[arcmt] Merge 'removeEmptyStatements' and 'removeDeallocMethod' passes to cut down on one compilation
pass and increase migration speed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133540 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ARCMigrate/CMakeLists.txt b/lib/ARCMigrate/CMakeLists.txt
index 56db384..7e5fc13 100644
--- a/lib/ARCMigrate/CMakeLists.txt
+++ b/lib/ARCMigrate/CMakeLists.txt
@@ -8,7 +8,6 @@
   TransARCAssign.cpp
   TransAutoreleasePool.cpp
   TransBlockObjCVariable.cpp
-  TransDeallocMethod.cpp
   TransEmptyStatements.cpp
   TransformActions.cpp
   Transforms.cpp
diff --git a/lib/ARCMigrate/TransDeallocMethod.cpp b/lib/ARCMigrate/TransDeallocMethod.cpp
deleted file mode 100644
index a7c3c1e..0000000
--- a/lib/ARCMigrate/TransDeallocMethod.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-//===--- TransDeallocMethod.cpp - Tranformations to ARC mode --------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#include "Transforms.h"
-#include "Internals.h"
-
-using namespace clang;
-using namespace arcmt;
-using namespace trans;
-using llvm::StringRef;
-
-void trans::removeDeallocMethod(MigrationPass &pass) {
-  ASTContext &Ctx = pass.Ctx;
-  TransformActions &TA = pass.TA;
-  DeclContext *DC = Ctx.getTranslationUnitDecl();
-  ObjCMethodDecl *DeallocMethodDecl = 0;
-  IdentifierInfo *II = &Ctx.Idents.get("dealloc");
-
-  for (DeclContext::decl_iterator
-         I = DC->decls_begin(), E = DC->decls_end(); I != E; ++I) {
-    Decl *D = *I;
-    if (ObjCImplementationDecl *IMD = dyn_cast<ObjCImplementationDecl>(D)) {
-      DeallocMethodDecl = 0;
-      for (ObjCImplementationDecl::instmeth_iterator
-             I = IMD->instmeth_begin(), E = IMD->instmeth_end();
-          I != E; ++I) {
-        ObjCMethodDecl *OMD = *I;
-        if (OMD->isInstanceMethod() &&
-            OMD->getSelector() == Ctx.Selectors.getSelector(0, &II)) {
-          DeallocMethodDecl = OMD;
-          break;
-        }
-      }
-      if (DeallocMethodDecl && 
-          DeallocMethodDecl->getCompoundBody()->body_empty()) {
-        Transaction Trans(TA);
-        TA.remove(DeallocMethodDecl->getSourceRange());
-      }
-    }
-  }
-}
diff --git a/lib/ARCMigrate/TransEmptyStatements.cpp b/lib/ARCMigrate/TransEmptyStatements.cpp
deleted file mode 100644
index 1b62bbf..0000000
--- a/lib/ARCMigrate/TransEmptyStatements.cpp
+++ /dev/null
@@ -1,161 +0,0 @@
-//===--- TransEmptyStatements.cpp - Tranformations to ARC mode ------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// removeEmptyStatements:
-//
-// Removes empty statements that are leftovers from previous transformations.
-// e.g for
-//
-//  [x retain];
-//
-// removeRetainReleaseDealloc will leave an empty ";" that removeEmptyStatements
-// will remove.
-//
-//===----------------------------------------------------------------------===//
-
-#include "Transforms.h"
-#include "Internals.h"
-#include "clang/AST/StmtVisitor.h"
-
-using namespace clang;
-using namespace arcmt;
-using namespace trans;
-using llvm::StringRef;
-
-namespace {
-
-class EmptyStatementsRemover :
-                            public RecursiveASTVisitor<EmptyStatementsRemover> {
-  MigrationPass &Pass;
-  llvm::DenseSet<unsigned> MacroLocs;
-
-public:
-  EmptyStatementsRemover(MigrationPass &pass) : Pass(pass) {
-    for (unsigned i = 0, e = Pass.ARCMTMacroLocs.size(); i != e; ++i)
-      MacroLocs.insert(Pass.ARCMTMacroLocs[i].getRawEncoding());
-  }
-
-  bool TraverseStmtExpr(StmtExpr *E) {
-    CompoundStmt *S = E->getSubStmt();
-    for (CompoundStmt::body_iterator
-           I = S->body_begin(), E = S->body_end(); I != E; ++I) {
-      if (I != E - 1)
-        check(*I);
-      TraverseStmt(*I);
-    }
-    return true;
-  }
-
-  bool VisitCompoundStmt(CompoundStmt *S) {
-    for (CompoundStmt::body_iterator
-           I = S->body_begin(), E = S->body_end(); I != E; ++I)
-      check(*I);
-    return true;
-  }
-
-  bool isMacroLoc(SourceLocation loc) {
-    if (loc.isInvalid()) return false;
-    return MacroLocs.count(loc.getRawEncoding());
-  }
-
-  ASTContext &getContext() { return Pass.Ctx; }
-
-private:
-  /// \brief Returns true if the statement became empty due to previous
-  /// transformations.
-  class EmptyChecker : public StmtVisitor<EmptyChecker, bool> {
-    EmptyStatementsRemover &Trans;
-
-  public:
-    EmptyChecker(EmptyStatementsRemover &trans) : Trans(trans) { }
-
-    bool VisitNullStmt(NullStmt *S) {
-      return Trans.isMacroLoc(S->getLeadingEmptyMacroLoc());
-    }
-    bool VisitCompoundStmt(CompoundStmt *S) {
-      if (S->body_empty())
-        return false; // was already empty, not because of transformations.
-      for (CompoundStmt::body_iterator
-             I = S->body_begin(), E = S->body_end(); I != E; ++I)
-        if (!Visit(*I))
-          return false;
-      return true;
-    }
-    bool VisitIfStmt(IfStmt *S) {
-      if (S->getConditionVariable())
-        return false;
-      Expr *condE = S->getCond();
-      if (!condE)
-        return false;
-      if (hasSideEffects(condE, Trans.getContext()))
-        return false;
-      if (!S->getThen() || !Visit(S->getThen()))
-        return false;
-      if (S->getElse() && !Visit(S->getElse()))
-        return false;
-      return true;
-    }
-    bool VisitWhileStmt(WhileStmt *S) {
-      if (S->getConditionVariable())
-        return false;
-      Expr *condE = S->getCond();
-      if (!condE)
-        return false;
-      if (hasSideEffects(condE, Trans.getContext()))
-        return false;
-      if (!S->getBody())
-        return false;
-      return Visit(S->getBody());
-    }
-    bool VisitDoStmt(DoStmt *S) {
-      Expr *condE = S->getCond();
-      if (!condE)
-        return false;
-      if (hasSideEffects(condE, Trans.getContext()))
-        return false;
-      if (!S->getBody())
-        return false;
-      return Visit(S->getBody());
-    }
-    bool VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
-      Expr *Exp = S->getCollection();
-      if (!Exp)
-        return false;
-      if (hasSideEffects(Exp, Trans.getContext()))
-        return false;
-      if (!S->getBody())
-        return false;
-      return Visit(S->getBody());
-    }
-    bool VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
-      if (!S->getSubStmt())
-        return false;
-      return Visit(S->getSubStmt());
-    }
-  };
-
-  void check(Stmt *S) {
-    if (!S) return;
-    if (EmptyChecker(*this).Visit(S)) {
-      Transaction Trans(Pass.TA);
-      Pass.TA.removeStmt(S);
-    }
-  }
-};
-
-} // anonymous namespace
-
-void trans::removeEmptyStatements(MigrationPass &pass) {
-  EmptyStatementsRemover(pass).TraverseDecl(pass.Ctx.getTranslationUnitDecl());
-
-  for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i) {
-    Transaction Trans(pass.TA);
-    pass.TA.remove(pass.ARCMTMacroLocs[i]);
-  }
-}
diff --git a/lib/ARCMigrate/TransEmptyStatementsAndDealloc.cpp b/lib/ARCMigrate/TransEmptyStatementsAndDealloc.cpp
new file mode 100644
index 0000000..d0bc332
--- /dev/null
+++ b/lib/ARCMigrate/TransEmptyStatementsAndDealloc.cpp
@@ -0,0 +1,211 @@
+//===--- TransEmptyStatements.cpp - Tranformations to ARC mode ------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// removeEmptyStatementsAndDealloc:
+//
+// Removes empty statements that are leftovers from previous transformations.
+// e.g for
+//
+//  [x retain];
+//
+// removeRetainReleaseDealloc will leave an empty ";" that removeEmptyStatements
+// will remove.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Transforms.h"
+#include "Internals.h"
+#include "clang/AST/StmtVisitor.h"
+
+using namespace clang;
+using namespace arcmt;
+using namespace trans;
+using llvm::StringRef;
+
+namespace {
+
+/// \brief Returns true if the statement became empty due to previous
+/// transformations.
+class EmptyChecker : public StmtVisitor<EmptyChecker, bool> {
+  ASTContext &Ctx;
+  llvm::DenseSet<unsigned> &MacroLocs;
+
+public:
+  EmptyChecker(ASTContext &ctx, llvm::DenseSet<unsigned> &macroLocs)
+    : Ctx(ctx), MacroLocs(macroLocs) { }
+
+  bool VisitNullStmt(NullStmt *S) {
+    return isMacroLoc(S->getLeadingEmptyMacroLoc());
+  }
+  bool VisitCompoundStmt(CompoundStmt *S) {
+    if (S->body_empty())
+      return false; // was already empty, not because of transformations.
+    for (CompoundStmt::body_iterator
+           I = S->body_begin(), E = S->body_end(); I != E; ++I)
+      if (!Visit(*I))
+        return false;
+    return true;
+  }
+  bool VisitIfStmt(IfStmt *S) {
+    if (S->getConditionVariable())
+      return false;
+    Expr *condE = S->getCond();
+    if (!condE)
+      return false;
+    if (hasSideEffects(condE, Ctx))
+      return false;
+    if (!S->getThen() || !Visit(S->getThen()))
+      return false;
+    if (S->getElse() && !Visit(S->getElse()))
+      return false;
+    return true;
+  }
+  bool VisitWhileStmt(WhileStmt *S) {
+    if (S->getConditionVariable())
+      return false;
+    Expr *condE = S->getCond();
+    if (!condE)
+      return false;
+    if (hasSideEffects(condE, Ctx))
+      return false;
+    if (!S->getBody())
+      return false;
+    return Visit(S->getBody());
+  }
+  bool VisitDoStmt(DoStmt *S) {
+    Expr *condE = S->getCond();
+    if (!condE)
+      return false;
+    if (hasSideEffects(condE, Ctx))
+      return false;
+    if (!S->getBody())
+      return false;
+    return Visit(S->getBody());
+  }
+  bool VisitObjCForCollectionStmt(ObjCForCollectionStmt *S) {
+    Expr *Exp = S->getCollection();
+    if (!Exp)
+      return false;
+    if (hasSideEffects(Exp, Ctx))
+      return false;
+    if (!S->getBody())
+      return false;
+    return Visit(S->getBody());
+  }
+  bool VisitObjCAutoreleasePoolStmt(ObjCAutoreleasePoolStmt *S) {
+    if (!S->getSubStmt())
+      return false;
+    return Visit(S->getSubStmt());
+  }
+
+private:
+  bool isMacroLoc(SourceLocation loc) {
+    if (loc.isInvalid()) return false;
+    return MacroLocs.count(loc.getRawEncoding());
+  }
+};
+
+class EmptyStatementsRemover :
+                            public RecursiveASTVisitor<EmptyStatementsRemover> {
+  MigrationPass &Pass;
+  llvm::DenseSet<unsigned> &MacroLocs;
+
+public:
+  EmptyStatementsRemover(MigrationPass &pass,
+                         llvm::DenseSet<unsigned> &macroLocs)
+    : Pass(pass), MacroLocs(macroLocs) { }
+
+  bool TraverseStmtExpr(StmtExpr *E) {
+    CompoundStmt *S = E->getSubStmt();
+    for (CompoundStmt::body_iterator
+           I = S->body_begin(), E = S->body_end(); I != E; ++I) {
+      if (I != E - 1)
+        check(*I);
+      TraverseStmt(*I);
+    }
+    return true;
+  }
+
+  bool VisitCompoundStmt(CompoundStmt *S) {
+    for (CompoundStmt::body_iterator
+           I = S->body_begin(), E = S->body_end(); I != E; ++I)
+      check(*I);
+    return true;
+  }
+
+  bool isMacroLoc(SourceLocation loc) {
+    if (loc.isInvalid()) return false;
+    return MacroLocs.count(loc.getRawEncoding());
+  }
+
+  ASTContext &getContext() { return Pass.Ctx; }
+
+private:
+  void check(Stmt *S) {
+    if (!S) return;
+    if (EmptyChecker(Pass.Ctx, MacroLocs).Visit(S)) {
+      Transaction Trans(Pass.TA);
+      Pass.TA.removeStmt(S);
+    }
+  }
+};
+
+} // anonymous namespace
+
+static bool isBodyEmpty(CompoundStmt *body,
+                        ASTContext &Ctx, llvm::DenseSet<unsigned> &MacroLocs) {
+  for (CompoundStmt::body_iterator
+         I = body->body_begin(), E = body->body_end(); I != E; ++I)
+    if (!EmptyChecker(Ctx, MacroLocs).Visit(*I))
+      return false;
+
+  return true;
+}
+
+static void removeDeallocMethod(MigrationPass &pass,
+                                llvm::DenseSet<unsigned> &MacroLocs) {
+  ASTContext &Ctx = pass.Ctx;
+  TransformActions &TA = pass.TA;
+  DeclContext *DC = Ctx.getTranslationUnitDecl();
+
+  typedef DeclContext::specific_decl_iterator<ObjCImplementationDecl>
+    impl_iterator;
+  for (impl_iterator I = impl_iterator(DC->decls_begin()),
+                     E = impl_iterator(DC->decls_end()); I != E; ++I) {
+    for (ObjCImplementationDecl::instmeth_iterator
+           MI = (*I)->instmeth_begin(),
+           ME = (*I)->instmeth_end(); MI != ME; ++MI) {
+      ObjCMethodDecl *MD = *MI;
+      if (MD->getMethodFamily() == OMF_dealloc) {
+        if (MD->hasBody() &&
+            isBodyEmpty(MD->getCompoundBody(), Ctx, MacroLocs)) {
+          Transaction Trans(TA);
+          TA.remove(MD->getSourceRange());
+        }
+        break;
+      }
+    }
+  }
+}
+
+void trans::removeEmptyStatementsAndDealloc(MigrationPass &pass) {
+  llvm::DenseSet<unsigned> MacroLocs;
+  for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i)
+    MacroLocs.insert(pass.ARCMTMacroLocs[i].getRawEncoding());
+
+  EmptyStatementsRemover(pass, MacroLocs)
+    .TraverseDecl(pass.Ctx.getTranslationUnitDecl());
+
+  removeDeallocMethod(pass, MacroLocs);
+
+  for (unsigned i = 0, e = pass.ARCMTMacroLocs.size(); i != e; ++i) {
+    Transaction Trans(pass.TA);
+    pass.TA.remove(pass.ARCMTMacroLocs[i]);
+  }
+}
diff --git a/lib/ARCMigrate/Transforms.cpp b/lib/ARCMigrate/Transforms.cpp
index 0650e3b..3c2e3fc 100644
--- a/lib/ARCMigrate/Transforms.cpp
+++ b/lib/ARCMigrate/Transforms.cpp
@@ -224,12 +224,9 @@
 std::vector<TransformFn> arcmt::getAllTransformations() {
   std::vector<TransformFn> transforms;
 
-  // This must come first since rewriteAutoreleasePool depends on -release
-  // calls being present to determine the @autorelease ending scope.
   transforms.push_back(independentTransforms);
-
-  transforms.push_back(removeEmptyStatements);
-  transforms.push_back(removeDeallocMethod);
+  // This depends on previous transformations removing various expressions.
+  transforms.push_back(removeEmptyStatementsAndDealloc);
 
   return transforms;
 }
diff --git a/lib/ARCMigrate/Transforms.h b/lib/ARCMigrate/Transforms.h
index d95b1bc..6cc6085 100644
--- a/lib/ARCMigrate/Transforms.h
+++ b/lib/ARCMigrate/Transforms.h
@@ -34,13 +34,13 @@
 void rewriteAllocCopyWithZone(MigrationPass &pass);
 void makeAssignARCSafe(MigrationPass &pass);
 void removeRetainReleaseDealloc(MigrationPass &pass);
-void removeEmptyStatements(MigrationPass &pass);
 void removeZeroOutPropsInDealloc(MigrationPass &pass);
 void changeIvarsOfAssignProperties(MigrationPass &pass);
 void rewriteBlockObjCVariable(MigrationPass &pass);
-void removeDeallocMethod(MigrationPass &pass);
 void rewriteUnusedInitDelegate(MigrationPass &pass);
 
+void removeEmptyStatementsAndDealloc(MigrationPass &pass);
+
 //===----------------------------------------------------------------------===//
 // Helpers.
 //===----------------------------------------------------------------------===//