office-gobmx/compilerplugins/clang/noexceptmove.cxx
Stephan Bergmann d1a2b80b9d Bump compiler plugins Clang baseline to 12.0.1
...as discussed in the mail thread starting at
<https://lists.freedesktop.org/archives/libreoffice/2020-November/086234.html>
"Bump --enable-compiler-plugins Clang baseline?" (and now picked up again at
<https://lists.freedesktop.org/archives/libreoffice/2022-February/088459.html>
"Re: Bump --enable-compiler-plugins Clang baseline?"), and clean up
compilerplugins/clang/ accordingly

Change-Id: I5e81c6fdcc363aeefd6227606225b526fdf7ac16
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/129989
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
2022-02-17 21:45:06 +01:00

331 lines
12 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* 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/.
*/
// versions before 9.0 didn't have getExceptionSpecType
#include "check.hxx"
#include "plugin.hxx"
#include "config_clang.h"
#include <string>
#include <set>
/**
Look for move constructors that can be noexcept.
*/
namespace
{
/// Look for the stuff that can be marked noexcept, but only if we also mark some of the callees noexcept.
/// Off by default so as not too annoy people.
constexpr bool bLookForStuffWeCanFix = false;
class NoExceptMove : public loplugin::FilteringPlugin<NoExceptMove>
{
public:
explicit NoExceptMove(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
virtual void run() override
{
StringRef fn(handler.getMainFileName());
// ONDXPagePtr::operator= calls ONDXPage::ReleaseRef which cannot be noexcept
if (loplugin::isSamePathname(fn,
SRCDIR "/connectivity/source/drivers/dbase/dindexnode.cxx"))
return;
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
bool shouldVisitImplicitCode() const { return true; }
bool TraverseCXXConstructorDecl(CXXConstructorDecl*);
bool TraverseCXXMethodDecl(CXXMethodDecl*);
bool VisitCallExpr(const CallExpr*);
bool VisitCXXConstructExpr(const CXXConstructExpr*);
bool VisitVarDecl(const VarDecl*);
private:
llvm::Optional<bool> IsCallThrows(const CallExpr* callExpr);
std::vector<bool> m_ConstructorThrows;
std::vector<std::vector<const Decl*>> m_Exclusions;
std::vector<bool> m_CannotFix;
};
bool NoExceptMove::TraverseCXXConstructorDecl(CXXConstructorDecl* constructorDecl)
{
const bool isMove = constructorDecl->isMoveConstructor()
&& constructorDecl->getExceptionSpecType() == EST_None
&& !constructorDecl->isDefaulted() && !constructorDecl->isDeleted()
&& !ignoreLocation(constructorDecl)
&& constructorDecl->isThisDeclarationADefinition()
&& constructorDecl->getBody() != nullptr;
if (isMove)
{
m_ConstructorThrows.push_back(false);
m_Exclusions.emplace_back();
m_CannotFix.push_back(false);
}
bool rv = RecursiveASTVisitor::TraverseCXXConstructorDecl(constructorDecl);
if (isMove)
{
if (!m_ConstructorThrows.back())
{
report(DiagnosticsEngine::Warning, "move constructor can be noexcept",
constructorDecl->getSourceRange().getBegin())
<< constructorDecl->getSourceRange();
auto canonicalDecl = constructorDecl->getCanonicalDecl();
if (canonicalDecl != constructorDecl)
report(DiagnosticsEngine::Note, "declaration here",
canonicalDecl->getSourceRange().getBegin())
<< canonicalDecl->getSourceRange();
}
else if (bLookForStuffWeCanFix && !m_CannotFix.back())
{
report(DiagnosticsEngine::Warning, "move constructor can be noexcept",
constructorDecl->getSourceRange().getBegin())
<< constructorDecl->getSourceRange();
auto canonicalDecl = constructorDecl->getCanonicalDecl();
if (canonicalDecl != constructorDecl)
report(DiagnosticsEngine::Note, "declaration here",
canonicalDecl->getSourceRange().getBegin())
<< canonicalDecl->getSourceRange();
for (const Decl* callDecl : m_Exclusions.back())
report(DiagnosticsEngine::Warning, "but need to fix this to be noexcept",
callDecl->getSourceRange().getBegin())
<< callDecl->getSourceRange();
}
m_ConstructorThrows.pop_back();
m_Exclusions.pop_back();
m_CannotFix.pop_back();
}
return rv;
}
bool NoExceptMove::TraverseCXXMethodDecl(CXXMethodDecl* methodDecl)
{
bool isMove = methodDecl->isMoveAssignmentOperator()
&& methodDecl->getExceptionSpecType() == EST_None && !methodDecl->isDefaulted()
&& !methodDecl->isDeleted() && !ignoreLocation(methodDecl)
&& methodDecl->isThisDeclarationADefinition() && methodDecl->getBody() != nullptr;
if (isMove)
{
StringRef fn = getFilenameOfLocation(
compiler.getSourceManager().getSpellingLoc(methodDecl->getBeginLoc()));
// SfxObjectShellLock::operator= calls SotObject::OwnerLock which in turn calls stuff which cannot be noexcept
if (loplugin::isSamePathname(fn, SRCDIR "/include/sfx2/objsh.hxx"))
isMove = false;
}
if (isMove)
{
m_ConstructorThrows.push_back(false);
m_Exclusions.emplace_back();
m_CannotFix.push_back(false);
}
bool rv = RecursiveASTVisitor::TraverseCXXMethodDecl(methodDecl);
if (isMove)
{
if (!m_ConstructorThrows.back())
{
report(DiagnosticsEngine::Warning, "move operator= can be noexcept",
methodDecl->getSourceRange().getBegin())
<< methodDecl->getSourceRange();
auto canonicalDecl = methodDecl->getCanonicalDecl();
if (canonicalDecl != methodDecl)
report(DiagnosticsEngine::Note, "declaration here",
canonicalDecl->getSourceRange().getBegin())
<< canonicalDecl->getSourceRange();
}
else if (bLookForStuffWeCanFix && !m_CannotFix.back())
{
report(DiagnosticsEngine::Warning, "move operator= can be noexcept",
methodDecl->getSourceRange().getBegin())
<< methodDecl->getSourceRange();
auto canonicalDecl = methodDecl->getCanonicalDecl();
if (canonicalDecl != methodDecl)
report(DiagnosticsEngine::Note, "declaration here",
canonicalDecl->getSourceRange().getBegin())
<< canonicalDecl->getSourceRange();
for (const Decl* callDecl : m_Exclusions.back())
report(DiagnosticsEngine::Warning, "but need to fix this to be noexcept",
callDecl->getSourceRange().getBegin())
<< callDecl->getSourceRange();
}
m_ConstructorThrows.pop_back();
m_Exclusions.pop_back();
m_CannotFix.pop_back();
}
return rv;
}
bool NoExceptMove::VisitCallExpr(const CallExpr* callExpr)
{
if (ignoreLocation(callExpr))
return true;
if (m_ConstructorThrows.empty())
return true;
llvm::Optional<bool> bCallThrows = IsCallThrows(callExpr);
if (!bCallThrows)
{
callExpr->dump();
if (callExpr->getCalleeDecl())
callExpr->getCalleeDecl()->dump();
report(DiagnosticsEngine::Warning, "what's up doc?", callExpr->getSourceRange().getBegin())
<< callExpr->getSourceRange();
m_ConstructorThrows.back() = true;
return true;
}
if (*bCallThrows)
m_ConstructorThrows.back() = true;
return true;
}
static bool IsCallThrowsSpec(clang::ExceptionSpecificationType est)
{
return !(est == EST_DynamicNone || est == EST_NoThrow || est == EST_BasicNoexcept
|| est == EST_NoexceptTrue);
}
bool NoExceptMove::VisitCXXConstructExpr(const CXXConstructExpr* constructExpr)
{
if (ignoreLocation(constructExpr))
return true;
if (m_ConstructorThrows.empty())
return true;
auto constructorDecl = constructExpr->getConstructor();
auto est = constructorDecl->getExceptionSpecType();
if (constructorDecl->isDefaulted() && est == EST_None)
; // ok, non-throwing
else if (IsCallThrowsSpec(est))
{
if (bLookForStuffWeCanFix)
{
if (est == EST_None && !ignoreLocation(constructorDecl))
m_Exclusions.back().push_back(constructorDecl);
else
m_CannotFix.back() = true;
}
m_ConstructorThrows.back() = true;
}
return true;
}
bool NoExceptMove::VisitVarDecl(const VarDecl* varDecl)
{
if (varDecl->getLocation().isValid() && ignoreLocation(varDecl))
return true;
if (m_ConstructorThrows.empty())
return true;
// The clang AST does not show me implicit calls to destructors at the end of a block,
// so assume any local var decls of class type will call their destructor.
