1 //===------------- Aliasing.cpp - clang-tidy ------------------------------===//
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 #include "Aliasing.h"
10
11 #include "clang/AST/Expr.h"
12
13 namespace clang {
14 namespace tidy {
15 namespace utils {
16
17 /// Return whether \p S is a reference to the declaration of \p Var.
isAccessForVar(const Stmt * S,const VarDecl * Var)18 static bool isAccessForVar(const Stmt *S, const VarDecl *Var) {
19 if (const auto *DRE = dyn_cast<DeclRefExpr>(S))
20 return DRE->getDecl() == Var;
21
22 return false;
23 }
24
25 /// Return whether \p Var has a pointer or reference in \p S.
isPtrOrReferenceForVar(const Stmt * S,const VarDecl * Var)26 static bool isPtrOrReferenceForVar(const Stmt *S, const VarDecl *Var) {
27 if (const auto *DS = dyn_cast<DeclStmt>(S)) {
28 for (const Decl *D : DS->getDeclGroup()) {
29 if (const auto *LeftVar = dyn_cast<VarDecl>(D)) {
30 if (LeftVar->hasInit() && LeftVar->getType()->isReferenceType()) {
31 return isAccessForVar(LeftVar->getInit(), Var);
32 }
33 }
34 }
35 } else if (const auto *UnOp = dyn_cast<UnaryOperator>(S)) {
36 if (UnOp->getOpcode() == UO_AddrOf)
37 return isAccessForVar(UnOp->getSubExpr(), Var);
38 }
39
40 return false;
41 }
42
43 /// Return whether \p Var has a pointer or reference in \p S.
hasPtrOrReferenceInStmt(const Stmt * S,const VarDecl * Var)44 static bool hasPtrOrReferenceInStmt(const Stmt *S, const VarDecl *Var) {
45 if (isPtrOrReferenceForVar(S, Var))
46 return true;
47
48 for (const Stmt *Child : S->children()) {
49 if (!Child)
50 continue;
51
52 if (hasPtrOrReferenceInStmt(Child, Var))
53 return true;
54 }
55
56 return false;
57 }
58
hasPtrOrReferenceInFunc(const FunctionDecl * Func,const VarDecl * Var)59 bool hasPtrOrReferenceInFunc(const FunctionDecl *Func, const VarDecl *Var) {
60 return hasPtrOrReferenceInStmt(Func->getBody(), Var);
61 }
62
63 } // namespace utils
64 } // namespace tidy
65 } // namespace clang
66