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
7 // an assignment.
8 // Example:
9 // type[n] a = initializer;
10 // will effectively become
11 // type[n] a;
12 // a = initializer;
13 //
14 // Note that if the array is declared as const, the initialization may still be split, making the
15 // AST technically invalid. Because of that this transformation should only be used when subsequent
16 // stages don't care about const qualifiers. However, the initialization will not be split if the
17 // initializer can be written as a HLSL literal.
18
19 #include "compiler/translator/SeparateArrayInitialization.h"
20
21 #include "compiler/translator/IntermNode.h"
22 #include "compiler/translator/OutputHLSL.h"
23
24 namespace sh
25 {
26
27 namespace
28 {
29
30 class SeparateArrayInitTraverser : private TIntermTraverser
31 {
32 public:
33 static void apply(TIntermNode *root);
34
35 private:
36 SeparateArrayInitTraverser();
37 bool visitDeclaration(Visit, TIntermDeclaration *node) override;
38 };
39
apply(TIntermNode * root)40 void SeparateArrayInitTraverser::apply(TIntermNode *root)
41 {
42 SeparateArrayInitTraverser separateInit;
43 root->traverse(&separateInit);
44 separateInit.updateTree();
45 }
46
SeparateArrayInitTraverser()47 SeparateArrayInitTraverser::SeparateArrayInitTraverser() : TIntermTraverser(true, false, false)
48 {
49 }
50
visitDeclaration(Visit,TIntermDeclaration * node)51 bool SeparateArrayInitTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
52 {
53 TIntermSequence *sequence = node->getSequence();
54 TIntermBinary *initNode = sequence->back()->getAsBinaryNode();
55 if (initNode != nullptr && initNode->getOp() == EOpInitialize)
56 {
57 TIntermTyped *initializer = initNode->getRight();
58 if (initializer->isArray() && !sh::OutputHLSL::canWriteAsHLSLLiteral(initializer))
59 {
60 // We rely on that array declarations have been isolated to single declarations.
61 ASSERT(sequence->size() == 1);
62 TIntermTyped *symbol = initNode->getLeft();
63 TIntermBlock *parentBlock = getParentNode()->getAsBlock();
64 ASSERT(parentBlock != nullptr);
65
66 TIntermSequence replacements;
67
68 TIntermDeclaration *replacementDeclaration = new TIntermDeclaration();
69 replacementDeclaration->appendDeclarator(symbol);
70 replacementDeclaration->setLine(symbol->getLine());
71 replacements.push_back(replacementDeclaration);
72
73 TIntermBinary *replacementAssignment =
74 new TIntermBinary(EOpAssign, symbol, initializer);
75 replacementAssignment->setLine(symbol->getLine());
76 replacements.push_back(replacementAssignment);
77
78 mMultiReplacements.push_back(
79 NodeReplaceWithMultipleEntry(parentBlock, node, replacements));
80 }
81 }
82 return false;
83 }
84
85 } // namespace
86
SeparateArrayInitialization(TIntermNode * root)87 void SeparateArrayInitialization(TIntermNode *root)
88 {
89 SeparateArrayInitTraverser::apply(root);
90 }
91
92 } // namespace sh
93