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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 clang::FunctionDecl *RSObjectRefCount::
     36     RSSetObjectFD[RSExportPrimitiveType::LastRSObjectType -
     37                   RSExportPrimitiveType::FirstRSObjectType + 1];
     38 clang::FunctionDecl *RSObjectRefCount::
     39     RSClearObjectFD[RSExportPrimitiveType::LastRSObjectType -
     40                     RSExportPrimitiveType::FirstRSObjectType + 1];
     41 
     42 void RSObjectRefCount::GetRSRefCountingFunctions(clang::ASTContext &C) {
     43   for (unsigned i = 0;
     44        i < (sizeof(RSClearObjectFD) / sizeof(clang::FunctionDecl*));
     45        i++) {
     46     RSSetObjectFD[i] = NULL;
     47     RSClearObjectFD[i] = NULL;
     48   }
     49 
     50   clang::TranslationUnitDecl *TUDecl = C.getTranslationUnitDecl();
     51 
     52   for (clang::DeclContext::decl_iterator I = TUDecl->decls_begin(),
     53           E = TUDecl->decls_end(); I != E; I++) {
     54     if ((I->getKind() >= clang::Decl::firstFunction) &&
     55         (I->getKind() <= clang::Decl::lastFunction)) {
     56       clang::FunctionDecl *FD = static_cast<clang::FunctionDecl*>(*I);
     57 
     58       // points to RSSetObjectFD or RSClearObjectFD
     59       clang::FunctionDecl **RSObjectFD;
     60 
     61       if (FD->getName() == "rsSetObject") {
     62         slangAssert((FD->getNumParams() == 2) &&
     63                     "Invalid rsSetObject function prototype (# params)");
     64         RSObjectFD = RSSetObjectFD;
     65       } else if (FD->getName() == "rsClearObject") {
     66         slangAssert((FD->getNumParams() == 1) &&
     67                     "Invalid rsClearObject function prototype (# params)");
     68         RSObjectFD = RSClearObjectFD;
     69       } else {
     70         continue;
     71       }
     72 
     73       const clang::ParmVarDecl *PVD = FD->getParamDecl(0);
     74       clang::QualType PVT = PVD->getOriginalType();
     75       // The first parameter must be a pointer like rs_allocation*
     76       slangAssert(PVT->isPointerType() &&
     77           "Invalid rs{Set,Clear}Object function prototype (pointer param)");
     78 
     79       // The rs object type passed to the FD
     80       clang::QualType RST = PVT->getPointeeType();
     81       RSExportPrimitiveType::DataType DT =
     82           RSExportPrimitiveType::GetRSSpecificType(RST.getTypePtr());
     83       slangAssert(RSExportPrimitiveType::IsRSObjectType(DT)
     84              && "must be RS object type");
     85 
     86       RSObjectFD[(DT - RSExportPrimitiveType::FirstRSObjectType)] = FD;
     87     }
     88   }
     89 }
     90 
     91 namespace {
     92 
     93 // This function constructs a new CompoundStmt from the input StmtList.
     94 static clang::CompoundStmt* BuildCompoundStmt(clang::ASTContext &C,
     95       std::list<clang::Stmt*> &StmtList, clang::SourceLocation Loc) {
     96   unsigned NewStmtCount = StmtList.size();
     97   unsigned CompoundStmtCount = 0;
     98 
     99   clang::Stmt **CompoundStmtList;
    100   CompoundStmtList = new clang::Stmt*[NewStmtCount];
    101 
    102   std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    103   std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    104   for ( ; I != E; I++) {
    105     CompoundStmtList[CompoundStmtCount++] = *I;
    106   }
    107   slangAssert(CompoundStmtCount == NewStmtCount);
    108 
    109   clang::CompoundStmt *CS = new(C) clang::CompoundStmt(C,
    110                                                        CompoundStmtList,
    111                                                        CompoundStmtCount,
    112                                                        Loc,
    113                                                        Loc);
    114 
    115   delete [] CompoundStmtList;
    116 
    117   return CS;
    118 }
    119 
    120 static void AppendAfterStmt(clang::ASTContext &C,
    121                             clang::CompoundStmt *CS,
    122                             clang::Stmt *S,
    123                             std::list<clang::Stmt*> &StmtList) {
    124   slangAssert(CS);
    125   clang::CompoundStmt::body_iterator bI = CS->body_begin();
    126   clang::CompoundStmt::body_iterator bE = CS->body_end();
    127   clang::Stmt **UpdatedStmtList =
    128       new clang::Stmt*[CS->size() + StmtList.size()];
    129 
    130   unsigned UpdatedStmtCount = 0;
    131   unsigned Once = 0;
    132   for ( ; bI != bE; bI++) {
    133     if (!S && ((*bI)->getStmtClass() == clang::Stmt::ReturnStmtClass)) {
    134       // If we come across a return here, we don't have anything we can
    135       // reasonably replace. We should have already inserted our destructor
    136       // code in the proper spot, so we just clean up and return.
    137       delete [] UpdatedStmtList;
    138 
    139       return;
    140     }
    141 
    142     UpdatedStmtList[UpdatedStmtCount++] = *bI;
    143 
    144     if ((*bI == S) && !Once) {
    145       Once++;
    146       std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    147       std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    148       for ( ; I != E; I++) {
    149         UpdatedStmtList[UpdatedStmtCount++] = *I;
    150       }
    151     }
    152   }
    153   slangAssert(Once <= 1);
    154 
    155   // When S is NULL, we are appending to the end of the CompoundStmt.
    156   if (!S) {
    157     slangAssert(Once == 0);
    158     std::list<clang::Stmt*>::const_iterator I = StmtList.begin();
    159     std::list<clang::Stmt*>::const_iterator E = StmtList.end();
    160     for ( ; I != E; I++) {
    161       UpdatedStmtList[UpdatedStmtCount++] = *I;
    162     }
    163   }
    164 
    165   CS->setStmts(C, UpdatedStmtList, UpdatedStmtCount);
    166 
    167   delete [] UpdatedStmtList;
    168 
    169   return;
    170 }
    171 
    172 // This class visits a compound statement and inserts DtorStmt
    173 // in proper locations. This includes inserting it before any
    174 // return statement in any sub-block, at the end of the logical enclosing
    175 // scope (compound statement), and/or before any break/continue statement that
    176 // would resume outside the declared scope. We will not handle the case for
    177 // goto statements that leave a local scope.
    178 //
    179 // To accomplish these goals, it collects a list of sub-Stmt's that
    180 // correspond to scope exit points. It then uses an RSASTReplace visitor to
    181 // transform the AST, inserting appropriate destructors before each of those
    182 // sub-Stmt's (and also before the exit of the outermost containing Stmt for
    183 // the scope).
    184 class DestructorVisitor : public clang::StmtVisitor<DestructorVisitor> {
    185  private:
    186   clang::ASTContext &mCtx;
    187 
    188   // The loop depth of the currently visited node.
    189   int mLoopDepth;
    190 
    191   // The switch statement depth of the currently visited node.
    192   // Note that this is tracked separately from the loop depth because
    193   // SwitchStmt-contained ContinueStmt's should have destructors for the
    194   // corresponding loop scope.
    195   int mSwitchDepth;
    196 
    197   // The outermost statement block that we are currently visiting.
    198   // This should always be a CompoundStmt.
    199   clang::Stmt *mOuterStmt;
    200 
    201   // The destructor to execute for this scope/variable.
    202   clang::Stmt* mDtorStmt;
    203 
    204   // The stack of statements which should be replaced by a compound statement
    205   // containing the new destructor call followed by the original Stmt.
    206   std::stack<clang::Stmt*> mReplaceStmtStack;
    207 
    208   // The source location for the variable declaration that we are trying to
    209   // insert destructors for. Note that InsertDestructors() will not generate
    210   // destructor calls for source locations that occur lexically before this
    211   // location.
    212   clang::SourceLocation mVarLoc;
    213 
    214  public:
    215   DestructorVisitor(clang::ASTContext &C,
    216                     clang::Stmt* OuterStmt,
    217                     clang::Stmt* DtorStmt,
    218                     clang::SourceLocation VarLoc);
    219 
    220   // This code walks the collected list of Stmts to replace and actually does
    221   // the replacement. It also finishes up by appending the destructor to the
    222   // current outermost CompoundStmt.
    223   void InsertDestructors() {
    224     clang::Stmt *S = NULL;
    225     clang::SourceManager &SM = mCtx.getSourceManager();
    226     std::list<clang::Stmt *> StmtList;
    227     StmtList.push_back(mDtorStmt);
    228 
    229     while (!mReplaceStmtStack.empty()) {
    230       S = mReplaceStmtStack.top();
    231       mReplaceStmtStack.pop();
    232 
    233       // Skip all source locations that occur before the variable's
    234       // declaration, since it won't have been initialized yet.
    235       if (SM.isBeforeInTranslationUnit(S->getLocStart(), mVarLoc)) {
    236         continue;
    237       }
    238 
    239       StmtList.push_back(S);
    240       clang::CompoundStmt *CS =
    241           BuildCompoundStmt(mCtx, StmtList, S->getLocEnd());
    242       StmtList.pop_back();
    243 
    244       RSASTReplace R(mCtx);
    245       R.ReplaceStmt(mOuterStmt, S, CS);
    246     }
    247     clang::CompoundStmt *CS =
    248       llvm::dyn_cast<clang::CompoundStmt>(mOuterStmt);
    249     slangAssert(CS);
    250     AppendAfterStmt(mCtx, CS, NULL, StmtList);
    251   }
    252 
    253   void VisitStmt(clang::Stmt *S);
    254   void VisitCompoundStmt(clang::CompoundStmt *CS);
    255 
    256   void VisitBreakStmt(clang::BreakStmt *BS);
    257   void VisitCaseStmt(clang::CaseStmt *CS);
    258   void VisitContinueStmt(clang::ContinueStmt *CS);
    259   void VisitDefaultStmt(clang::DefaultStmt *DS);
    260   void VisitDoStmt(clang::DoStmt *DS);
    261   void VisitForStmt(clang::ForStmt *FS);
    262   void VisitIfStmt(clang::IfStmt *IS);
    263   void VisitReturnStmt(clang::ReturnStmt *RS);
    264   void VisitSwitchCase(clang::SwitchCase *SC);
    265   void VisitSwitchStmt(clang::SwitchStmt *SS);
    266   void VisitWhileStmt(clang::WhileStmt *WS);
    267 };
    268 
    269 DestructorVisitor::DestructorVisitor(clang::ASTContext &C,
    270                          clang::Stmt *OuterStmt,
    271                          clang::Stmt *DtorStmt,
    272                          clang::SourceLocation VarLoc)
    273   : mCtx(C),
    274     mLoopDepth(0),
    275     mSwitchDepth(0),
    276     mOuterStmt(OuterStmt),
    277     mDtorStmt(DtorStmt),
    278     mVarLoc(VarLoc) {
    279   return;
    280 }
    281 
    282 void DestructorVisitor::VisitStmt(clang::Stmt *S) {
    283   for (clang::Stmt::child_iterator I = S->child_begin(), E = S->child_end();
    284        I != E;
    285        I++) {
    286     if (clang::Stmt *Child = *I) {
    287       Visit(Child);
    288     }
    289   }
    290   return;
    291 }
    292 
    293 void DestructorVisitor::VisitCompoundStmt(clang::CompoundStmt *CS) {
    294   VisitStmt(CS);
    295   return;
    296 }
    297 
    298 void DestructorVisitor::VisitBreakStmt(clang::BreakStmt *BS) {
    299   VisitStmt(BS);
    300   if ((mLoopDepth == 0) && (mSwitchDepth == 0)) {
    301     mReplaceStmtStack.push(BS);
    302   }
    303   return;
    304 }
    305 
    306 void DestructorVisitor::VisitCaseStmt(clang::CaseStmt *CS) {
    307   VisitStmt(CS);
    308   return;
    309 }
    310 
    311 void DestructorVisitor::VisitContinueStmt(clang::ContinueStmt *CS) {
    312   VisitStmt(CS);
    313   if (mLoopDepth == 0) {
    314     // Switch statements can have nested continues.
    315     mReplaceStmtStack.push(CS);
    316   }
    317   return;
    318 }
    319 
    320 void DestructorVisitor::VisitDefaultStmt(clang::DefaultStmt *DS) {
    321   VisitStmt(DS);
    322   return;
    323 }
    324 
    325 void DestructorVisitor::VisitDoStmt(clang::DoStmt *DS) {
    326   mLoopDepth++;
    327   VisitStmt(DS);
    328   mLoopDepth--;
    329   return;
    330 }
    331 
    332 void DestructorVisitor::VisitForStmt(clang::ForStmt *FS) {
    333   mLoopDepth++;
    334   VisitStmt(FS);
    335   mLoopDepth--;
    336   return;
    337 }
    338 
    339 void DestructorVisitor::VisitIfStmt(clang::IfStmt *IS) {
    340   VisitStmt(IS);
    341   return;
    342 }
    343 
    344 void DestructorVisitor::VisitReturnStmt(clang::ReturnStmt *RS) {
    345   mReplaceStmtStack.push(RS);
    346   return;
    347 }
    348 
    349 void DestructorVisitor::VisitSwitchCase(clang::SwitchCase *SC) {
    350   slangAssert(false && "Both case and default have specialized handlers");
    351   VisitStmt(SC);
    352   return;
    353 }
    354 
    355 void DestructorVisitor::VisitSwitchStmt(clang::SwitchStmt *SS) {
    356   mSwitchDepth++;
    357   VisitStmt(SS);
    358   mSwitchDepth--;
    359   return;
    360 }
    361 
    362 void DestructorVisitor::VisitWhileStmt(clang::WhileStmt *WS) {
    363   mLoopDepth++;
    364   VisitStmt(WS);
    365   mLoopDepth--;
    366   return;
    367 }
    368 
    369 clang::Expr *ClearSingleRSObject(clang::ASTContext &C,
    370                                  clang::Expr *RefRSVar,
    371                                  clang::SourceLocation Loc) {
    372   slangAssert(RefRSVar);
    373   const clang::Type *T = RefRSVar->getType().getTypePtr();
    374   slangAssert(!T->isArrayType() &&
    375               "Should not be destroying arrays with this function");
    376 
    377   clang::FunctionDecl *ClearObjectFD = RSObjectRefCount::GetRSClearObjectFD(T);
    378   slangAssert((ClearObjectFD != NULL) &&
    379               "rsClearObject doesn't cover all RS object types");
    380 
    381   clang::QualType ClearObjectFDType = ClearObjectFD->getType();
    382   clang::QualType ClearObjectFDArgType =
    383       ClearObjectFD->getParamDecl(0)->getOriginalType();
    384 
    385   // Example destructor for "rs_font localFont;"
    386   //
    387   // (CallExpr 'void'
    388   //   (ImplicitCastExpr 'void (*)(rs_font *)' <FunctionToPointerDecay>
    389   //     (DeclRefExpr 'void (rs_font *)' FunctionDecl='rsClearObject'))
    390   //   (UnaryOperator 'rs_font *' prefix '&'
    391   //     (DeclRefExpr 'rs_font':'rs_font' Var='localFont')))
    392 
    393   // Get address of targeted RS object
    394   clang::Expr *AddrRefRSVar =
    395       new(C) clang::UnaryOperator(RefRSVar,
    396                                   clang::UO_AddrOf,
    397                                   ClearObjectFDArgType,
    398                                   clang::VK_RValue,
    399                                   clang::OK_Ordinary,
    400                                   Loc);
    401 
    402   clang::Expr *RefRSClearObjectFD =
    403       clang::DeclRefExpr::Create(C,
    404                                  clang::NestedNameSpecifierLoc(),
    405                                  clang::SourceLocation(),
    406                                  ClearObjectFD,
    407                                  false,
    408                                  ClearObjectFD->getLocation(),
    409                                  ClearObjectFDType,
    410                                  clang::VK_RValue,
    411                                  NULL);
    412 
    413   clang::Expr *RSClearObjectFP =
    414       clang::ImplicitCastExpr::Create(C,
    415                                       C.getPointerType(ClearObjectFDType),
    416                                       clang::CK_FunctionToPointerDecay,
    417                                       RefRSClearObjectFD,
    418                                       NULL,
    419                                       clang::VK_RValue);
    420 
    421   llvm::SmallVector<clang::Expr*, 1> ArgList;
    422   ArgList.push_back(AddrRefRSVar);
    423 
    424   clang::CallExpr *RSClearObjectCall =
    425       new(C) clang::CallExpr(C,
    426                              RSClearObjectFP,
    427                              ArgList,
    428                              ClearObjectFD->getCallResultType(),
    429                              clang::VK_RValue,
    430                              Loc);
    431 
    432   return RSClearObjectCall;
    433 }
    434 
    435 static int ArrayDim(const clang::Type *T) {
    436   if (!T || !T->isArrayType()) {
    437     return 0;
    438   }
    439 
    440   const clang::ConstantArrayType *CAT =
    441     static_cast<const clang::ConstantArrayType *>(T);
    442   return static_cast<int>(CAT->getSize().getSExtValue());
    443 }
    444 
    445 static clang::Stmt *ClearStructRSObject(
    446     clang::ASTContext &C,
    447     clang::DeclContext *DC,
    448     clang::Expr *RefRSStruct,
    449     clang::SourceLocation StartLoc,
    450     clang::SourceLocation Loc);
    451 
    452 static clang::Stmt *ClearArrayRSObject(
    453     clang::ASTContext &C,
    454     clang::DeclContext *DC,
    455     clang::Expr *RefRSArr,
    456     clang::SourceLocation StartLoc,
    457     clang::SourceLocation Loc) {
    458   const clang::Type *BaseType = RefRSArr->getType().getTypePtr();
    459   slangAssert(BaseType->isArrayType());
    460 
    461   int NumArrayElements = ArrayDim(BaseType);
    462   // Actually extract out the base RS object type for use later
    463   BaseType = BaseType->getArrayElementTypeNoTypeQual();
    464 
    465   clang::Stmt *StmtArray[2] = {NULL};
    466   int StmtCtr = 0;
    467 
    468   if (NumArrayElements <= 0) {
    469     return NULL;
    470   }
    471 
    472   // Example destructor loop for "rs_font fontArr[10];"
    473   //
    474   // (CompoundStmt
    475   //   (DeclStmt "int rsIntIter")
    476   //   (ForStmt
    477   //     (BinaryOperator 'int' '='
    478   //       (DeclRefExpr 'int' Var='rsIntIter')
    479   //       (IntegerLiteral 'int' 0))
    480   //     (BinaryOperator 'int' '<'
    481   //       (DeclRefExpr 'int' Var='rsIntIter')
    482   //       (IntegerLiteral 'int' 10)
    483   //     NULL << CondVar >>
    484   //     (UnaryOperator 'int' postfix '++'
    485   //       (DeclRefExpr 'int' Var='rsIntIter'))
    486   //     (CallExpr 'void'
    487   //       (ImplicitCastExpr 'void (*)(rs_font *)' <FunctionToPointerDecay>
    488   //         (DeclRefExpr 'void (rs_font *)' FunctionDecl='rsClearObject'))
    489   //       (UnaryOperator 'rs_font *' prefix '&'
    490   //         (ArraySubscriptExpr 'rs_font':'rs_font'
    491   //           (ImplicitCastExpr 'rs_font *' <ArrayToPointerDecay>
    492   //             (DeclRefExpr 'rs_font [10]' Var='fontArr'))
    493   //           (DeclRefExpr 'int' Var='rsIntIter')))))))
    494 
    495   // Create helper variable for iterating through elements
    496   clang::IdentifierInfo& II = C.Idents.get("rsIntIter");
    497   clang::VarDecl *IIVD =
    498       clang::VarDecl::Create(C,
    499                              DC,
    500                              StartLoc,
    501                              Loc,
    502                              &II,
    503                              C.IntTy,
    504                              C.getTrivialTypeSourceInfo(C.IntTy),
    505                              clang::SC_None,
    506                              clang::SC_None);
    507   clang::Decl *IID = (clang::Decl *)IIVD;
    508 
    509   clang::DeclGroupRef DGR = clang::DeclGroupRef::Create(C, &IID, 1);
    510   StmtArray[StmtCtr++] = new(C) clang::DeclStmt(DGR, Loc, Loc);
    511 
    512   // Form the actual destructor loop
    513   // for (Init; Cond; Inc)
    514   //   RSClearObjectCall;
    515 
    516   // Init -> "rsIntIter = 0"
    517   clang::DeclRefExpr *RefrsIntIter =
    518       clang::DeclRefExpr::Create(C,
    519                                  clang::NestedNameSpecifierLoc(),
    520                                  clang::SourceLocation(),
    521                                  IIVD,
    522                                  false,
    523                                  Loc,
    524                                  C.IntTy,
    525                                  clang::VK_RValue,
    526                                  NULL);
    527 
    528   clang::Expr *Int0 = clang::IntegerLiteral::Create(C,
    529       llvm::APInt(C.getTypeSize(C.IntTy), 0), C.IntTy, Loc);
    530 
    531   clang::BinaryOperator *Init =
    532       new(C) clang::BinaryOperator(RefrsIntIter,
    533                                    Int0,
    534                                    clang::BO_Assign,
    535                                    C.IntTy,
    536                                    clang::VK_RValue,
    537                                    clang::OK_Ordinary,
    538                                    Loc);
    539 
    540   // Cond -> "rsIntIter < NumArrayElements"
    541   clang::Expr *NumArrayElementsExpr = clang::IntegerLiteral::Create(C,
    542       llvm::APInt(C.getTypeSize(C.IntTy), NumArrayElements), C.IntTy, Loc);
    543 
    544   clang::BinaryOperator *Cond =
    545       new(C) clang::BinaryOperator(RefrsIntIter,
    546                                    NumArrayElementsExpr,
    547                                    clang::BO_LT,
    548                                    C.IntTy,
    549                                    clang::VK_RValue,
    550                                    clang::OK_Ordinary,
    551                                    Loc);
    552 
    553   // Inc -> "rsIntIter++"
    554   clang::UnaryOperator *Inc =
    555       new(C) clang::UnaryOperator(RefrsIntIter,
    556                                   clang::UO_PostInc,
    557                                   C.IntTy,
    558                                   clang::VK_RValue,
    559                                   clang::OK_Ordinary,
    560                                   Loc);
    561 
    562   // Body -> "rsClearObject(&VD[rsIntIter]);"
    563   // Destructor loop operates on individual array elements
    564 
    565   clang::Expr *RefRSArrPtr =
    566       clang::ImplicitCastExpr::Create(C,
    567           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    568           clang::CK_ArrayToPointerDecay,
    569           RefRSArr,
    570           NULL,
    571           clang::VK_RValue);
    572 
    573   clang::Expr *RefRSArrPtrSubscript =
    574       new(C) clang::ArraySubscriptExpr(RefRSArrPtr,
    575                                        RefrsIntIter,
    576                                        BaseType->getCanonicalTypeInternal(),
    577                                        clang::VK_RValue,
    578                                        clang::OK_Ordinary,
    579                                        Loc);
    580 
    581   RSExportPrimitiveType::DataType DT =
    582       RSExportPrimitiveType::GetRSSpecificType(BaseType);
    583 
    584   clang::Stmt *RSClearObjectCall = NULL;
    585   if (BaseType->isArrayType()) {
    586     RSClearObjectCall =
    587         ClearArrayRSObject(C, DC, RefRSArrPtrSubscript, StartLoc, Loc);
    588   } else if (DT == RSExportPrimitiveType::DataTypeUnknown) {
    589     RSClearObjectCall =
    590         ClearStructRSObject(C, DC, RefRSArrPtrSubscript, StartLoc, Loc);
    591   } else {
    592     RSClearObjectCall = ClearSingleRSObject(C, RefRSArrPtrSubscript, Loc);
    593   }
    594 
    595   clang::ForStmt *DestructorLoop =
    596       new(C) clang::ForStmt(C,
    597                             Init,
    598                             Cond,
    599                             NULL,  // no condVar
    600                             Inc,
    601                             RSClearObjectCall,
    602                             Loc,
    603                             Loc,
    604                             Loc);
    605 
    606   StmtArray[StmtCtr++] = DestructorLoop;
    607   slangAssert(StmtCtr == 2);
    608 
    609   clang::CompoundStmt *CS =
    610       new(C) clang::CompoundStmt(C, StmtArray, StmtCtr, Loc, Loc);
    611 
    612   return CS;
    613 }
    614 
    615 static unsigned CountRSObjectTypes(clang::ASTContext &C,
    616                                    const clang::Type *T,
    617                                    clang::SourceLocation Loc) {
    618   slangAssert(T);
    619   unsigned RSObjectCount = 0;
    620 
    621   if (T->isArrayType()) {
    622     return CountRSObjectTypes(C, T->getArrayElementTypeNoTypeQual(), Loc);
    623   }
    624 
    625   RSExportPrimitiveType::DataType DT =
    626       RSExportPrimitiveType::GetRSSpecificType(T);
    627   if (DT != RSExportPrimitiveType::DataTypeUnknown) {
    628     return (RSExportPrimitiveType::IsRSObjectType(DT) ? 1 : 0);
    629   }
    630 
    631   if (T->isUnionType()) {
    632     clang::RecordDecl *RD = T->getAsUnionType()->getDecl();
    633     RD = RD->getDefinition();
    634     for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    635            FE = RD->field_end();
    636          FI != FE;
    637          FI++) {
    638       const clang::FieldDecl *FD = *FI;
    639       const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    640       if (CountRSObjectTypes(C, FT, Loc)) {
    641         slangAssert(false && "can't have unions with RS object types!");
    642         return 0;
    643       }
    644     }
    645   }
    646 
    647   if (!T->isStructureType()) {
    648     return 0;
    649   }
    650 
    651   clang::RecordDecl *RD = T->getAsStructureType()->getDecl();
    652   RD = RD->getDefinition();
    653   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    654          FE = RD->field_end();
    655        FI != FE;
    656        FI++) {
    657     const clang::FieldDecl *FD = *FI;
    658     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    659     if (CountRSObjectTypes(C, FT, Loc)) {
    660       // Sub-structs should only count once (as should arrays, etc.)
    661       RSObjectCount++;
    662     }
    663   }
    664 
    665   return RSObjectCount;
    666 }
    667 
    668 static clang::Stmt *ClearStructRSObject(
    669     clang::ASTContext &C,
    670     clang::DeclContext *DC,
    671     clang::Expr *RefRSStruct,
    672     clang::SourceLocation StartLoc,
    673     clang::SourceLocation Loc) {
    674   const clang::Type *BaseType = RefRSStruct->getType().getTypePtr();
    675 
    676   slangAssert(!BaseType->isArrayType());
    677 
    678   // Structs should show up as unknown primitive types
    679   slangAssert(RSExportPrimitiveType::GetRSSpecificType(BaseType) ==
    680               RSExportPrimitiveType::DataTypeUnknown);
    681 
    682   unsigned FieldsToDestroy = CountRSObjectTypes(C, BaseType, Loc);
    683 
    684   unsigned StmtCount = 0;
    685   clang::Stmt **StmtArray = new clang::Stmt*[FieldsToDestroy];
    686   for (unsigned i = 0; i < FieldsToDestroy; i++) {
    687     StmtArray[i] = NULL;
    688   }
    689 
    690   // Populate StmtArray by creating a destructor for each RS object field
    691   clang::RecordDecl *RD = BaseType->getAsStructureType()->getDecl();
    692   RD = RD->getDefinition();
    693   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
    694          FE = RD->field_end();
    695        FI != FE;
    696        FI++) {
    697     // We just look through all field declarations to see if we find a
    698     // declaration for an RS object type (or an array of one).
    699     bool IsArrayType = false;
    700     clang::FieldDecl *FD = *FI;
    701     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
    702     const clang::Type *OrigType = FT;
    703     while (FT && FT->isArrayType()) {
    704       FT = FT->getArrayElementTypeNoTypeQual();
    705       IsArrayType = true;
    706     }
    707 
    708     if (RSExportPrimitiveType::IsRSObjectType(FT)) {
    709       clang::DeclAccessPair FoundDecl =
    710           clang::DeclAccessPair::make(FD, clang::AS_none);
    711       clang::MemberExpr *RSObjectMember =
    712           clang::MemberExpr::Create(C,
    713                                     RefRSStruct,
    714                                     false,
    715                                     clang::NestedNameSpecifierLoc(),
    716                                     clang::SourceLocation(),
    717                                     FD,
    718                                     FoundDecl,
    719                                     clang::DeclarationNameInfo(),
    720                                     NULL,
    721                                     OrigType->getCanonicalTypeInternal(),
    722                                     clang::VK_RValue,
    723                                     clang::OK_Ordinary);
    724 
    725       slangAssert(StmtCount < FieldsToDestroy);
    726 
    727       if (IsArrayType) {
    728         StmtArray[StmtCount++] = ClearArrayRSObject(C,
    729                                                     DC,
    730                                                     RSObjectMember,
    731                                                     StartLoc,
    732                                                     Loc);
    733       } else {
    734         StmtArray[StmtCount++] = ClearSingleRSObject(C,
    735                                                      RSObjectMember,
    736                                                      Loc);
    737       }
    738     } else if (FT->isStructureType() && CountRSObjectTypes(C, FT, Loc)) {
    739       // In this case, we have a nested struct. We may not end up filling all
    740       // of the spaces in StmtArray (sub-structs should handle themselves
    741       // with separate compound statements).
    742       clang::DeclAccessPair FoundDecl =
    743           clang::DeclAccessPair::make(FD, clang::AS_none);
    744       clang::MemberExpr *RSObjectMember =
    745           clang::MemberExpr::Create(C,
    746                                     RefRSStruct,
    747                                     false,
    748                                     clang::NestedNameSpecifierLoc(),
    749                                     clang::SourceLocation(),
    750                                     FD,
    751                                     FoundDecl,
    752                                     clang::DeclarationNameInfo(),
    753                                     NULL,
    754                                     OrigType->getCanonicalTypeInternal(),
    755                                     clang::VK_RValue,
    756                                     clang::OK_Ordinary);
    757 
    758       if (IsArrayType) {
    759         StmtArray[StmtCount++] = ClearArrayRSObject(C,
    760                                                     DC,
    761                                                     RSObjectMember,
    762                                                     StartLoc,
    763                                                     Loc);
    764       } else {
    765         StmtArray[StmtCount++] = ClearStructRSObject(C,
    766                                                      DC,
    767                                                      RSObjectMember,
    768                                                      StartLoc,
    769                                                      Loc);
    770       }
    771     }
    772   }
    773 
    774   slangAssert(StmtCount > 0);
    775   clang::CompoundStmt *CS =
    776       new(C) clang::CompoundStmt(C, StmtArray, StmtCount, Loc, Loc);
    777 
    778   delete [] StmtArray;
    779 
    780   return CS;
    781 }
    782 
    783 static clang::Stmt *CreateSingleRSSetObject(clang::ASTContext &C,
    784                                             clang::Expr *DstExpr,
    785                                             clang::Expr *SrcExpr,
    786                                             clang::SourceLocation StartLoc,
    787                                             clang::SourceLocation Loc) {
    788   const clang::Type *T = DstExpr->getType().getTypePtr();
    789   clang::FunctionDecl *SetObjectFD = RSObjectRefCount::GetRSSetObjectFD(T);
    790   slangAssert((SetObjectFD != NULL) &&
    791               "rsSetObject doesn't cover all RS object types");
    792 
    793   clang::QualType SetObjectFDType = SetObjectFD->getType();
    794   clang::QualType SetObjectFDArgType[2];
    795   SetObjectFDArgType[0] = SetObjectFD->getParamDecl(0)->getOriginalType();
    796   SetObjectFDArgType[1] = SetObjectFD->getParamDecl(1)->getOriginalType();
    797 
    798   clang::Expr *RefRSSetObjectFD =
    799       clang::DeclRefExpr::Create(C,
    800                                  clang::NestedNameSpecifierLoc(),
    801                                  clang::SourceLocation(),
    802                                  SetObjectFD,
    803                                  false,
    804                                  Loc,
    805                                  SetObjectFDType,
    806                                  clang::VK_RValue,
    807                                  NULL);
    808 
    809   clang::Expr *RSSetObjectFP =
    810       clang::ImplicitCastExpr::Create(C,
    811                                       C.getPointerType(SetObjectFDType),
    812                                       clang::CK_FunctionToPointerDecay,
    813                                       RefRSSetObjectFD,
    814                                       NULL,
    815                                       clang::VK_RValue);
    816 
    817   llvm::SmallVector<clang::Expr*, 2> ArgList;
    818   ArgList.push_back(new(C) clang::UnaryOperator(DstExpr,
    819                                                 clang::UO_AddrOf,
    820                                                 SetObjectFDArgType[0],
    821                                                 clang::VK_RValue,
    822                                                 clang::OK_Ordinary,
    823                                                 Loc));
    824   ArgList.push_back(SrcExpr);
    825 
    826   clang::CallExpr *RSSetObjectCall =
    827       new(C) clang::CallExpr(C,
    828                              RSSetObjectFP,
    829                              ArgList,
    830                              SetObjectFD->getCallResultType(),
    831                              clang::VK_RValue,
