Line data    Source code

       1             : /*
       2             :  * Copyright 2016 Google Inc.
       3             :  *
       4             :  * Use of this source code is governed by a BSD-style license that can be
       5             :  * found in the LICENSE file.
       6             :  */
       7             : 
       8             : #ifndef SKSL_VARIABLE
       9             : #define SKSL_VARIABLE
      10             : 
      11             : #include "SkSLModifiers.h"
      12             : #include "SkSLPosition.h"
      13             : #include "SkSLSymbol.h"
      14             : #include "SkSLType.h"
      15             : 
      16             : namespace SkSL {
      17             : 
      18             : /**
      19             :  * Represents a variable, whether local, global, or a function parameter. This represents the
      20             :  * variable itself (the storage location), which is shared between all VariableReferences which
      21             :  * read or write that storage location.
      22             :  */
      23           0 : struct Variable : public Symbol {
      24             :     enum Storage {
      25             :         kGlobal_Storage,
      26             :         kLocal_Storage,
      27             :         kParameter_Storage
      28             :     };
      29             : 
      30           0 :     Variable(Position position, Modifiers modifiers, String name, const Type& type,
      31             :              Storage storage)
      32           0 :     : INHERITED(position, kVariable_Kind, std::move(name))
      33             :     , fModifiers(modifiers)
      34             :     , fType(type)
      35             :     , fStorage(storage)
      36             :     , fReadCount(0)
      37           0 :     , fWriteCount(0) {}
      38             : 
      39           0 :     virtual String description() const override {
      40           0 :         return fModifiers.description() + fType.fName + " " + fName;
      41             :     }
      42             : 
      43             :     mutable Modifiers fModifiers;
      44             :     const Type& fType;
      45             :     const Storage fStorage;
      46             : 
      47             :     // Tracks how many sites read from the variable. If this is zero for a non-out variable (or
      48             :     // becomes zero during optimization), the variable is dead and may be eliminated.
      49             :     mutable int fReadCount;
      50             :     // Tracks how many sites write to the variable. If this is zero, the variable is dead and may be
      51             :     // eliminated.
      52             :     mutable int fWriteCount;
      53             : 
      54             :     typedef Symbol INHERITED;
      55             : };
      56             : 
      57             : } // namespace SkSL
      58             : 
      59             : #endif