Verified Commit 380638db authored by serge-sans-paille's avatar serge-sans-paille Committed by ma1
Browse files

Bug 2039238 - Enforce usage of MOZ_EMPTY_BASES r=tsmith 

Unlike VS, we're not constrained by legacy behavior and should always
turn this attribute on where it's needed. There's no VS flag for it, but
we can use clang-tidy to detect when it's needed.

It's okay to use that attribute when it has no effect, so don't bother
trying to be smart in dom/bindings/Codegen.py and always add it.

Differential Revision: https://phabricator.services.mozilla.com/D300299
parent b4c7ffb8

build/clang-plugin/Checks.inc

+1 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ CHECK(JSHandleRootedTypedefChecker, "js-handle-rooted-typedef") 
CHECK(KungFuDeathGripChecker, "kungfu-death-grip")

CHECK(KnownLiveChecker, "known-live")

#ifdef TARGET_IS_WINDOWS

CHECK(EmptyBasesChecker, "empty-bases")

CHECK(LoadLibraryUsageChecker, "load-library-usage")

CHECK(FopenUsageChecker, "fopen-usage")

#endif

build/clang-plugin/ChecksIncludes.inc

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include "ExplicitImplicitChecker.h"

#include "ExplicitOperatorBoolChecker.h"

#ifdef TARGET_IS_WINDOWS

#include "EmptyBasesChecker.h"

#include "LoadLibraryUsageChecker.h"

#include "FopenUsageChecker.h"

#endif

build/clang-plugin/EmptyBasesChecker.cpp

0 → 100644
+42 −0
Original line number Diff line number Diff line 
/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */



#include "EmptyBasesChecker.h"

#include "CustomMatchers.h"



namespace clang {

namespace ast_matchers {



AST_MATCHER_P(CXXRecordDecl, emptyBaseCountAtLeast, unsigned, N) {

  unsigned NumEmptyBases = 0;

  for(const auto & Base : Node.bases()) {

    if(const Type* BaseType = Base.getType().getTypePtrOrNull()) {

      if(const CXXRecordDecl*  CRD = BaseType->getAsCXXRecordDecl(); CRD && CRD->isEmpty())

        NumEmptyBases += 1;

    }

  }

  return NumEmptyBases >= N;

}



AST_MATCHER(CXXRecordDecl, hasMozEmptyBasesAttr) {

  return Node.hasAttr<EmptyBasesAttr>();

}



}



}



void EmptyBasesChecker::registerMatchers(MatchFinder *AstMatcher) {

  AstMatcher->addMatcher(

      cxxRecordDecl(isDefinition(), isFirstParty(), emptyBaseCountAtLeast(2), unless(hasMozEmptyBasesAttr()))

          .bind("class"),

      this);

}



void EmptyBasesChecker::check(const MatchFinder::MatchResult &Result) {

  const CXXRecordDecl *Cls = Result.Nodes.getNodeAs<CXXRecordDecl>("class");

    diag(Cls->getBeginLoc(),

        "Missing MOZ_EMPTY_BASES",

        DiagnosticIDs::Error);

}

build/clang-plugin/EmptyBasesChecker.h

0 → 100644
+24 −0
Original line number Diff line number Diff line 
/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */



#ifndef EmptyBasesChecker_h_

#define EmptyBasesChecker_h_



#include "plugin.h"



class EmptyBasesChecker : public BaseCheck {

public:

  EmptyBasesChecker(StringRef CheckName, ContextType *Context = nullptr)

      : BaseCheck(CheckName, Context), CI(nullptr) {}

  void registerMatchers(MatchFinder *AstMatcher) override;

  void check(const MatchFinder::MatchResult &Result) override;

  bool isLanguageVersionSupported(const LangOptions &LangOpts) const override {

    return LangOpts.CPlusPlus;

  }



private:

  const CompilerInstance *CI;

};



#endif

build/clang-plugin/moz.build

+1 −0
Original line number Diff line number Diff line
@@ -55,6 +55,7 @@ HOST_SOURCES += [ 
if CONFIG["OS_ARCH"] == "WINNT":

    HOST_DEFINES["TARGET_IS_WINDOWS"] = True

    HOST_SOURCES += [

        "EmptyBasesChecker.cpp",

        "FopenUsageChecker.cpp",

        "LoadLibraryUsageChecker.cpp",

    ]