    832                              Loc);
    833 
    834   return RSSetObjectCall;
    835 }
    836 
    837 static clang::Stmt *CreateStructRSSetObject(clang::ASTContext &C,
    838                                             clang::Expr *LHS,
    839                                             clang::Expr *RHS,
    840                                             clang::SourceLocation StartLoc,
    841                                             clang::SourceLocation Loc);
    842 
    843 /*static clang::Stmt *CreateArrayRSSetObject(clang::ASTContext &C,
    844                                            clang::Expr *DstArr,
    845                                            clang::Expr *SrcArr,
    846                                            clang::SourceLocation StartLoc,
    847                                            clang::SourceLocation Loc) {
    848   clang::DeclContext *DC = NULL;
    849   const clang::Type *BaseType = DstArr->getType().getTypePtr();
    850   slangAssert(BaseType->isArrayType());
    851 
    852   int NumArrayElements = ArrayDim(BaseType);
    853   // Actually extract out the base RS object type for use later
    854   BaseType = BaseType->getArrayElementTypeNoTypeQual();
    855 
    856   clang::Stmt *StmtArray[2] = {NULL};
    857   int StmtCtr = 0;
    858 
    859   if (NumArrayElements <= 0) {
    860     return NULL;
    861   }
    862 
    863   // Create helper variable for iterating through elements
    864   clang::IdentifierInfo& II = C.Idents.get("rsIntIter");
    865   clang::VarDecl *IIVD =
    866       clang::VarDecl::Create(C,
    867                              DC,
    868                              StartLoc,
    869                              Loc,
    870                              &II,
    871                              C.IntTy,
    872                              C.getTrivialTypeSourceInfo(C.IntTy),
    873                              clang::SC_None,
    874                              clang::SC_None);
    875   clang::Decl *IID = (clang::Decl *)IIVD;
    876 
    877   clang::DeclGroupRef DGR = clang::DeclGroupRef::Create(C, &IID, 1);
    878   StmtArray[StmtCtr++] = new(C) clang::DeclStmt(DGR, Loc, Loc);
    879 
    880   // Form the actual loop
    881   // for (Init; Cond; Inc)
    882   //   RSSetObjectCall;
    883 
    884   // Init -> "rsIntIter = 0"
    885   clang::DeclRefExpr *RefrsIntIter =
    886       clang::DeclRefExpr::Create(C,
    887                                  clang::NestedNameSpecifierLoc(),
    888                                  IIVD,
    889                                  Loc,
    890                                  C.IntTy,
    891                                  clang::VK_RValue,
    892                                  NULL);
    893 
    894   clang::Expr *Int0 = clang::IntegerLiteral::Create(C,
    895       llvm::APInt(C.getTypeSize(C.IntTy), 0), C.IntTy, Loc);
    896 
    897   clang::BinaryOperator *Init =
    898       new(C) clang::BinaryOperator(RefrsIntIter,
    899                                    Int0,
    900                                    clang::BO_Assign,
    901                                    C.IntTy,
    902                                    clang::VK_RValue,
    903                                    clang::OK_Ordinary,
    904                                    Loc);
    905 
    906   // Cond -> "rsIntIter < NumArrayElements"
    907   clang::Expr *NumArrayElementsExpr = clang::IntegerLiteral::Create(C,
    908       llvm::APInt(C.getTypeSize(C.IntTy), NumArrayElements), C.IntTy, Loc);
    909 
    910   clang::BinaryOperator *Cond =
    911       new(C) clang::BinaryOperator(RefrsIntIter,
    912                                    NumArrayElementsExpr,
    913                                    clang::BO_LT,
    914                                    C.IntTy,
    915                                    clang::VK_RValue,
    916                                    clang::OK_Ordinary,
    917                                    Loc);
    918 
    919   // Inc -> "rsIntIter++"
    920   clang::UnaryOperator *Inc =
    921       new(C) clang::UnaryOperator(RefrsIntIter,
    922                                   clang::UO_PostInc,
    923                                   C.IntTy,
    924                                   clang::VK_RValue,
    925                                   clang::OK_Ordinary,
    926                                   Loc);
    927 
    928   // Body -> "rsSetObject(&Dst[rsIntIter], Src[rsIntIter]);"
    929   // Loop operates on individual array elements
    930 
    931   clang::Expr *DstArrPtr =
    932       clang::ImplicitCastExpr::Create(C,
    933           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    934           clang::CK_ArrayToPointerDecay,
    935           DstArr,
    936           NULL,
    937           clang::VK_RValue);
    938 
    939   clang::Expr *DstArrPtrSubscript =
    940       new(C) clang::ArraySubscriptExpr(DstArrPtr,
    941                                        RefrsIntIter,
    942                                        BaseType->getCanonicalTypeInternal(),
    943                                        clang::VK_RValue,
    944                                        clang::OK_Ordinary,
    945                                        Loc);
    946 
    947   clang::Expr *SrcArrPtr =
    948       clang::ImplicitCastExpr::Create(C,
    949           C.getPointerType(BaseType->getCanonicalTypeInternal()),
    950           clang::CK_ArrayToPointerDecay,
    951           SrcArr,
    952           NULL,
    953           clang::VK_RValue);
    954 
    955   clang::Expr *SrcArrPtrSubscript =
    956       new(C) clang::ArraySubscriptExpr(SrcArrPtr,
    957                                        RefrsIntIter,
    958                                        BaseType->getCanonicalTypeInternal(),
    959                                        clang::VK_RValue,
    960                                        clang::OK_Ordinary,
    961                                        Loc);
    962 
    963   RSExportPrimitiveType::DataType DT =
    964       RSExportPrimitiveType::GetRSSpecificType(BaseType);
    965 
    966   clang::Stmt *RSSetObjectCall = NULL;
    967   if (BaseType->isArrayType()) {
    968     RSSetObjectCall = CreateArrayRSSetObject(C, DstArrPtrSubscript,
    969                                              SrcArrPtrSubscript,
    970                                              StartLoc, Loc);
    971   } else if (DT == RSExportPrimitiveType::DataTypeUnknown) {
    972     RSSetObjectCall = CreateStructRSSetObject(C, DstArrPtrSubscript,
    973                                               SrcArrPtrSubscript,
    974                                               StartLoc, Loc);
    975   } else {
    976     RSSetObjectCall = CreateSingleRSSetObject(C, DstArrPtrSubscript,
    977                                               SrcArrPtrSubscript,
    978                                               StartLoc, Loc);
    979   }
    980 
    981   clang::ForStmt *DestructorLoop =
    982       new(C) clang::ForStmt(C,
    983                             Init,
    984                             Cond,
    985                             NULL,  // no condVar
    986                             Inc,
    987                             RSSetObjectCall,
    988                             Loc,
    989                             Loc,
    990                             Loc);
    991 
    992   StmtArray[StmtCtr++] = DestructorLoop;
    993   slangAssert(StmtCtr == 2);
    994 
    995   clang::CompoundStmt *CS =
    996       new(C) clang::CompoundStmt(C, StmtArray, StmtCtr, Loc, Loc);
    997 
    998   return CS;
    999 } */
   1000 
   1001 static clang::Stmt *CreateStructRSSetObject(clang::ASTContext &C,
   1002                                             clang::Expr *LHS,
   1003                                             clang::Expr *RHS,
   1004                                             clang::SourceLocation StartLoc,
   1005                                             clang::SourceLocation Loc) {
   1006   clang::QualType QT = LHS->getType();
   1007   const clang::Type *T = QT.getTypePtr();
   1008   slangAssert(T->isStructureType());
   1009   slangAssert(!RSExportPrimitiveType::IsRSObjectType(T));
   1010 
   1011   // Keep an extra slot for the original copy (memcpy)
   1012   unsigned FieldsToSet = CountRSObjectTypes(C, T, Loc) + 1;
   1013 
   1014   unsigned StmtCount = 0;
