748c139ade
Asserting on invalid input isn't very nice, hence the patch to emit an error instead. This is the first of many patches to overhaul the way we handle checker options. Differential Revision: https://reviews.llvm.org/D57850 llvm-svn: 355704
214 lines
8.3 KiB
C++
214 lines
8.3 KiB
C++
//===--- CloneChecker.cpp - Clone detection checker -------------*- C++ -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
///
|
|
/// \file
|
|
/// CloneChecker is a checker that reports clones in the current translation
|
|
/// unit.
|
|
///
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
|
|
#include "clang/Analysis/CloneDetection.h"
|
|
#include "clang/Basic/Diagnostic.h"
|
|
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
|
|
#include "clang/StaticAnalyzer/Core/Checker.h"
|
|
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
namespace {
|
|
class CloneChecker
|
|
: public Checker<check::ASTCodeBody, check::EndOfTranslationUnit> {
|
|
public:
|
|
// Checker options.
|
|
int MinComplexity;
|
|
bool ReportNormalClones;
|
|
StringRef IgnoredFilesPattern;
|
|
|
|
private:
|
|
mutable CloneDetector Detector;
|
|
mutable std::unique_ptr<BugType> BT_Exact, BT_Suspicious;
|
|
|
|
public:
|
|
void checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
|
|
BugReporter &BR) const;
|
|
|
|
void checkEndOfTranslationUnit(const TranslationUnitDecl *TU,
|
|
AnalysisManager &Mgr, BugReporter &BR) const;
|
|
|
|
/// Reports all clones to the user.
|
|
void reportClones(BugReporter &BR, AnalysisManager &Mgr,
|
|
std::vector<CloneDetector::CloneGroup> &CloneGroups) const;
|
|
|
|
/// Reports only suspicious clones to the user along with information
|
|
/// that explain why they are suspicious.
|
|
void reportSuspiciousClones(
|
|
BugReporter &BR, AnalysisManager &Mgr,
|
|
std::vector<CloneDetector::CloneGroup> &CloneGroups) const;
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
void CloneChecker::checkASTCodeBody(const Decl *D, AnalysisManager &Mgr,
|
|
BugReporter &BR) const {
|
|
// Every statement that should be included in the search for clones needs to
|
|
// be passed to the CloneDetector.
|
|
Detector.analyzeCodeBody(D);
|
|
}
|
|
|
|
void CloneChecker::checkEndOfTranslationUnit(const TranslationUnitDecl *TU,
|
|
AnalysisManager &Mgr,
|
|
BugReporter &BR) const {
|
|
// At this point, every statement in the translation unit has been analyzed by
|
|
// the CloneDetector. The only thing left to do is to report the found clones.
|
|
|
|
// Let the CloneDetector create a list of clones from all the analyzed
|
|
// statements. We don't filter for matching variable patterns at this point
|
|
// because reportSuspiciousClones() wants to search them for errors.
|
|
std::vector<CloneDetector::CloneGroup> AllCloneGroups;
|
|
|
|
Detector.findClones(
|
|
AllCloneGroups, FilenamePatternConstraint(IgnoredFilesPattern),
|
|
RecursiveCloneTypeIIHashConstraint(), MinGroupSizeConstraint(2),
|
|
MinComplexityConstraint(MinComplexity),
|
|
RecursiveCloneTypeIIVerifyConstraint(), OnlyLargestCloneConstraint());
|
|
|
|
reportSuspiciousClones(BR, Mgr, AllCloneGroups);
|
|
|
|
// We are done for this translation unit unless we also need to report normal
|
|
// clones.
|
|
if (!ReportNormalClones)
|
|
return;
|
|
|
|
// Now that the suspicious clone detector has checked for pattern errors,
|
|
// we also filter all clones who don't have matching patterns
|
|
CloneDetector::constrainClones(AllCloneGroups,
|
|
MatchingVariablePatternConstraint(),
|
|
MinGroupSizeConstraint(2));
|
|
|
|
reportClones(BR, Mgr, AllCloneGroups);
|
|
}
|
|
|
|
static PathDiagnosticLocation makeLocation(const StmtSequence &S,
|
|
AnalysisManager &Mgr) {
|
|
ASTContext &ACtx = Mgr.getASTContext();
|
|
return PathDiagnosticLocation::createBegin(
|
|
S.front(), ACtx.getSourceManager(),
|
|
Mgr.getAnalysisDeclContext(ACtx.getTranslationUnitDecl()));
|
|
}
|
|
|
|
void CloneChecker::reportClones(
|
|
BugReporter &BR, AnalysisManager &Mgr,
|
|
std::vector<CloneDetector::CloneGroup> &CloneGroups) const {
|
|
|
|
if (!BT_Exact)
|
|
BT_Exact.reset(new BugType(this, "Exact code clone", "Code clone"));
|
|
|
|
for (const CloneDetector::CloneGroup &Group : CloneGroups) {
|
|
// We group the clones by printing the first as a warning and all others
|
|
// as a note.
|
|
auto R = llvm::make_unique<BugReport>(*BT_Exact, "Duplicate code detected",
|
|
makeLocation(Group.front(), Mgr));
|
|
R->addRange(Group.front().getSourceRange());
|
|
|
|
for (unsigned i = 1; i < Group.size(); ++i)
|
|
R->addNote("Similar code here", makeLocation(Group[i], Mgr),
|
|
Group[i].getSourceRange());
|
|
BR.emitReport(std::move(R));
|
|
}
|
|
}
|
|
|
|
void CloneChecker::reportSuspiciousClones(
|
|
BugReporter &BR, AnalysisManager &Mgr,
|
|
std::vector<CloneDetector::CloneGroup> &CloneGroups) const {
|
|
std::vector<VariablePattern::SuspiciousClonePair> Pairs;
|
|
|
|
for (const CloneDetector::CloneGroup &Group : CloneGroups) {
|
|
for (unsigned i = 0; i < Group.size(); ++i) {
|
|
VariablePattern PatternA(Group[i]);
|
|
|
|
for (unsigned j = i + 1; j < Group.size(); ++j) {
|
|
VariablePattern PatternB(Group[j]);
|
|
|
|
VariablePattern::SuspiciousClonePair ClonePair;
|
|
// For now, we only report clones which break the variable pattern just
|
|
// once because multiple differences in a pattern are an indicator that
|
|
// those differences are maybe intended (e.g. because it's actually a
|
|
// different algorithm).
|
|
// FIXME: In very big clones even multiple variables can be unintended,
|
|
// so replacing this number with a percentage could better handle such
|
|
// cases. On the other hand it could increase the false-positive rate
|
|
// for all clones if the percentage is too high.
|
|
if (PatternA.countPatternDifferences(PatternB, &ClonePair) == 1) {
|
|
Pairs.push_back(ClonePair);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!BT_Suspicious)
|
|
BT_Suspicious.reset(
|
|
new BugType(this, "Suspicious code clone", "Code clone"));
|
|
|
|
ASTContext &ACtx = BR.getContext();
|
|
SourceManager &SM = ACtx.getSourceManager();
|
|
AnalysisDeclContext *ADC =
|
|
Mgr.getAnalysisDeclContext(ACtx.getTranslationUnitDecl());
|
|
|
|
for (VariablePattern::SuspiciousClonePair &Pair : Pairs) {
|
|
// FIXME: We are ignoring the suggestions currently, because they are
|
|
// only 50% accurate (even if the second suggestion is unavailable),
|
|
// which may confuse the user.
|
|
// Think how to perform more accurate suggestions?
|
|
|
|
auto R = llvm::make_unique<BugReport>(
|
|
*BT_Suspicious,
|
|
"Potential copy-paste error; did you really mean to use '" +
|
|
Pair.FirstCloneInfo.Variable->getNameAsString() + "' here?",
|
|
PathDiagnosticLocation::createBegin(Pair.FirstCloneInfo.Mention, SM,
|
|
ADC));
|
|
R->addRange(Pair.FirstCloneInfo.Mention->getSourceRange());
|
|
|
|
R->addNote("Similar code using '" +
|
|
Pair.SecondCloneInfo.Variable->getNameAsString() + "' here",
|
|
PathDiagnosticLocation::createBegin(Pair.SecondCloneInfo.Mention,
|
|
SM, ADC),
|
|
Pair.SecondCloneInfo.Mention->getSourceRange());
|
|
|
|
BR.emitReport(std::move(R));
|
|
}
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Register CloneChecker
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
void ento::registerCloneChecker(CheckerManager &Mgr) {
|
|
auto *Checker = Mgr.registerChecker<CloneChecker>();
|
|
|
|
Checker->MinComplexity = Mgr.getAnalyzerOptions().getCheckerIntegerOption(
|
|
Checker, "MinimumCloneComplexity", 50);
|
|
|
|
if (Checker->MinComplexity < 0)
|
|
Mgr.reportInvalidCheckerOptionValue(
|
|
Checker, "MinimumCloneComplexity", "a non-negative value");
|
|
|
|
Checker->ReportNormalClones = Mgr.getAnalyzerOptions().getCheckerBooleanOption(
|
|
Checker, "ReportNormalClones", true);
|
|
|
|
Checker->IgnoredFilesPattern = Mgr.getAnalyzerOptions()
|
|
.getCheckerStringOption(Checker, "IgnoredFilesPattern", "");
|
|
}
|
|
|
|
bool ento::shouldRegisterCloneChecker(const LangOptions &LO) {
|
|
return true;
|
|
}
|