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