   1015   clang::Stmt **StmtArray = new clang::Stmt*[FieldsToSet];
   1016   for (unsigned i = 0; i < FieldsToSet; i++) {
   1017     StmtArray[i] = NULL;
   1018   }
   1019 
   1020   clang::RecordDecl *RD = T->getAsStructureType()->getDecl();
   1021   RD = RD->getDefinition();
   1022   for (clang::RecordDecl::field_iterator FI = RD->field_begin(),
   1023          FE = RD->field_end();
   1024        FI != FE;
   1025        FI++) {
   1026     bool IsArrayType = false;
   1027     clang::FieldDecl *FD = *FI;
   1028     const clang::Type *FT = RSExportType::GetTypeOfDecl(FD);
   1029     const clang::Type *OrigType = FT;
   1030 
   1031     if (!CountRSObjectTypes(C, FT, Loc)) {
   1032       // Skip to next if we don't have any viable RS object types
   1033       continue;
   1034     }
   1035 
   1036     clang::DeclAccessPair FoundDecl =
   1037         clang::DeclAccessPair::make(FD, clang::AS_none);
   1038     clang::MemberExpr *DstMember =
   1039         clang::MemberExpr::Create(C,
   1040                                   LHS,
   1041                                   false,
   1042                                   clang::NestedNameSpecifierLoc(),
   1043                                   clang::SourceLocation(),
   1044                                   FD,
   1045                                   FoundDecl,
   1046                                   clang::DeclarationNameInfo(),
   1047                                   NULL,
   1048                                   OrigType->getCanonicalTypeInternal(),
   1049                                   clang::VK_RValue,
   1050                                   clang::OK_Ordinary);
   1051 
   1052     clang::MemberExpr *SrcMember =
   1053         clang::MemberExpr::Create(C,
   1054                                   RHS,
   1055                                   false,
   1056                                   clang::NestedNameSpecifierLoc(),
   1057                                   clang::SourceLocation(),
   1058                                   FD,
   1059                                   FoundDecl,
   1060                                   clang::DeclarationNameInfo(),
   1061                                   NULL,
   1062                                   OrigType->getCanonicalTypeInternal(),
   1063                                   clang::VK_RValue,
   1064                                   clang::OK_Ordinary);
   1065 
   1066     if (FT->isArrayType()) {
   1067       FT = FT->getArrayElementTypeNoTypeQual();
   1068       IsArrayType = true;
   1069     }
   1070 
   1071     RSExportPrimitiveType::DataType DT =
   1072         RSExportPrimitiveType::GetRSSpecificType(FT);
   1073 
   1074     if (IsArrayType) {
   1075       clang::DiagnosticsEngine &DiagEngine = C.getDiagnostics();
   1076       DiagEngine.Report(
   1077         clang::FullSourceLoc(Loc, C.getSourceManager()),
   1078         DiagEngine.getCustomDiagID(
   1079           clang::DiagnosticsEngine::Error,
   1080           "Arrays of RS object types within structures cannot be copied"));
   1081       // TODO(srhines): Support setting arrays of RS objects
   1082       // StmtArray[StmtCount++] =
   1083       //    CreateArrayRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1084     } else if (DT == RSExportPrimitiveType::DataTypeUnknown) {
   1085       StmtArray[StmtCount++] =
   1086           CreateStructRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1087     } else if (RSExportPrimitiveType::IsRSObjectType(DT)) {
   1088       StmtArray[StmtCount++] =
   1089           CreateSingleRSSetObject(C, DstMember, SrcMember, StartLoc, Loc);
   1090     } else {
   1091       slangAssert(false);
   1092     }
   1093   }
   1094 
   1095   slangAssert(StmtCount > 0 && StmtCount < FieldsToSet);
   1096 
   1097   // We still need to actually do the overall struct copy. For simplicity,
   1098   // we just do a straight-up assignment (which will still preserve all
   1099   // the proper RS object reference counts).
   1100   clang::BinaryOperator *CopyStruct =
   1101       new(C) clang::BinaryOperator(LHS, RHS, clang::BO_Assign, QT,
   1102                                    clang::VK_RValue, clang::OK_Ordinary, Loc);
   1103   StmtArray[StmtCount++] = CopyStruct;
   1104 
   1105   clang::CompoundStmt *CS =
   1106       new(C) clang::CompoundStmt(C, StmtArray, StmtCount, Loc, Loc);
   1107 
   1108   delete [] StmtArray;
   1109 
   1110   return CS;
   1111 }
   1112 
   1113 }  // namespace
   1114 
   1115 void RSObjectRefCount::Scope::ReplaceRSObjectAssignment(
   1116     clang::BinaryOperator *AS) {
   1117 
   1118   clang::QualType QT = AS->getType();
   1119 
   1120   clang::ASTContext &C = RSObjectRefCount::GetRSSetObjectFD(
   1121       RSExportPrimitiveType::DataTypeRSFont)->getASTContext();
   1122 
   1123   clang::SourceLocation Loc = AS->getExprLoc();
   1124   clang::SourceLocation StartLoc = AS->getLHS()->getExprLoc();
   1125   clang::Stmt *UpdatedStmt = NULL;
   1126 
   1127   if (!RSExportPrimitiveType::IsRSObjectType(QT.getTypePtr())) {
   1128     // By definition, this is a struct assignment if we get here
   1129     UpdatedStmt =
   1130         CreateStructRSSetObject(C, AS->getLHS(), AS->getRHS(), StartLoc, Loc);
   1131   } else {
   1132     UpdatedStmt =
   1133         CreateSingleRSSetObject(C, AS->getLHS(), AS->getRHS(), StartLoc, Loc);
   1134   }
   1135 
   1136   RSASTReplace R(C);
   1137   R.ReplaceStmt(mCS, AS, UpdatedStmt);
   1138   return;
   1139 }
   1140 
   1141 void RSObjectRefCount::Scope::AppendRSObjectInit(
   1142     clang::VarDecl *VD,
   1143     clang::DeclStmt *DS,
   1144     RSExportPrimitiveType::DataType DT,
   1145     clang::Expr *InitExpr) {
   1146   slangAssert(VD);
   1147 
   1148   if (!InitExpr) {
   1149     return;
   1150   }
   1151 
   1152   clang::ASTContext &C = RSObjectRefCount::GetRSSetObjectFD(
   1153       RSExportPrimitiveType::DataTypeRSFont)->getASTContext();
   1154   clang::SourceLocation Loc = RSObjectRefCount::GetRSSetObjectFD(
   1155       RSExportPrimitiveType::DataTypeRSFont)->getLocation();
   1156   clang::SourceLocation StartLoc = RSObjectRefCount::GetRSSetObjectFD(
   1157       RSExportPrimitiveType::DataTypeRSFont)->getInnerLocStart();
   1158 
   1159   if (DT == RSExportPrimitiveType::DataTypeIsStruct) {
   1160     const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1161     clang::DeclRefExpr *RefRSVar =
   1162         clang::DeclRefExpr::Create(C,
   1163                                    clang::NestedNameSpecifierLoc(),
   1164                                    clang::SourceLocation(),
   1165                                    VD,
   1166                                    false,
   1167                                    Loc,
   1168                                    T->getCanonicalTypeInternal(),
   1169                                    clang::VK_RValue,
   1170                                    NULL);
   1171 
   1172     clang::Stmt *RSSetObjectOps =
   1173         CreateStructRSSetObject(C, RefRSVar, InitExpr, StartLoc, Loc);
   1174 
   1175     std::list<clang::Stmt*> StmtList;
   1176     StmtList.push_back(RSSetObjectOps);
   1177     AppendAfterStmt(C, mCS, DS, StmtList);
   1178     return;
   1179   }
   1180 
   1181   clang::FunctionDecl *SetObjectFD = RSObjectRefCount::GetRSSetObjectFD(DT);
   1182   slangAssert((SetObjectFD != NULL) &&
   1183               "rsSetObject doesn't cover all RS object types");
   1184 
   1185   clang::QualType SetObjectFDType = SetObjectFD->getType();
   1186   clang::QualType SetObjectFDArgType[2];
   1187   SetObjectFDArgType[0] = SetObjectFD->getParamDecl(0)->getOriginalType();
   1188   SetObjectFDArgType[1] = SetObjectFD->getParamDecl(1)->getOriginalType();
   1189 
   1190   clang::Expr *RefRSSetObjectFD =
   1191       clang::DeclRefExpr::Create(C,
   1192                                  clang::NestedNameSpecifierLoc(),
   1193                                  clang::SourceLocation(),
   1194                                  SetObjectFD,
   1195                                  false,
   1196                                  Loc,
   1197                                  SetObjectFDType,
   1198                                  clang::VK_RValue,
   1199                                  NULL);
   1200 
   1201   clang::Expr *RSSetObjectFP =
   1202       clang::ImplicitCastExpr::Create(C,
   1203                                       C.getPointerType(SetObjectFDType),
   1204                                       clang::CK_FunctionToPointerDecay,
   1205                                       RefRSSetObjectFD,
   1206                                       NULL,
   1207                                       clang::VK_RValue);
   1208 
   1209   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1210   clang::DeclRefExpr *RefRSVar =
   1211       clang::DeclRefExpr::Create(C,
   1212                                  clang::NestedNameSpecifierLoc(),
   1213                                  clang::SourceLocation(),
   1214                                  VD,
   1215                                  false,
   1216                                  Loc,
   1217                                  T->getCanonicalTypeInternal(),
   1218                                  clang::VK_RValue,
   1219                                  NULL);
   1220 
   1221   llvm::SmallVector<clang::Expr*, 2> ArgList;
   1222   ArgList.push_back(new(C) clang::UnaryOperator(RefRSVar,
   1223                                                 clang::UO_AddrOf,
   1224                                                 SetObjectFDArgType[0],
   1225                                                 clang::VK_RValue,
   1226                                                 clang::OK_Ordinary,
   1227                                                 Loc));
   1228   ArgList.push_back(InitExpr);
   1229 
   1230   clang::CallExpr *RSSetObjectCall =
   1231       new(C) clang::CallExpr(C,
   1232                              RSSetObjectFP,
   1233                              ArgList,
   1234                              SetObjectFD->getCallResultType(),
   1235                              clang::VK_RValue,
   1236                              Loc);
   1237 
   1238   std::list<clang::Stmt*> StmtList;
   1239   StmtList.push_back(RSSetObjectCall);
   1240   AppendAfterStmt(C, mCS, DS, StmtList);
   1241 
   1242   return;
   1243 }
   1244 
   1245 void RSObjectRefCount::Scope::InsertLocalVarDestructors() {
   1246   for (std::list<clang::VarDecl*>::const_iterator I = mRSO.begin(),
   1247           E = mRSO.end();
   1248         I != E;
   1249         I++) {
   1250     clang::VarDecl *VD = *I;
   1251     clang::Stmt *RSClearObjectCall = ClearRSObject(VD, VD->getDeclContext());
   1252     if (RSClearObjectCall) {
   1253       DestructorVisitor DV((*mRSO.begin())->getASTContext(),
   1254                            mCS,
   1255                            RSClearObjectCall,
   1256                            VD->getSourceRange().getBegin());
   1257       DV.Visit(mCS);
   1258       DV.InsertDestructors();
   1259     }
   1260   }
   1261   return;
   1262 }
   1263 
   1264 clang::Stmt *RSObjectRefCount::Scope::ClearRSObject(
   1265     clang::VarDecl *VD,
   1266     clang::DeclContext *DC) {
   1267   slangAssert(VD);
   1268   clang::ASTContext &C = VD->getASTContext();
   1269   clang::SourceLocation Loc = VD->getLocation();
   1270   clang::SourceLocation StartLoc = VD->getInnerLocStart();
   1271   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1272 
   1273   // Reference expr to target RS object variable
   1274   clang::DeclRefExpr *RefRSVar =
   1275       clang::DeclRefExpr::Create(C,
   1276                                  clang::NestedNameSpecifierLoc(),
   1277                                  clang::SourceLocation(),
   1278                                  VD,
   1279                                  false,
   1280                                  Loc,
   1281                                  T->getCanonicalTypeInternal(),
   1282                                  clang::VK_RValue,
   1283                                  NULL);
   1284 
   1285   if (T->isArrayType()) {
   1286     return ClearArrayRSObject(C, DC, RefRSVar, StartLoc, Loc);
   1287   }
   1288 
   1289   RSExportPrimitiveType::DataType DT =
   1290       RSExportPrimitiveType::GetRSSpecificType(T);
   1291 
   1292   if (DT == RSExportPrimitiveType::DataTypeUnknown ||
   1293       DT == RSExportPrimitiveType::DataTypeIsStruct) {
   1294     return ClearStructRSObject(C, DC, RefRSVar, StartLoc, Loc);
   1295   }
   1296 
   1297   slangAssert((RSExportPrimitiveType::IsRSObjectType(DT)) &&
   1298               "Should be RS object");
   1299 
   1300   return ClearSingleRSObject(C, RefRSVar, Loc);
   1301 }
   1302 
   1303 bool RSObjectRefCount::InitializeRSObject(clang::VarDecl *VD,
   1304                                           RSExportPrimitiveType::DataType *DT,
   1305                                           clang::Expr **InitExpr) {
   1306   slangAssert(VD && DT && InitExpr);
   1307   const clang::Type *T = RSExportType::GetTypeOfDecl(VD);
   1308 
   1309   // Loop through array types to get to base type
   1310   while (T && T->isArrayType()) {
   1311     T = T->getArrayElementTypeNoTypeQual();
   1312   }
   1313 
   1314   bool DataTypeIsStructWithRSObject = false;
   1315   *DT = RSExportPrimitiveType::GetRSSpecificType(T);
   1316 
   1317   if (*DT == RSExportPrimitiveType::DataTypeUnknown) {
   1318     if (RSExportPrimitiveType::IsStructureTypeWithRSObject(T)) {
   1319       *DT = RSExportPrimitiveType::DataTypeIsStruct;
   1320       DataTypeIsStructWithRSObject = true;
   1321     } else {
   1322       return false;
   1323     }
   1324   }
   1325 
   1326   bool DataTypeIsRSObject = false;
   1327   if (DataTypeIsStructWithRSObject) {
   1328     DataTypeIsRSObject = true;
   1329   } else {
   1330     DataTypeIsRSObject = RSExportPrimitiveType::IsRSObjectType(*DT);
   1331   }
   1332   *InitExpr = VD->getInit();
   1333 
   1334   if (!DataTypeIsRSObject && *InitExpr) {
   1335     // If we already have an initializer for a matrix type, we are done.
   1336     return DataTypeIsRSObject;
   1337   }
   1338 
   1339   clang::Expr *ZeroInitializer =
   1340       CreateZeroInitializerForRSSpecificType(*DT,
   1341                                              VD->getASTContext(),
   1342                                              VD->getLocation());
   1343 
   1344   if (ZeroInitializer) {
   1345     ZeroInitializer->setType(T->getCanonicalTypeInternal());
   1346     VD->setInit(ZeroInitializer);
   1347   }
   1348 
   1349   return DataTypeIsRSObject;
   1350 }
   1351 
   1352 clang::Expr *RSObjectRefCount::CreateZeroInitializerForRSSpecificType(
   1353     RSExportPrimitiveType::DataType DT,
   1354     clang::ASTContext &C,
   1355     const clang::SourceLocation &Loc) {
   1356   clang::Expr *Res = NULL;
   1357   switch (DT) {
   1358     case RSExportPrimitiveType::DataTypeIsStruct:
   1359     case RSExportPrimitiveType::DataTypeRSElement:
   1360     case RSExportPrimitiveType::DataTypeRSType:
   1361     case RSExportPrimitiveType::DataTypeRSAllocation:
   1362     case RSExportPrimitiveType::DataTypeRSSampler:
   1363     case RSExportPrimitiveType::DataTypeRSScript:
   1364     case RSExportPrimitiveType::DataTypeRSMesh:
   1365     case RSExportPrimitiveType::DataTypeRSPath:
   1366     case RSExportPrimitiveType::DataTypeRSProgramFragment:
   1367     case RSExportPrimitiveType::DataTypeRSProgramVertex:
   1368     case RSExportPrimitiveType::DataTypeRSProgramRaster:
   1369     case RSExportPrimitiveType::DataTypeRSProgramStore:
   1370     case RSExportPrimitiveType::DataTypeRSFont: {
   1371       //    (ImplicitCastExpr 'nullptr_t'
   1372       //      (IntegerLiteral 0)))
   1373       llvm::APInt Zero(C.getTypeSize(C.IntTy), 0);
   1374       clang::Expr *Int0 = clang::IntegerLiteral::Create(C, Zero, C.IntTy, Loc);
   1375       clang::Expr *CastToNull =
   1376           clang::ImplicitCastExpr::Create(C,
   1377                                           C.NullPtrTy,
   1378                                           clang::CK_IntegralToPointer,
   1379                                           Int0,
   1380                                           NULL,
   1381                                           clang::VK_RValue);
   1382 
   1383       llvm::SmallVector<clang::Expr*, 1>InitList;
   1384       InitList.push_back(CastToNull);
   1385 
   1386       Res = new(C) clang::InitListExpr(C, Loc, InitList, Loc);
   1387       break;
   1388     }
   1389     case RSExportPrimitiveType::DataTypeRSMatrix2x2:
   1390     case RSExportPrimitiveType::DataTypeRSMatrix3x3:
   1391     case RSExportPrimitiveType::DataTypeRSMatrix4x4: {
   1392       // RS matrix is not completely an RS object. They hold data by themselves.
