Implemented validation for loop and indexing limitations specified by GLSL ES…

include/GLSLANG/ShaderLang.h

@@ -17,7 +17,7 @@ extern "C" {
 
 // Version number for shader translation API.
 // It is incremented everytime the API changes.
-#define SH_VERSION 102
+#define SH_VERSION 103
 
 //
 // The names of the following enums have been derived by replacing GL prefix
@@ -68,11 +68,10 @@ typedef enum {
 // Compile options.
 typedef enum {
   SH_VALIDATE               = 0,
-  SH_VALIDATE_CONTROL_FLOW = 0x0001,
-  SH_VALIDATE_INDEXING     = 0x0002,
-  SH_INTERMEDIATE_TREE     = 0x0004,
-  SH_OBJECT_CODE           = 0x0008,
-  SH_ATTRIBUTES_UNIFORMS   = 0x0010
+  SH_VALIDATE_LOOP_INDEXING = 0x0001,
+  SH_INTERMEDIATE_TREE      = 0x0002,
+  SH_OBJECT_CODE            = 0x0004,
+  SH_ATTRIBUTES_UNIFORMS    = 0x0008
 } ShCompileOptions;
 
 //
@@ -146,16 +145,12 @@ void ShDestruct(ShHandle handle);
 // compileOptions: A mask containing the following parameters:
 // SH_VALIDATE: Validates shader to ensure that it conforms to the spec
 //              specified during compiler construction.
-// SH_VALIDATE_CONTROL_FLOW: Validates control flow in the shader to ensure
-//                           that they do not exceed the minimum functionality
-//                           mandated in GLSL 1.0 spec, Appendix A, Section 4.
+// SH_VALIDATE_LOOP_INDEXING: Validates loop and indexing in the shader to
+//                            ensure that they do not exceed the minimum
+//                            functionality mandated in GLSL 1.0 spec,
+//                            Appendix A, Section 4 and 5.
 //                            There is no need to specify this parameter when
 //                            compiling for WebGL - it is implied.
-// SH_VALIDATE_INDEXING: Validates indexing of arrays, vectors, and matrices
-//                       in the shader to ensure that they do not exceed the
-//                       minimum functionality mandated in GLSL 1.0 spec,
-//                       Appendix A, Section 5. There is no need to specify this
-//                       parameter when compiling for WebGL - it is implied.
 // SH_INTERMEDIATE_TREE: Writes intermediate tree to info log.
 //                       Can be queried by calling ShGetInfoLog().
 // SH_OBJECT_CODE: Translates intermediate tree to glsl or hlsl shader.

src/build_angle.gyp

@@ -59,6 +59,8 @@
         'compiler/unistd.h',
         'compiler/util.cpp',
         'compiler/util.h',
+        'compiler/ValidateLimitations.cpp',
+        'compiler/ValidateLimitations.h',
         'compiler/VariableInfo.cpp',
         'compiler/VariableInfo.h',
         'compiler/preprocessor/atom.c',

src/compiler/Compiler.cpp

@@ -7,6 +7,7 @@
 #include "compiler/Initialize.h"
 #include "compiler/ParseHelper.h"
 #include "compiler/ShHandle.h"
+#include "compiler/ValidateLimitations.h"
 
 namespace {
 bool InitializeSymbolTable(
@@ -110,10 +111,9 @@ bool TCompiler::compile(const char* const shaderStrings[],
     if (numStrings == 0)
         return true;
 
-    // If compiling for WebGL, validate control-flow and indexing as well.
-    if (shaderSpec == SH_WEBGL_SPEC) {
-        compileOptions |= SH_VALIDATE_CONTROL_FLOW | SH_VALIDATE_INDEXING;
-    }
+    // If compiling for WebGL, validate loop and indexing as well.
+    if (shaderSpec == SH_WEBGL_SPEC)
+        compileOptions |= SH_VALIDATE_LOOP_INDEXING;
 
