1 //===--- UnhandledExceptionAtNewCheck.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 "UnhandledExceptionAtNewCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12
13 using namespace clang::ast_matchers;
14
15 namespace clang {
16 namespace tidy {
17 namespace bugprone {
18
AST_MATCHER_P(CXXTryStmt,hasHandlerFor,ast_matchers::internal::Matcher<QualType>,InnerMatcher)19 AST_MATCHER_P(CXXTryStmt, hasHandlerFor,
20 ast_matchers::internal::Matcher<QualType>, InnerMatcher) {
21 for (unsigned NH = Node.getNumHandlers(), I = 0; I < NH; ++I) {
22 const CXXCatchStmt *CatchS = Node.getHandler(I);
23 // Check for generic catch handler (match anything).
24 if (CatchS->getCaughtType().isNull())
25 return true;
26 ast_matchers::internal::BoundNodesTreeBuilder Result(*Builder);
27 if (InnerMatcher.matches(CatchS->getCaughtType(), Finder, &Result)) {
28 *Builder = std::move(Result);
29 return true;
30 }
31 }
32 return false;
33 }
34
AST_MATCHER(CXXNewExpr,mayThrow)35 AST_MATCHER(CXXNewExpr, mayThrow) {
36 FunctionDecl *OperatorNew = Node.getOperatorNew();
37 if (!OperatorNew)
38 return false;
39 return !OperatorNew->getType()->castAs<FunctionProtoType>()->isNothrow();
40 }
41
UnhandledExceptionAtNewCheck(StringRef Name,ClangTidyContext * Context)42 UnhandledExceptionAtNewCheck::UnhandledExceptionAtNewCheck(
43 StringRef Name, ClangTidyContext *Context)
44 : ClangTidyCheck(Name, Context) {}
45
registerMatchers(MatchFinder * Finder)46 void UnhandledExceptionAtNewCheck::registerMatchers(MatchFinder *Finder) {
47 auto BadAllocType =
48 recordType(hasDeclaration(cxxRecordDecl(hasName("::std::bad_alloc"))));
49 auto ExceptionType =
50 recordType(hasDeclaration(cxxRecordDecl(hasName("::std::exception"))));
51 auto BadAllocReferenceType = referenceType(pointee(BadAllocType));
52 auto ExceptionReferenceType = referenceType(pointee(ExceptionType));
53
54 auto CatchBadAllocType =
55 qualType(hasCanonicalType(anyOf(BadAllocType, BadAllocReferenceType,
56 ExceptionType, ExceptionReferenceType)));
57 auto BadAllocCatchingTryBlock = cxxTryStmt(hasHandlerFor(CatchBadAllocType));
58
59 auto FunctionMayNotThrow = functionDecl(isNoThrow());
60
61 Finder->addMatcher(cxxNewExpr(mayThrow(),
62 unless(hasAncestor(BadAllocCatchingTryBlock)),
63 hasAncestor(FunctionMayNotThrow))
64 .bind("new-expr"),
65 this);
66 }
67
check(const MatchFinder::MatchResult & Result)68 void UnhandledExceptionAtNewCheck::check(
69 const MatchFinder::MatchResult &Result) {
70 const auto *MatchedExpr = Result.Nodes.getNodeAs<CXXNewExpr>("new-expr");
71 if (MatchedExpr)
72 diag(MatchedExpr->getBeginLoc(),
73 "missing exception handler for allocation failure at 'new'");
74 }
75
76 } // namespace bugprone
77 } // namespace tidy
78 } // namespace clang
79