   1393       // (InitListExpr rs_matrix2x2
   1394       //   (InitListExpr float[4]
   1395       //     (FloatingLiteral 0)
   1396       //     (FloatingLiteral 0)
   1397       //     (FloatingLiteral 0)
   1398       //     (FloatingLiteral 0)))
   1399       clang::QualType FloatTy = C.FloatTy;
   1400       // Constructor sets value to 0.0f by default
   1401       llvm::APFloat Val(C.getFloatTypeSemantics(FloatTy));
   1402       clang::FloatingLiteral *Float0Val =
   1403           clang::FloatingLiteral::Create(C,
   1404                                          Val,
   1405                                          /* isExact = */true,
   1406                                          FloatTy,
   1407                                          Loc);
   1408 
   1409       unsigned N = 0;
   1410       if (DT == RSExportPrimitiveType::DataTypeRSMatrix2x2)
   1411         N = 2;
   1412       else if (DT == RSExportPrimitiveType::DataTypeRSMatrix3x3)
   1413         N = 3;
   1414       else if (DT == RSExportPrimitiveType::DataTypeRSMatrix4x4)
   1415         N = 4;
   1416       unsigned N_2 = N * N;
   1417 
   1418       // Assume we are going to be allocating 16 elements, since 4x4 is max.
   1419       llvm::SmallVector<clang::Expr*, 16> InitVals;
   1420       for (unsigned i = 0; i < N_2; i++)
   1421         InitVals.push_back(Float0Val);
   1422       clang::Expr *InitExpr =
   1423           new(C) clang::InitListExpr(C, Loc, InitVals, Loc);
   1424       InitExpr->setType(C.getConstantArrayType(FloatTy,
   1425                                                llvm::APInt(32, N_2),
   1426                                                clang::ArrayType::Normal,
   1427                                                /* EltTypeQuals = */0));
   1428       llvm::SmallVector<clang::Expr*, 1> InitExprVec;
   1429       InitExprVec.push_back(InitExpr);
   1430 
   1431       Res = new(C) clang::InitListExpr(C, Loc, InitExprVec, Loc);
   1432       break;
   1433     }
   1434     case RSExportPrimitiveType::DataTypeUnknown:
   1435     case RSExportPrimitiveType::DataTypeFloat16:
   1436     case RSExportPrimitiveType::DataTypeFloat32:
   1437     case RSExportPrimitiveType::DataTypeFloat64:
   1438     case RSExportPrimitiveType::DataTypeSigned8:
   1439     case RSExportPrimitiveType::DataTypeSigned16:
   1440     case RSExportPrimitiveType::DataTypeSigned32:
   1441     case RSExportPrimitiveType::DataTypeSigned64:
   1442     case RSExportPrimitiveType::DataTypeUnsigned8:
   1443     case RSExportPrimitiveType::DataTypeUnsigned16:
   1444     case RSExportPrimitiveType::DataTypeUnsigned32:
   1445     case RSExportPrimitiveType::DataTypeUnsigned64:
   1446     case RSExportPrimitiveType::DataTypeBoolean:
   1447     case RSExportPrimitiveType::DataTypeUnsigned565:
   1448     case RSExportPrimitiveType::DataTypeUnsigned5551:
   1449     case RSExportPrimitiveType::DataTypeUnsigned4444:
   1450     case RSExportPrimitiveType::DataTypeMax: {
   1451       slangAssert(false && "Not RS object type!");
   1452     }
   1453     // No default case will enable compiler detecting the missing cases
   1454   }
   1455 
   1456   return Res;
   1457 }
   1458 
   1459 void RSObjectRefCount::VisitDeclStmt(clang::DeclStmt *DS) {
   1460   for (clang::DeclStmt::decl_iterator I = DS->decl_begin(), E = DS->decl_end();
   1461        I != E;
   1462        I++) {
   1463     clang::Decl *D = *I;
   1464     if (D->getKind() == clang::Decl::Var) {
   1465       clang::VarDecl *VD = static_cast<clang::VarDecl*>(D);
   1466       RSExportPrimitiveType::DataType DT =
   1467           RSExportPrimitiveType::DataTypeUnknown;
   1468       clang::Expr *InitExpr = NULL;
   1469       if (InitializeRSObject(VD, &DT, &InitExpr)) {
   1470         getCurrentScope()->addRSObject(VD);
   1471         getCurrentScope()->AppendRSObjectInit(VD, DS, DT, InitExpr);
   1472       }
   1473     }
   1474   }
   1475   return;
   1476 }
   1477 
   1478 void RSObjectRefCount::VisitCompoundStmt(clang::CompoundStmt *CS) {
   1479   if (!CS->body_empty()) {
   1480     // Push a new scope
   1481     Scope *S = new Scope(CS);
   1482     mScopeStack.push(S);
   1483 
   1484     VisitStmt(CS);
   1485 
   1486     // Destroy the scope
   1487     slangAssert((getCurrentScope() == S) && "Corrupted scope stack!");
   1488     S->InsertLocalVarDestructors();
   1489     mScopeStack.pop();
   1490     delete S;
   1491   }
   1492   return;
   1493 }
   1494 
   1495 void RSObjectRefCount::VisitBinAssign(clang::BinaryOperator *AS) {
   1496   clang::QualType QT = AS->getType();
   1497 
   1498   if (CountRSObjectTypes(mCtx, QT.getTypePtr(), AS->getExprLoc())) {
   1499     getCurrentScope()->ReplaceRSObjectAssignment(AS);
   1500   }
   1501 
   1502   return;
   1503 }
   1504 
   1505 void RSObjectRefCount::VisitStmt(clang::Stmt *S) {
   1506   for (clang::Stmt::child_iterator I = S->child_begin(), E = S->child_end();
   1507        I != E;
   1508        I++) {
   1509     if (clang::Stmt *Child = *I) {
   1510       Visit(Child);
   1511     }
   1512   }
   1513   return;
   1514 }
   1515 
   1516 // This function walks the list of global variables and (potentially) creates
   1517 // a single global static destructor function that properly decrements
   1518 // reference counts on the contained RS object types.
   1519 clang::FunctionDecl *RSObjectRefCount::CreateStaticGlobalDtor() {
   1520   Init();
   1521 
   1522   clang::DeclContext *DC = mCtx.getTranslationUnitDecl();
   1523   clang::SourceLocation loc;
   1524 
   1525   llvm::StringRef SR(".rs.dtor");
   1526   clang::IdentifierInfo &II = mCtx.Idents.get(SR);
   1527   clang::DeclarationName N(&II);
   1528   clang::FunctionProtoType::ExtProtoInfo EPI;
   1529   clang::QualType T = mCtx.getFunctionType(mCtx.VoidTy, NULL, 0, EPI);
   1530   clang::FunctionDecl *FD = NULL;
   1531 
   1532   // Generate rsClearObject() call chains for every global variable
   1533   // (whether static or extern).
   1534   std::list<clang::Stmt *> StmtList;
   1535   for (clang::DeclContext::decl_iterator I = DC->decls_begin(),
   1536           E = DC->decls_end(); I != E; I++) {
   1537     clang::VarDecl *VD = llvm::dyn_cast<clang::VarDecl>(*I);
   1538     if (VD) {
   1539       if (CountRSObjectTypes(mCtx, VD->getType().getTypePtr(), loc)) {
   1540         if (!FD) {
   1541           // Only create FD if we are going to use it.
   1542           FD = clang::FunctionDecl::Create(mCtx, DC, loc, loc, N, T, NULL);
   1543         }
   1544         // Make sure to create any helpers within the function's DeclContext,
   1545         // not the one associated with the global translation unit.
   1546         clang::Stmt *RSClearObjectCall = Scope::ClearRSObject(VD, FD);
   1547         StmtList.push_back(RSClearObjectCall);
   1548       }
   1549     }
   1550   }
   1551 
   1552   // Nothing needs to be destroyed, so don't emit a dtor.
   1553   if (StmtList.empty()) {
   1554     return NULL;
   1555   }
   1556 
   1557   clang::CompoundStmt *CS = BuildCompoundStmt(mCtx, StmtList, loc);
   1558 
   1559   FD->setBody(CS);
   1560 
   1561   return FD;
   1562 }
   1563 
   1564 }  // namespace slang
   1565