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      1 /*
      2  * Copyright 2010, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "slang_rs_object_ref_count.h"
     18 
     19 #include <list>
     20 
     21 #include "clang/AST/DeclGroup.h"
     22 #include "clang/AST/Expr.h"
     23 #include "clang/AST/NestedNameSpecifier.h"
     24 #include "clang/AST/OperationKinds.h"
     25 #include "clang/AST/Stmt.h"
     26 #include "clang/AST/StmtVisitor.h"
     27 
     28 #include "slang_assert.h"
     29 #include "slang_rs.h"
     30 #include "slang_rs_ast_replace.h"
     31 #include "slang_rs_export_type.h"
     32 
     33 namespace slang {
     34 
     35 /* Even though those two arrays are of size DataTypeMax, only entries that
     36  * correspond to object types will be set.
     37  */
     38 clang::FunctionDecl *
     39 RSObjectRefCount::RSSetObjectFD[DataTypeMax];
     40 clang::FunctionDecl *
     41 RSObjectRefCount::RSClearObjectFD[DataTypeMax];
     42 
     43 void RSObjectRefCount::GetRSRefCountingFunctions(clang::ASTContext &C) {
     44   for (unsigned i = 0; i < DataTypeMax; i++) {
     45     RSSetObjectFD[i] = NULL;
     46     RSClearObjectFD[i] = NULL;
     47   }
     48 
     49   clang::TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
     50 
     51   for (clang::DeclContext::decl_iterator I = TUDecl->decls_begin(),
     52           E = TUDecl->decls_end(); I != E; I++) {
     53     if ((I->getKind() >= clang::Decl::firstFunction) &&
     54         (I->getKind() <= clang::Decl::lastFunction)) {
     55       clang::FunctionDecl *FD = static_cast<clang::FunctionDecl*>(*I);
     56 
     57       // points to RSSetObjectFD or RSClearObjectFD
     58       clang::FunctionDecl **RSObjectFD;
     59 
     60       if (FD->getName() == "rsSetObject") {
     61         slangAssert((FD->getNumParams() == 2) &&
     62                     "Invalid rsSetObject function prototype (# params)");
     63         RSObjectFD = RSSetObjectFD;
     64       } else if (FD->getName() == "rsClearObject") {
     65         slangAssert((FD->getNumParams() == 1) &&
     66                     "Invalid rsClearObject function prototype (# params)");
     67         RSObjectFD = RSClearObjectFD;
     68       } else {
     69         continue;
     70       }
     71 
     72       const clang::ParmVarDecl *PVD = FD->getParamDecl(0);
     73       clang::QualType PVT = PVD->getOriginalType();
     74       // The first parameter must be a pointer like rs_allocation*
     75       slangAssert(PVT->isPointerType() &&
     76           "Invalid rs{Set,Clear}Object function prototype (pointer param)");
     77 
     78       // The rs object type passed to the FD
     79       clang::QualType RST = PVT->getPointeeType();
     80       DataType DT = RSExportPrimitiveType::GetRSSpecificType(RST.getTypePtr());
     81       slangAssert(RSExportPrimitiveType::IsRSObjectType(DT)
     82              && "must be RS object type");
     83 
     84       if (DT >= 0 && DT < DataTypeMax) {
     85           RSObjectFD[DT] = FD;
     86       } else {
     87           slangAssert(false && "incorrect type");
     88       }
     89     }
     90   }
     91 }
     92 
     93 namespace {
     94 
     95 // This function constructs a new CompoundStmt from the input StmtList.
     96 static clang::CompoundStmt* BuildCompoundStmt(clang::ASTContext &C,
     97       std::list<clang::Stmt*> &StmtList, clang::SourceLocation Loc) {
     98   unsigned NewStmtCount = StmtList.size();
     99   unsigned CompoundStmtCount = 0;
    100 
    101   clang::Stmt **CompoundStmtList;
    102   CompoundStmtList = new clang::Stmt*[NewStmtCount];
    103 
    104   std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    105   std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    106   for ( ; I != E; I++) {
    107     CompoundStmtList[CompoundStmtCount++] = *I;
    108   }
    109   slangAssert(CompoundStmtCount == NewStmtCount);
    110 
    111   clang::CompoundStmt *CS = new(C) clang::CompoundStmt(
    112       C, llvm::makeArrayRef(CompoundStmtList, CompoundStmtCount), Loc, Loc);
    113 
    114   delete [] CompoundStmtList;
    115 
    116   return CS;
    117 }
    118 
    119 static void AppendAfterStmt(clang::ASTContext &C,
    120                             clang::CompoundStmt *CS,
    121                             clang::Stmt *S,
    122                             std::list<clang::Stmt*> &StmtList) {
    123   slangAssert(CS);
    124   clang::CompoundStmt::body_iterator bI = CS->body_begin();
    125   clang::CompoundStmt::body_iterator bE = CS->body_end();
    126   clang::Stmt **UpdatedStmtList =
    127       new clang::Stmt*[CS->size() + StmtList.size()];
    128 
    129   unsigned UpdatedStmtCount = 0;
    130   unsigned Once = 0;
    131   for ( ; bI != bE; bI++) {
    132     if (!S && ((*bI)->getStmtClass() == clang::Stmt::ReturnStmtClass)) {
    133       // If we come across a return here, we don't have anything we can
    134       // reasonably replace. We should have already inserted our destructor
    135       // code in the proper spot, so we just clean up and return.
    136       delete [] UpdatedStmtList;
    137 
    138       return;
    139     }
    140 
    141     UpdatedStmtList[UpdatedStmtCount++] = *bI;
    142 
    143     if ((*bI == S) && !Once) {
    144       Once++;
    145       std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    146       std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    147       for ( ; I != E; I++) {
    148         UpdatedStmtList[UpdatedStmtCount++] = *I;
    149       }
    150     }
    151   }
    152   slangAssert(Once <= 1);
    153 
    154   // When S is NULL, we are appending to the end of the CompoundStmt.
    155   if (!S) {
    156     slangAssert(Once == 0);
    157     std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    158     std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    159     for ( ; I != E; I++) {
    160       UpdatedStmtList[UpdatedStmtCount++] = *I;
    161     }
    162   }
    163 
    164   CS->setStmts(C, UpdatedStmtList, UpdatedStmtCount);
    165 
    166   delete [] UpdatedStmtList;
    167 }
    168 
    169 // This class visits a compound statement and inserts DtorStmt
    170 // in proper locations. This includes inserting it before any
    171 // return statement in any sub-block, at the end of the logical enclosing
    172 // scope (compound statement), and/or before any break/continue statement that
    173 // would resume outside the declared scope. We will not handle the case for
    174 // goto statements that leave a local scope.
    175 //
    176 // To accomplish these goals, it collects a list of sub-Stmt's that
    177 // correspond to scope exit points. It then uses an RSASTReplace visitor to
    178 // transform the AST, inserting appropriate destructors before each of those
    179 // sub-Stmt's (and also before the exit of the outermost containing Stmt for
    180 // the scope).
    181 class DestructorVisitor : public clang::StmtVisitor<DestructorVisitor> {
    182  private:
    183   clang::ASTContext &mCtx;
    184 
    185   // The loop depth of the currently visited node.
    186   int mLoopDepth;
    187 
    188   // The switch statement depth of the currently visited node.
    189   // Note that this is tracked separately from the loop depth because
    190   // SwitchStmt-contained ContinueStmt's should have destructors for the
    191   // corresponding loop scope.
    192   int mSwitchDepth;
    193 
    194   // The outermost statement block that we are currently visiting.
    195   // This should always be a CompoundStmt.
    196   clang::Stmt *mOuterStmt;
    197 
    198   // The destructor to execute for this scope/variable.
    199   clang::Stmt* mDtorStmt;
    200 
    201   // The stack of statements which should be replaced by a compound statement
    202   // containing the new destructor call followed by the original Stmt.
    203   std::stack<clang::Stmt*> mReplaceStmtStack;
    204 
    205   // The source location for the variable declaration that we are trying to
    206   // insert destructors for. Note that InsertDestructors() will not generate
    207   // destructor calls for source locations that occur lexically before this
    208   // location.