     TIntermediate intermediate(infoSink);
     TParseContext parseContext(symbolTable, extensionBehavior, intermediate,
@@ -131,16 +131,20 @@ bool TCompiler::compile(const char* const shaderStrings[],
         (PaParseStrings(numStrings, shaderStrings, NULL, &parseContext) == 0) &&
         (parseContext.treeRoot != NULL);
     if (success) {
-        success = intermediate.postProcess(parseContext.treeRoot);
+        TIntermNode* root = parseContext.treeRoot;
+        success = intermediate.postProcess(root);
+
+        if (success && (compileOptions & SH_VALIDATE_LOOP_INDEXING))
+            success = validateLimitations(root);
 
         if (success && (compileOptions & SH_INTERMEDIATE_TREE))
-            intermediate.outputTree(parseContext.treeRoot);
+            intermediate.outputTree(root);
 
         if (success && (compileOptions & SH_OBJECT_CODE))
-            translate(parseContext.treeRoot);
+            translate(root);
 
         if (success && (compileOptions & SH_ATTRIBUTES_UNIFORMS))
-            collectAttribsUniforms(parseContext.treeRoot);
+            collectAttribsUniforms(root);
     }
 
     // Cleanup memory.
@@ -172,6 +176,12 @@ void TCompiler::clearResults()
     uniforms.clear();
 }
 
+bool TCompiler::validateLimitations(TIntermNode* root) {
+    ValidateLimitations validate(shaderType, infoSink.info);
+    root->traverse(&validate);
+    return validate.numErrors() == 0;
+}
+
 void TCompiler::collectAttribsUniforms(TIntermNode* root)
 {
     CollectAttribsUniforms collect(attribs, uniforms);

src/compiler/Intermediate.cpp

@@ -22,6 +22,101 @@ static TPrecision GetHigherPrecision( TPrecision left, TPrecision right ){
     return left > right ? left : right;
 }
 
+const char* getOperatorString(TOperator op) {
+    switch (op) {
+      case EOpInitialize: return "=";
+      case EOpAssign: return "=";
+      case EOpAddAssign: return "+=";
+      case EOpSubAssign: return "-=";
+      case EOpDivAssign: return "/=";
+
+      // Fall-through.
+      case EOpMulAssign: 
+      case EOpVectorTimesMatrixAssign:
+      case EOpVectorTimesScalarAssign:
+      case EOpMatrixTimesScalarAssign:
+      case EOpMatrixTimesMatrixAssign: return "*=";
+
+      // Fall-through.
+      case EOpIndexDirect:
+      case EOpIndexIndirect: return "[]";
+
+      case EOpIndexDirectStruct: return ".";
+      case EOpVectorSwizzle: return ".";
+      case EOpAdd: return "+";
+      case EOpSub: return "-";
+      case EOpMul: return "*";
+      case EOpDiv: return "/";
+      case EOpMod: UNIMPLEMENTED(); break;
+      case EOpEqual: return "==";
+      case EOpNotEqual: return "!=";
+      case EOpLessThan: return "<";
+      case EOpGreaterThan: return ">";
+      case EOpLessThanEqual: return "<=";
+      case EOpGreaterThanEqual: return ">=";
+
+      // Fall-through.
+      case EOpVectorTimesScalar:
+      case EOpVectorTimesMatrix:
+      case EOpMatrixTimesVector:
+      case EOpMatrixTimesScalar:
+      case EOpMatrixTimesMatrix: return "*";
+
+      case EOpLogicalOr: return "||";
+      case EOpLogicalXor: return "^^";
+      case EOpLogicalAnd: return "&&";
+      case EOpNegative: return "-";
+      case EOpVectorLogicalNot: return "not";
+      case EOpLogicalNot: return "!";
+      case EOpPostIncrement: return "++";
+      case EOpPostDecrement: return "--";
+      case EOpPreIncrement: return "++";
+      case EOpPreDecrement: return "--";
+
+      // Fall-through.
+      case EOpConvIntToBool:
+      case EOpConvFloatToBool: return "bool";
+ 
+      // Fall-through.
+      case EOpConvBoolToFloat:
+      case EOpConvIntToFloat: return "float";
+ 
+      // Fall-through.
+      case EOpConvFloatToInt:
+      case EOpConvBoolToInt: return "int";
+
+      case EOpRadians: return "radians";
+      case EOpDegrees: return "degrees";
+      case EOpSin: return "sin";
+      case EOpCos: return "cos";
+      case EOpTan: return "tan";
+      case EOpAsin: return "asin";
+      case EOpAcos: return "acos";
+      case EOpAtan: return "atan";
+      case EOpExp: return "exp";
+      case EOpLog: return "log";
+      case EOpExp2: return "exp2";
+      case EOpLog2: return "log2";
+      case EOpSqrt: return "sqrt";
+      case EOpInverseSqrt: return "inversesqrt";
+      case EOpAbs: return "abs";
+      case EOpSign: return "sign";
+      case EOpFloor: return "floor";
+      case EOpCeil: return "ceil";
+      case EOpFract: return "fract";
+      case EOpLength: return "length";
+      case EOpNormalize: return "normalize";
+      case EOpDFdx: return "dFdx";
+      case EOpDFdy: return "dFdy";
+      case EOpFwidth: return "fwidth";
+      case EOpAny: return "any";
+      case EOpAll: return "all";
+
+      default: break;
+    }
+    return "";
+}
+
 ////////////////////////////////////////////////////////////////////////////
 //
 // First set of functions are to help build the intermediate representation.

src/compiler/ShHandle.h

@@ -65,6 +65,9 @@ protected:
     bool InitBuiltInSymbolTable(const ShBuiltInResources& resources);
     // Clears the results from the previous compilation.
     void clearResults();
+    // Returns true if the given shader does not exceed the minimum
+    // functionality mandated in GLSL 1.0 spec Appendix A.
+    bool validateLimitations(TIntermNode* root);
     // Collect info for all attribs and uniforms.
     void collectAttribsUniforms(TIntermNode* root);
     // Translate to object code.

src/compiler/ValidateLimitations.h

+//
+// Copyright (c) 2010 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+
+#include "GLSLANG/ShaderLang.h"
+#include "compiler/intermediate.h"
+
+class TInfoSinkBase;
+
+struct TLoopInfo {
+    struct TIndex {
+        int id;  // symbol id.
+    } index;
+};
+typedef TVector<TLoopInfo> TLoopStack;
+
+// Traverses intermediate tree to ensure that the shader does not exceed the
+// minimum functionality mandated in GLSL 1.0 spec, Appendix A.
+class ValidateLimitations : public TIntermTraverser {
+public:
+    ValidateLimitations(ShShaderType shaderType, TInfoSinkBase& sink);
+
+    int numErrors() const { return mNumErrors; }
+
+    virtual void visitSymbol(TIntermSymbol*);
+    virtual void visitConstantUnion(TIntermConstantUnion*);
+    virtual bool visitBinary(Visit, TIntermBinary*);
+    virtual bool visitUnary(Visit, TIntermUnary*);
+    virtual bool visitSelection(Visit, TIntermSelection*);
+    virtual bool visitAggregate(Visit, TIntermAggregate*);
+    virtual bool visitLoop(Visit, TIntermLoop*);
+    virtual bool visitBranch(Visit, TIntermBranch*);
+
+private:
+    void error(TSourceLoc loc, const char *reason, const char* token);
+
+    bool withinLoopBody() const;
+    bool isLoopIndex(const TIntermSymbol* symbol) const;
+    bool validateLoopType(TIntermLoop* node);
+    bool validateForLoopHeader(TIntermLoop* node, TLoopInfo* info);
+    bool validateForLoopInit(TIntermLoop* node, TLoopInfo* info);
+    bool validateForLoopCond(TIntermLoop* node, TLoopInfo* info);
+    bool validateForLoopExpr(TIntermLoop* node, TLoopInfo* info);
+    // Returns true if none of the loop indices is used as the argument to
+    // the given function out or inout parameter.
+    bool validateFunctionCall(TIntermAggregate* node);
+    bool validateOperation(TIntermOperator* node, TIntermNode* operand);
+
+    // Returns true if indexing does not exceed the minimum functionality
+    // mandated in GLSL 1.0 spec, Appendix A, Section 5.
+    bool isConstExpr(TIntermNode* node);
+    bool isConstIndexExpr(TIntermNode* node);
+    bool validateIndexing(TIntermBinary* node);
+
+    ShShaderType mShaderType;
+    TInfoSinkBase& mSink;
+    int mNumErrors;
+    TLoopStack mLoopStack;
+};
+

src/compiler/intermediate.h

@@ -184,6 +184,8 @@ enum TOperator {
     EOpDivAssign,
 };
 
+extern const char* getOperatorString(TOperator op);
+
 class TIntermTraverser;
 class TIntermAggregate;
 class TIntermBinary;