xref: /llvm-project/clang/lib/AST/StmtIterator.cpp (revision dec6324cb05ac1d339c1b2bd43add968f2931c62)
1 //===- StmtIterator.cpp - Iterators for Statements ------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines internal methods for StmtIterator.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/StmtIterator.h"
14 #include "clang/AST/Decl.h"
15 #include "clang/AST/Type.h"
16 #include "clang/Basic/LLVM.h"
17 #include <cassert>
18 #include <cstdint>
19 
20 using namespace clang;
21 
22 // FIXME: Add support for dependent-sized array types in C++?
23 // Does it even make sense to build a CFG for an uninstantiated template?
24 static inline const VariableArrayType *FindVA(const Type* t) {
25   while (const ArrayType *vt = dyn_cast<ArrayType>(t)) {
26     if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt))
27       if (vat->getSizeExpr())
28         return vat;
29 
30     t = vt->getElementType().getTypePtr();
31   }
32 
33   return nullptr;
34 }
35 
36 void StmtIteratorBase::NextVA() {
37   assert(getVAPtr());
38 
39   const VariableArrayType *p = getVAPtr();
40   p = FindVA(p->getElementType().getTypePtr());
41   setVAPtr(p);
42 
43   if (p)
44     return;
45 
46   if (inDeclGroup()) {
47     if (VarDecl* VD = dyn_cast<VarDecl>(*DGI))
48       if (VD->hasInit())
49         return;
50 
51     NextDecl();
52   }
53   else {
54     assert(inSizeOfTypeVA());
55     RawVAPtr = 0;
56   }
57 }
58 
59 void StmtIteratorBase::NextDecl(bool ImmediateAdvance) {
60   assert(getVAPtr() == nullptr);
61   assert(inDeclGroup());
62 
63   if (ImmediateAdvance)
64     ++DGI;
65 
66   for ( ; DGI != DGE; ++DGI)
67     if (HandleDecl(*DGI))
68       return;
69 
70   RawVAPtr = 0;
71 }
72 
73 bool StmtIteratorBase::HandleDecl(Decl* D) {
74   if (VarDecl* VD = dyn_cast<VarDecl>(D)) {
75     if (const VariableArrayType* VAPtr = FindVA(VD->getType().getTypePtr())) {
76       setVAPtr(VAPtr);
77       return true;
78     }
79 
80     if (VD->getInit())
81       return true;
82   }
83   else if (TypedefNameDecl* TD = dyn_cast<TypedefNameDecl>(D)) {
84     if (const VariableArrayType* VAPtr =
85         FindVA(TD->getUnderlyingType().getTypePtr())) {
86       setVAPtr(VAPtr);
87       return true;
88     }
89   }
90   else if (EnumConstantDecl* ECD = dyn_cast<EnumConstantDecl>(D)) {
91     if (ECD->getInitExpr())
92       return true;
93   }
94 
95   return false;
96 }
97 
98 StmtIteratorBase::StmtIteratorBase(Decl** dgi, Decl** dge)
99     : DGI(dgi), RawVAPtr(DeclGroupMode), DGE(dge) {
100   NextDecl(false);
101 }
102 
103 StmtIteratorBase::StmtIteratorBase(const VariableArrayType* t)
104     : DGI(nullptr), RawVAPtr(SizeOfTypeVAMode) {
105   RawVAPtr |= reinterpret_cast<uintptr_t>(t);
106 }
107 
108 Stmt*& StmtIteratorBase::GetDeclExpr() const {
109   if (const VariableArrayType* VAPtr = getVAPtr()) {
110     assert(VAPtr->SizeExpr);
111     return const_cast<Stmt*&>(VAPtr->SizeExpr);
112   }
113 
114   assert(inDeclGroup());
115   VarDecl* VD = cast<VarDecl>(*DGI);
116   return *VD->getInitAddress();
117 }
118