1 //
2 // Copyright 2002 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/tree_ops/d3d/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 ANGLE_NO_DISCARD static bool apply(TCompiler *compiler, TIntermNode *root);
34
35 private:
36 SeparateArrayInitTraverser();
37 bool visitDeclaration(Visit, TIntermDeclaration *node) override;
38 };
39
apply(TCompiler * compiler,TIntermNode * root)40 bool SeparateArrayInitTraverser::apply(TCompiler *compiler, TIntermNode *root)
41 {
42 SeparateArrayInitTraverser separateInit;
43 root->traverse(&separateInit);
44 return separateInit.updateTree(compiler, root);
45 }
46
SeparateArrayInitTraverser()47 SeparateArrayInitTraverser::SeparateArrayInitTraverser() : TIntermTraverser(true, false, false) {}
48
visitDeclaration(Visit,TIntermDeclaration * node)49 bool SeparateArrayInitTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
50 {
51 TIntermSequence *sequence = node->getSequence();
52 TIntermBinary *initNode = sequence->back()->getAsBinaryNode();
53 if (initNode != nullptr && initNode->getOp() == EOpInitialize)
54 {
55 TIntermTyped *initializer = initNode->getRight();
56 if (initializer->isArray() && !initializer->hasConstantValue())
57 {
58 // We rely on that array declarations have been isolated to single declarations.
59 ASSERT(sequence->size() == 1);
60 TIntermTyped *symbol = initNode->getLeft();
61 TIntermBlock *parentBlock = getParentNode()->getAsBlock();
62 ASSERT(parentBlock != nullptr);
63
64 TIntermSequence replacements;
65
66 TIntermDeclaration *replacementDeclaration = new TIntermDeclaration();
67 replacementDeclaration->appendDeclarator(symbol);
68 replacementDeclaration->setLine(symbol->getLine());
69 replacements.push_back(replacementDeclaration);
70
71 TIntermBinary *replacementAssignment =
72 new TIntermBinary(EOpAssign, symbol, initializer);
73 replacementAssignment->setLine(symbol->getLine());
74 replacements.push_back(replacementAssignment);
75
76 mMultiReplacements.emplace_back(parentBlock, node, std::move(replacements));
77 }
78 }
79 return false;
80 }
81
82 } // namespace
83
SeparateArrayInitialization(TCompiler * compiler,TIntermNode * root)84 bool SeparateArrayInitialization(TCompiler *compiler, TIntermNode *root)
85 {
86 return SeparateArrayInitTraverser::apply(compiler, root);
87 }
88
89 } // namespace sh
90