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 "llvm/Support/Casting.h"
18 #include <cassert>
19 #include <cstdint>
20 
21 using namespace clang;
22 
23 // FIXME: Add support for dependent-sized array types in C++?
24 // Does it even make sense to build a CFG for an uninstantiated template?
25 static inline const VariableArrayType *FindVA(const Type* t) {
26   while (const ArrayType *vt = dyn_cast<ArrayType>(t)) {
27     if (const VariableArrayType *vat = dyn_cast<VariableArrayType>(vt))
28       if (vat->getSizeExpr())
29         return vat;
30 
31     t = vt->getElementType().getTypePtr();
32   }
33 
34   return nullptr;
35 }
36 
37 void StmtIteratorBase::NextVA() {
38   assert(getVAPtr());
39 
40   const VariableArrayType *p = getVAPtr();
41   p = FindVA(p->getElementType().getTypePtr());
42   setVAPtr(p);
43 
44   if (p)
45     return;
46 
47   if (inDeclGroup()) {
48     if (VarDecl* VD = dyn_cast<VarDecl>(*DGI))
49       if (VD->hasInit())
50         return;
51 
52     NextDecl();
53   }
54   else {
55     assert(inSizeOfTypeVA());
56     RawVAPtr = 0;
57   }
58 }
59 
60 void StmtIteratorBase::NextDecl(bool ImmediateAdvance) {
61   assert(getVAPtr() == nullptr);
62   assert(inDeclGroup());
63 
64   if (ImmediateAdvance)
65     ++DGI;
66 
67   for ( ; DGI != DGE; ++DGI)
68     if (HandleDecl(*DGI))
69       return;
70 
71   RawVAPtr = 0;
72 }
73 
74 bool StmtIteratorBase::HandleDecl(Decl* D) {
75   if (VarDecl* VD = dyn_cast<VarDecl>(D)) {
76     if (const VariableArrayType* VAPtr = FindVA(VD->getType().getTypePtr())) {
77       setVAPtr(VAPtr);
78       return true;
79     }
80 
81     if (VD->getInit())
82       return true;
83   }
84   else if (TypedefNameDecl* TD = dyn_cast<TypedefNameDecl>(D)) {
85     if (const VariableArrayType* VAPtr =
86         FindVA(TD->getUnderlyingType().getTypePtr())) {
87       setVAPtr(VAPtr);
88       return true;
89     }
90   }
91   else if (EnumConstantDecl* ECD = dyn_cast<EnumConstantDecl>(D)) {
92     if (ECD->getInitExpr())
93       return true;
94   }
95 
96   return false;
97 }
98 
99 StmtIteratorBase::StmtIteratorBase(Decl** dgi, Decl** dge)
100     : DGI(dgi), RawVAPtr(DeclGroupMode), DGE(dge) {
101   NextDecl(false);
102 }
103 
104 StmtIteratorBase::StmtIteratorBase(const VariableArrayType* t)
105     : DGI(nullptr), RawVAPtr(SizeOfTypeVAMode) {
106   RawVAPtr |= reinterpret_cast<uintptr_t>(t);
107 }
108 
109 Stmt*& StmtIteratorBase::GetDeclExpr() const {
110   if (const VariableArrayType* VAPtr = getVAPtr()) {
111     assert(VAPtr->SizeExpr);
112     return const_cast<Stmt*&>(VAPtr->SizeExpr);
113   }
114 
115   assert(inDeclGroup());
116   VarDecl* VD = cast<VarDecl>(*DGI);
117   return *VD->getInitAddress();
118 }
119