103 lines · cpp
1//===- unittests/StaticAnalyzer/SValSimplifyerTest.cpp --------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "CheckerRegistration.h"10#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"11#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"12#include "clang/StaticAnalyzer/Core/Checker.h"13#include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"14#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"15#include "clang/StaticAnalyzer/Frontend/AnalysisConsumer.h"16#include "clang/StaticAnalyzer/Frontend/CheckerRegistry.h"17#include "llvm/ADT/Twine.h"18#include "llvm/Support/raw_ostream.h"19#include "gtest/gtest.h"20 21using namespace clang;22using namespace ento;23 24static std::string toString(SVal V) {25 std::string Result;26 llvm::raw_string_ostream Stream(Result);27 V.dumpToStream(Stream);28 return Result;29}30 31static void replace(std::string &Content, StringRef Substr,32 StringRef Replacement) {33 std::size_t Pos = 0;34 while ((Pos = Content.find(Substr, Pos)) != std::string::npos) {35 Content.replace(Pos, Substr.size(), Replacement);36 Pos += Replacement.size();37 }38}39 40namespace {41 42class SimplifyChecker : public Checker<check::PreCall> {43 const BugType Bug{this, "SimplifyChecker"};44 const CallDescription SimplifyCall{CDM::SimpleFunc, {"simplify"}, 1};45 46 void report(CheckerContext &C, const Expr *E, StringRef Description) const {47 PathDiagnosticLocation Loc(E->getExprLoc(), C.getSourceManager());48 auto Report = std::make_unique<BasicBugReport>(Bug, Description, Loc);49 C.emitReport(std::move(Report));50 }51 52public:53 void checkPreCall(const CallEvent &Call, CheckerContext &C) const {54 if (!SimplifyCall.matches(Call))55 return;56 const Expr *Arg = Call.getArgExpr(0);57 SVal Val = C.getSVal(Arg);58 SVal SimplifiedVal = C.getSValBuilder().simplifySVal(C.getState(), Val);59 std::string Subject = toString(Val);60 std::string Simplified = toString(SimplifiedVal);61 std::string Message = (llvm::Twine{Subject} + " -> " + Simplified).str();62 report(C, Arg, Message);63 }64};65} // namespace66 67static void addSimplifyChecker(AnalysisASTConsumer &AnalysisConsumer,68 AnalyzerOptions &AnOpts) {69 AnOpts.CheckersAndPackages = {{"SimplifyChecker", true}};70 AnalysisConsumer.AddCheckerRegistrationFn([](CheckerRegistry &Registry) {71 Registry.addChecker<SimplifyChecker>("SimplifyChecker", "MockDescription");72 });73}74 75static void runThisCheckerOnCode(const std::string &Code, std::string &Diags) {76 ASSERT_TRUE(runCheckerOnCode<addSimplifyChecker>(Code, Diags,77 /*OnlyEmitWarnings=*/true));78 ASSERT_FALSE(Diags.empty());79 ASSERT_EQ(Diags.back(), '\n');80 Diags.pop_back();81}82 83namespace {84 85TEST(SValSimplifyerTest, LHSConstrainedNullPtrDiff) {86 constexpr auto Code = R"cpp(87template <class T> void simplify(T);88void LHSConstrainedNullPtrDiff(char *p, char *q) {89 int diff = p - q;90 if (!p)91 simplify(diff);92})cpp";93 94 std::string Diags;95 runThisCheckerOnCode(Code, Diags);96 replace(Diags, "(reg_$0<char * p>)", "reg_p");97 replace(Diags, "(reg_$1<char * q>)", "reg_q");98 // This should not be simplified to "Unknown".99 EXPECT_EQ(Diags, "SimplifyChecker: reg_p - reg_q -> 0U - reg_q");100}101 102} // namespace103