1//===--- TransARCAssign.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//
9// makeAssignARCSafe:
10//
11// Add '__strong' where appropriate.
12//
13// for (id x in collection) {
14// x = 0;
15// }
16// ---->
17// for (__strong id x in collection) {
18// x = 0;
19// }
20//
21//===----------------------------------------------------------------------===//
22
23#include "Transforms.h"
24#include "Internals.h"
25#include "clang/AST/ASTContext.h"
26#include "clang/Sema/SemaDiagnostic.h"
27
28using namespace clang;
29using namespace arcmt;
30using namespace trans;
31
32namespace {
33
34class ARCAssignChecker : public RecursiveASTVisitor<ARCAssignChecker> {
35 MigrationPass &Pass;
36 llvm::DenseSet<VarDecl *> ModifiedVars;
37
38public:
39 ARCAssignChecker(MigrationPass &pass) : Pass(pass) { }
40
41 bool VisitBinaryOperator(BinaryOperator *Exp) {
42 if (Exp->getType()->isDependentType())
43 return true;
44
45 Expr *E = Exp->getLHS();
46 SourceLocation OrigLoc = E->getExprLoc();
47 SourceLocation Loc = OrigLoc;
48 DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(Val: E->IgnoreParenCasts());
49 if (declRef && isa<VarDecl>(Val: declRef->getDecl())) {
50 ASTContext &Ctx = Pass.Ctx;
51 Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(Ctx, Loc: &Loc);
52 if (IsLV != Expr::MLV_ConstQualified)
53 return true;
54 VarDecl *var = cast<VarDecl>(Val: declRef->getDecl());
55 if (var->isARCPseudoStrong()) {
56 Transaction Trans(Pass.TA);
57 if (Pass.TA.clearDiagnostic(IDs: diag::err_typecheck_arr_assign_enumeration,
58 range: Exp->getOperatorLoc())) {
59 if (!ModifiedVars.count(V: var)) {
60 TypeLoc TLoc = var->getTypeSourceInfo()->getTypeLoc();
61 Pass.TA.insert(loc: TLoc.getBeginLoc(), text: "__strong ");
62 ModifiedVars.insert(V: var);
63 }
64 }
65 }
66 }
67
68 return true;
69 }
70};
71
72} // anonymous namespace
73
74void trans::makeAssignARCSafe(MigrationPass &pass) {
75 ARCAssignChecker assignCheck(pass);
76 assignCheck.TraverseDecl(D: pass.Ctx.getTranslationUnitDecl());
77}
78