if (!varDecl->getType()->isRecordType())
return true;
auto cxxRecordDecl = varDecl->getType()->getAsCXXRecordDecl();
if (!cxxRecordDecl)
return true;
auto destructorDecl = cxxRecordDecl->getDestructor();
if (!destructorDecl)
return true;
auto est = destructorDecl->getExceptionSpecType();
if (destructorDecl->isDefaulted() && est == EST_None)
; // ok, non-throwing
else if (IsCallThrowsSpec(est))
{
if (bLookForStuffWeCanFix)
{
if (est == EST_None && !ignoreLocation(destructorDecl))
m_Exclusions.back().push_back(destructorDecl);
else
m_CannotFix.back() = true;
}
m_ConstructorThrows.back() = true;
}
return true;
}
llvm::Optional<bool> NoExceptMove::IsCallThrows(const CallExpr* callExpr)
{
const FunctionDecl* calleeFunctionDecl = callExpr->getDirectCallee();
if (calleeFunctionDecl)
{
auto est = calleeFunctionDecl->getExceptionSpecType();
if (bLookForStuffWeCanFix)
{
if (est == EST_None && !ignoreLocation(calleeFunctionDecl))
m_Exclusions.back().push_back(calleeFunctionDecl);
else
m_CannotFix.back() = true;
}
// Allowlist of functions that could be noexcept, but we can't change them because of backwards-compatibility reasons
// css::uno::XInterface::acquire
// css::uno::XInterface::release
if (calleeFunctionDecl->getIdentifier())
{
auto name = calleeFunctionDecl->getName();
if (auto cxxMethodDecl = dyn_cast<CXXMethodDecl>(calleeFunctionDecl))
if (loplugin::ContextCheck(cxxMethodDecl->getParent()->getDeclContext())
.Namespace("uno")
.Namespace("star")
.Namespace("sun")
.Namespace("com")
.GlobalNamespace()
&& (name == "acquire" || name == "release"))
return false;
if (name == "osl_releasePipe" || name == "osl_destroySocketAddr")
return false;
}
return IsCallThrowsSpec(est);
}
auto calleeExpr = callExpr->getCallee();
if (isa<CXXDependentScopeMemberExpr>(calleeExpr) || isa<UnresolvedLookupExpr>(calleeExpr))
{
m_CannotFix.back() = true;
return true;
}
// check for call via function-pointer
clang::QualType calleeType;
if (auto fieldDecl = dyn_cast_or_null<FieldDecl>(callExpr->getCalleeDecl()))
calleeType = fieldDecl->getType();
else if (auto varDecl = dyn_cast_or_null<VarDecl>(callExpr->getCalleeDecl()))
calleeType = varDecl->getType();
else
{
m_CannotFix.back() = true;
return llvm::Optional<bool>();
}
// allowlist of functions that could be noexcept, but we can't change them because of backwards-compatibility reasons
if (auto typedefType = calleeType->getAs<TypedefType>())
if (typedefType->getDecl()->getName() == "uno_ReleaseMappingFunc")
return false;
if (calleeType->isPointerType())
calleeType = calleeType->getPointeeType();
auto funcProto = calleeType->getAs<FunctionProtoType>();
if (!funcProto)
{
m_CannotFix.back() = true;
return llvm::Optional<bool>();
}
auto est = funcProto->getExceptionSpecType();
if (bLookForStuffWeCanFix)
{
m_CannotFix.back() = true; // TODO, could improve
}
return IsCallThrowsSpec(est);
}
loplugin::Plugin::Registration<NoExceptMove> noexceptmove("noexceptmove");
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */