we can safely insert a new variable. +// Some examples: +// +// Basic Example: +// z := 1 +// y := z + x +// If x is undeclared, then this function would return `y := z + x`, so that we +// can insert `x := ` on the line before `y := z + x`. +// +// If stmt example: +// if z == 1 { +// } else if z == y {} +// If y is undeclared, then this function would return `if z == 1 {`, because we cannot +// insert a statement between an if and an else if statement. As a result, we need to find +// the top of the if chain to insert `y := ` before. +func StmtToInsertVarBefore(path []ast.Node) ast.Stmt { + enclosingIndex := -1 + for i, p := range path { + if _, ok := p.(ast.Stmt); ok { + enclosingIndex = i + break + } + } + if enclosingIndex == -1 { + return nil + } + enclosingStmt := path[enclosingIndex] + switch enclosingStmt.(type) { + case *ast.IfStmt: + // The enclosingStmt is inside of the if declaration, + // We need to check if we are in an else-if stmt and + // get the base if statement. + return baseIfStmt(path, enclosingIndex) + case *ast.CaseClause: + // Get the enclosing switch stmt if the enclosingStmt is + // inside of the case statement. + for i := enclosingIndex + 1; i < len(path); i++ { + if node, ok := path[i].(*ast.SwitchStmt); ok { + return node + } else if node, ok := path[i].(*ast.TypeSwitchStmt); ok { + return node + } + } + } + if len(path) <= enclosingIndex+1 { + return enclosingStmt.(ast.Stmt) + } + // Check if the enclosing statement is inside another node. + switch expr := path[enclosingIndex+1].(type) { + case *ast.IfStmt: + // Get the base if statement. + return baseIfStmt(path, enclosingIndex+1) + case *ast.ForStmt: + if expr.Init == enclosingStmt || expr.Post == enclosingStmt { + return expr + } + } + return enclosingStmt.(ast.Stmt) +} + +// baseIfStmt walks up the if/else-if chain until we get to +// the top of the current if chain. +func baseIfStmt(path []ast.Node, index int) ast.Stmt { + stmt := path[index] + for i := index + 1; i < len(path); i++ { + if node, ok := path[i].(*ast.IfStmt); ok && node.Else == stmt { + stmt = node + continue + } + break + } + return stmt.(ast.Stmt) +} + +// WalkASTWithParent walks the AST rooted at n. The semantics are +// similar to ast.Inspect except it does not call f(nil). +func WalkASTWithParent(n ast.Node, f func(n ast.Node, parent ast.Node) bool) { + var ancestors []ast.Node + ast.Inspect(n, func(n ast.Node) (recurse bool) { + if n == nil { + ancestors = ancestors[:len(ancestors)-1] + return false + } + + var parent ast.Node + if len(ancestors) > 0 { + parent = ancestors[len(ancestors)-1] + } + ancestors = append(ancestors, n) + return f(n, parent) + }) +} + +// FindMatchingIdents finds all identifiers in 'node' that match any of the given types. +// 'pos' represents the position at which the identifiers may be inserted. 'pos' must be within +// the scope of each of identifier we select. Otherwise, we will insert a variable at 'pos' that +// is unrecognized. +func FindMatchingIdents(typs []types.Type, node ast.Node, pos token.Pos, info *types.Info, pkg *types.Package) map[types.Type][]*ast.Ident { + matches := map[types.Type][]*ast.Ident{} + // Initialize matches to contain the variable types we are searching for. + for _, typ := range typs { + if typ == nil { + continue + } + matches[typ] = []*ast.Ident{} + } + seen := map[types.Object]struct{}{} + ast.Inspect(node, func(n ast.Node) bool { + if n == nil { + return false + } + // Prevent circular definitions. If 'pos' is within an assignment statement, do not + // allow any identifiers in that assignment statement to be selected. Otherwise, + // we could do the following, where 'x' satisfies the type of 'f0': + // + // x := fakeStruct{f0: x} + // + assignment, ok := n.(*ast.AssignStmt) + if ok && pos > assignment.Pos() && pos <= assignment.End() { + return false + } + if n.End() > pos { + return n.Pos() <= pos + } + ident, ok := n.(*ast.Ident) + if !ok || ident.Name == "_" { + return true + } + obj := info.Defs[ident] + if obj == nil || obj.Type() == nil { + return true + } + if _, ok := obj.(*types.TypeName); ok { + return true + } + // Prevent duplicates in matches' values. + if _, ok = seen[obj]; ok { + return true + } + seen[obj] = struct{}{} + // Find the scope for the given position. Then, check whether the object + // exists within the scope. + innerScope := pkg.Scope().Innermost(pos) + if innerScope == nil { + return true + } + _, foundObj := innerScope.LookupParent(ident.Name, pos) + if foundObj != obj { + return true + } + // The object must match one of the types that we are searching for. + if idents, ok := matches[obj.Type()]; ok { + matches[obj.Type()] = append(idents, ast.NewIdent(ident.Name)) + } + // If the object type does not exactly match any of the target types, greedily + // find the first target type that the object type can satisfy. + for typ := range matches { + if obj.Type() == typ { + continue + } + if equivalentTypes(obj.Type(), typ) { + matches[typ] = append(matches[typ], ast.NewIdent(ident.Name)) + } + } + return true + }) + return matches +} + +func equivalentTypes(want, got types.Type) bool { + if want == got || types.Identical(want, got) { + return true + } + // Code segment to help check for untyped equality from (golang/go#32146). + if rhs, ok := want.(*types.Basic); ok && rhs.Info()&types.IsUntyped > 0 { + if lhs, ok := got.Underlying().(*types.Basic); ok { + return rhs.Info()&types.IsConstType == lhs.Info()&types.IsConstType + } + } + return types.AssignableTo(want, got) +} + +// FindBestMatch employs fuzzy matching to evaluate the similarity of each given identifier to the +// given pattern. We return the identifier whose name is most similar to the pattern. +func FindBestMatch(pattern string, idents []*ast.Ident) ast.Expr { + fuzz := fuzzy.NewMatcher(pattern) + var bestFuzz ast.Expr + highScore := float32(0) // minimum score is 0 (no match) + for _, ident := range idents { + // TODO: Improve scoring algorithm. + score := fuzz.Score(ident.Name) + if score > highScore { + highScore = score + bestFuzz = ident + } else if score == 0 { + // Order matters in the fuzzy matching algorithm. If we find no match + // when matching the target to the identifier, try matching the identifier + // to the target. + revFuzz := fuzzy.NewMatcher(ident.Name) + revScore := revFuzz.Score(pattern) + if revScore > highScore { + highScore = revScore + bestFuzz = ident + } + } + } + return bestFuzz +} |