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Diffstat (limited to 'tools/go_generics/imports.go')
-rw-r--r-- | tools/go_generics/imports.go | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/tools/go_generics/imports.go b/tools/go_generics/imports.go deleted file mode 100644 index 148dc7216..000000000 --- a/tools/go_generics/imports.go +++ /dev/null @@ -1,150 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package main - -import ( - "bytes" - "fmt" - "go/ast" - "go/format" - "go/parser" - "go/token" - "strconv" - - "gvisor.dev/gvisor/tools/go_generics/globals" -) - -type importedPackage struct { - newName string - path string -} - -// updateImportIdent modifies the given import identifier with the new name -// stored in the used map. If the identifier doesn't exist in the used map yet, -// a new name is generated and inserted into the map. -func updateImportIdent(orig string, imports mapValue, id *ast.Ident, used map[string]*importedPackage) error { - importName := id.Name - - // If the name is already in the table, just use the new name. - m := used[importName] - if m != nil { - id.Name = m.newName - return nil - } - - // Create a new entry in the used map. - path := imports[importName] - if path == "" { - return fmt.Errorf("Unknown path to package '%s', used in '%s'", importName, orig) - } - - m = &importedPackage{ - newName: fmt.Sprintf("__generics_imported%d", len(used)), - path: strconv.Quote(path), - } - used[importName] = m - - id.Name = m.newName - - return nil -} - -// convertExpression creates a new string that is a copy of the input one with -// all imports references renamed to the names in the "used" map. If the -// referenced import isn't in "used" yet, a new one is created based on the path -// in "imports" and stored in "used". For example, if string s is -// "math.MaxUint32-math.MaxUint16+10", it would be converted to -// "x.MaxUint32-x.MathUint16+10", where x is a generated name. -func convertExpression(s string, imports mapValue, used map[string]*importedPackage) (string, error) { - // Parse the expression in the input string. - expr, err := parser.ParseExpr(s) - if err != nil { - return "", fmt.Errorf("Unable to parse \"%s\": %v", s, err) - } - - // Go through the AST and update references. - var retErr error - ast.Inspect(expr, func(n ast.Node) bool { - switch x := n.(type) { - case *ast.SelectorExpr: - if id := globals.GetIdent(x.X); id != nil { - if err := updateImportIdent(s, imports, id, used); err != nil { - retErr = err - } - return false - } - } - return true - }) - if retErr != nil { - return "", retErr - } - - // Convert the modified AST back to a string. - fset := token.NewFileSet() - var buf bytes.Buffer - if err := format.Node(&buf, fset, expr); err != nil { - return "", err - } - - return string(buf.Bytes()), nil -} - -// updateImports replaces all maps in the input slice with copies where the -// mapped values have had all references to imported packages renamed to -// generated names. It also returns an import declaration for all the renamed -// import packages. -// -// For example, if the input maps contains A=math.B and C=math.D, the updated -// maps will instead contain A=__generics_imported0.B and -// C=__generics_imported0.C, and the 'import __generics_imported0 "math"' would -// be returned as the import declaration. -func updateImports(maps []mapValue, imports mapValue) (ast.Decl, error) { - importsUsed := make(map[string]*importedPackage) - - // Update all maps. - for i, m := range maps { - newMap := make(mapValue) - for n, e := range m { - updated, err := convertExpression(e, imports, importsUsed) - if err != nil { - return nil, err - } - - newMap[n] = updated - } - maps[i] = newMap - } - - // Nothing else to do if no imports are used in the expressions. - if len(importsUsed) == 0 { - return nil, nil - } - - // Create spec array for each new import. - specs := make([]ast.Spec, 0, len(importsUsed)) - for _, i := range importsUsed { - specs = append(specs, &ast.ImportSpec{ - Name: &ast.Ident{Name: i.newName}, - Path: &ast.BasicLit{Value: i.path}, - }) - } - - return &ast.GenDecl{ - Tok: token.IMPORT, - Specs: specs, - Lparen: token.NoPos + 1, - }, nil -} |