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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 <fstream>
#include <set>
#include "config_clang.h"
#include "compat.hxx"
#include "plugin.hxx"
/**
Look for comparisons where the constant is on the left, it should be on the right.
*/
namespace {
class ComparisonWithConstant :
public loplugin::FilteringRewritePlugin<ComparisonWithConstant>
{
public:
explicit ComparisonWithConstant(loplugin::InstantiationData const & data): FilteringRewritePlugin(data) {}
virtual void run() override
{
TraverseDecl(compiler.getASTContext().getTranslationUnitDecl());
}
// Deliberately drop RecursiveASTVisitor::TraverseBinaryOperator's DataRecursionQueue
// parameter; TraverseBinaryOperator must use stack instead of data recursion for any
// children's VisitBinaryOperator to see changes to occurrence_ by a parent
// VisitBinaryOperator:
bool TraverseBinaryOperator(BinaryOperator * S)
{
auto const op = S->getOpcode();
if (op != BO_EQ && op != BO_NE) {
return RecursiveASTVisitor::TraverseBinaryOperator(S);
}
auto const saved = occurrence_;
auto const ret = RecursiveASTVisitor::TraverseBinaryOperator(S);
occurrence_ = saved;
return ret;
}
#if CLANG_VERSION < 110000
bool TraverseBinEQ(BinaryOperator * expr) { return TraverseBinaryOperator(expr); }
bool TraverseBinNE(BinaryOperator * expr) { return TraverseBinaryOperator(expr); }
#endif
bool VisitBinaryOperator(const BinaryOperator *);
private:
bool rewrite(const BinaryOperator *);
std::string getExprAsString(SourceRange range);
SourceRange ignoreMacroExpansions(SourceRange range);
bool occurrence_ = false;
};
bool ComparisonWithConstant::VisitBinaryOperator(const BinaryOperator* binaryOp)
{
if (ignoreLocation(binaryOp)) {
return true;
}
if (!(binaryOp->getOpcode() == BO_EQ || binaryOp->getOpcode() == BO_NE)) {
return true;
}
// protect against clang assert
if (binaryOp->getLHS()->isValueDependent() || binaryOp->getRHS()->isValueDependent()) {
return true;
}
if (!binaryOp->getLHS()->isEvaluatable(compiler.getASTContext())) {
return true;
}
if (binaryOp->getRHS()->isEvaluatable(compiler.getASTContext())) {
return true;
}
if (occurrence_ || !rewrite(binaryOp))
{
report(
DiagnosticsEngine::Warning, "Rather put constant on right when comparing",
binaryOp->getSourceRange().getBegin())
<< binaryOp->getSourceRange();
}
occurrence_ = true;
return true;
}
bool ComparisonWithConstant::rewrite(const BinaryOperator * binaryOp) {
if (rewriter == nullptr) {
return false;
}
auto lhsRange = ignoreMacroExpansions(binaryOp->getLHS()->getSourceRange());
if (!lhsRange.isValid()) {
return false;
}
auto rhsRange = ignoreMacroExpansions(binaryOp->getRHS()->getSourceRange());
if (!rhsRange.isValid()) {
return false;
}
const std::string lhsString = getExprAsString(lhsRange);
const std::string rhsString = getExprAsString(rhsRange);
// switch LHS and RHS
if (!replaceText(lhsRange, rhsString)) {
return false;
}
if (!replaceText(rhsRange, lhsString)) {
return false;
}
return true;
}
// get the expression contents
std::string ComparisonWithConstant::getExprAsString(SourceRange range)
{
SourceManager& SM = compiler.getSourceManager();
SourceLocation startLoc = range.getBegin();
SourceLocation endLoc = range.getEnd();
const char *p1 = SM.getCharacterData( startLoc );
const char *p2 = SM.getCharacterData( endLoc );
unsigned n = Lexer::MeasureTokenLength( endLoc, SM, compiler.getLangOpts());
return std::string( p1, p2 - p1 + n);
}
SourceRange ComparisonWithConstant::ignoreMacroExpansions(SourceRange range) {
while (compiler.getSourceManager().isMacroArgExpansion(range.getBegin())) {
range.setBegin(
compiler.getSourceManager().getImmediateMacroCallerLoc(
range.getBegin()));
}
if (range.getBegin().isMacroID()) {
SourceLocation loc;
if (Lexer::isAtStartOfMacroExpansion(
range.getBegin(), compiler.getSourceManager(),
compiler.getLangOpts(), &loc))
{
range.setBegin(loc);
}
}
while (compiler.getSourceManager().isMacroArgExpansion(range.getEnd())) {
range.setEnd(
compiler.getSourceManager().getImmediateMacroCallerLoc(
range.getEnd()));
}
if (range.getEnd().isMacroID()) {
SourceLocation loc;
if (Lexer::isAtEndOfMacroExpansion(
range.getEnd(), compiler.getSourceManager(),
compiler.getLangOpts(), &loc))
{
range.setEnd(loc);
}
}
return range.getBegin().isMacroID() || range.getEnd().isMacroID()
? SourceRange() : range;
}
loplugin::Plugin::Registration< ComparisonWithConstant > X("comparisonwithconstant", false);
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
