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1 //
2 // Copyright (c) 2002-2013 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 "compiler/translator/BuiltInFunctionEmulator.h"
18 #include "compiler/translator/ExtensionBehavior.h"
19 #include "compiler/translator/HashNames.h"
20 #include "compiler/translator/InfoSink.h"
21 #include "compiler/translator/SymbolTable.h"
22 #include "compiler/translator/VariableInfo.h"
23 #include "third_party/compiler/ArrayBoundsClamper.h"
24 
25 class TCompiler;
26 class TDependencyGraph;
27 class TranslatorHLSL;
28 
29 //
30 // Helper function to identify specs that are based on the WebGL spec,
31 // like the CSS Shaders spec.
32 //
33 bool IsWebGLBasedSpec(ShShaderSpec spec);
34 
35 //
36 // The base class used to back handles returned to the driver.
37 //
38 class TShHandleBase {
39 public:
40     TShHandleBase();
41     virtual ~TShHandleBase();
getAsCompiler()42     virtual TCompiler* getAsCompiler() { return 0; }
getAsTranslatorHLSL()43     virtual TranslatorHLSL* getAsTranslatorHLSL() { return 0; }
44 
45 protected:
46     // Memory allocator. Allocates and tracks memory required by the compiler.
47     // Deallocates all memory when compiler is destructed.
48     TPoolAllocator allocator;
49 };
50 
51 //
52 // The base class for the machine dependent compiler to derive from
53 // for managing object code from the compile.
54 //
55 class TCompiler : public TShHandleBase {
56 public:
57     TCompiler(ShShaderType type, ShShaderSpec spec, ShShaderOutput output);
58     virtual ~TCompiler();
getAsCompiler()59     virtual TCompiler* getAsCompiler() { return this; }
60 
61     bool Init(const ShBuiltInResources& resources);
62     bool compile(const char* const shaderStrings[],
63                  size_t numStrings,
64                  int compileOptions);
65 
66     // Get results of the last compilation.
getShaderVersion()67     int getShaderVersion() const { return shaderVersion; }
getInfoSink()68     TInfoSink& getInfoSink() { return infoSink; }
getAttribs()69     const TVariableInfoList& getAttribs() const { return attribs; }
getUniforms()70     const TVariableInfoList& getUniforms() const { return uniforms; }
getVaryings()71     const TVariableInfoList& getVaryings() const { return varyings; }
72 
getHashFunction()73     ShHashFunction64 getHashFunction() const { return hashFunction; }
getNameMap()74     NameMap& getNameMap() { return nameMap; }
getSymbolTable()75     TSymbolTable& getSymbolTable() { return symbolTable; }
getShaderSpec()76     ShShaderSpec getShaderSpec() const { return shaderSpec; }
getOutputType()77     ShShaderOutput getOutputType() const { return outputType; }
getBuiltInResourcesString()78     std::string getBuiltInResourcesString() const { return builtInResourcesString; }
79 
80 protected:
getShaderType()81     ShShaderType getShaderType() const { return shaderType; }
82     // Initialize symbol-table with built-in symbols.
83     bool InitBuiltInSymbolTable(const ShBuiltInResources& resources);
84     // Compute the string representation of the built-in resources
85     void setResourceString();
86     // Clears the results from the previous compilation.
87     void clearResults();
88     // Return true if function recursion is detected or call depth exceeded.
89     bool detectCallDepth(TIntermNode* root, TInfoSink& infoSink, bool limitCallStackDepth);
90     // Returns true if a program has no conflicting or missing fragment outputs
91     bool validateOutputs(TIntermNode* root);
92     // Rewrites a shader's intermediate tree according to the CSS Shaders spec.
93     void rewriteCSSShader(TIntermNode* root);
94     // Returns true if the given shader does not exceed the minimum
95     // functionality mandated in GLSL 1.0 spec Appendix A.
96     bool validateLimitations(TIntermNode* root);
97     // Collect info for all attribs, uniforms, varyings.
98     void collectVariables(TIntermNode* root);
99     // Translate to object code.
100     virtual void translate(TIntermNode* root) = 0;
101     // Returns true if, after applying the packing rules in the GLSL 1.017 spec
102     // Appendix A, section 7, the shader does not use too many uniforms.
103     bool enforcePackingRestrictions();
104     // Insert statements to initialize varyings without static use in the beginning
105     // of main(). It is to work around a Mac driver where such varyings in a vertex
106     // shader may be optimized out incorrectly at compile time, causing a link failure.
107     // This function should only be applied to vertex shaders.
108     void initializeVaryingsWithoutStaticUse(TIntermNode* root);
109     // Insert gl_Position = vec4(0,0,0,0) to the beginning of main().
110     // It is to work around a Linux driver bug where missing this causes compile failure
111     // while spec says it is allowed.
112     // This function should only be applied to vertex shaders.
113     void initializeGLPosition(TIntermNode* root);
114     // Returns true if the shader passes the restrictions that aim to prevent timing attacks.
115     bool enforceTimingRestrictions(TIntermNode* root, bool outputGraph);
116     // Returns true if the shader does not use samplers.
117     bool enforceVertexShaderTimingRestrictions(TIntermNode* root);
118     // Returns true if the shader does not use sampler dependent values to affect control
119     // flow or in operations whose time can depend on the input values.
120     bool enforceFragmentShaderTimingRestrictions(const TDependencyGraph& graph);
121     // Return true if the maximum expression complexity is below the limit.
122     bool limitExpressionComplexity(TIntermNode* root);
123     // Get built-in extensions with default behavior.
124     const TExtensionBehavior& getExtensionBehavior() const;
125     // Get the resources set by InitBuiltInSymbolTable
126     const ShBuiltInResources& getResources() const;
127 
128     const ArrayBoundsClamper& getArrayBoundsClamper() const;
129     ShArrayIndexClampingStrategy getArrayIndexClampingStrategy() const;
130     const BuiltInFunctionEmulator& getBuiltInFunctionEmulator() const;
131 
132 private:
133     ShShaderType shaderType;
134     ShShaderSpec shaderSpec;
135     ShShaderOutput outputType;
136 
137     int maxUniformVectors;
138     int maxExpressionComplexity;
139     int maxCallStackDepth;
140 
141     ShBuiltInResources compileResources;
142     std::string builtInResourcesString;
143 
144     // Built-in symbol table for the given language, spec, and resources.
145     // It is preserved from compile-to-compile.
146     TSymbolTable symbolTable;
147     // Built-in extensions with default behavior.
148     TExtensionBehavior extensionBehavior;
149     bool fragmentPrecisionHigh;
150 
151     ArrayBoundsClamper arrayBoundsClamper;
152     ShArrayIndexClampingStrategy clampingStrategy;
153     BuiltInFunctionEmulator builtInFunctionEmulator;
154 
155     // Results of compilation.
156     int shaderVersion;
157     TInfoSink infoSink;  // Output sink.
158     TVariableInfoList attribs;  // Active attributes in the compiled shader.
159     TVariableInfoList uniforms;  // Active uniforms in the compiled shader.
160     TVariableInfoList varyings;  // Varyings in the compiled shader.
161 
162     // name hashing.
163     ShHashFunction64 hashFunction;
164     NameMap nameMap;
165 };
166 
167 //
168 // This is the interface between the machine independent code
169 // and the machine dependent code.
170 //
171 // The machine dependent code should derive from the classes
172 // above. Then Construct*() and Delete*() will create and
173 // destroy the machine dependent objects, which contain the
174 // above machine independent information.
175 //
176 TCompiler* ConstructCompiler(
177     ShShaderType type, ShShaderSpec spec, ShShaderOutput output);
178 void DeleteCompiler(TCompiler*);
179 
180 #endif // _SHHANDLE_INCLUDED_
181