clang-tools  16.0.0git
AvoidNonConstGlobalVariablesCheck.cpp
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1 //===--- AvoidNonConstGlobalVariablesCheck.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 
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/ASTMatchers/ASTMatchers.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace cppcoreguidelines {
19 
20 namespace {
21 AST_MATCHER(VarDecl, isLocalVarDecl) { return Node.isLocalVarDecl(); }
22 } // namespace
23 
24 void AvoidNonConstGlobalVariablesCheck::registerMatchers(MatchFinder *Finder) {
25  auto GlobalVariable = varDecl(
26  hasGlobalStorage(),
27  unless(anyOf(
28  isLocalVarDecl(), isConstexpr(), hasType(isConstQualified()),
29  hasType(referenceType())))); // References can't be changed, only the
30  // data they reference can be changed.
31 
32  auto GlobalReferenceToNonConst =
33  varDecl(hasGlobalStorage(), hasType(referenceType()),
34  unless(hasType(references(qualType(isConstQualified())))));
35 
36  auto GlobalPointerToNonConst =
37  varDecl(hasGlobalStorage(),
38  hasType(pointerType(pointee(unless(isConstQualified())))));
39 
40  Finder->addMatcher(GlobalVariable.bind("non-const_variable"), this);
41  Finder->addMatcher(GlobalReferenceToNonConst.bind("indirection_to_non-const"),
42  this);
43  Finder->addMatcher(GlobalPointerToNonConst.bind("indirection_to_non-const"),
44  this);
45 }
46 
48  const MatchFinder::MatchResult &Result) {
49 
50  if (const auto *Variable =
51  Result.Nodes.getNodeAs<VarDecl>("non-const_variable")) {
52  diag(Variable->getLocation(), "variable %0 is non-const and globally "
53  "accessible, consider making it const")
54  << Variable; // FIXME: Add fix-it hint to Variable
55  // Don't return early, a non-const variable may also be a pointer or
56  // reference to non-const data.
57  }
58 
59  if (const auto *VD =
60  Result.Nodes.getNodeAs<VarDecl>("indirection_to_non-const")) {
61  diag(VD->getLocation(),
62  "variable %0 provides global access to a non-const object; consider "
63  "making the %select{referenced|pointed-to}1 data 'const'")
64  << VD
65  << VD->getType()->isPointerType(); // FIXME: Add fix-it hint to Variable
66  }
67 }
68 
69 } // namespace cppcoreguidelines
70 } // namespace tidy
71 } // namespace clang
AvoidNonConstGlobalVariablesCheck.h
clang::ast_matchers
Definition: AbseilMatcher.h:14
clang::ast_matchers::AST_MATCHER
AST_MATCHER(Decl, declHasNoReturnAttr)
matches a Decl if it has a "no return" attribute of any kind
Definition: InfiniteLoopCheck.cpp:24
clang
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Definition: ApplyReplacements.h:27
clang::clangd::check
bool check(llvm::StringRef File, const ThreadsafeFS &TFS, const ClangdLSPServer::Options &Opts)
Definition: Check.cpp:415