    209   clang::SourceLocation mVarLoc;
    210 
    211  public:
    212   DestructorVisitor(clang::ASTContext &C,
    213                     clang::Stmt* OuterStmt,
    214                     clang::Stmt* DtorStmt,
    215                     clang::SourceLocation VarLoc);
    216 
    217   // This code walks the collected list of Stmts to replace and actually does
    218   // the replacement. It also finishes up by appending the destructor to the
    219   // current outermost CompoundStmt.
    220   void InsertDestructors() {
    221     clang::Stmt *S = NULL;
    222     clang::SourceManager &SM = mCtx.getSourceManager();
    223     std::list<clang::Stmt *> StmtList;
    224     StmtList.push_back(mDtorStmt);
    225 
    226     while (!mReplaceStmtStack.empty()) {
    227       S = mReplaceStmtStack.top();
    228       mReplaceStmtStack.pop();
    229 
    230       // Skip all source locations that occur before the variable's
    231       // declaration, since it won't have been initialized yet.
    232       if (SM.isBeforeInTranslationUnit(S->getLocStart(), mVarLoc)) {
    233         continue;
    234       }
    235 
    236       StmtList.push_back(S);
    237       clang::CompoundStmt *CS =
    238           BuildCompoundStmt(mCtx, StmtList, S->getLocEnd());
    239       StmtList.pop_back();
    240 
    241       RSASTReplace R(mCtx);
    242       R.ReplaceStmt(mOuterStmt, S, CS);
    243     }
    244     clang::CompoundStmt *CS =
    245       llvm::dyn_cast<clang::CompoundStmt>(mOuterStmt);
    246     slangAssert(CS);
    247     AppendAfterStmt(mCtx, CS, NULL, StmtList);
    248   }
    249 
    250   void VisitStmt(clang::Stmt *S);
    251   void VisitCompoundStmt(clang::CompoundStmt *CS);
    252 
    253   void VisitBreakStmt(clang::BreakStmt *BS);
    254   void VisitCaseStmt(clang::CaseStmt *CS);
    255   void VisitContinueStmt(clang::ContinueStmt *CS);
    256   void VisitDefaultStmt(clang::DefaultStmt *DS);
    257   void VisitDoStmt(clang::DoStmt *DS);
    258   void VisitForStmt(clang::ForStmt *FS);
    259   void VisitIfStmt(clang::IfStmt *IS);
    260   void VisitReturnStmt(clang::ReturnStmt *RS);
    261   void VisitSwitchCase(clang::SwitchCase *SC);
    262   void VisitSwitchStmt(clang::SwitchStmt *SS);
    263   void VisitWhileStmt(clang::WhileStmt *WS);
    264 };
    265 
    266 DestructorVisitor::DestructorVisitor(clang::ASTContext &C,
    267                          clang::Stmt *OuterStmt,
    268                          clang::Stmt *DtorStmt,
    269                          clang::SourceLocation VarLoc)
    270   : mCtx(C),
    271     mLoopDepth(0),
    272     mSwitchDepth(0),
    273     mOuterStmt(OuterStmt),
    274     mDtorStmt(DtorStmt),
    275     mVarLoc(VarLoc) {
    276 }
    277 
    278 void DestructorVisitor::VisitStmt(clang::Stmt *S) {
    279   for (clang::Stmt::child_iterator I = S->child_begin(), E = S->child_end();
    280        I != E;
    281        I++) {
    282     if (clang::Stmt *Child = *I) {
    283       Visit(Child);
    284     }
    285   }
    286 }
    287 
    288 void DestructorVisitor::VisitCompoundStmt(clang::CompoundStmt *CS) {
    289   VisitStmt(CS);
    290 }
    291 
    292 void DestructorVisitor::VisitBreakStmt(clang::BreakStmt *BS) {
    293   VisitStmt(BS);
    294   if ((mLoopDepth == 0) && (mSwitchDepth == 0)) {
    295     mReplaceStmtStack.push(BS);
    296   }
    297 }
    298 
    299 void DestructorVisitor::VisitCaseStmt(clang::CaseStmt *CS) {
    300   VisitStmt(CS);
    301 }
    302 
    303 void DestructorVisitor::VisitContinueStmt(clang::ContinueStmt *CS) {
    304   VisitStmt(CS);
    305   if (mLoopDepth == 0) {
    306     // Switch statements can have nested continues.
    307     mReplaceStmtStack.push(CS);
    308   }
    309 }
    310 
    311 void DestructorVisitor::VisitDefaultStmt(clang::DefaultStmt *DS) {
    312   VisitStmt(DS);
    313 }
    314 
    315 void DestructorVisitor::VisitDoStmt(clang::DoStmt *DS) {
    316   mLoopDepth++;
    317   VisitStmt(DS);
    318   mLoopDepth--;
    319 }
    320 
    321 void DestructorVisitor::VisitForStmt(clang::ForStmt *FS) {
    322   mLoopDepth++;
    323   VisitStmt(FS);
    324   mLoopDepth--;
    325 }
    326 
    327 void DestructorVisitor::VisitIfStmt(clang::IfStmt *IS) {
    328   VisitStmt(IS);
    329 }
    330 
    331 void DestructorVisitor::VisitReturnStmt(clang::ReturnStmt *RS) {
    332   mReplaceStmtStack.push(RS);
    333 }
    334 
    335 void DestructorVisitor::VisitSwitchCase(clang::SwitchCase *SC) {
    336   slangAssert(false && "Both case and default have specialized handlers");
    337   VisitStmt(SC);
    338 }
    339 
    340 void DestructorVisitor::VisitSwitchStmt(clang::SwitchStmt *SS) {
    341   mSwitchDepth++;
    342   VisitStmt(SS);
    343   mSwitchDepth--;
    344 }
    345 
    346 void DestructorVisitor::VisitWhileStmt(clang::WhileStmt *WS) {
    347   mLoopDepth++;
    348   VisitStmt(WS);
    349   mLoopDepth--;
    350 }
    351 
    352 clang::Expr *ClearSingleRSObject(clang::ASTContext &C,
    353                                  clang::Expr *RefRSVar,
    354                                  clang::SourceLocation Loc) {
    355   slangAssert(RefRSVar);
    356   const clang::Type *T = RefRSVar->getType().getTypePtr();
    357   slangAssert(!T->isArrayType() &&
    358               "Should not be destroying arrays with this function");
    359 
    360   clang::FunctionDecl *ClearObjectFD = RSObjectRefCount::GetRSClearObjectFD(T);
    361   slangAssert((ClearObjectFD != NULL) &&
    362               "rsClearObject doesn't cover all RS object types");
    363 
    364   clang::QualType ClearObjectFDType = ClearObjectFD->getType();
    365   clang::QualType ClearObjectFDArgType =
    366       ClearObjectFD->getParamDecl(0)->getOriginalType();
    367 
    368   // Example destructor for "rs_font localFont;"
    369   //
    370   // (CallExpr 'void'
    371   //   (ImplicitCastExpr 'void (*)(rs_font *)' <FunctionToPointerDecay>
    372   //     (DeclRefExpr 'void (rs_font *)' FunctionDecl='rsClearObject'))
    373   //   (UnaryOperator 'rs_font *' prefix '&'
    374   //     (DeclRefExpr 'rs_font':'rs_font' Var='localFont')))
    375 
    376   // Get address of targeted RS object
    377   clang::Expr *AddrRefRSVar =
    378       new(C) clang::UnaryOperator(RefRSVar,
    379                                   clang::UO_AddrOf,
    380                                   ClearObjectFDArgType,
    381                                   clang::VK_RValue,
    382                                   clang::OK_Ordinary,
    383                                   Loc);
    384 
    385   clang::Expr *RefRSClearObjectFD =
    386       clang::DeclRefExpr::Create(C,
    387                                  clang::NestedNameSpecifierLoc(),
    388                                  clang::SourceLocation(),
    389                                  ClearObjectFD,
    390                                  false,
    391                                  ClearObjectFD->getLocation(),
    392                                  ClearObjectFDType,
    393                                  clang::VK_RValue,
    394                                  NULL);
    395 
    396   clang::Expr *RSClearObjectFP =
    397       clang::ImplicitCastExpr::Create(C,
    398                                       C.getPointerType(ClearObjectFDType),
    399                                       clang::CK_FunctionToPointerDecay,
    400                                       RefRSClearObjectFD,
    401                                       NULL,
    402                                       clang::VK_RValue);
    403 
    404   llvm::SmallVector<clang::Expr*, 1> ArgList;
    405   ArgList.push_back(AddrRefRSVar);
    406 
    407   clang::CallExpr *RSClearObjectCall =
    408       new(C) clang::CallExpr(C,
    409                              RSClearObjectFP,
    410                              ArgList,
    411                              ClearObjectFD->getCallResultType(),
    412                              clang::VK_RValue,
    413                              Loc);
    414 
    415   return RSClearObjectCall;
    416 }
    417 
    418 static int ArrayDim(const clang::Type *T) {
    419   if (!T || !T->isArrayType()) {
    420     return 0;
    421   }
    422 
    423   const clang::ConstantArrayType *CAT =
    424     static_cast<const clang::ConstantArrayType *>(T);
    425   return static_cast<int>(CAT->getSize().getSExtValue());
    426 }
    427 
    428 static clang::Stmt *ClearStructRSObject(
    429     clang::ASTContext &C,
    430     clang::DeclContext *DC,
    431     clang::Expr *RefRSStruct,
    432     clang::SourceLocation StartLoc,
    433     clang::SourceLocation Loc);
    434 
    435 static clang::Stmt *ClearArrayRSObject(
    436     clang::ASTContext &C,
    437     clang::DeclContext *DC,
    438     clang::Expr *RefRSArr,
    439     clang::SourceLocation StartLoc,
    440     clang::SourceLocation Loc) {
    441   const clang::Type *BaseType = RefRSArr->getType().getTypePtr();
    442   slangAssert(BaseType->isArrayType());
    443 
    444   int NumArrayElements = ArrayDim(BaseType);
    445   // Actually extract out the base RS object type for use later
    446   BaseType = BaseType->getArrayElementTypeNoTypeQual();
    447 
    448   clang::Stmt *StmtArray[2] = {NULL};
    449   int StmtCtr = 0;
    450 
    451   if (NumArrayElements <= 0) {
    452     return NULL;
    453   }
    454 
    455   // Example destructor loop for "rs_font fontArr[10];"
    456   //
    457   // (CompoundStmt
    458   //   (DeclStmt "int rsIntIter")
    459   //   (ForStmt
    460   //     (BinaryOperator 'int' '='
    461   //       (DeclRefExpr 'int' Var='rsIntIter')
    462   //       (IntegerLiteral 'int' 0))
    463   //     (BinaryOperator 'int' '<'
    464   //       (DeclRefExpr 'int' Var='rsIntIter')
    465   //       (IntegerLiteral 'int' 10)
    466   //     NULL << CondVar >>
    467   //     (UnaryOperator 'int' postfix '++'
    468   //       (DeclRefExpr 'int' Var='rsIntIter'))
    469   //     (CallExpr 'void'
    470   //       (ImplicitCastExpr 'void (*)(rs_font *)' <FunctionToPointerDecay>
    471   //         (DeclRefExpr 'void (rs_font *)' FunctionDecl='rsClearObject'))
    472   //       (UnaryOperator 'rs_font *' prefix '&'
    473   //         (ArraySubscriptExpr 'rs_font':'rs_font'
    474   //           (ImplicitCastExpr 'rs_font *' <ArrayToPointerDecay>
    475   //             (DeclRefExpr 'rs_font [10]' Var='fontArr'))
    476   //           (DeclRefExpr 'int' Var='rsIntIter')))))))
    477 
    478   // Create helper variable for iterating through elements
    479   clang::IdentifierInfo& II = C.Idents.get("rsIntIter");
    480   clang::VarDecl *IIVD =
    481       clang::VarDecl::Create(C,
    482                              DC,
    483                              StartLoc,
    484                              Loc,
    485                              &II,
    486                              C.IntTy,
    487                              C.getTrivialTypeSourceInfo(C.IntTy),
    488                              clang::SC_None);
    489   clang::Decl *IID = (clang::Decl *)IIVD;
    490 
    491   clang::DeclGroupRef DGR = clang::DeclGroupRef::Create(C, &IID, 1);
    492   StmtArray[StmtCtr++] = new(C) clang::DeclStmt(DGR, Loc, Loc);
    493 
    494   // Form the actual destructor loop
    495   // for (Init; Cond; Inc)
    496   //   RSClearObjectCall;
    497 
    498   // Init -> "rsIntIter = 0"
    499   clang::DeclRefExpr *RefrsIntIter =
    500       clang::DeclRefExpr::Create(C,
    501                                  clang::NestedNameSpecifierLoc(),
    502                                  clang::SourceLocation(),
    503                                  IIVD,
    504                                  false,
    505                                  Loc,
    506                                  C.IntTy,
    507                                  clang::VK_RValue,
    508                                  NULL);
    509 
    510   clang::Expr *Int0 = clang::IntegerLiteral::Create(C,
    511       llvm::APInt(C.getTypeSize(C.IntTy), 0), C.IntTy, Loc);
    512 
    513   clang::BinaryOperator *Init =
    514       new(C) clang::BinaryOperator(RefrsIntIter,
    515                                    Int0,
    516                                    clang::BO_Assign,
    517                                    C.IntTy,
    518                                    clang::VK_RValue,
    519                                    clang::OK_Ordinary,
    520                                    Loc,
    521                                    false);
    522 
    523   // Cond -> "rsIntIter < NumArrayElements"
    524   clang::Expr *NumArrayElementsExpr = clang::IntegerLiteral::Create(C,
    525       llvm::APInt(C.getTypeSize(C.IntTy), NumArrayElements), C.IntTy, Loc);
    526 
    527   clang::BinaryOperator *Cond =
    528       new(C) clang::BinaryOperator(RefrsIntIter,
    529                                    NumArrayElementsExpr,
    530                                    clang::BO_LT,
    531                                    C.IntTy,
    532                                    clang::VK_RValue,
    533                                    clang::OK_Ordinary,
    534                                    Loc,
    535                                    false);
    536 
    537   // Inc -> "rsIntIter++"
    538   clang::UnaryOperator *Inc =
    539       new(C) clang::UnaryOperator(RefrsIntIter,
    540                                   clang::UO_PostInc,
    541                                   C.IntTy,
    542                                   clang::VK_RValue,
    543                                   clang::OK_Ordinary,
    544                                   Loc);
    545 
    546   // Body -> "rsClearObject(&VD[rsIntIter]);"
    547   // Destructor loop operates on individual array elements
    548 
    549   clang::Expr *RefRSArrPtr =
    550       clang::ImplicitCastExpr::Create(C,
    551           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    552           clang::CK_ArrayToPointerDecay,
    553           RefRSArr,
    554           NULL,
    555           clang::VK_RValue);
    556 
    557   clang::Expr *RefRSArrPtrSubscript =
    558       new(C) clang::ArraySubscriptExpr(RefRSArrPtr,
    559                                        RefrsIntIter,
    560                                        BaseType->getCanonicalTypeInternal(),
    561                                        clang::VK_RValue,
    562                                        clang::OK_Ordinary,
    563                                        Loc);
    564 
    565   DataType DT = RSExportPrimitiveType::GetRSSpecificType(BaseType);
    566 
    567   clang::Stmt *RSClearObjectCall = NULL;
    568   if (BaseType->isArrayType()) {
    569     RSClearObjectCall =
    570         ClearArrayRSObject(C, DC, RefRSArrPtrSubscript, StartLoc, Loc);
    571   } else if (DT == DataTypeUnknown) {
    572     RSClearObjectCall =
    573         ClearStructRSObject(C, DC, RefRSArrPtrSubscript, StartLoc, Loc);
    574   } else {
    575     RSClearObjectCall = ClearSingleRSObject(C, RefRSArrPtrSubscript, Loc);
    576   }
    577 
    578   clang::ForStmt *DestructorLoop =
    579       new(C) clang::ForStmt(C,
    580                             Init,
    581                             Cond,
    582                             NULL,  // no condVar
    583                             Inc,
    584                             RSClearObjectCall,
    585                             Loc,
    586                             Loc,
    587                             Loc);
    588 
    589   StmtArray[StmtCtr++] = DestructorLoop;
    590   slangAssert(StmtCtr == 2);
    591 
    592   clang::CompoundStmt *CS = new(C) clang::CompoundStmt(
    593       C, llvm::makeArrayRef(StmtArray, StmtCtr), Loc, Loc);
    594 
    595   return CS;
    596 }
    597 
    598 static unsigned CountRSObjectTypes(clang::ASTContext &C,
    599                                    const clang::Type *T,
    600                                    clang::SourceLocation Loc) {
    601   slangAssert(T);
    602   unsigned RSObjectCount = 0;
    603 
    604   if (T->isArrayType()) {
    605     return CountRSObjectTypes(C, T->getArrayElementTypeNoTypeQual(), Loc);
    606   }
    607 
    608   DataType DT = RSExportPrimitiveType::GetRSSpecificType(T);
    609   if (DT != DataTypeUnknown) {
    610     return (RSExportPrimitiveType::IsRSObjectType(DT) ? 1 : 0);
    611   }
    612 
    613   if (T->isUnionType()) {
    614     clang::RecordDecl *RD = T->getAsUnionType()->getDecl();
    615     RD = RD->getDefinition();
    616     for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    617            FE = RD->field_end();
    618          FI != FE;
    619          FI++) {
    620       const clang::FieldDecl *FD = *FI;
    621       const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    622       if (CountRSObjectTypes(C, FT, Loc)) {
    623         slangAssert(false && "can't have unions with RS object types!");
    624         return 0;
    625       }
    626     }
    627   }
    628 
    629   if (!T->isStructureType()) {
    630     return 0;
    631   }
    632 
    633   clang::RecordDecl *RD = T->getAsStructureType()->getDecl();
    634   RD = RD->getDefinition();
    635   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    636          FE = RD->field_end();
    637        FI != FE;
    638        FI++) {
    639     const clang::FieldDecl *FD = *FI;
    640     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    641     if (CountRSObjectTypes(C, FT, Loc)) {
    642       // Sub-structs should only count once (as should arrays, etc.)
