| 1 | //===--- TransUnusedInitDelegate.cpp - Transformations to ARC mode --------===// |
|---|---|
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // Transformations: |
| 9 | //===----------------------------------------------------------------------===// |
| 10 | // |
| 11 | // rewriteUnusedInitDelegate: |
| 12 | // |
| 13 | // Rewrites an unused result of calling a delegate initialization, to assigning |
| 14 | // the result to self. |
| 15 | // e.g |
| 16 | // [self init]; |
| 17 | // ----> |
| 18 | // self = [self init]; |
| 19 | // |
| 20 | //===----------------------------------------------------------------------===// |
| 21 | |
| 22 | #include "Transforms.h" |
| 23 | #include "Internals.h" |
| 24 | #include "clang/AST/ASTContext.h" |
| 25 | #include "clang/Sema/SemaDiagnostic.h" |
| 26 | |
| 27 | using namespace clang; |
| 28 | using namespace arcmt; |
| 29 | using namespace trans; |
| 30 | |
| 31 | namespace { |
| 32 | |
| 33 | class UnusedInitRewriter : public RecursiveASTVisitor<UnusedInitRewriter> { |
| 34 | Stmt *Body; |
| 35 | MigrationPass &Pass; |
| 36 | |
| 37 | ExprSet Removables; |
| 38 | |
| 39 | public: |
| 40 | UnusedInitRewriter(MigrationPass &pass) |
| 41 | : Body(nullptr), Pass(pass) { } |
| 42 | |
| 43 | void transformBody(Stmt *body, Decl *ParentD) { |
| 44 | Body = body; |
| 45 | collectRemovables(S: body, exprs&: Removables); |
| 46 | TraverseStmt(body); |
| 47 | } |
| 48 | |
| 49 | bool VisitObjCMessageExpr(ObjCMessageExpr *ME) { |
| 50 | if (ME->isDelegateInitCall() && |
| 51 | isRemovable(ME) && |
| 52 | Pass.TA.hasDiagnostic(diag::err_arc_unused_init_message, |
| 53 | ME->getExprLoc())) { |
| 54 | Transaction Trans(Pass.TA); |
| 55 | Pass.TA.clearDiagnostic(diag::err_arc_unused_init_message, |
| 56 | ME->getExprLoc()); |
| 57 | SourceRange ExprRange = ME->getSourceRange(); |
| 58 | Pass.TA.insert(loc: ExprRange.getBegin(), text: "if (!(self = "); |
| 59 | std::string retStr = ")) return "; |
| 60 | retStr += getNilString(Pass); |
| 61 | Pass.TA.insertAfterToken(loc: ExprRange.getEnd(), text: retStr); |
| 62 | } |
| 63 | return true; |
| 64 | } |
| 65 | |
| 66 | private: |
| 67 | bool isRemovable(Expr *E) const { |
| 68 | return Removables.count(E); |
| 69 | } |
| 70 | }; |
| 71 | |
| 72 | } // anonymous namespace |
| 73 | |
| 74 | void trans::rewriteUnusedInitDelegate(MigrationPass &pass) { |
| 75 | BodyTransform<UnusedInitRewriter> trans(pass); |
| 76 | trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl()); |
| 77 | } |
| 78 |