Line data    Source code

       1             : //
       2             : // Copyright (c) 2002-2015 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             : // The SeparateArrayInitialization function splits each array initialization into a declaration and an assignment.
       7             : // Example:
       8             : //     type[n] a = initializer;
       9             : // will effectively become
      10             : //     type[n] a;
      11             : //     a = initializer;
      12             : //
      13             : // Note that if the array is declared as const, the initialization may still be split, making the
      14             : // AST technically invalid. Because of that this transformation should only be used when subsequent
      15             : // stages don't care about const qualifiers. However, the initialization will not be split if the
      16             : // initializer can be written as a HLSL literal.
      17             : 
      18             : #include "compiler/translator/SeparateArrayInitialization.h"
      19             : 
      20             : #include "compiler/translator/IntermNode.h"
      21             : #include "compiler/translator/OutputHLSL.h"
      22             : 
      23             : namespace sh
      24             : {
      25             : 
      26             : namespace
      27             : {
      28             : 
      29           0 : class SeparateArrayInitTraverser : private TIntermTraverser
      30             : {
      31             :   public:
      32             :     static void apply(TIntermNode *root);
      33             :   private:
      34             :     SeparateArrayInitTraverser();
      35             :     bool visitDeclaration(Visit, TIntermDeclaration *node) override;
      36             : };
      37             : 
      38           0 : void SeparateArrayInitTraverser::apply(TIntermNode *root)
      39             : {
      40           0 :     SeparateArrayInitTraverser separateInit;
      41           0 :     root->traverse(&separateInit);
      42           0 :     separateInit.updateTree();
      43           0 : }
      44             : 
      45           0 : SeparateArrayInitTraverser::SeparateArrayInitTraverser()
      46           0 :     : TIntermTraverser(true, false, false)
      47             : {
      48           0 : }
      49             : 
      50           0 : bool SeparateArrayInitTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
      51             : {
      52           0 :     TIntermSequence *sequence = node->getSequence();
      53           0 :     TIntermBinary *initNode   = sequence->back()->getAsBinaryNode();
      54           0 :     if (initNode != nullptr && initNode->getOp() == EOpInitialize)
      55             :     {
      56           0 :         TIntermTyped *initializer = initNode->getRight();
      57           0 :         if (initializer->isArray() && !sh::OutputHLSL::canWriteAsHLSLLiteral(initializer))
      58             :         {
      59             :             // We rely on that array declarations have been isolated to single declarations.
      60           0 :             ASSERT(sequence->size() == 1);
      61           0 :             TIntermTyped *symbol      = initNode->getLeft();
      62           0 :             TIntermBlock *parentBlock = getParentNode()->getAsBlock();
      63           0 :             ASSERT(parentBlock != nullptr);
      64             : 
      65           0 :             TIntermSequence replacements;
      66             : 
      67           0 :             TIntermDeclaration *replacementDeclaration = new TIntermDeclaration();
      68           0 :             replacementDeclaration->appendDeclarator(symbol);
      69           0 :             replacementDeclaration->setLine(symbol->getLine());
      70           0 :             replacements.push_back(replacementDeclaration);
      71             : 
      72             :             TIntermBinary *replacementAssignment =
      73           0 :                 new TIntermBinary(EOpAssign, symbol, initializer);
      74           0 :             replacementAssignment->setLine(symbol->getLine());
      75           0 :             replacements.push_back(replacementAssignment);
      76             : 
      77           0 :             mMultiReplacements.push_back(
      78           0 :                 NodeReplaceWithMultipleEntry(parentBlock, node, replacements));
      79             :         }
      80             :     }
      81           0 :     return false;
      82             : }
      83             : 
      84             : } // namespace
      85             : 
      86           0 : void SeparateArrayInitialization(TIntermNode *root)
      87             : {
      88           0 :     SeparateArrayInitTraverser::apply(root);
      89           0 : }
      90             : 
      91             : }  // namespace sh