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/* -*- 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/.
*/
#ifndef LO_CLANG_SHARED_PLUGINS
#include <cassert>
#include <string>
#include <iostream>
#include <unordered_map>
#include <unordered_set>
#include "plugin.hxx"
#include "check.hxx"
#include "clang/AST/CXXInheritance.h"
#include "clang/AST/StmtVisitor.h"
/**
Look for places where we are making a substring copy of an OUString, and then passing it to a
function that takes a u16string_view, in which case it is more efficient to pass a view
of the OUString, rather than making a copy.
TODO currently does not check if there is some other visible overload of the callee, that can take
a string_view.
TODO handle OUStringBuffer/OStringBuffer similarly
*/
namespace
{
class StringView : public loplugin::FilteringPlugin<StringView>
{
public:
explicit StringView(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
bool preRun() override { return true; }
virtual void run() override
{
if (!preRun())
return;
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
bool VisitCallExpr(CallExpr const*);
bool VisitCXXConstructExpr(CXXConstructExpr const*);
bool VisitFunctionDecl(FunctionDecl const*);
bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
bool VisitImplicitCastExpr(ImplicitCastExpr const*);
};
bool StringView::VisitCallExpr(CallExpr const* callExpr)
{
if (ignoreLocation(callExpr))
return true;
const FunctionDecl* functionDecl;
if (isa<CXXMemberCallExpr>(callExpr))
functionDecl = dyn_cast<CXXMemberCallExpr>(callExpr)->getMethodDecl();
else
functionDecl = callExpr->getDirectCallee();
if (!functionDecl)
return true;
unsigned len = std::min(callExpr->getNumArgs(), functionDecl->getNumParams());
for (unsigned i = 0; i < len; ++i)
{
const Expr* argExpr = callExpr->getArg(i);
auto paramDecl = functionDecl->getParamDecl(i);
auto paramRecordDecl = dyn_cast_or_null<RecordDecl>(
paramDecl->getType()->getUnqualifiedDesugaredType()->getAsTagDecl());
if (!paramRecordDecl || !paramRecordDecl->getIdentifier()
|| paramRecordDecl->getName() != "basic_string_view")
continue;
// unwrap the operator that converts to std::u16string_view
auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(argExpr->IgnoreImpCasts());
if (!memberCallExpr)
continue;
// unwrap the call to copy()
auto memberCallExpr2 = dyn_cast<CXXMemberCallExpr>(
compat::IgnoreImplicit(memberCallExpr->getImplicitObjectArgument()));
if (!memberCallExpr2)
continue;
auto methodDecl = memberCallExpr2->getMethodDecl();
if (!methodDecl->getIdentifier() || methodDecl->getName() != "copy")
continue;
report(DiagnosticsEngine::Warning, "rather than copy, pass with a view using subView()",
compat::getBeginLoc(argExpr))
<< argExpr->getSourceRange();
}
return true;
}
bool StringView::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOperatorCallExpr)
{
if (ignoreLocation(cxxOperatorCallExpr))
return true;
auto check = [&](const Expr* expr) -> void {
auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(compat::IgnoreImplicit(expr));
if (!memberCallExpr)
return;
auto methodDecl = memberCallExpr->getMethodDecl();
if (!methodDecl->getIdentifier() || methodDecl->getName() != "copy")
return;
report(DiagnosticsEngine::Warning, "rather than copy, pass with a view using subView()",
compat::getBeginLoc(expr))
<< expr->getSourceRange();
};
auto op = cxxOperatorCallExpr->getOperator();
if (op == OO_Plus && cxxOperatorCallExpr->getNumArgs() == 2)
{
check(cxxOperatorCallExpr->getArg(0));
check(cxxOperatorCallExpr->getArg(1));
}
if (compat::isComparisonOp(cxxOperatorCallExpr))
{
check(cxxOperatorCallExpr->getArg(0));
check(cxxOperatorCallExpr->getArg(1));
}
else if (op == OO_PlusEqual)
check(cxxOperatorCallExpr->getArg(1));
else if (op == OO_Subscript)
check(cxxOperatorCallExpr->getArg(0));
return true;
}
bool StringView::VisitFunctionDecl(FunctionDecl const* functionDecl)
{
if (ignoreLocation(functionDecl))
return true;
// debugging
// if (functionDecl->getIdentifier() && functionDecl->getName() == "f1")
// functionDecl->dump();
return true;
}
bool StringView::VisitCXXConstructExpr(CXXConstructExpr const* constructExpr)
{
if (ignoreLocation(constructExpr))
return true;
const CXXConstructorDecl* constructorDecl = constructExpr->getConstructor();
if (!constructorDecl)
return true;
unsigned len = std::min(constructExpr->getNumArgs(), constructorDecl->getNumParams());
for (unsigned i = 0; i < len; ++i)
{
const Expr* argExpr = constructExpr->getArg(i);
auto paramDecl = constructorDecl->getParamDecl(i);
auto paramRecordDecl = dyn_cast_or_null<RecordDecl>(
paramDecl->getType()->getUnqualifiedDesugaredType()->getAsTagDecl());
if (!paramRecordDecl || !paramRecordDecl->getIdentifier()
|| paramRecordDecl->getName() != "basic_string_view")
continue;
// unwrap the operator that converts to std::u16string_view
auto memberCallExpr = dyn_cast<CXXMemberCallExpr>(argExpr->IgnoreImpCasts());
if (!memberCallExpr)
continue;
// unwrap the call to copy()
auto memberCallExpr2 = dyn_cast<CXXMemberCallExpr>(
compat::IgnoreImplicit(memberCallExpr->getImplicitObjectArgument()));
if (!memberCallExpr2)
continue;
auto methodDecl = memberCallExpr2->getMethodDecl();
if (!methodDecl->getIdentifier() || methodDecl->getName() != "copy")
continue;
report(DiagnosticsEngine::Warning, "rather than copy, pass with a view using subView()",
compat::getBeginLoc(argExpr))
<< argExpr->getSourceRange();
}
return true;
}
bool StringView::VisitImplicitCastExpr(ImplicitCastExpr const* expr)
{
if (ignoreLocation(expr))
{
return true;
}
if (!loplugin::TypeCheck(expr->getType()).ClassOrStruct("basic_string_view").StdNamespace())
{
return true;
}
auto const e = dyn_cast<CXXConstructExpr>(expr->getSubExprAsWritten()->IgnoreParens());
if (e == nullptr)
{
return true;
}
if (e->getNumArgs() != 0)
{
return true;
}
auto const tc = loplugin::TypeCheck(e->getType());
if (!(tc.Class("OString").Namespace("rtl").GlobalNamespace()
|| tc.Class("OUString").Namespace("rtl").GlobalNamespace()))
{
return true;
}
report(DiagnosticsEngine::Warning,
"instead of an empty %0, pass an empty '%select{std::string_view|std::u16string_view}1'",
e->getLocation())
<< e->getType() << (tc.Class("OString").Namespace("rtl").GlobalNamespace() ? 0 : 1)
<< e->getSourceRange();
return true;
}
loplugin::Plugin::Registration<StringView> stringview("stringview");
}
#endif // LO_CLANG_SHARED_PLUGINS
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