    643       RSObjectCount++;
    644     }
    645   }
    646 
    647   return RSObjectCount;
    648 }
    649 
    650 static clang::Stmt *ClearStructRSObject(
    651     clang::ASTContext &C,
    652     clang::DeclContext *DC,
    653     clang::Expr *RefRSStruct,
    654     clang::SourceLocation StartLoc,
    655     clang::SourceLocation Loc) {
    656   const clang::Type *BaseType = RefRSStruct->getType().getTypePtr();
    657 
    658   slangAssert(!BaseType->isArrayType());
    659 
    660   // Structs should show up as unknown primitive types
    661   slangAssert(RSExportPrimitiveType::GetRSSpecificType(BaseType) ==
    662               DataTypeUnknown);
    663 
    664   unsigned FieldsToDestroy = CountRSObjectTypes(C, BaseType, Loc);
    665   slangAssert(FieldsToDestroy != 0);
    666 
    667   unsigned StmtCount = 0;
    668   clang::Stmt **StmtArray = new clang::Stmt*[FieldsToDestroy];
    669   for (unsigned i = 0; i < FieldsToDestroy; i++) {
    670     StmtArray[i] = NULL;
    671   }
    672 
    673   // Populate StmtArray by creating a destructor for each RS object field
    674   clang::RecordDecl *RD = BaseType->getAsStructureType()->getDecl();
    675   RD = RD->getDefinition();
    676   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    677          FE = RD->field_end();
    678        FI != FE;
    679        FI++) {
    680     // We just look through all field declarations to see if we find a
    681     // declaration for an RS object type (or an array of one).
    682     bool IsArrayType = false;
    683     clang::FieldDecl *FD = *FI;
    684     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    685     const clang::Type *OrigType = FT;
    686     while (FT && FT->isArrayType()) {
    687       FT = FT->getArrayElementTypeNoTypeQual();
    688       IsArrayType = true;
    689     }
    690 
    691     if (RSExportPrimitiveType::IsRSObjectType(FT)) {
    692       clang::DeclAccessPair FoundDecl =
    693           clang::DeclAccessPair::make(FD, clang::AS_none);
    694       clang::MemberExpr *RSObjectMember =
    695           clang::MemberExpr::Create(C,
    696                                     RefRSStruct,
    697                                     false,
    698                                     clang::NestedNameSpecifierLoc(),
    699                                     clang::SourceLocation(),
    700                                     FD,
    701                                     FoundDecl,
    702                                     clang::DeclarationNameInfo(),
    703                                     NULL,
    704                                     OrigType->getCanonicalTypeInternal(),
    705                                     clang::VK_RValue,
    706                                     clang::OK_Ordinary);
    707 
    708       slangAssert(StmtCount < FieldsToDestroy);
    709 
    710       if (IsArrayType) {
    711         StmtArray[StmtCount++] = ClearArrayRSObject(C,
    712                                                     DC,
    713                                                     RSObjectMember,
    714                                                     StartLoc,
    715                                                     Loc);
    716       } else {
    717         StmtArray[StmtCount++] = ClearSingleRSObject(C,
    718                                                      RSObjectMember,
    719                                                      Loc);
    720       }
    721     } else if (FT->isStructureType() && CountRSObjectTypes(C, FT, Loc)) {
    722       // In this case, we have a nested struct. We may not end up filling all
    723       // of the spaces in StmtArray (sub-structs should handle themselves
    724       // with separate compound statements).
    725       clang::DeclAccessPair FoundDecl =
    726           clang::DeclAccessPair::make(FD, clang::AS_none);
    727       clang::MemberExpr *RSObjectMember =
    728           clang::MemberExpr::Create(C,
    729                                     RefRSStruct,
    730                                     false,
    731                                     clang::NestedNameSpecifierLoc(),
    732                                     clang::SourceLocation(),
    733                                     FD,
    734                                     FoundDecl,
    735                                     clang::DeclarationNameInfo(),
    736                                     NULL,
    737                                     OrigType->getCanonicalTypeInternal(),
    738                                     clang::VK_RValue,
    739                                     clang::OK_Ordinary);
    740 
    741       if (IsArrayType) {
    742         StmtArray[StmtCount++] = ClearArrayRSObject(C,
    743                                                     DC,
    744                                                     RSObjectMember,
    745                                                     StartLoc,
    746                                                     Loc);
    747       } else {
    748         StmtArray[StmtCount++] = ClearStructRSObject(C,
    749                                                      DC,
    750                                                      RSObjectMember,
    751                                                      StartLoc,
    752                                                      Loc);
    753       }
    754     }
    755   }
    756 
    757   slangAssert(StmtCount > 0);
    758   clang::CompoundStmt *CS = new(C) clang::CompoundStmt(
    759       C, llvm::makeArrayRef(StmtArray, StmtCount), Loc, Loc);
    760 
    761   delete [] StmtArray;
    762 
    763   return CS;
    764 }
    765 
    766 static clang::Stmt *CreateSingleRSSetObject(clang::ASTContext &C,
    767                                             clang::Expr *DstExpr,
    768                                             clang::Expr *SrcExpr,
    769                                             clang::SourceLocation StartLoc,
    770                                             clang::SourceLocation Loc) {
    771   const clang::Type *T = DstExpr->getType().getTypePtr();
    772   clang::FunctionDecl *SetObjectFD = RSObjectRefCount::GetRSSetObjectFD(T);
    773   slangAssert((SetObjectFD != NULL) &&
    774               "rsSetObject doesn't cover all RS object types");
    775 
    776   clang::QualType SetObjectFDType = SetObjectFD->getType();
    777   clang::QualType SetObjectFDArgType[2];
    778   SetObjectFDArgType[0] = SetObjectFD->getParamDecl(0)->getOriginalType();
    779   SetObjectFDArgType[1] = SetObjectFD->getParamDecl(1)->getOriginalType();
    780 
    781   clang::Expr *RefRSSetObjectFD =
    782       clang::DeclRefExpr::Create(C,
    783                                  clang::NestedNameSpecifierLoc(),
    784                                  clang::SourceLocation(),
    785                                  SetObjectFD,
    786                                  false,
    787                                  Loc,
    788                                  SetObjectFDType,
    789                                  clang::VK_RValue,
    790                                  NULL);
    791 
    792   clang::Expr *RSSetObjectFP =
    793       clang::ImplicitCastExpr::Create(C,
    794                                       C.getPointerType(SetObjectFDType),
    795                                       clang::CK_FunctionToPointerDecay,
    796                                       RefRSSetObjectFD,
    797                                       NULL,
    798                                       clang::VK_RValue);
    799 
    800   llvm::SmallVector<clang::Expr*, 2> ArgList;
    801   ArgList.push_back(new(C) clang::UnaryOperator(DstExpr,
    802                                                 clang::UO_AddrOf,
    803                                                 SetObjectFDArgType[0],
    804                                                 clang::VK_RValue,
    805                                                 clang::OK_Ordinary,
    806                                                 Loc));
    807   ArgList.push_back(SrcExpr);
    808 
    809   clang::CallExpr *RSSetObjectCall =
    810       new(C) clang::CallExpr(C,
    811                              RSSetObjectFP,
    812                              ArgList,
    813                              SetObjectFD->getCallResultType(),
    814                              clang::VK_RValue,
    815                              Loc);
    816 
    817   return RSSetObjectCall;
    818 }
    819 
    820 static clang::Stmt *CreateStructRSSetObject(clang::ASTContext &C,
    821                                             clang::Expr *LHS,
    822                                             clang::Expr *RHS,
    823                                             clang::SourceLocation StartLoc,
    824                                             clang::SourceLocation Loc);
    825 
    826 /*static clang::Stmt *CreateArrayRSSetObject(clang::ASTContext &C,
    827                                            clang::Expr *DstArr,
    828                                            clang::Expr *SrcArr,
    829                                            clang::SourceLocation StartLoc,
    830                                            clang::SourceLocation Loc) {
    831   clang::DeclContext *DC = NULL;
    832   const clang::Type *BaseType = DstArr->getType().getTypePtr();
    833   slangAssert(BaseType->isArrayType());
    834 
    835   int NumArrayElements = ArrayDim(BaseType);
    836   // Actually extract out the base RS object type for use later
    837   BaseType = BaseType->getArrayElementTypeNoTypeQual();
    838 
    839   clang::Stmt *StmtArray[2] = {NULL};
    840   int StmtCtr = 0;
    841 
    842   if (NumArrayElements <= 0) {
    843     return NULL;
    844   }
    845 
    846   // Create helper variable for iterating through elements
    847   clang::IdentifierInfo& II = C.Idents.get("rsIntIter");
    848   clang::VarDecl *IIVD =
    849       clang::VarDecl::Create(C,
    850                              DC,
    851                              StartLoc,
    852                              Loc,
    853                              &II,
    854                              C.IntTy,
    855                              C.getTrivialTypeSourceInfo(C.IntTy),
    856                              clang::SC_None,
    857                              clang::SC_None);
    858   clang::Decl *IID = (clang::Decl *)IIVD;
    859 
    860   clang::DeclGroupRef DGR = clang::DeclGroupRef::Create(C, &IID, 1);
    861   StmtArray[StmtCtr++] = new(C) clang::DeclStmt(DGR, Loc, Loc);
    862 
    863   // Form the actual loop
    864   // for (Init; Cond; Inc)
    865   //   RSSetObjectCall;
    866 
    867   // Init -> "rsIntIter = 0"
    868   clang::DeclRefExpr *RefrsIntIter =
    869       clang::DeclRefExpr::Create(C,
    870                                  clang::NestedNameSpecifierLoc(),
    871                                  IIVD,
    872                                  Loc,
    873                                  C.IntTy,
    874                                  clang::VK_RValue,
    875                                  NULL);
    876 
    877   clang::Expr *Int0 = clang::IntegerLiteral::Create(C,
    878       llvm::APInt(C.getTypeSize(C.IntTy), 0), C.IntTy, Loc);
    879 
    880   clang::BinaryOperator *Init =
    881       new(C) clang::BinaryOperator(RefrsIntIter,
    882                                    Int0,
    883                                    clang::BO_Assign,
    884                                    C.IntTy,
    885                                    clang::VK_RValue,
    886                                    clang::OK_Ordinary,
    887                                    Loc);
    888 
    889   // Cond -> "rsIntIter < NumArrayElements"
    890   clang::Expr *NumArrayElementsExpr = clang::IntegerLiteral::Create(C,
    891       llvm::APInt(C.getTypeSize(C.IntTy), NumArrayElements), C.IntTy, Loc);
    892 
    893   clang::BinaryOperator *Cond =
    894       new(C) clang::BinaryOperator(RefrsIntIter,
    895                                    NumArrayElementsExpr,
    896                                    clang::BO_LT,
    897                                    C.IntTy,
    898                                    clang::VK_RValue,
    899                                    clang::OK_Ordinary,
    900                                    Loc);
    901 
    902   // Inc -> "rsIntIter++"
    903   clang::UnaryOperator *Inc =
    904       new(C) clang::UnaryOperator(RefrsIntIter,
    905                                   clang::UO_PostInc,
    906                                   C.IntTy,
    907                                   clang::VK_RValue,
    908                                   clang::OK_Ordinary,
    909                                   Loc);
    910 
    911   // Body -> "rsSetObject(&Dst[rsIntIter], Src[rsIntIter]);"
    912   // Loop operates on individual array elements
    913 
    914   clang::Expr *DstArrPtr =
    915       clang::ImplicitCastExpr::Create(C,
    916           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    917           clang::CK_ArrayToPointerDecay,
    918           DstArr,
    919           NULL,
    920           clang::VK_RValue);
    921 
    922   clang::Expr *DstArrPtrSubscript =
    923       new(C) clang::ArraySubscriptExpr(DstArrPtr,
    924                                        RefrsIntIter,
    925                                        BaseType->getCanonicalTypeInternal(),
    926                                        clang::VK_RValue,
    927                                        clang::OK_Ordinary,
    928                                        Loc);
    929 
    930   clang::Expr *SrcArrPtr =
    931       clang::ImplicitCastExpr::Create(C,
    932           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    933           clang::CK_ArrayToPointerDecay,
    934           SrcArr,
    935           NULL,
    936           clang::VK_RValue);
    937 
    938   clang::Expr *SrcArrPtrSubscript =
    939       new(C) clang::ArraySubscriptExpr(SrcArrPtr,
    940                                        RefrsIntIter,
    941                                        BaseType->getCanonicalTypeInternal(),
    942                                        clang::VK_RValue,
    943                                        clang::OK_Ordinary,
    944                                        Loc);
    945 
    946   DataType DT = RSExportPrimitiveType::GetRSSpecificType(BaseType);
    947 
    948   clang::Stmt *RSSetObjectCall = NULL;
    949   if (BaseType->isArrayType()) {
    950     RSSetObjectCall = CreateArrayRSSetObject(C, DstArrPtrSubscript,
    951                                              SrcArrPtrSubscript,
    952                                              StartLoc, Loc);
    953   } else if (DT == DataTypeUnknown) {
    954     RSSetObjectCall = CreateStructRSSetObject(C, DstArrPtrSubscript,
    955                                               SrcArrPtrSubscript,
    956                                               StartLoc, Loc);
    957   } else {
    958     RSSetObjectCall = CreateSingleRSSetObject(C, DstArrPtrSubscript,
    959                                               SrcArrPtrSubscript,
    960                                               StartLoc, Loc);
    961   }
    962 
    963   clang::ForStmt *DestructorLoop =
    964       new(C) clang::ForStmt(C,
    965                             Init,
    966                             Cond,
    967                             NULL,  // no condVar
    968                             Inc,
    969                             RSSetObjectCall,
    970                             Loc,
    971                             Loc,
    972                             Loc);
    973 
    974   StmtArray[StmtCtr++] = DestructorLoop;
    975   slangAssert(StmtCtr == 2);
    976 
    977   clang::CompoundStmt *CS =
    978       new(C) clang::CompoundStmt(C, StmtArray, StmtCtr, Loc, Loc);
    979 
    980   return CS;
    981 } */
    982 
    983 static clang::Stmt *CreateStructRSSetObject(clang::ASTContext &C,
    984                                             clang::Expr *LHS,
    985                                             clang::Expr *RHS,
    986                                             clang::SourceLocation StartLoc,
    987                                             clang::SourceLocation Loc) {
    988   clang::QualType QT = LHS->getType();
    989   const clang::Type *T = QT.getTypePtr();
    990   slangAssert(T->isStructureType());
    991   slangAssert(!RSExportPrimitiveType::IsRSObjectType(T));
    992 
    993   // Keep an extra slot for the original copy (memcpy)
    994   unsigned FieldsToSet = CountRSObjectTypes(C, T, Loc) + 1;
    995 
    996   unsigned StmtCount = 0;
    997   clang::Stmt **StmtArray = new clang::Stmt*[FieldsToSet];
    998   for (unsigned i = 0; i < FieldsToSet; i++) {
    999     StmtArray[i] = NULL;
   1000   }
   1001 
   1002   clang::RecordDecl *RD = T->getAsStructureType()->getDecl();
   1003   RD = RD->getDefinition();
   1004   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
   1005          FE = RD->field_end();
   1006        FI != FE;
   1007        FI++) {
   1008     bool IsArrayType = false;
   1009     clang::FieldDecl *FD = *FI;
   1010     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
   1011     const clang::Type *OrigType = FT;
   1012 
   1013     if (!CountRSObjectTypes(C, FT, Loc)) {
   1014       // Skip to next if we don't have any viable RS object types
   1015       continue;
   1016     }
   1017 
   1018     clang::DeclAccessPair FoundDecl =
   1019         clang::DeclAccessPair::make(FD, clang::AS_none);
   1020     clang::MemberExpr *DstMember =
   1021         clang::MemberExpr::Create(C,
   1022                                   LHS,
   1023                                   false,
   1024                                   clang::NestedNameSpecifierLoc(),
   1025                                   clang::SourceLocation(),
   1026                                   FD,
   1027                                   FoundDecl,
   1028                                   clang::DeclarationNameInfo(),
   1029                                   NULL,
   1030                                   OrigType->getCanonicalTypeInternal(),
   1031                                   clang::VK_RValue,
   1032                                   clang::OK_Ordinary);
   1033 
   1034     clang::MemberExpr *SrcMember =
   1035         clang::MemberExpr::Create(C,
   1036                                   RHS,
   1037                                   false,
   1038                                   clang::NestedNameSpecifierLoc(),
   1039                                   clang::SourceLocation(),
   1040                                   FD,
   1041                                   FoundDecl,
   1042                                   clang::DeclarationNameInfo(),
   1043                                   NULL,
   1044                                   OrigType->getCanonicalTypeInternal(),
   1045                                   clang::VK_RValue,
   1046                                   clang::OK_Ordinary);
   1047 
   1048     if (FT->isArrayType()) {
   1049       FT = FT->getArrayElementTypeNoTypeQual();
   1050       IsArrayType = true;
   1051     }
   1052 
   1053     DataType DT = RSExportPrimitiveType::GetRSSpecificType(FT);
   1054 
   1055     if (IsArrayType) {
   1056       clang::DiagnosticsEngine &DiagEngine = C.getDiagnostics();
   1057       DiagEngine.Report(
   1058         clang::FullSourceLoc(Loc, C.getSourceManager()),
   1059         DiagEngine.getCustomDiagID(
   1060           clang::DiagnosticsEngine::Error,
   1061           "Arrays of RS object types within structures cannot be copied"));
   1062       // TODO(srhines): Support setting arrays of RS objects
   1063       // StmtArray[StmtCount++] =
   1064       //    CreateArrayRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1065     } else if (DT == DataTypeUnknown) {
   1066       StmtArray[StmtCount++] =
   1067           CreateStructRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1068     } else if (RSExportPrimitiveType::IsRSObjectType(DT)) {
   1069       StmtArray[StmtCount++] =
   1070           CreateSingleRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1071     } else {
   1072       slangAssert(false);
   1073     }
   1074   }
   1075 
   1076   slangAssert(StmtCount < FieldsToSet);
   1077 
   1078   // We still need to actually do the overall struct copy. For simplicity,
   1079   // we just do a straight-up assignment (which will still preserve all
   1080   // the proper RS object reference counts).
   1081   clang::BinaryOperator *CopyStruct =
   1082       new(C) clang::BinaryOperator(LHS, RHS, clang::BO_Assign, QT,
   1083                                    clang::VK_RValue, clang::OK_Ordinary, Loc,
   1084                                    false);
   1085   StmtArray[StmtCount++] = CopyStruct;
   1086 
   1087   clang::CompoundStmt *CS = new(C) clang::CompoundStmt(
   1088       C, llvm::makeArrayRef(StmtArray, StmtCount), Loc, Loc);
   1089 
   1090   delete [] StmtArray;
   1091 
   1092   return CS;
   1093 }
   1094 
   1095 }  // namespace
   1096 
   1097 void RSObjectRefCount::Scope::ReplaceRSObjectAssignment(
   1098     clang::BinaryOperator *AS) {
   1099 
   1100   clang::QualType QT = AS->getType();
   1101 
   1102   clang::ASTContext &C = RSObjectRefCount::GetRSSetObjectFD(
   1103       DataTypeRSAllocation)->getASTContext();
   1104 
   1105   clang::SourceLocation Loc = AS->getExprLoc();
   1106   clang::SourceLocation StartLoc = AS->getLHS()->getExprLoc();
   1107   clang::Stmt *UpdatedStmt = NULL;
   1108 
   1109   if (!RSExportPrimitiveType::IsRSObjectType(QT.getTypePtr())) {
   1110     // By definition, this is a struct assignment if we get here
   1111     UpdatedStmt =
   1112         CreateStructRSSetObject(C, AS->getLHS(), AS->getRHS(), StartLoc, Loc);
   1113   } else {
   1114     UpdatedStmt =
   1115         CreateSingleRSSetObject(C, AS->getLHS(), AS->getRHS(), StartLoc, Loc);
   1116   }
   1117 
   1118   RSASTReplace R(C);
   1119   R.ReplaceStmt(mCS, AS, UpdatedStmt);
   1120 }
   1121 
   1122 void RSObjectRefCount::Scope::AppendRSObjectInit(
   1123     clang::VarDecl *VD,
   1124     clang::DeclStmt *DS,
   1125     DataType DT,
   1126     clang::Expr *InitExpr) {
   1127   slangAssert(VD);
   1128 
   1129   if (!InitExpr) {
   1130     return;
   1131   }
   1132 
   1133   clang::ASTContext &C = RSObjectRefCount::GetRSSetObjectFD(
   1134       DataTypeRSAllocation)->getASTContext();
   1135   clang::SourceLocation Loc = RSObjectRefCount::GetRSSetObjectFD(
   1136       DataTypeRSAllocation)->getLocation();
   1137   clang::SourceLocation StartLoc = RSObjectRefCount::GetRSSetObjectFD(
   1138       DataTypeRSAllocation)->getInnerLocStart();
   1139 
   1140   if (DT == DataTypeIsStruct) {
   1141     const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1142     clang::DeclRefExpr *RefRSVar =
   1143         clang::DeclRefExpr::Create(C,
   1144                                    clang::NestedNameSpecifierLoc(),
   1145                                    clang::SourceLocation(),
   1146                                    VD,
   1147                                    false,
   1148                                    Loc,
   1149                                    T->getCanonicalTypeInternal(),
   1150                                    clang::VK_RValue,
   1151                                    NULL);
   1152 
   1153     clang::Stmt *RSSetObjectOps =
   1154         CreateStructRSSetObject(C, RefRSVar, InitExpr, StartLoc, Loc);
   1155 
   1156     std::list<clang::Stmt*> StmtList;
   1157     StmtList.push_back(RSSetObjectOps);
   1158     AppendAfterStmt(C, mCS, DS, StmtList);
   1159     return;
   1160   }
   1161 
   1162   clang::FunctionDecl *SetObjectFD = RSObjectRefCount::GetRSSetObjectFD(DT);
   1163   slangAssert((SetObjectFD != NULL) &&
   1164               "rsSetObject doesn't cover all RS object types");
   1165 
   1166   clang::QualType SetObjectFDType = SetObjectFD->getType();
   1167   clang::QualType SetObjectFDArgType[2];
   1168   SetObjectFDArgType[0] = SetObjectFD->getParamDecl(0)->getOriginalType();
   1169   SetObjectFDArgType[1] = SetObjectFD->getParamDecl(1)->getOriginalType();
   1170 
   1171   clang::Expr *RefRSSetObjectFD =
   1172       clang::DeclRefExpr::Create(C,
   1173                                  clang::NestedNameSpecifierLoc(),
   1174                                  clang::SourceLocation(),
   1175                                  SetObjectFD,
   1176                                  false,
   1177                                  Loc,
   1178                                  SetObjectFDType,
   1179                                  clang::VK_RValue,
   1180                                  NULL);
   1181 
   1182   clang::Expr *RSSetObjectFP =
   1183       clang::ImplicitCastExpr::Create(C,
   1184                                       C.getPointerType(SetObjectFDType),
   1185                                       clang::CK_FunctionToPointerDecay,
   1186                                       RefRSSetObjectFD,
   1187                                       NULL,
   1188                                       clang::VK_RValue);
   1189 
   1190   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1191   clang::DeclRefExpr *RefRSVar =
   1192       clang::DeclRefExpr::Create(C,
   1193                                  clang::NestedNameSpecifierLoc(),
   1194                                  clang::SourceLocation(),
   1195                                  VD,
   1196                                  false,
   1197                                  Loc,
   1198                                  T->getCanonicalTypeInternal(),
   1199                                  clang::VK_RValue,
   1200                                  NULL);
   1201 
   1202   llvm::SmallVector<clang::Expr*, 2> ArgList;
   1203   ArgList.push_back(new(C) clang::UnaryOperator(RefRSVar,
   1204                                                 clang::UO_AddrOf,
   1205                                                 SetObjectFDArgType[0],
   1206                                                 clang::VK_RValue,
   1207                                                 clang::OK_Ordinary,
   1208                                                 Loc));
   1209   ArgList.push_back(InitExpr);
   1210 
   1211   clang::CallExpr *RSSetObjectCall =
   1212       new(C) clang::CallExpr(C,
   1213                              RSSetObjectFP,
   1214                              ArgList,
   1215                              SetObjectFD->getCallResultType(),
   1216                              clang::VK_RValue,
   1217                              Loc);
   1218 
   1219   std::list<clang::Stmt*> StmtList;
   1220   StmtList.push_back(RSSetObjectCall);
   1221   AppendAfterStmt(C, mCS, DS, StmtList);
   1222 }
   1223 
   1224 void RSObjectRefCount::Scope::InsertLocalVarDestructors() {
   1225   for (std::list<clang::VarDecl*>::const_iterator I = mRSO.begin(),
   1226           E = mRSO.end();
   1227         I != E;
   1228         I++) {
   1229     clang::VarDecl *VD = *I;
   1230     clang::Stmt *RSClearObjectCall = ClearRSObject(VD, VD->getDeclContext());
   1231     if (RSClearObjectCall) {
   1232       DestructorVisitor DV((*mRSO.begin())->getASTContext(),
   1233                            mCS,
   1234                            RSClearObjectCall,
   1235                            VD->getSourceRange().getBegin());
   1236       DV.Visit(mCS);
   1237       DV.InsertDestructors();
   1238     }
   1239   }
   1240 }
   1241 
   1242 clang::Stmt *RSObjectRefCount::Scope::ClearRSObject(
   1243     clang::VarDecl *VD,
   1244     clang::DeclContext *DC) {
   1245   slangAssert(VD);
   1246   clang::ASTContext &C = VD->getASTContext();
   1247   clang::SourceLocation Loc = VD->getLocation();
   1248   clang::SourceLocation StartLoc = VD->getInnerLocStart();
   1249   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1250 
   1251   // Reference expr to target RS object variable
   1252   clang::DeclRefExpr *RefRSVar =
   1253       clang::DeclRefExpr::Create(C,
   1254                                  clang::NestedNameSpecifierLoc(),
   1255                                  clang::SourceLocation(),
   1256                                  VD,
   1257                                  false,
   1258                                  Loc,
   1259                                  T->getCanonicalTypeInternal(),
   1260                                  clang::VK_RValue,
   1261                                  NULL);
   1262 
   1263   if (T->isArrayType()) {
   1264     return ClearArrayRSObject(C, DC, RefRSVar, StartLoc, Loc);
   1265   }
   1266 
   1267   DataType DT = RSExportPrimitiveType::GetRSSpecificType(T);
   1268 
   1269   if (DT == DataTypeUnknown ||
   1270       DT == DataTypeIsStruct) {
   1271     return ClearStructRSObject(C, DC, RefRSVar, StartLoc, Loc);
   1272   }
   1273 
   1274   slangAssert((RSExportPrimitiveType::IsRSObjectType(DT)) &&
   1275               "Should be RS object");
   1276 
   1277   return ClearSingleRSObject(C, RefRSVar, Loc);
   1278 }
   1279 
   1280 bool RSObjectRefCount::InitializeRSObject(clang::VarDecl *VD,
   1281                                           DataType *DT,
   1282                                           clang::Expr **InitExpr) {
   1283   slangAssert(VD && DT && InitExpr);
   1284   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1285 
   1286   // Loop through array types to get to base type
   1287   while (T && T->isArrayType()) {
   1288     T = T->getArrayElementTypeNoTypeQual();
   1289   }
   1290 
   1291   bool DataTypeIsStructWithRSObject = false;
   1292   *DT = RSExportPrimitiveType::GetRSSpecificType(T);
   1293 
   1294   if (*DT == DataTypeUnknown) {
   1295     if (RSExportPrimitiveType::IsStructureTypeWithRSObject(T)) {
   1296       *DT = DataTypeIsStruct;
   1297       DataTypeIsStructWithRSObject = true;
   1298     } else {
   1299       return false;
   1300     }
   1301   }
   1302 
   1303   bool DataTypeIsRSObject = false;
   1304   if (DataTypeIsStructWithRSObject) {
   1305     DataTypeIsRSObject = true;
   1306   } else {
   1307     DataTypeIsRSObject = RSExportPrimitiveType::IsRSObjectType(*DT);
   1308   }
   1309   *InitExpr = VD->getInit();
   1310 
   1311   if (!DataTypeIsRSObject && *InitExpr) {
   1312     // If we already have an initializer for a matrix type, we are done.
   1313     return DataTypeIsRSObject;
   1314   }
   1315 
   1316   clang::Expr *ZeroInitializer =
   1317       CreateZeroInitializerForRSSpecificType(*DT,
   1318                                              VD->getASTContext(),
   1319                                              VD->getLocation());
   1320 
   1321   if (ZeroInitializer) {
   1322     ZeroInitializer->setType(T->getCanonicalTypeInternal());
   1323     VD->setInit(ZeroInitializer);
   1324   }
   1325 
   1326   return DataTypeIsRSObject;
   1327 }
   1328 
   1329 clang::Expr *RSObjectRefCount::CreateZeroInitializerForRSSpecificType(
   1330     DataType DT,
   1331     clang::ASTContext &C,
   1332     const clang::SourceLocation &Loc) {
   1333   clang::Expr *Res = NULL;
   1334   switch (DT) {
   1335     case DataTypeIsStruct:
   1336     case DataTypeRSElement:
   1337     case DataTypeRSType:
   1338     case DataTypeRSAllocation:
   1339     case DataTypeRSSampler:
   1340     case DataTypeRSScript:
   1341     case DataTypeRSMesh:
   1342     case DataTypeRSPath:
   1343     case DataTypeRSProgramFragment:
   1344     case DataTypeRSProgramVertex:
   1345     case DataTypeRSProgramRaster:
   1346     case DataTypeRSProgramStore:
   1347     case DataTypeRSFont: {
   1348       //    (ImplicitCastExpr 'nullptr_t'
   1349       //      (IntegerLiteral 0)))
   1350       llvm::APInt Zero(C.getTypeSize(C.IntTy), 0);
   1351       clang::Expr *Int0 = clang::IntegerLiteral::Create(C, Zero, C.IntTy, Loc);
   1352       clang::Expr *CastToNull =
   1353           clang::ImplicitCastExpr::Create(C,
   1354                                           C.NullPtrTy,
   1355                                           clang::CK_IntegralToPointer,
   1356                                           Int0,
   1357                                           NULL,
   1358                                           clang::VK_RValue);
   1359 
   1360       llvm::SmallVector<clang::Expr*, 1>InitList;
   1361       InitList.push_back(CastToNull);
   1362 
   1363       Res = new(C) clang::InitListExpr(C, Loc, InitList, Loc);
   1364       break;
   1365     }
   1366     case DataTypeRSMatrix2x2:
   1367     case DataTypeRSMatrix3x3:
   1368     case DataTypeRSMatrix4x4: {
   1369       // RS matrix is not completely an RS object. They hold data by themselves.
   1370       // (InitListExpr rs_matrix2x2
   1371       //   (InitListExpr float[4]
   1372       //     (FloatingLiteral 0)
   1373       //     (FloatingLiteral 0)
   1374       //     (FloatingLiteral 0)
   1375       //     (FloatingLiteral 0)))
   1376       clang::QualType FloatTy = C.FloatTy;
   1377       // Constructor sets value to 0.0f by default
   1378       llvm::APFloat Val(C.getFloatTypeSemantics(FloatTy));
   1379       clang::FloatingLiteral *Float0Val =
   1380           clang::FloatingLiteral::Create(C,
   1381                                          Val,
   1382                                          /* isExact = */true,
   1383                                          FloatTy,
   1384                                          Loc);
   1385 
   1386       unsigned N = 0;
   1387       if (DT == DataTypeRSMatrix2x2)
   1388         N = 2;
   1389       else if (DT == DataTypeRSMatrix3x3)
   1390         N = 3;
   1391       else if (DT == DataTypeRSMatrix4x4)
   1392         N = 4;
   1393       unsigned N_2 = N * N;
   1394 
   1395       // Assume we are going to be allocating 16 elements, since 4x4 is max.
   1396       llvm::SmallVector<clang::Expr*, 16> InitVals;
   1397       for (unsigned i = 0; i < N_2; i++)
   1398         InitVals.push_back(Float0Val);
   1399       clang::Expr *InitExpr =
   1400           new(C) clang::InitListExpr(C, Loc, InitVals, Loc);
   1401       InitExpr->setType(C.getConstantArrayType(FloatTy,
   1402                                                llvm::APInt(32, N_2),
   1403                                                clang::ArrayType::Normal,
   1404                                                /* EltTypeQuals = */0));
   1405       llvm::SmallVector<clang::Expr*, 1> InitExprVec;
   1406       InitExprVec.push_back(InitExpr);
   1407 
   1408       Res = new(C) clang::InitListExpr(C, Loc, InitExprVec, Loc);
   1409       break;
   1410     }
   1411     case DataTypeUnknown:
   1412     case DataTypeFloat16:
   1413     case DataTypeFloat32:
   1414     case DataTypeFloat64:
   1415     case DataTypeSigned8:
   1416     case DataTypeSigned16:
   1417     case DataTypeSigned32:
   1418     case DataTypeSigned64:
   1419     case DataTypeUnsigned8:
   1420     case DataTypeUnsigned16:
   1421     case DataTypeUnsigned32:
   1422     case DataTypeUnsigned64:
   1423     case DataTypeBoolean:
   1424     case DataTypeUnsigned565:
   1425     case DataTypeUnsigned5551:
   1426     case DataTypeUnsigned4444:
   1427     case DataTypeMax: {
   1428       slangAssert(false && "Not RS object type!");
   1429     }
   1430     // No default case will enable compiler detecting the missing cases
   1431   }
   1432 
   1433   return Res;
   1434 }
   1435 
   1436 void RSObjectRefCount::VisitDeclStmt(clang::DeclStmt *DS) {
   1437   for (clang::DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
   1438        I != E;
   1439        I++) {
   1440     clang::Decl *D = *I;
   1441     if (D->getKind() == clang::Decl::Var) {
   1442       clang::VarDecl *VD = static_cast<clang::VarDecl*>(D);
   1443       DataType DT = DataTypeUnknown;
   1444       clang::Expr *InitExpr = NULL;
   1445       if (InitializeRSObject(VD, &DT, &InitExpr)) {
   1446         // We need to zero-init all RS object types (including matrices), ...
   1447         getCurrentScope()->AppendRSObjectInit(VD, DS, DT, InitExpr);
   1448         // ... but, only add to the list of RS objects if we have some
   1449         // non-matrix RS object fields.
   1450         if (CountRSObjectTypes(mCtx, VD->getType().getTypePtr(),
   1451                                VD->getLocation())) {
   1452           getCurrentScope()->addRSObject(VD);
   1453         }
   1454       }
   1455     }
   1456   }
   1457 }
   1458 
   1459 void RSObjectRefCount::VisitCompoundStmt(clang::CompoundStmt *CS) {
   1460   if (!CS->body_empty()) {
   1461     // Push a new scope
   1462     Scope *S = new Scope(CS);
   1463     mScopeStack.push(S);
   1464 
   1465     VisitStmt(CS);
   1466 
   1467     // Destroy the scope
   1468     slangAssert((getCurrentScope() == S) && "Corrupted scope stack!");
   1469     S->InsertLocalVarDestructors();
   1470     mScopeStack.pop();
   1471     delete S;
   1472   }
   1473 }
   1474 
   1475 void RSObjectRefCount::VisitBinAssign(clang::BinaryOperator *AS) {
   1476   clang::QualType QT = AS->getType();
   1477 
   1478   if (CountRSObjectTypes(mCtx, QT.getTypePtr(), AS->getExprLoc())) {
   1479     getCurrentScope()->ReplaceRSObjectAssignment(AS);
   1480   }
   1481 }
   1482 
   1483 void RSObjectRefCount::VisitStmt(clang::Stmt *S) {
   1484   for (clang::Stmt::child_iterator I = S->child_begin(), E = S->child_end();
   1485        I != E;
   1486        I++) {
   1487     if (clang::Stmt *Child = *I) {
   1488       Visit(Child);
   1489     }
   1490   }
   1491 }
   1492 
   1493 // This function walks the list of global variables and (potentially) creates
   1494 // a single global static destructor function that properly decrements
   1495 // reference counts on the contained RS object types.
   1496 clang::FunctionDecl *RSObjectRefCount::CreateStaticGlobalDtor() {
   1497   Init();
   1498 
   1499   clang::DeclContext *DC = mCtx.getTranslationUnitDecl();
   1500   clang::SourceLocation loc;
   1501 
   1502   llvm::StringRef SR(".rs.dtor");
   1503   clang::IdentifierInfo &II = mCtx.Idents.get(SR);
   1504   clang::DeclarationName N(&II);
   1505   clang::FunctionProtoType::ExtProtoInfo EPI;
   1506   clang::QualType T = mCtx.getFunctionType(mCtx.VoidTy,
   1507       llvm::ArrayRef<clang::QualType>(), EPI);
   1508   clang::FunctionDecl *FD = NULL;
   1509 
   1510   // Generate rsClearObject() call chains for every global variable
   1511   // (whether static or extern).
   1512   std::list<clang::Stmt *> StmtList;
   1513   for (clang::DeclContext::decl_iterator I = DC->decls_begin(),
   1514           E = DC->decls_end(); I != E; I++) {
   1515     clang::VarDecl *VD = llvm::dyn_cast<clang::VarDecl>(*I);
   1516     if (VD) {
   1517       if (CountRSObjectTypes(mCtx, VD->getType().getTypePtr(), loc)) {
   1518         if (!FD) {
   1519           // Only create FD if we are going to use it.
   1520           FD = clang::FunctionDecl::Create(mCtx, DC, loc, loc, N, T, NULL,
   1521                                            clang::SC_None);
   1522         }
   1523         // Make sure to create any helpers within the function's DeclContext,
   1524         // not the one associated with the global translation unit.
   1525         clang::Stmt *RSClearObjectCall = Scope::ClearRSObject(VD, FD);
   1526         StmtList.push_back(RSClearObjectCall);
   1527       }
   1528     }
   1529   }
   1530 
   1531   // Nothing needs to be destroyed, so don't emit a dtor.
   1532   if (StmtList.empty()) {
   1533     return NULL;
   1534   }
   1535 
   1536   clang::CompoundStmt *CS = BuildCompoundStmt(mCtx, StmtList, loc);
   1537 
   1538   FD->setBody(CS);
   1539 
   1540   return FD;
   1541 }
   1542 
   1543 }  // namespace slang
   1544