michael@0: //
michael@0: // Copyright (c) 2002-2012 The ANGLE Project Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: //
michael@0: 
michael@0: #include "compiler/VersionGLSL.h"
michael@0: 
michael@0: static const int GLSL_VERSION_110 = 110;
michael@0: static const int GLSL_VERSION_120 = 120;
michael@0: 
michael@0: // We need to scan for the following:
michael@0: // 1. "invariant" keyword: This can occur in both - vertex and fragment shaders
michael@0: //    but only at the global scope.
michael@0: // 2. "gl_PointCoord" built-in variable: This can only occur in fragment shader
michael@0: //    but inside any scope.
michael@0: // 3. Call to a matrix constructor with another matrix as argument.
michael@0: //    (These constructors were reserved in GLSL version 1.10.)
michael@0: // 4. Arrays as "out" function parameters.
michael@0: //    GLSL spec section 6.1.1: "When calling a function, expressions that do
michael@0: //    not evaluate to l-values cannot be passed to parameters declared as
michael@0: //    out or inout."
michael@0: //    GLSL 1.1 section 5.8: "Other binary or unary expressions,
michael@0: //    non-dereferenced arrays, function names, swizzles with repeated fields,
michael@0: //    and constants cannot be l-values."
michael@0: //    GLSL 1.2 relaxed the restriction on arrays, section 5.8: "Variables that
michael@0: //    are built-in types, entire structures or arrays... are all l-values."
michael@0: //
michael@0: // TODO(alokp): The following two cases of invariant decalaration get lost
michael@0: // during parsing - they do not get carried over to the intermediate tree.
michael@0: // Handle these cases:
michael@0: // 1. When a pragma is used to force all output variables to be invariant:
michael@0: //    - #pragma STDGL invariant(all)
michael@0: // 2. When a previously decalared or built-in variable is marked invariant:
michael@0: //    - invariant gl_Position;
michael@0: //    - varying vec3 color; invariant color;
michael@0: //
michael@0: TVersionGLSL::TVersionGLSL(ShShaderType type)
michael@0:     : mShaderType(type),
michael@0:       mVersion(GLSL_VERSION_110)
michael@0: {
michael@0: }
michael@0: 
michael@0: void TVersionGLSL::visitSymbol(TIntermSymbol* node)
michael@0: {
michael@0:     if (node->getSymbol() == "gl_PointCoord")
michael@0:         updateVersion(GLSL_VERSION_120);
michael@0: }
michael@0: 
michael@0: void TVersionGLSL::visitConstantUnion(TIntermConstantUnion*)
michael@0: {
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitBinary(Visit, TIntermBinary*)
michael@0: {
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitUnary(Visit, TIntermUnary*)
michael@0: {
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitSelection(Visit, TIntermSelection*)
michael@0: {
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitAggregate(Visit, TIntermAggregate* node)
michael@0: {
michael@0:     bool visitChildren = true;
michael@0: 
michael@0:     switch (node->getOp()) {
michael@0:       case EOpSequence:
michael@0:         // We need to visit sequence children to get to global or inner scope.
michael@0:         visitChildren = true;
michael@0:         break;
michael@0:       case EOpDeclaration: {
michael@0:         const TIntermSequence& sequence = node->getSequence();
michael@0:         TQualifier qualifier = sequence.front()->getAsTyped()->getQualifier();
michael@0:         if ((qualifier == EvqInvariantVaryingIn) ||
michael@0:             (qualifier == EvqInvariantVaryingOut)) {
michael@0:             updateVersion(GLSL_VERSION_120);
michael@0:         }
michael@0:         break;
michael@0:       }
michael@0:       case EOpParameters: {
michael@0:         const TIntermSequence& params = node->getSequence();
michael@0:         for (TIntermSequence::const_iterator iter = params.begin();
michael@0:              iter != params.end(); ++iter)
michael@0:         {
michael@0:             const TIntermTyped* param = (*iter)->getAsTyped();
michael@0:             if (param->isArray())
michael@0:             {
michael@0:                 TQualifier qualifier = param->getQualifier();
michael@0:                 if ((qualifier == EvqOut) || (qualifier ==  EvqInOut))
michael@0:                 {
michael@0:                     updateVersion(GLSL_VERSION_120);
michael@0:                     break;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:         // Fully processed. No need to visit children.
michael@0:         visitChildren = false;
michael@0:         break;
michael@0:       }
michael@0:       case EOpConstructMat2:
michael@0:       case EOpConstructMat3:
michael@0:       case EOpConstructMat4: {
michael@0:         const TIntermSequence& sequence = node->getSequence();
michael@0:         if (sequence.size() == 1) {
michael@0:           TIntermTyped* typed = sequence.front()->getAsTyped();
michael@0:           if (typed && typed->isMatrix()) {
michael@0:             updateVersion(GLSL_VERSION_120);
michael@0:           }
michael@0:         }
michael@0:         break;
michael@0:       }
michael@0: 
michael@0:       default: break;
michael@0:     }
michael@0: 
michael@0:     return visitChildren;
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitLoop(Visit, TIntermLoop*)
michael@0: {
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool TVersionGLSL::visitBranch(Visit, TIntermBranch*)
michael@0: {
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: void TVersionGLSL::updateVersion(int version)
michael@0: {
michael@0:     mVersion = std::max(version, mVersion);
michael@0: }
michael@0: