summaryrefslogtreecommitdiffstats
path: root/compilerplugins/clang/referencecasting.cxx
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:06:44 +0000
commited5640d8b587fbcfed7dd7967f3de04b37a76f26 (patch)
tree7a5f7c6c9d02226d7471cb3cc8fbbf631b415303 /compilerplugins/clang/referencecasting.cxx
parentInitial commit. (diff)
downloadlibreoffice-cb75148ebd0135178ff46f89a30139c44f8d2040.tar.xz
libreoffice-cb75148ebd0135178ff46f89a30139c44f8d2040.zip
Adding upstream version 4:7.4.7.upstream/4%7.4.7upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compilerplugins/clang/referencecasting.cxx')
-rw-r--r--compilerplugins/clang/referencecasting.cxx538
1 files changed, 538 insertions, 0 deletions
diff --git a/compilerplugins/clang/referencecasting.cxx b/compilerplugins/clang/referencecasting.cxx
new file mode 100644
index 000000000..08895f723
--- /dev/null
+++ b/compilerplugins/clang/referencecasting.cxx
@@ -0,0 +1,538 @@
+/* -*- 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: */