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      1 //
      2 // Copyright (c) 2002-2012 The ANGLE Project Authors. All rights reserved.
      3 // Use of this source code is governed by a BSD-style license that can be
      4 // found in the LICENSE file.
      5 //
      6 
      7 #ifndef _SHHANDLE_INCLUDED_
      8 #define _SHHANDLE_INCLUDED_
      9 
     10 //
     11 // Machine independent part of the compiler private objects
     12 // sent as ShHandle to the driver.
     13 //
     14 // This should not be included by driver code.
     15 //
     16 
     17 #include "GLSLANG/ShaderLang.h"
     18 
     19 #include "compiler/BuiltInFunctionEmulator.h"
     20 #include "compiler/ExtensionBehavior.h"
     21 #include "compiler/HashNames.h"
     22 #include "compiler/InfoSink.h"
     23 #include "compiler/SymbolTable.h"
     24 #include "compiler/VariableInfo.h"
     25 #include "third_party/compiler/ArrayBoundsClamper.h"
     26 
     27 class LongNameMap;
     28 class TCompiler;
     29 class TDependencyGraph;
     30 class TranslatorHLSL;
     31 
     32 //
     33 // Helper function to identify specs that are based on the WebGL spec,
     34 // like the CSS Shaders spec.
     35 //
     36 bool isWebGLBasedSpec(ShShaderSpec spec);
     37 
     38 //
     39 // The base class used to back handles returned to the driver.
     40 //
     41 class TShHandleBase {
     42 public:
     43     TShHandleBase();
     44     virtual ~TShHandleBase();
     45     virtual TCompiler* getAsCompiler() { return 0; }
     46     virtual TranslatorHLSL* getAsTranslatorHLSL() { return 0; }
     47 
     48 protected:
     49     // Memory allocator. Allocates and tracks memory required by the compiler.
     50     // Deallocates all memory when compiler is destructed.
     51     TPoolAllocator allocator;
     52 };
     53 
     54 //
     55 // The base class for the machine dependent compiler to derive from
     56 // for managing object code from the compile.
     57 //
     58 class TCompiler : public TShHandleBase {
     59 public:
     60     TCompiler(ShShaderType type, ShShaderSpec spec);
     61     virtual ~TCompiler();
     62     virtual TCompiler* getAsCompiler() { return this; }
     63 
     64     bool Init(const ShBuiltInResources& resources);
     65     bool compile(const char* const shaderStrings[],
     66                  size_t numStrings,
     67                  int compileOptions);
     68 
     69     // Get results of the last compilation.
     70     TInfoSink& getInfoSink() { return infoSink; }
     71     const TVariableInfoList& getAttribs() const { return attribs; }
     72     const TVariableInfoList& getUniforms() const { return uniforms; }
     73     int getMappedNameMaxLength() const;
     74 
     75     ShHashFunction64 getHashFunction() const { return hashFunction; }
     76     NameMap& getNameMap() { return nameMap; }
     77     TSymbolTable& getSymbolTable() { return symbolTable; }
     78 
     79 protected:
     80     ShShaderType getShaderType() const { return shaderType; }
     81     ShShaderSpec getShaderSpec() const { return shaderSpec; }
     82     // Initialize symbol-table with built-in symbols.
     83     bool InitBuiltInSymbolTable(const ShBuiltInResources& resources);
     84     // Clears the results from the previous compilation.
     85     void clearResults();
     86     // Return true if function recursion is detected or call depth exceeded.
     87     bool detectCallDepth(TIntermNode* root, TInfoSink& infoSink, bool limitCallStackDepth);
     88     // Rewrites a shader's intermediate tree according to the CSS Shaders spec.
     89     void rewriteCSSShader(TIntermNode* root);
     90     // Returns true if the given shader does not exceed the minimum
     91     // functionality mandated in GLSL 1.0 spec Appendix A.
     92     bool validateLimitations(TIntermNode* root);
     93     // Collect info for all attribs and uniforms.
     94     void collectAttribsUniforms(TIntermNode* root);
     95     // Map long variable names into shorter ones.
     96     void mapLongVariableNames(TIntermNode* root);
     97     // Translate to object code.
     98     virtual void translate(TIntermNode* root) = 0;
     99     // Returns true if, after applying the packing rules in the GLSL 1.017 spec
    100     // Appendix A, section 7, the shader does not use too many uniforms.
    101     bool enforcePackingRestrictions();
    102     // Returns true if the shader passes the restrictions that aim to prevent timing attacks.
    103     bool enforceTimingRestrictions(TIntermNode* root, bool outputGraph);
    104     // Returns true if the shader does not use samplers.
    105     bool enforceVertexShaderTimingRestrictions(TIntermNode* root);
    106     // Returns true if the shader does not use sampler dependent values to affect control
    107     // flow or in operations whose time can depend on the input values.
    108     bool enforceFragmentShaderTimingRestrictions(const TDependencyGraph& graph);
    109     // Return true if the maximum expression complexity below the limit.
    110     bool limitExpressionComplexity(TIntermNode* root);
    111     // Get built-in extensions with default behavior.
    112     const TExtensionBehavior& getExtensionBehavior() const;
    113     // Get the resources set by InitBuiltInSymbolTable
    114     const ShBuiltInResources& getResources() const;
    115 
    116     const ArrayBoundsClamper& getArrayBoundsClamper() const;
    117     ShArrayIndexClampingStrategy getArrayIndexClampingStrategy() const;
    118     const BuiltInFunctionEmulator& getBuiltInFunctionEmulator() const;
    119 
    120 private:
    121     ShShaderType shaderType;
    122     ShShaderSpec shaderSpec;
    123 
    124     int maxUniformVectors;
    125     int maxExpressionComplexity;
    126     int maxCallStackDepth;
    127 
    128     ShBuiltInResources compileResources;
    129 
    130     // Built-in symbol table for the given language, spec, and resources.
    131     // It is preserved from compile-to-compile.
    132     TSymbolTable symbolTable;
    133     // Built-in extensions with default behavior.
    134     TExtensionBehavior extensionBehavior;
    135     bool fragmentPrecisionHigh;
    136 
    137     ArrayBoundsClamper arrayBoundsClamper;
    138     ShArrayIndexClampingStrategy clampingStrategy;
    139     BuiltInFunctionEmulator builtInFunctionEmulator;
    140 
    141     // Results of compilation.
    142     TInfoSink infoSink;  // Output sink.
    143     TVariableInfoList attribs;  // Active attributes in the compiled shader.
    144     TVariableInfoList uniforms;  // Active uniforms in the compiled shader.
    145 
    146     // Cached copy of the ref-counted singleton.
    147     LongNameMap* longNameMap;
    148 
    149     // name hashing.
    150     ShHashFunction64 hashFunction;
    151     NameMap nameMap;
    152 };
    153 
    154 //
    155 // This is the interface between the machine independent code
    156 // and the machine dependent code.
    157 //
    158 // The machine dependent code should derive from the classes
    159 // above. Then Construct*() and Delete*() will create and
    160 // destroy the machine dependent objects, which contain the
    161 // above machine independent information.
    162 //
    163 TCompiler* ConstructCompiler(
    164     ShShaderType type, ShShaderSpec spec, ShShaderOutput output);
    165 void DeleteCompiler(TCompiler*);
    166 
    167 #endif // _SHHANDLE_INCLUDED_
    168