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#ifndef _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_OBJECT_REF_COUNT_H_  // NOLINT
18#define _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_OBJECT_REF_COUNT_H_
19
20#include <list>
21#include <stack>
22
23#include "clang/AST/StmtVisitor.h"
24
25#include "slang_assert.h"
26#include "slang_rs_export_type.h"
27
28namespace clang {
29  class Expr;
30  class Stmt;
31}
32
33namespace slang {
34
35// This class provides the overall reference counting mechanism for handling
36// local variables of RS object types (rs_font, rs_allocation, ...). This
37// class ensures that appropriate functions (rsSetObject, rsClearObject) are
38// called at proper points in the object's lifetime.
39// 1) Each local object of appropriate type must be zero-initialized (to
40// prevent corruption) during subsequent rsSetObject()/rsClearObject() calls.
41// 2) Assignments using these types must also be converted into the
42// appropriate (possibly a series of) rsSetObject() calls.
43// 3) Finally, each local object must call rsClearObject() when it goes out
44// of scope.
45class RSObjectRefCount : public clang::StmtVisitor<RSObjectRefCount> {
46 private:
47  class Scope {
48   private:
49    clang::CompoundStmt *mCS;      // Associated compound statement ({ ... })
50    std::list<clang::VarDecl*> mRSO;  // Declared RS objects in this scope
51
52   public:
53    explicit Scope(clang::CompoundStmt *CS) : mCS(CS) {
54    }
55
56    inline void addRSObject(clang::VarDecl* VD) {
57      mRSO.push_back(VD);
58    }
59
60    void ReplaceRSObjectAssignment(clang::BinaryOperator *AS);
61
62    void AppendRSObjectInit(clang::VarDecl *VD,
63                            clang::DeclStmt *DS,
64                            DataType DT,
65                            clang::Expr *InitExpr);
66
67    void InsertLocalVarDestructors();
68
69    static clang::Stmt *ClearRSObject(clang::VarDecl *VD,
70                                      clang::DeclContext *DC);
71  };
72
73  clang::ASTContext &mCtx;
74  std::stack<Scope*> mScopeStack;
75  bool RSInitFD;
76
77  // RSSetObjectFD and RSClearObjectFD holds FunctionDecl of rsSetObject()
78  // and rsClearObject() in the current ASTContext.
79  static clang::FunctionDecl *RSSetObjectFD[];
80  static clang::FunctionDecl *RSClearObjectFD[];
81
82  inline Scope *getCurrentScope() {
83    return mScopeStack.top();
84  }
85
86  // Initialize RSSetObjectFD and RSClearObjectFD.
87  static void GetRSRefCountingFunctions(clang::ASTContext &C);
88
89  // Return false if the type of variable declared in VD does not contain
90  // an RS object type.
91  static bool InitializeRSObject(clang::VarDecl *VD,
92                                 DataType *DT,
93                                 clang::Expr **InitExpr);
94
95  // Return a zero-initializer expr of the type DT. This processes both
96  // RS matrix type and RS object type.
97  static clang::Expr *CreateZeroInitializerForRSSpecificType(
98      DataType DT,
99      clang::ASTContext &C,
100      const clang::SourceLocation &Loc);
101
102 public:
103  explicit RSObjectRefCount(clang::ASTContext &C)
104      : mCtx(C),
105        RSInitFD(false) {
106  }
107
108  void Init() {
109    if (!RSInitFD) {
110      GetRSRefCountingFunctions(mCtx);
111      RSInitFD = true;
112    }
113  }
114
115  static clang::FunctionDecl *GetRSSetObjectFD(DataType DT) {
116    slangAssert(RSExportPrimitiveType::IsRSObjectType(DT));
117    if (DT >= 0 && DT < DataTypeMax) {
118      return RSSetObjectFD[DT];
119    } else {
120      slangAssert(false && "incorrect type");
121      return NULL;
122    }
123  }
124
125  static clang::FunctionDecl *GetRSSetObjectFD(const clang::Type *T) {
126    return GetRSSetObjectFD(RSExportPrimitiveType::GetRSSpecificType(T));
127  }
128
129  static clang::FunctionDecl *GetRSClearObjectFD(DataType DT) {
130    slangAssert(RSExportPrimitiveType::IsRSObjectType(DT));
131    if (DT >= 0 && DT < DataTypeMax) {
132      return RSClearObjectFD[DT];
133    } else {
134      slangAssert(false && "incorrect type");
135      return NULL;
136    }
137  }
138
139  static clang::FunctionDecl *GetRSClearObjectFD(const clang::Type *T) {
140    return GetRSClearObjectFD(RSExportPrimitiveType::GetRSSpecificType(T));
141  }
142
143  void VisitStmt(clang::Stmt *S);
144  void VisitDeclStmt(clang::DeclStmt *DS);
145  void VisitCompoundStmt(clang::CompoundStmt *CS);
146  void VisitBinAssign(clang::BinaryOperator *AS);
147  // We believe that RS objects are never involved in CompoundAssignOperator.
148  // I.e., rs_allocation foo; foo += bar;
149
150  // Emit a global destructor to clean up RS objects.
151  clang::FunctionDecl *CreateStaticGlobalDtor();
152};
153
154}  // namespace slang
155
156#endif  // _FRAMEWORKS_COMPILE_SLANG_SLANG_RS_OBJECT_REF_COUNT_H_  NOLINT
157