clang-tools-extra/clang-tidy/hicpp/ExceptionBaseclassCheck.cpp

   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::tidy::hicpp {
  16
  17 void ExceptionBaseclassCheck::registerMatchers(MatchFinder *Finder) {
  18   Finder->addMatcher(
  19       cxxThrowExpr(
  20           unless(has(expr(anyOf(isTypeDependent(), isValueDependent())))),
  21           // The thrown value is not derived from 'std::exception'.
  22           has(expr(unless(
  23               hasType(qualType(hasCanonicalType(hasDeclaration(cxxRecordDecl(
  24                   isSameOrDerivedFrom(hasName("::std::exception")))))))))),
  25           // This condition is always true, but will bind to the
  26           // template value if the thrown type is templated.
  27           anyOf(has(expr(
  28                     hasType(substTemplateTypeParmType().bind("templ_type")))),
  29                 anything()),
  30           // Bind to the declaration of the type of the value that
  31           // is thrown. 'anything()' is necessary to always succeed
  32           // in the 'eachOf' because builtin types are not
  33           // 'namedDecl'.
  34           eachOf(has(expr(hasType(namedDecl().bind("decl")))), anything()))
  35           .bind("bad_throw"),
  36       this);
  37 }
  38
  39 void ExceptionBaseclassCheck::check(const MatchFinder::MatchResult &Result) {
  40   const auto *BadThrow = Result.Nodes.getNodeAs<CXXThrowExpr>("bad_throw");
  41   assert(BadThrow && "Did not match the throw expression");
  42
  43   diag(BadThrow->getSubExpr()->getBeginLoc(), "throwing an exception whose "
  44                                               "type %0 is not derived from "
  45                                               "'std::exception'")
  46       << BadThrow->getSubExpr()->getType() << BadThrow->getSourceRange();
  47
  48   if (const auto *Template =
  49           Result.Nodes.getNodeAs<SubstTemplateTypeParmType>("templ_type"))
  50     diag(BadThrow->getSubExpr()->getBeginLoc(),
  51          "type %0 is a template instantiation of %1", DiagnosticIDs::Note)
  52         << BadThrow->getSubExpr()->getType()
  53         << Template->getReplacedParameter();
  54
  55   if (const auto *TypeDecl = Result.Nodes.getNodeAs<NamedDecl>("decl"))
  56     diag(TypeDecl->getBeginLoc(), "type defined here", DiagnosticIDs::Note);
  57 }
  58
  59 } // namespace clang::tidy::hicpp