1 //===--- TransEmptyStatements.cpp - Tranformations 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/StmtVisitor.h"
26 using namespace clang;
27 using namespace arcmt;
28 using namespace trans;
29 using llvm::StringRef;
33 /// \brief Returns true if the statement became empty due to previous
35 class EmptyChecker : public StmtVisitor<EmptyChecker, bool> {
37 llvm::DenseSet<unsigned> &MacroLocs;
40 EmptyChecker(ASTContext &ctx, llvm::DenseSet<unsigned> ¯oLocs)
41 : Ctx(ctx), MacroLocs(macroLocs) { }
43 bool VisitNullStmt(NullStmt *S) {
44 return isMacroLoc(S->getLeadingEmptyMacroLoc());
46 bool VisitCompoundStmt(CompoundStmt *S) {
48 return false; // was already empty, not because of transformations.
49 for (CompoundStmt::body_iterator
50 I = S->body_begin(), E = S->body_end(); I != E; ++I)
55 bool VisitIfStmt(IfStmt *S) {
56 if (S->getConditionVariable())
58 Expr *condE = S->getCond();
61 if (hasSideEffects(condE, Ctx))
63 if (!S->getThen() || !Visit(S->getThen()))
65 if (S->getElse() && !Visit(S->getElse()))
69 bool VisitWhileStmt(WhileStmt *S) {
70 if (S->getConditionVariable())
72 Expr *condE = S->getCond();
75 if (hasSideEffects(condE, Ctx))
79 return Visit(S->getBody());
81 bool VisitDoStmt(DoStmt *S) {
82 Expr *condE = S->getCond();
85 if (hasSideEffects(condE, Ctx))
89 return Visit(S->getBody());
91 bool VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
92 Expr *Exp = S->getCollection();
95 if (hasSideEffects(Exp, Ctx))
99 return Visit(S->getBody());
101 bool VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
102 if (!S->getSubStmt())
104 return Visit(S->getSubStmt());
108 bool isMacroLoc(SourceLocation loc) {
109 if (loc.isInvalid()) return false;
110 return MacroLocs.count(loc.getRawEncoding());
114 class EmptyStatementsRemover :
115 public RecursiveASTVisitor<EmptyStatementsRemover> {
117 llvm::DenseSet<unsigned> &MacroLocs;
120 EmptyStatementsRemover(MigrationPass &pass,
121 llvm::DenseSet<unsigned> ¯oLocs)
122 : Pass(pass), MacroLocs(macroLocs) { }
124 bool TraverseStmtExpr(StmtExpr *E) {
125 CompoundStmt *S = E->getSubStmt();
126 for (CompoundStmt::body_iterator
127 I = S->body_begin(), E = S->body_end(); I != E; ++I) {
135 bool VisitCompoundStmt(CompoundStmt *S) {
136 for (CompoundStmt::body_iterator
137 I = S->body_begin(), E = S->body_end(); I != E; ++I)
142 bool isMacroLoc(SourceLocation loc) {
143 if (loc.isInvalid()) return false;
144 return MacroLocs.count(loc.getRawEncoding());
147 ASTContext &getContext() { return Pass.Ctx; }
150 void check(Stmt *S) {
152 if (EmptyChecker(Pass.Ctx, MacroLocs).Visit(S)) {
153 Transaction Trans(Pass.TA);
154 Pass.TA.removeStmt(S);
159 } // anonymous namespace
161 static bool isBodyEmpty(CompoundStmt *body,
162 ASTContext &Ctx, llvm::DenseSet<unsigned> &MacroLocs) {
163 for (CompoundStmt::body_iterator
164 I = body->body_begin(), E = body->body_end(); I != E; ++I)
165 if (!EmptyChecker(Ctx, MacroLocs).Visit(*I))
171 static void removeDeallocMethod(MigrationPass &pass,
172 llvm::DenseSet<unsigned> &MacroLocs) {
173 ASTContext &Ctx = pass.Ctx;
174 TransformActions &TA = pass.TA;
175 DeclContext *DC = Ctx.getTranslationUnitDecl();
177 typedef DeclContext::specific_decl_iterator<ObjCImplementationDecl>
179 for (impl_iterator I = impl_iterator(DC->decls_begin()),
180 E = impl_iterator(DC->decls_end()); I != E; ++I) {
181 for (ObjCImplementationDecl::instmeth_iterator
182 MI = (*I)->instmeth_begin(),
183 ME = (*I)->instmeth_end(); MI != ME; ++MI) {
184 ObjCMethodDecl *MD = *MI;
185 if (MD->getMethodFamily() == OMF_dealloc) {
187 isBodyEmpty(MD->getCompoundBody(), Ctx, MacroLocs)) {
188 Transaction Trans(TA);
189 TA.remove(MD->getSourceRange());
197 void trans::removeEmptyStatementsAndDealloc(MigrationPass &pass) {
198 llvm::DenseSet<unsigned> MacroLocs;
199 for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i)
200 MacroLocs.insert(pass.ARCMTMacroLocs[i].getRawEncoding());
202 EmptyStatementsRemover(pass, MacroLocs)
203 .TraverseDecl(pass.Ctx.getTranslationUnitDecl());
205 removeDeallocMethod(pass, MacroLocs);
207 for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i) {
208 Transaction Trans(pass.TA);
209 pass.TA.remove(pass.ARCMTMacroLocs[i]);