xref: /llvm-project/clang-tools-extra/clang-tidy/hicpp/ExceptionBaseclassCheck.cpp (revision bcd9ba2b7e64f6ce54defd2fa73fc8e0fee5707c)
1 //===--- ExceptionBaseclassCheck.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 "ExceptionBaseclassCheck.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 hicpp {
18 
19 void ExceptionBaseclassCheck::registerMatchers(MatchFinder *Finder) {
20   Finder->addMatcher(
21       cxxThrowExpr(
22           unless(has(expr(anyOf(isTypeDependent(), isValueDependent())))),
23           // The thrown value is not derived from 'std::exception'.
24           has(expr(unless(
25               hasType(qualType(hasCanonicalType(hasDeclaration(cxxRecordDecl(
26                   isSameOrDerivedFrom(hasName("::std::exception")))))))))),
27           // This condition is always true, but will bind to the
28           // template value if the thrown type is templated.
29           anyOf(has(expr(
30                     hasType(substTemplateTypeParmType().bind("templ_type")))),
31                 anything()),
32           // Bind to the declaration of the type of the value that
33           // is thrown. 'anything()' is necessary to always succeed
34           // in the 'eachOf' because builtin types are not
35           // 'namedDecl'.
36           eachOf(has(expr(hasType(namedDecl().bind("decl")))), anything()))
37           .bind("bad_throw"),
38       this);
39 }
40 
41 void ExceptionBaseclassCheck::check(const MatchFinder::MatchResult &Result) {
42   const auto *BadThrow = Result.Nodes.getNodeAs<CXXThrowExpr>("bad_throw");
43   assert(BadThrow && "Did not match the throw expression");
44 
45   diag(BadThrow->getSubExpr()->getBeginLoc(), "throwing an exception whose "
46                                               "type %0 is not derived from "
47                                               "'std::exception'")
48       << BadThrow->getSubExpr()->getType() << BadThrow->getSourceRange();
49 
50   if (const auto *Template =
51           Result.Nodes.getNodeAs<SubstTemplateTypeParmType>("templ_type"))
52     diag(BadThrow->getSubExpr()->getBeginLoc(),
53          "type %0 is a template instantiation of %1", DiagnosticIDs::Note)
54         << BadThrow->getSubExpr()->getType()
55         << Template->getReplacedParameter();
56 
57   if (const auto *TypeDecl = Result.Nodes.getNodeAs<NamedDecl>("decl"))
58     diag(TypeDecl->getBeginLoc(), "type defined here", DiagnosticIDs::Note);
59 }
60 
61 } // namespace hicpp
62 } // namespace tidy
63 } // namespace clang
64