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author | vitalyisaev <vitalyisaev@yandex-team.com> | 2023-06-29 10:00:50 +0300 |
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committer | vitalyisaev <vitalyisaev@yandex-team.com> | 2023-06-29 10:00:50 +0300 |
commit | 6ffe9e53658409f212834330e13564e4952558f6 (patch) | |
tree | 85b1e00183517648b228aafa7c8fb07f5276f419 /contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp | |
parent | 726057070f9c5a91fc10fde0d5024913d10f1ab9 (diff) | |
download | ydb-6ffe9e53658409f212834330e13564e4952558f6.tar.gz |
YQ Connector: support managed ClickHouse
Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.
Diffstat (limited to 'contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp')
-rw-r--r-- | contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp b/contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp new file mode 100644 index 0000000000..8e02ef74c6 --- /dev/null +++ b/contrib/libs/clang14/lib/StaticAnalyzer/Checkers/GCDAntipatternChecker.cpp @@ -0,0 +1,230 @@ +//===- GCDAntipatternChecker.cpp ---------------------------------*- 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 +// +//===----------------------------------------------------------------------===// +// +// This file defines GCDAntipatternChecker which checks against a common +// antipattern when synchronous API is emulated from asynchronous callbacks +// using a semaphore: +// +// dispatch_semaphore_t sema = dispatch_semaphore_create(0); +// +// AnyCFunctionCall(^{ +// // code… +// dispatch_semaphore_signal(sema); +// }) +// dispatch_semaphore_wait(sema, *) +// +// Such code is a common performance problem, due to inability of GCD to +// properly handle QoS when a combination of queues and semaphores is used. +// Good code would either use asynchronous API (when available), or perform +// the necessary action in asynchronous callback. +// +// Currently, the check is performed using a simple heuristical AST pattern +// matching. +// +//===----------------------------------------------------------------------===// + +#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.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" +#include "llvm/Support/Debug.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 = "waitcall"; + +class GCDAntipatternChecker : public Checker<check::ASTCodeBody> { +public: + void checkASTCodeBody(const Decl *D, + AnalysisManager &AM, + BugReporter &BR) const; +}; + +decltype(auto) callsName(const char *FunctionName) { + return callee(functionDecl(hasName(FunctionName))); +} + +decltype(auto) equalsBoundArgDecl(int ArgIdx, const char *DeclName) { + return hasArgument(ArgIdx, ignoringParenCasts(declRefExpr( + to(varDecl(equalsBoundNode(DeclName)))))); +} + +decltype(auto) bindAssignmentToDecl(const char *DeclName) { + return hasLHS(ignoringParenImpCasts( + declRefExpr(to(varDecl().bind(DeclName))))); +} + +/// The pattern is very common in tests, and it is OK to use it there. +/// We have to heuristics for detecting tests: method name starts with "test" +/// (used in XCTest), and a class name contains "mock" or "test" (used in +/// helpers which are not tests themselves, but used exclusively in tests). +static bool isTest(const Decl *D) { + if (const auto* ND = dyn_cast<NamedDecl>(D)) { + std::string DeclName = ND->getNameAsString(); + if (StringRef(DeclName).startswith("test")) + return true; + } + if (const auto *OD = dyn_cast<ObjCMethodDecl>(D)) { + if (const auto *CD = dyn_cast<ObjCContainerDecl>(OD->getParent())) { + std::string ContainerName = CD->getNameAsString(); + StringRef CN(ContainerName); + if (CN.contains_insensitive("test") || CN.contains_insensitive("mock")) + return true; + } + } + return false; +} + +static auto findGCDAntiPatternWithSemaphore() -> decltype(compoundStmt()) { + + const char *SemaphoreBinding = "semaphore_name"; + auto SemaphoreCreateM = callExpr(allOf( + callsName("dispatch_semaphore_create"), + hasArgument(0, ignoringParenCasts(integerLiteral(equals(0)))))); + + auto SemaphoreBindingM = anyOf( + forEachDescendant( + varDecl(hasDescendant(SemaphoreCreateM)).bind(SemaphoreBinding)), + forEachDescendant(binaryOperator(bindAssignmentToDecl(SemaphoreBinding), + hasRHS(SemaphoreCreateM)))); + + auto HasBlockArgumentM = hasAnyArgument(hasType( + hasCanonicalType(blockPointerType()) + )); + + auto ArgCallsSignalM = hasAnyArgument(stmt(hasDescendant(callExpr( + allOf( + callsName("dispatch_semaphore_signal"), + equalsBoundArgDecl(0, SemaphoreBinding) + ))))); + + auto HasBlockAndCallsSignalM = allOf(HasBlockArgumentM, ArgCallsSignalM); + + auto HasBlockCallingSignalM = + forEachDescendant( + stmt(anyOf( + callExpr(HasBlockAndCallsSignalM), + objcMessageExpr(HasBlockAndCallsSignalM) + ))); + + auto SemaphoreWaitM = forEachDescendant( + callExpr( + allOf( + callsName("dispatch_semaphore_wait"), + equalsBoundArgDecl(0, SemaphoreBinding) + ) + ).bind(WarnAtNode)); + + return compoundStmt( + SemaphoreBindingM, HasBlockCallingSignalM, SemaphoreWaitM); +} + +static auto findGCDAntiPatternWithGroup() -> decltype(compoundStmt()) { + + const char *GroupBinding = "group_name"; + auto DispatchGroupCreateM = callExpr(callsName("dispatch_group_create")); + + auto GroupBindingM = anyOf( + forEachDescendant( + varDecl(hasDescendant(DispatchGroupCreateM)).bind(GroupBinding)), + forEachDescendant(binaryOperator(bindAssignmentToDecl(GroupBinding), + hasRHS(DispatchGroupCreateM)))); + + auto GroupEnterM = forEachDescendant( + stmt(callExpr(allOf(callsName("dispatch_group_enter"), + equalsBoundArgDecl(0, GroupBinding))))); + + auto HasBlockArgumentM = hasAnyArgument(hasType( + hasCanonicalType(blockPointerType()) + )); + + auto ArgCallsSignalM = hasAnyArgument(stmt(hasDescendant(callExpr( + allOf( + callsName("dispatch_group_leave"), + equalsBoundArgDecl(0, GroupBinding) + ))))); + + auto HasBlockAndCallsLeaveM = allOf(HasBlockArgumentM, ArgCallsSignalM); + + auto AcceptsBlockM = + forEachDescendant( + stmt(anyOf( + callExpr(HasBlockAndCallsLeaveM), + objcMessageExpr(HasBlockAndCallsLeaveM) + ))); + + auto GroupWaitM = forEachDescendant( + callExpr( + allOf( + callsName("dispatch_group_wait"), + equalsBoundArgDecl(0, GroupBinding) + ) + ).bind(WarnAtNode)); + + return compoundStmt(GroupBindingM, GroupEnterM, AcceptsBlockM, GroupWaitM); +} + +static void emitDiagnostics(const BoundNodes &Nodes, + const char* Type, + BugReporter &BR, + AnalysisDeclContext *ADC, + const GCDAntipatternChecker *Checker) { + const auto *SW = Nodes.getNodeAs<CallExpr>(WarnAtNode); + assert(SW); + + std::string Diagnostics; + llvm::raw_string_ostream OS(Diagnostics); + OS << "Waiting on a callback using a " << Type << " creates useless threads " + << "and is subject to priority inversion; consider " + << "using a synchronous API or changing the caller to be asynchronous"; + + BR.EmitBasicReport( + ADC->getDecl(), + Checker, + /*Name=*/"GCD performance anti-pattern", + /*BugCategory=*/"Performance", + OS.str(), + PathDiagnosticLocation::createBegin(SW, BR.getSourceManager(), ADC), + SW->getSourceRange()); +} + +void GCDAntipatternChecker::checkASTCodeBody(const Decl *D, + AnalysisManager &AM, + BugReporter &BR) const { + if (isTest(D)) + return; + + AnalysisDeclContext *ADC = AM.getAnalysisDeclContext(D); + + auto SemaphoreMatcherM = findGCDAntiPatternWithSemaphore(); + auto Matches = match(SemaphoreMatcherM, *D->getBody(), AM.getASTContext()); + for (BoundNodes Match : Matches) + emitDiagnostics(Match, "semaphore", BR, ADC, this); + + auto GroupMatcherM = findGCDAntiPatternWithGroup(); + Matches = match(GroupMatcherM, *D->getBody(), AM.getASTContext()); + for (BoundNodes Match : Matches) + emitDiagnostics(Match, "group", BR, ADC, this); +} + +} // end of anonymous namespace + +void ento::registerGCDAntipattern(CheckerManager &Mgr) { + Mgr.registerChecker<GCDAntipatternChecker>(); +} + +bool ento::shouldRegisterGCDAntipattern(const CheckerManager &mgr) { + return true; +} |