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 SeparateDeclarations function processes declarations, so that in the end each declaration
7 // contains only one declarator.
8 // This is useful as an intermediate step when initialization needs to be separated from
9 // declaration, or when things need to be unfolded out of the initializer.
10 // Example:
11 // int a[1] = int[1](1), b[1] = int[1](2);
12 // gets transformed when run through this class into the AST equivalent of:
13 // int a[1] = int[1](1);
14 // int b[1] = int[1](2);
15
16 #include "compiler/translator/tree_ops/SeparateDeclarations.h"
17
18 #include "compiler/translator/tree_util/IntermTraverse.h"
19
20 namespace sh
21 {
22
23 namespace
24 {
25
26 class SeparateDeclarationsTraverser : private TIntermTraverser
27 {
28 public:
29 ANGLE_NO_DISCARD static bool apply(TCompiler *compiler, TIntermNode *root);
30
31 private:
32 SeparateDeclarationsTraverser();
33 bool visitDeclaration(Visit, TIntermDeclaration *node) override;
34 };
35
apply(TCompiler * compiler,TIntermNode * root)36 bool SeparateDeclarationsTraverser::apply(TCompiler *compiler, TIntermNode *root)
37 {
38 SeparateDeclarationsTraverser separateDecl;
39 root->traverse(&separateDecl);
40 return separateDecl.updateTree(compiler, root);
41 }
42
SeparateDeclarationsTraverser()43 SeparateDeclarationsTraverser::SeparateDeclarationsTraverser()
44 : TIntermTraverser(true, false, false)
45 {}
46
visitDeclaration(Visit,TIntermDeclaration * node)47 bool SeparateDeclarationsTraverser::visitDeclaration(Visit, TIntermDeclaration *node)
48 {
49 TIntermSequence *sequence = node->getSequence();
50 if (sequence->size() > 1)
51 {
52 TIntermBlock *parentBlock = getParentNode()->getAsBlock();
53 ASSERT(parentBlock != nullptr);
54
55 TIntermSequence replacementDeclarations;
56 for (size_t ii = 0; ii < sequence->size(); ++ii)
57 {
58 TIntermDeclaration *replacementDeclaration = new TIntermDeclaration();
59
60 replacementDeclaration->appendDeclarator(sequence->at(ii)->getAsTyped());
61 replacementDeclaration->setLine(sequence->at(ii)->getLine());
62 replacementDeclarations.push_back(replacementDeclaration);
63 }
64
65 mMultiReplacements.emplace_back(parentBlock, node, std::move(replacementDeclarations));
66 }
67 return false;
68 }
69
70 } // namespace
71
SeparateDeclarations(TCompiler * compiler,TIntermNode * root)72 bool SeparateDeclarations(TCompiler *compiler, TIntermNode *root)
73 {
74 return SeparateDeclarationsTraverser::apply(compiler, root);
75 }
76
77 } // namespace sh
78