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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/.
*/
#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"
/**
TODO deal with C++ operator overload assign
*/
namespace
{
//static bool startswith(const std::string& rStr, const char* pSubStr) {
// return rStr.compare(0, strlen(pSubStr), pSubStr) == 0;
//}
class BuriedAssign : public loplugin::FilteringPlugin<BuriedAssign>
{
public:
explicit BuriedAssign(loplugin::InstantiationData const& data)
: FilteringPlugin(data)
{
}
virtual void run() override
{
std::string fn(handler.getMainFileName());
loplugin::normalizeDotDotInFilePath(fn);
// getParentStmt appears not to be working very well here
if (fn == SRCDIR "/stoc/source/inspect/introspection.cxx"
|| fn == SRCDIR "/stoc/source/corereflection/criface.cxx")
return;
// calling an acquire via function pointer
if (fn == SRCDIR "/cppu/source/uno/lbenv.cxx"
|| fn == SRCDIR "cppu/source/typelib/static_types.cxx")
return;
// false+, not sure why
if (fn == SRCDIR "/vcl/source/window/menu.cxx")
return;
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
bool VisitBinaryOperator(BinaryOperator const*);
bool VisitCXXOperatorCallExpr(CXXOperatorCallExpr const*);
private:
void checkExpr(Expr const*);
};
static bool isAssignmentOp(clang::BinaryOperatorKind op)
{
// We ignore BO_ShrAssign i.e. >>= because we use that everywhere for
// extracting data from css::uno::Any
return op == BO_Assign || op == BO_MulAssign || op == BO_DivAssign || op == BO_RemAssign
|| op == BO_AddAssign || op == BO_SubAssign || op == BO_ShlAssign || op == BO_AndAssign
|| op == BO_XorAssign || op == BO_OrAssign;
}
static bool isAssignmentOp(clang::OverloadedOperatorKind Opc)
{
// Same logic as CXXOperatorCallExpr::isAssignmentOp(), which our supported clang
// doesn't have yet.
// Except that we ignore OO_GreaterGreaterEqual i.e. >>= because we use that everywhere for
// extracting data from css::uno::Any
return Opc == OO_Equal || Opc == OO_StarEqual || Opc == OO_SlashEqual || Opc == OO_PercentEqual
|| Opc == OO_PlusEqual || Opc == OO_MinusEqual || Opc == OO_LessLessEqual
|| Opc == OO_AmpEqual || Opc == OO_CaretEqual || Opc == OO_PipeEqual;
}
bool BuriedAssign::VisitBinaryOperator(BinaryOperator const* binaryOp)
{
if (ignoreLocation(binaryOp))
return true;
if (!isAssignmentOp(binaryOp->getOpcode()))
return true;
checkExpr(binaryOp);
return true;
}
bool BuriedAssign::VisitCXXOperatorCallExpr(CXXOperatorCallExpr const* cxxOper)
{
if (ignoreLocation(cxxOper))
return true;
if (!isAssignmentOp(cxxOper->getOperator()))
return true;
checkExpr(cxxOper);
return true;
}
void BuriedAssign::checkExpr(Expr const* binaryOp)
{
if (compiler.getSourceManager().isMacroBodyExpansion(compat::getBeginLoc(binaryOp)))
return;
if (compiler.getSourceManager().isMacroArgExpansion(compat::getBeginLoc(binaryOp)))
return;
/**
Note: I tried writing this plugin without getParentStmt, but in order to make that work, I had to
hack things like TraverseWhileStmt to call TraverseStmt on the child nodes myself, so I could know whether I was inside the body or the condition.
But I could not get that to work, so switched to this approach.
*/
// look up past the temporary nodes
Stmt const* child = binaryOp;
Stmt const* parent = getParentStmt(binaryOp);
while (true)
{
// This part is not ideal, but getParentStmt() appears to fail us in some cases, notably when the assignment
// is inside a decl like:
// int x = a = 1;
if (!parent)
return;
if (!(isa<MaterializeTemporaryExpr>(parent) || isa<CXXBindTemporaryExpr>(parent)
|| isa<ImplicitCastExpr>(parent) || isa<CXXConstructExpr>(parent)
|| isa<ParenExpr>(parent) || isa<ExprWithCleanups>(parent)))
break;
child = parent;
parent = getParentStmt(parent);
}
if (isa<CompoundStmt>(parent))
return;
// ignore chained assignment like "a = b = 1;"
if (auto cxxOper = dyn_cast<CXXOperatorCallExpr>(parent))
{
if (cxxOper->getOperator() == OO_Equal)
return;
}
// ignore chained assignment like "a = b = 1;"
if (auto parentBinOp = dyn_cast<BinaryOperator>(parent))
{
if (parentBinOp->getOpcode() == BO_Assign)
return;
}
// ignore chained assignment like "int a = b = 1;"
if (isa<DeclStmt>(parent))
return;
if (isa<CaseStmt>(parent) || isa<DefaultStmt>(parent) || isa<LabelStmt>(parent)
|| isa<ForStmt>(parent) || isa<CXXForRangeStmt>(parent) || isa<IfStmt>(parent)
|| isa<DoStmt>(parent) || isa<WhileStmt>(parent) || isa<ReturnStmt>(parent))
return;
// now check for the statements where we don't care at all if we see a buried assignment
while (true)
{
if (isa<CompoundStmt>(parent))
break;
if (isa<CaseStmt>(parent) || isa<DefaultStmt>(parent) || isa<LabelStmt>(parent))
return;
// Ignore assign in these statements, just seems to be part of the "natural" idiom of C/C++
// TODO: perhaps include ReturnStmt?
if (auto forStmt = dyn_cast<ForStmt>(parent))
{
if (child == forStmt->getBody())
break;
return;
}
if (auto forRangeStmt = dyn_cast<CXXForRangeStmt>(parent))
{
if (child == forRangeStmt->getBody())
break;
return;
}
if (auto ifStmt = dyn_cast<IfStmt>(parent))
{
if (child == ifStmt->getCond())
return;
}
if (auto doStmt = dyn_cast<DoStmt>(parent))
{
if (child == doStmt->getCond())
return;
}
if (auto whileStmt = dyn_cast<WhileStmt>(parent))
{
if (child == whileStmt->getBody())
break;
return;
}
if (isa<ReturnStmt>(parent))
return;
// This appears to be a valid way of making it obvious that we need to call acquire when assigning such ref-counted
// stuff e.g.
// rtl_uString_acquire( a = b );
if (auto callExpr = dyn_cast<CallExpr>(parent))
{
if (callExpr->getDirectCallee() && callExpr->getDirectCallee()->getIdentifier())
{
auto name = callExpr->getDirectCallee()->getName();
if (name == "rtl_uString_acquire" || name == "_acquire"
|| name == "typelib_typedescriptionreference_acquire")
return;
}
}
child = parent;
parent = getParentStmt(parent);
if (!parent)
break;
}
report(DiagnosticsEngine::Warning, "buried assignment, very hard to read",
compat::getBeginLoc(binaryOp))
<< binaryOp->getSourceRange();
}
// off by default because it uses getParentStmt so it's more expensive to run
loplugin::Plugin::Registration<BuriedAssign> X("buriedassign", false);
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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