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//
// Copyright 2002 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 "compiler/translator/ValidateGlobalInitializer.h"
#include "compiler/translator/tree_util/IntermTraverse.h"
namespace sh
{
namespace
{
const int kMaxAllowedTraversalDepth = 256;
class ValidateGlobalInitializerTraverser : public TIntermTraverser
{
public:
ValidateGlobalInitializerTraverser(int shaderVersion,
bool isWebGL,
bool hasExtNonConstGlobalInitializers);
void visitSymbol(TIntermSymbol *node) override;
void visitConstantUnion(TIntermConstantUnion *node) override;
bool visitAggregate(Visit visit, TIntermAggregate *node) override;
bool visitBinary(Visit visit, TIntermBinary *node) override;
bool visitUnary(Visit visit, TIntermUnary *node) override;
bool isValid() const { return mIsValid && mMaxDepth < mMaxAllowedDepth; }
bool issueWarning() const { return mIssueWarning; }
private:
ANGLE_INLINE void onNonConstInitializerVisit(bool accept)
{
if (accept)
{
if (!mExtNonConstGlobalInitializers)
{
mIssueWarning = true;
}
}
else
{
mIsValid = false;
}
}
int mShaderVersion;
bool mIsWebGL;
bool mExtNonConstGlobalInitializers;
bool mIsValid;
bool mIssueWarning;
};
void ValidateGlobalInitializerTraverser::visitSymbol(TIntermSymbol *node)
{
// ESSL 1.00 section 4.3 (or ESSL 3.00 section 4.3):
// Global initializers must be constant expressions.
switch (node->getType().getQualifier())
{
case EvqConst:
break;
case EvqGlobal:
case EvqTemporary:
case EvqUniform:
// We allow these cases to be compatible with legacy ESSL 1.00 content.
// Implement stricter rules for ESSL 3.00 since there's no legacy content to deal
// with.
onNonConstInitializerVisit(mExtNonConstGlobalInitializers ||
((mShaderVersion < 300) && mIsWebGL));
break;
default:
mIsValid = false;
}
}
void ValidateGlobalInitializerTraverser::visitConstantUnion(TIntermConstantUnion *node)
{
// Constant unions that are not constant expressions may result from folding a ternary
// expression.
switch (node->getType().getQualifier())
{
case EvqConst:
break;
case EvqTemporary:
onNonConstInitializerVisit(mExtNonConstGlobalInitializers ||
((mShaderVersion < 300) && mIsWebGL));
break;
default:
UNREACHABLE();
}
}
bool ValidateGlobalInitializerTraverser::visitAggregate(Visit visit, TIntermAggregate *node)
{
// Disallow calls to user-defined functions and texture lookup functions in global variable
// initializers. For simplicity, all non-math built-in calls are disallowed.
if (node->isFunctionCall() ||
(BuiltInGroup::IsBuiltIn(node->getOp()) && !BuiltInGroup::IsMath(node->getOp())))
{
onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
}
return true;
}
bool ValidateGlobalInitializerTraverser::visitBinary(Visit visit, TIntermBinary *node)
{
if (node->isAssignment())
{
onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
}
return true;
}
bool ValidateGlobalInitializerTraverser::visitUnary(Visit visit, TIntermUnary *node)
{
if (node->isAssignment())
{
onNonConstInitializerVisit(mExtNonConstGlobalInitializers);
}
return true;
}
ValidateGlobalInitializerTraverser::ValidateGlobalInitializerTraverser(
int shaderVersion,
bool isWebGL,
bool hasExtNonConstGlobalInitializers)
: TIntermTraverser(true, false, false, nullptr),
mShaderVersion(shaderVersion),
mIsWebGL(isWebGL),
mExtNonConstGlobalInitializers(hasExtNonConstGlobalInitializers),
mIsValid(true),
mIssueWarning(false)
{
setMaxAllowedDepth(kMaxAllowedTraversalDepth);
}
} // namespace
bool ValidateGlobalInitializer(TIntermTyped *initializer,
int shaderVersion,
bool isWebGL,
bool hasExtNonConstGlobalInitializers,
bool *warning)
{
ValidateGlobalInitializerTraverser validate(shaderVersion, isWebGL,
hasExtNonConstGlobalInitializers);
initializer->traverse(&validate);
ASSERT(warning != nullptr);
*warning = validate.issueWarning();
return validate.isValid();
}
} // namespace sh