1 //===--- TransEmptyStatements.cpp - Transformations to ARC mode -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // removeEmptyStatementsAndDealloc:
12 // Removes empty statements that are leftovers from previous transformations.
17 // removeRetainReleaseDealloc will leave an empty ";" that removeEmptyStatements
20 //===----------------------------------------------------------------------===//
22 #include "Transforms.h"
23 #include "Internals.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/StmtVisitor.h"
26 #include "clang/Basic/SourceManager.h"
28 using namespace clang;
29 using namespace arcmt;
30 using namespace trans;
32 static bool isEmptyARCMTMacroStatement(NullStmt *S,
33 std::vector<SourceLocation> &MacroLocs,
35 if (!S->hasLeadingEmptyMacro())
38 SourceLocation SemiLoc = S->getSemiLoc();
39 if (SemiLoc.isInvalid() || SemiLoc.isMacroID())
42 if (MacroLocs.empty())
45 SourceManager &SM = Ctx.getSourceManager();
46 std::vector<SourceLocation>::iterator
47 I = std::upper_bound(MacroLocs.begin(), MacroLocs.end(), SemiLoc,
48 BeforeThanCompare<SourceLocation>(SM));
51 AfterMacroLoc = I->getLocWithOffset(getARCMTMacroName().size());
52 assert(AfterMacroLoc.isFileID());
54 if (AfterMacroLoc == SemiLoc)
58 if (!SM.isInSameSLocAddrSpace(AfterMacroLoc, SemiLoc, &RelOffs))
63 // We make the reasonable assumption that a semicolon after 100 characters
64 // means that it is not the next token after our macro. If this assumption
65 // fails it is not critical, we will just fail to clear out, e.g., an empty
67 if (RelOffs - getARCMTMacroName().size() > 100)
70 SourceLocation AfterMacroSemiLoc = findSemiAfterLocation(AfterMacroLoc, Ctx);
71 return AfterMacroSemiLoc == SemiLoc;
76 /// \brief Returns true if the statement became empty due to previous
78 class EmptyChecker : public StmtVisitor<EmptyChecker, bool> {
80 std::vector<SourceLocation> &MacroLocs;
83 EmptyChecker(ASTContext &ctx, std::vector<SourceLocation> ¯oLocs)
84 : Ctx(ctx), MacroLocs(macroLocs) { }
86 bool VisitNullStmt(NullStmt *S) {
87 return isEmptyARCMTMacroStatement(S, MacroLocs, Ctx);
89 bool VisitCompoundStmt(CompoundStmt *S) {
91 return false; // was already empty, not because of transformations.
92 for (auto *I : S->body())
97 bool VisitIfStmt(IfStmt *S) {
98 if (S->getConditionVariable())
100 Expr *condE = S->getCond();
103 if (hasSideEffects(condE, Ctx))
105 if (!S->getThen() || !Visit(S->getThen()))
107 return !S->getElse() || Visit(S->getElse());
109 bool VisitWhileStmt(WhileStmt *S) {
110 if (S->getConditionVariable())
112 Expr *condE = S->getCond();
115 if (hasSideEffects(condE, Ctx))
119 return Visit(S->getBody());
121 bool VisitDoStmt(DoStmt *S) {
122 Expr *condE = S->getCond();
125 if (hasSideEffects(condE, Ctx))
129 return Visit(S->getBody());
131 bool VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
132 Expr *Exp = S->getCollection();
135 if (hasSideEffects(Exp, Ctx))
139 return Visit(S->getBody());
141 bool VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
142 if (!S->getSubStmt())
144 return Visit(S->getSubStmt());
148 class EmptyStatementsRemover :
149 public RecursiveASTVisitor<EmptyStatementsRemover> {
153 EmptyStatementsRemover(MigrationPass &pass) : Pass(pass) { }
155 bool TraverseStmtExpr(StmtExpr *E) {
156 CompoundStmt *S = E->getSubStmt();
157 for (CompoundStmt::body_iterator
158 I = S->body_begin(), E = S->body_end(); I != E; ++I) {
166 bool VisitCompoundStmt(CompoundStmt *S) {
167 for (auto *I : S->body())
172 ASTContext &getContext() { return Pass.Ctx; }
175 void check(Stmt *S) {
177 if (EmptyChecker(Pass.Ctx, Pass.ARCMTMacroLocs).Visit(S)) {
178 Transaction Trans(Pass.TA);
179 Pass.TA.removeStmt(S);
184 } // anonymous namespace
186 static bool isBodyEmpty(CompoundStmt *body, ASTContext &Ctx,
187 std::vector<SourceLocation> &MacroLocs) {
188 for (auto *I : body->body())
189 if (!EmptyChecker(Ctx, MacroLocs).Visit(I))
195 static void cleanupDeallocOrFinalize(MigrationPass &pass) {
196 ASTContext &Ctx = pass.Ctx;
197 TransformActions &TA = pass.TA;
198 DeclContext *DC = Ctx.getTranslationUnitDecl();
199 Selector FinalizeSel =
200 Ctx.Selectors.getNullarySelector(&pass.Ctx.Idents.get("finalize"));
202 typedef DeclContext::specific_decl_iterator<ObjCImplementationDecl>
204 for (impl_iterator I = impl_iterator(DC->decls_begin()),
205 E = impl_iterator(DC->decls_end()); I != E; ++I) {
206 ObjCMethodDecl *DeallocM = nullptr;
207 ObjCMethodDecl *FinalizeM = nullptr;
208 for (auto *MD : I->instance_methods()) {
212 if (MD->getMethodFamily() == OMF_dealloc) {
214 } else if (MD->isInstanceMethod() && MD->getSelector() == FinalizeSel) {
220 if (isBodyEmpty(DeallocM->getCompoundBody(), Ctx, pass.ARCMTMacroLocs)) {
221 Transaction Trans(TA);
222 TA.remove(DeallocM->getSourceRange());
226 Transaction Trans(TA);
227 TA.remove(FinalizeM->getSourceRange());
230 } else if (FinalizeM) {
231 if (isBodyEmpty(FinalizeM->getCompoundBody(), Ctx, pass.ARCMTMacroLocs)) {
232 Transaction Trans(TA);
233 TA.remove(FinalizeM->getSourceRange());
235 Transaction Trans(TA);
236 TA.replaceText(FinalizeM->getSelectorStartLoc(), "finalize", "dealloc");
242 void trans::removeEmptyStatementsAndDeallocFinalize(MigrationPass &pass) {
243 EmptyStatementsRemover(pass).TraverseDecl(pass.Ctx.getTranslationUnitDecl());
245 cleanupDeallocOrFinalize(pass);
247 for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i) {
248 Transaction Trans(pass.TA);
249 pass.TA.remove(pass.ARCMTMacroLocs[i]);