mgrang updated this revision to Diff 161165.
mgrang edited the summary of this revision.
mgrang added a comment.
Added checks for more algorithms: stable_sort, is_sorted, partial_sort,
partition, stable_partition, nth_element.
https://reviews.llvm.org/D50488
Files:
include/clang/StaticAnalyzer/Checkers/Checkers.td
lib/StaticAnalyzer/Checkers/CMakeLists.txt
lib/StaticAnalyzer/Checkers/PointerSortingChecker.cpp
test/Analysis/ptr-sort.cpp
Index: test/Analysis/ptr-sort.cpp
===================================================================
--- /dev/null
+++ test/Analysis/ptr-sort.cpp
@@ -0,0 +1,57 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,alpha.nondeterminism.PointerSorting %s -analyzer-output=text -verify
+
+#include "Inputs/system-header-simulator-cxx.h"
+namespace std {
+ template<class ForwardIt>
+ bool is_sorted(ForwardIt first, ForwardIt last);
+
+ template <class RandomIt>
+ void nth_element(RandomIt first, RandomIt nth, RandomIt last);
+
+ template<class RandomIt>
+ void partial_sort(RandomIt first, RandomIt middle, RandomIt last);
+
+ template<class RandomIt>
+ void sort (RandomIt first, RandomIt last);
+
+ template<class RandomIt>
+ void stable_sort(RandomIt first, RandomIt last);
+
+ template<class BidirIt, class UnaryPredicate>
+ BidirIt partition(BidirIt first, BidirIt last, UnaryPredicate p);
+
+ template<class BidirIt, class UnaryPredicate>
+ BidirIt stable_partition(BidirIt first, BidirIt last, UnaryPredicate p);
+}
+
+bool f (int x) { return true; }
+bool g (int *x) { return true; }
+
+void PointerSorting() {
+ int a = 1, b = 2, c = 3;
+ std::vector<int> V1 = {a, b};
+ std::vector<int *> V2 = {&a, &b};
+
+ std::is_sorted(V1.begin(), V1.end()); // no-warning
+ std::nth_element(V1.begin(), V1.begin() + 1, V1.end()); // no-warning
+ std::partial_sort(V1.begin(), V1.begin() + 1, V1.end()); // no-warning
+ std::sort(V1.begin(), V1.end()); // no-warning
+ std::stable_sort(V1.begin(), V1.end()); // no-warning
+ std::partition(V1.begin(), V1.end(), f); // no-warning
+ std::stable_partition(V1.begin(), V1.end(), g); // no-warning
+
+ std::is_sorted(V2.begin(), V2.end()); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::nth_element(V2.begin(), V2.begin() + 1, V2.end()); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::partial_sort(V2.begin(), V2.begin() + 1, V2.end()); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::sort(V2.begin(), V2.end()); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::stable_sort(V2.begin(), V2.end()); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::partition(V2.begin(), V2.end(), f); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ std::stable_partition(V2.begin(), V2.end(), g); // expected-warning {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+ // expected-note@-1 {{Sorting pointer-like keys can result in non-deterministic ordering}} [alpha.nondeterminism.PointerSorting]
+}
Index: lib/StaticAnalyzer/Checkers/PointerSortingChecker.cpp
===================================================================
--- /dev/null
+++ lib/StaticAnalyzer/Checkers/PointerSortingChecker.cpp
@@ -0,0 +1,110 @@
+//===------------------ PointerSortingChecker.cpp -------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines PointerSortingChecker which checks for non-determinism
+// caused due to sorting containers with pointer-like elements.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ClangSACheckers.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
+
+using namespace clang;
+using namespace ento;
+using namespace ast_matchers;
+
+namespace {
+
+// ID of a node at which the diagnostic would be emitted.
+const char *WarnAtNode = "sort";
+
+class PointerSortingChecker : public Checker<check::ASTCodeBody> {
+public:
+ void checkASTCodeBody(const Decl *D,
+ AnalysisManager &AM,
+ BugReporter &BR) const;
+};
+
+static void emitDiagnostics(const BoundNodes &Match, const Decl *D,
+ BugReporter &BR, AnalysisManager &AM,
+ const PointerSortingChecker *Checker) {
+ auto *ADC = AM.getAnalysisDeclContext(D);
+
+ const auto *MarkedStmt = Match.getNodeAs<CallExpr>(WarnAtNode);
+ assert(MarkedStmt);
+
+ auto Range = MarkedStmt->getSourceRange();
+ auto Location = PathDiagnosticLocation::createBegin(MarkedStmt,
+ BR.getSourceManager(),
+ ADC);
+ std::string Diagnostics;
+ llvm::raw_string_ostream OS(Diagnostics);
+ OS << "Sorting pointer-like keys can result in non-deterministic ordering";
+
+ BR.EmitBasicReport(ADC->getDecl(), Checker,
+ "Sorting of pointer-like keys", "Non-determinism",
+ OS.str(), Location, Range);
+}
+
+auto callsName(const char *FunctionName) -> decltype(callee(functionDecl())) {
+ return callee(functionDecl(hasName(FunctionName)));
+}
+
+// FIXME: Currently we simply check if std::sort is used with pointer-like
+// keys. This approach can have a big false positive rate. Using std::sort,
+// std::unique and then erase is common technique for deduplicating a container
+// (which in some cases might even be quicker than using, let's say std::set).
+// In case my container contains arbitrary memory addresses (e.g. multiple
+// things give me different stuff but might give the same thing multiple times)
+// which I don't want to do things with more than once, I might use
+// sort-unique-erase and the sort call will emit a report.
+auto matchSortWithPointers() -> decltype(decl()) {
+ auto IteratesPointerKeysM = hasType(cxxRecordDecl(has(
+ fieldDecl(hasType(hasCanonicalType(
+ pointsTo(hasCanonicalType(pointerType()))
+ )))
+ )));
+
+ auto SortFuncM = stmt(callExpr(
+ allOf(
+ anyOf(
+ callsName("std::is_sorted"),
+ callsName("std::nth_element"),
+ callsName("std::partial_sort"),
+ callsName("std::sort"),
+ callsName("std::stable_sort"),
+ callsName("std::partition"),
+ callsName("std::stable_partition")
+ ),
+ hasArgument(0, IteratesPointerKeysM)
+ ))
+ ).bind(WarnAtNode);
+
+ return decl(forEachDescendant(SortFuncM));
+}
+
+void PointerSortingChecker::checkASTCodeBody(const Decl *D,
+ AnalysisManager &AM,
+ BugReporter &BR) const {
+ auto MatcherM = matchSortWithPointers();
+
+ auto Matches = match(MatcherM, *D, AM.getASTContext());
+ for (BoundNodes Match : Matches)
+ emitDiagnostics(Match, D, BR, AM, this);
+}
+
+} // end of anonymous namespace
+
+void ento::registerPointerSortingChecker(CheckerManager &Mgr) {
+ Mgr.registerChecker<PointerSortingChecker>();
+}
Index: lib/StaticAnalyzer/Checkers/CMakeLists.txt
===================================================================
--- lib/StaticAnalyzer/Checkers/CMakeLists.txt
+++ lib/StaticAnalyzer/Checkers/CMakeLists.txt
@@ -74,6 +74,7 @@
ObjCUnusedIVarsChecker.cpp
PaddingChecker.cpp
PointerArithChecker.cpp
+ PointerSortingChecker.cpp
PointerSubChecker.cpp
PthreadLockChecker.cpp
RetainCountChecker.cpp
Index: include/clang/StaticAnalyzer/Checkers/Checkers.td
===================================================================
--- include/clang/StaticAnalyzer/Checkers/Checkers.td
+++ include/clang/StaticAnalyzer/Checkers/Checkers.td
@@ -94,6 +94,8 @@
def CloneDetectionAlpha : Package<"clone">, InPackage<Alpha>, Hidden;
+def NonDeterminismAlpha : Package<"nondeterminism">, InPackage<Alpha>, Hidden;
+
//===----------------------------------------------------------------------===//
// Core Checkers.
//===----------------------------------------------------------------------===//
@@ -825,3 +827,15 @@
DescFile<"UnixAPIChecker.cpp">;
} // end optin.portability
+
+//===----------------------------------------------------------------------===//
+// NonDeterminism checkers.
+//===----------------------------------------------------------------------===//
+
+let ParentPackage = NonDeterminismAlpha in {
+
+def PointerSortingChecker : Checker<"PointerSorting">,
+ HelpText<"Checks for non-determinism caused by sorting of pointer-like keys">,
+ DescFile<"PointerSortingChecker.cpp">;
+
+} // end alpha.nondeterminism
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