office-gobmx/compilerplugins/clang/referencecasting.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

538 lines
19 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* Based on LLVM/Clang.
*
* This file is distributed under the University of Illinois Open Source
* License. See LICENSE.TXT for details.
*
*/
#ifndef LO_CLANG_SHARED_PLUGINS
#include "plugin.hxx"
#include "check.hxx"
#include "config_clang.h"
#include <iostream>
/*
This is a compile-time checker.
Check for cases where we have
- two IDL interfaces A and B,
- B extends A
- we are converting a Reference<B> to a Reference<A> using UNO_QUERY
This makes the code simpler and cheaper, because UNO_QUERY can be surprisingly expensive if used a lot.
*/
namespace
{
class ReferenceCasting : public loplugin::FilteringPlugin<ReferenceCasting>
{
public:
explicit ReferenceCasting(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
bool preRun() override
{
std::string fn(handler.getMainFileName());
loplugin::normalizeDotDotInFilePath(fn);
// macros
if (fn == SRCDIR "/dbaccess/source/ui/browser/formadapter.cxx")
return false;
// UNO aggregation
if (fn == SRCDIR "/toolkit/source/controls/stdtabcontroller.cxx")
return false;
return true;
}
void run() override
{
if (preRun())
{
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
}
bool VisitCXXConstructExpr(const CXXConstructExpr* cce);
bool VisitCXXMemberCallExpr(const CXXMemberCallExpr* mce);
bool VisitCallExpr(const CallExpr*);
bool VisitInitListExpr(const InitListExpr*);
private:
bool CheckForUnnecessaryGet(const Expr*, bool includeRtlReference);
};
static const RecordType* extractTemplateType(QualType);
static bool isDerivedFrom(const CXXRecordDecl* subtypeRecord, const CXXRecordDecl* baseRecord);
bool ReferenceCasting::VisitInitListExpr(const InitListExpr* ile)
{
if (ignoreLocation(ile))
return true;
for (const Expr* expr : ile->inits())
{
if (CheckForUnnecessaryGet(expr, /*includeRtlReference*/ true))
{
report(DiagnosticsEngine::Warning, "unnecessary get() call", expr->getBeginLoc())
<< expr->getSourceRange();
return true;
}
}
return true;
}
bool ReferenceCasting::VisitCXXConstructExpr(const CXXConstructExpr* cce)
{
if (ignoreLocation(cce))
return true;
// don't bother processing anything in the Reference.h file. Makes my life easier when debugging this.
StringRef aFileName
= getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(cce->getBeginLoc()));
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.h"))
return true;
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.hxx"))
return true;
if (cce->getNumArgs() == 0)
return true;
// look for calls to the Reference<T>(x, UNO_something) constructor
auto constructorClass = cce->getConstructor()->getParent();
auto dc = loplugin::DeclCheck(constructorClass);
bool isUnoReference(dc.Class("Reference").Namespace("uno"));
bool isRtlReference(dc.Class("Reference").Namespace("rtl").GlobalNamespace());
if (!isUnoReference && !isRtlReference)
return true;
if (isUnoReference)
if (CheckForUnnecessaryGet(cce->getArg(0), /*includeRtlReference*/ cce->getNumArgs() == 1))
{
report(DiagnosticsEngine::Warning, "unnecessary get() call",
cce->getArg(0)->getBeginLoc())
<< cce->getArg(0)->getSourceRange();
return true;
}
if (isRtlReference && cce->getNumArgs() == 1)
if (CheckForUnnecessaryGet(cce->getArg(0), /*includeRtlReference*/ true))
{
report(DiagnosticsEngine::Warning, "unnecessary get() call",
cce->getArg(0)->getBeginLoc())
<< cce->getArg(0)->getSourceRange();
return true;
}
if (isRtlReference)
return true;
if (isUnoReference && cce->getNumArgs() != 2)
return true;
// ignore the up-casting constructor, which has a std::enable_if second parameter
if (isUnoReference && cce->getNumArgs() == 2
&& !isa<EnumType>(cce->getConstructor()->getParamDecl(1)->getType()))
return true;
// extract the type parameter passed to the template
const RecordType* templateParamType = extractTemplateType(cce->getType());
if (!templateParamType)
return true;
// extract the type of the first parameter passed to the constructor
const Expr* constructorArg0 = cce->getArg(0);
if (!constructorArg0)
return true;
// drill down the expression tree till we hit the bottom, because at the top, the type is BaseReference
QualType argType;
for (;;)
{
if (auto castExpr = dyn_cast<CastExpr>(constructorArg0))
{
constructorArg0 = castExpr->getSubExpr();
continue;
}
if (auto matTempExpr = dyn_cast<MaterializeTemporaryExpr>(constructorArg0))
{
constructorArg0 = matTempExpr->getSubExpr();
continue;
}
if (auto bindTempExpr = dyn_cast<CXXBindTemporaryExpr>(constructorArg0))
{
constructorArg0 = bindTempExpr->getSubExpr();
continue;
}
if (auto tempObjExpr = dyn_cast<CXXTemporaryObjectExpr>(constructorArg0))
{
constructorArg0 = tempObjExpr->getArg(0);
continue;
}
if (auto parenExpr = dyn_cast<ParenExpr>(constructorArg0))
{
constructorArg0 = parenExpr->getSubExpr();
continue;
}
argType = constructorArg0->getType();
break;
}
const RecordType* argTemplateType = extractTemplateType(argType);
if (!argTemplateType)
return true;
CXXRecordDecl* templateParamRD = dyn_cast<CXXRecordDecl>(templateParamType->getDecl());
CXXRecordDecl* constructorArgRD = dyn_cast<CXXRecordDecl>(argTemplateType->getDecl());
// querying for XInterface (instead of doing an upcast) has special semantics,
// to check for UNO object equivalence.
if (templateParamRD->getName() == "XInterface")
return true;
// XShape is used in UNO aggregates in very "entertaining" ways, which means an UNO_QUERY
// can return a completely different object, e.g. see SwXShape::queryInterface
if (templateParamRD->getName() == "XShape")
return true;
if (cce->getNumArgs() == 2)
if (auto declRefExpr = dyn_cast<DeclRefExpr>(cce->getArg(1)))
{
// no warning expected, used to reject null references
if (auto enumConstantDecl = dyn_cast<EnumConstantDecl>(declRefExpr->getDecl()))
{
if (enumConstantDecl->getName() == "UNO_SET_THROW")
return true;
if (enumConstantDecl->getName() == "UNO_QUERY_THROW")
return true;
if (enumConstantDecl->getName() == "SAL_NO_ACQUIRE")
return true;
}
}
if (constructorArgRD->Equals(templateParamRD)
|| isDerivedFrom(constructorArgRD, templateParamRD))
{
report(DiagnosticsEngine::Warning,
"the source reference is already a subtype of the destination reference, just use =",
cce->getBeginLoc())
<< cce->getSourceRange();
}
return true;
}
bool ReferenceCasting::VisitCXXMemberCallExpr(const CXXMemberCallExpr* mce)
{
if (ignoreLocation(mce))
return true;
// don't bother processing anything in the Reference.h file. Makes my life easier when debugging this.
StringRef aFileName
= getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(mce->getBeginLoc()));
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.h"))
return true;
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.hxx"))
return true;
if (mce->getNumArgs() == 0)
return true;
// look for calls to the Reference<T>.set(x, UNO_QUERY) constructor
auto method = mce->getMethodDecl();
if (!method || !method->getIdentifier() || method->getName() != "set")
return true;
auto methodRecordDecl = dyn_cast<ClassTemplateSpecializationDecl>(mce->getRecordDecl());
if (!methodRecordDecl || !methodRecordDecl->getIdentifier()
|| methodRecordDecl->getName() != "Reference")
return true;
if (CheckForUnnecessaryGet(mce->getArg(0), /*includeRtlReference*/ mce->getNumArgs() == 1))
{
report(DiagnosticsEngine::Warning, "unnecessary get() call", mce->getArg(0)->getBeginLoc())
<< mce->getArg(0)->getSourceRange();
return true;
}
if (mce->getNumArgs() != 2)
return true;
// extract the type parameter passed to the template
const RecordType* templateParamType
= dyn_cast<RecordType>(methodRecordDecl->getTemplateArgs()[0].getAsType());
if (!templateParamType)
return true;
// extract the type of the first parameter passed to the method
const Expr* arg0 = mce->getArg(0);
if (!arg0)
return true;
// drill down the expression tree till we hit the bottom, because at the top, the type is BaseReference
QualType argType;
for (;;)
{
if (auto castExpr = dyn_cast<CastExpr>(arg0))
{
arg0 = castExpr->getSubExpr();
continue;
}
if (auto matTempExpr = dyn_cast<MaterializeTemporaryExpr>(arg0))
{
arg0 = matTempExpr->getSubExpr();
continue;
}
if (auto bindTempExpr = dyn_cast<CXXBindTemporaryExpr>(arg0))
{
arg0 = bindTempExpr->getSubExpr();
continue;
}
if (auto tempObjExpr = dyn_cast<CXXTemporaryObjectExpr>(arg0))
{
arg0 = tempObjExpr->getArg(0);
continue;
}
if (auto parenExpr = dyn_cast<ParenExpr>(arg0))
{
arg0 = parenExpr->getSubExpr();
continue;
}
argType = arg0->getType();
break;
}
const RecordType* argTemplateType = extractTemplateType(argType);
if (!argTemplateType)
return true;
CXXRecordDecl* templateParamRD = dyn_cast<CXXRecordDecl>(templateParamType->getDecl());
CXXRecordDecl* methodArgRD = dyn_cast<CXXRecordDecl>(argTemplateType->getDecl());
// querying for XInterface (instead of doing an upcast) has special semantics,
// to check for UNO object equivalence.
if (templateParamRD->getName() == "XInterface")
return true;
// XShape is used in UNO aggregates in very "entertaining" ways, which means an UNO_QUERY
// can return a completely different object, e.g. see SwXShape::queryInterface
if (templateParamRD->getName() == "XShape")
return true;
if (mce->getNumArgs() == 2)
if (auto declRefExpr = dyn_cast<DeclRefExpr>(mce->getArg(1)))
{
// no warning expected, used to reject null references
if (auto enumConstantDecl = dyn_cast<EnumConstantDecl>(declRefExpr->getDecl()))
{
if (enumConstantDecl->getName() == "UNO_SET_THROW")
return true;
if (enumConstantDecl->getName() == "UNO_QUERY_THROW")
return true;
if (enumConstantDecl->getName() == "SAL_NO_ACQUIRE")
return true;
}
}
if (methodArgRD->Equals(templateParamRD) || isDerivedFrom(methodArgRD, templateParamRD))
{
report(DiagnosticsEngine::Warning,
"the source reference is already a subtype of the destination reference, just use =",
mce->getBeginLoc())
<< mce->getSourceRange();
}
return true;
}
bool ReferenceCasting::VisitCallExpr(const CallExpr* ce)
{
if (ignoreLocation(ce))
return true;
// don't bother processing anything in the Reference.h file. Makes my life easier when debugging this.
StringRef aFileName
= getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(ce->getBeginLoc()));
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.h"))
return true;
if (loplugin::isSamePathname(aFileName, SRCDIR "/include/com/sun/star/uno/Reference.hxx"))
return true;
// look for calls to Reference<T>::query(x)
auto method = dyn_cast_or_null<CXXMethodDecl>(ce->getDirectCallee());
if (!method || !method->getIdentifier() || method->getName() != "query")
return true;
if (ce->getNumArgs() != 1)
return true;
auto methodRecordDecl = dyn_cast<ClassTemplateSpecializationDecl>(method->getParent());
if (!methodRecordDecl || !methodRecordDecl->getIdentifier()
|| methodRecordDecl->getName() != "Reference")
return true;
if (CheckForUnnecessaryGet(ce->getArg(0), /*includeRtlReference*/ true))
report(DiagnosticsEngine::Warning, "unnecessary get() call", ce->getArg(0)->getBeginLoc())
<< ce->getArg(0)->getSourceRange();
// extract the type parameter passed to the template
const RecordType* templateParamType
= dyn_cast<RecordType>(methodRecordDecl->getTemplateArgs()[0].getAsType());
if (!templateParamType)
return true;
// extract the type of the first parameter passed to the method
const Expr* arg0 = ce->getArg(0);
if (!arg0)
return true;
// drill down the expression tree till we hit the bottom, because at the top, the type is BaseReference
QualType argType;
for (;;)
{
if (auto castExpr = dyn_cast<CastExpr>(arg0))
{
arg0 = castExpr->getSubExpr();
continue;
}
if (auto matTempExpr = dyn_cast<MaterializeTemporaryExpr>(arg0))
{
arg0 = matTempExpr->getSubExpr();
continue;
}
if (auto bindTempExpr = dyn_cast<CXXBindTemporaryExpr>(arg0))
{
arg0 = bindTempExpr->getSubExpr();
continue;
}
if (auto tempObjExpr = dyn_cast<CXXTemporaryObjectExpr>(arg0))
{
arg0 = tempObjExpr->getArg(0);
continue;
}
if (auto parenExpr = dyn_cast<ParenExpr>(arg0))
{
arg0 = parenExpr->getSubExpr();
continue;
}
argType = arg0->getType();
break;
}
const RecordType* argTemplateType = extractTemplateType(argType);
if (!argTemplateType)
return true;
CXXRecordDecl* templateParamRD = dyn_cast<CXXRecordDecl>(templateParamType->getDecl());
CXXRecordDecl* methodArgRD = dyn_cast<CXXRecordDecl>(argTemplateType->getDecl());
// querying for XInterface (instead of doing an upcast) has special semantics,
// to check for UNO object equivalence.
if (templateParamRD->getName() == "XInterface")
return true;
// XShape is used in UNO aggregates in very "entertaining" ways, which means an UNO_QUERY
// can return a completely different object, e.g. see SwXShape::queryInterface
if (templateParamRD->getName() == "XShape")
return true;
if (methodArgRD->Equals(templateParamRD) || isDerivedFrom(methodArgRD, templateParamRD))
{
report(DiagnosticsEngine::Warning,
"the source reference is already a subtype of the destination reference, just use =",
ce->getBeginLoc())
<< ce->getSourceRange();
}
return true;
}
/**
Check for
Reference<T>(x.get(), UNO_QUERY)
because sometimes simplifying that means the main purpose of this plugin can kick in.
*/
bool ReferenceCasting::CheckForUnnecessaryGet(const Expr* expr, bool includeRtlReference)
{
expr = expr->IgnoreImplicit();
auto cxxMemberCallExpr = dyn_cast<CXXMemberCallExpr>(expr);
if (!cxxMemberCallExpr)
return false;
auto methodDecl = cxxMemberCallExpr->getMethodDecl();
if (!methodDecl)
return false;
if (!methodDecl->getIdentifier() || methodDecl->getName() != "get")
return false;
if (!loplugin::TypeCheck(expr->getType()).Pointer())
return false;
auto dc = loplugin::DeclCheck(methodDecl->getParent());
if (dc.Class("Reference").Namespace("uno"))
; // ok
else if (includeRtlReference && dc.Class("Reference").Namespace("rtl"))
; // ok
else
return false;
StringRef aFileName
= getFilenameOfLocation(compiler.getSourceManager().getSpellingLoc(expr->getBeginLoc()));
if (loplugin::isSamePathname(aFileName, SRCDIR "/cppu/qa/test_reference.cxx"))
return false;
return true;
}
static const RecordType* extractTemplateType(QualType cceType)
{
// check for passing raw pointer to interface case
if (cceType->isPointerType())
{
auto pointeeType = cceType->getPointeeType();
if (auto elaboratedType = dyn_cast<ElaboratedType>(pointeeType))
pointeeType = elaboratedType->desugar();
if (auto substTemplateTypeParmType = dyn_cast<SubstTemplateTypeParmType>(pointeeType))
pointeeType = substTemplateTypeParmType->desugar();
if (auto recordType = dyn_cast<RecordType>(pointeeType))
return recordType;
}
// extract Foo from Reference<Foo>
if (auto subst = dyn_cast<SubstTemplateTypeParmType>(cceType))
{
if (auto recType = dyn_cast<RecordType>(subst->desugar()))
{
if (auto ctsd = dyn_cast<ClassTemplateSpecializationDecl>(recType->getDecl()))
{
auto const& args = ctsd->getTemplateArgs();
if (args.size() > 0 && args[0].getKind() == TemplateArgument::ArgKind::Type)
return dyn_cast_or_null<RecordType>(args[0].getAsType().getTypePtr());
}
}
}
if (auto elaboratedType = dyn_cast<ElaboratedType>(cceType))
cceType = elaboratedType->desugar();
auto cceTST = dyn_cast<TemplateSpecializationType>(cceType);
if (!cceTST)
return NULL;
if (cceTST->getNumArgs() != 1)
return NULL;
const TemplateArgument& cceTA = cceTST->getArg(0);
QualType templateParamType = cceTA.getAsType();
if (auto elaboratedType = dyn_cast<ElaboratedType>(templateParamType))
templateParamType = elaboratedType->desugar();
return dyn_cast<RecordType>(templateParamType);
}
/**
Implement my own isDerived because we can't always see all the definitions of the classes involved.
which will cause an assert with the normal clang isDerivedFrom code.
*/
static bool isDerivedFrom(const CXXRecordDecl* subtypeRecord, const CXXRecordDecl* baseRecord)
{
// if there is more than one case, then we have an ambiguous conversion, and we can't change the code
// to use the upcasting constructor.
return loplugin::derivedFromCount(subtypeRecord, baseRecord) == 1;
}
loplugin::Plugin::Registration<ReferenceCasting> referencecasting("referencecasting");
} // namespace
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */