| //=== NoReturnFunctionChecker.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 defines NoReturnFunctionChecker, which evaluates functions that do not |
| // return to the caller. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/Analysis/SelectorExtras.h" |
| #include "clang/StaticAnalyzer/Core/Checker.h" |
| #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include <cstdarg> |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| |
| class NoReturnFunctionChecker : public Checker< check::PostCall, |
| check::PostObjCMessage > { |
| mutable Selector HandleFailureInFunctionSel; |
| mutable Selector HandleFailureInMethodSel; |
| public: |
| void checkPostCall(const CallEvent &CE, CheckerContext &C) const; |
| void checkPostObjCMessage(const ObjCMethodCall &msg, CheckerContext &C) const; |
| }; |
| |
| } |
| |
| void NoReturnFunctionChecker::checkPostCall(const CallEvent &CE, |
| CheckerContext &C) const { |
| bool BuildSinks = false; |
| |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CE.getDecl())) |
| BuildSinks = FD->hasAttr<AnalyzerNoReturnAttr>() || FD->isNoReturn(); |
| |
| const Expr *Callee = CE.getOriginExpr(); |
| if (!BuildSinks && Callee) |
| BuildSinks = getFunctionExtInfo(Callee->getType()).getNoReturn(); |
| |
| if (!BuildSinks && CE.isGlobalCFunction()) { |
| if (const IdentifierInfo *II = CE.getCalleeIdentifier()) { |
| // HACK: Some functions are not marked noreturn, and don't return. |
| // Here are a few hardwired ones. If this takes too long, we can |
| // potentially cache these results. |
| BuildSinks |
| = llvm::StringSwitch<bool>(StringRef(II->getName())) |
| .Case("exit", true) |
| .Case("panic", true) |
| .Case("error", true) |
| .Case("Assert", true) |
| // FIXME: This is just a wrapper around throwing an exception. |
| // Eventually inter-procedural analysis should handle this easily. |
| .Case("ziperr", true) |
| .Case("assfail", true) |
| .Case("db_error", true) |
| .Case("__assert", true) |
| .Case("__assert2", true) |
| // For the purpose of static analysis, we do not care that |
| // this MSVC function will return if the user decides to continue. |
| .Case("_wassert", true) |
| .Case("__assert_rtn", true) |
| .Case("__assert_fail", true) |
| .Case("dtrace_assfail", true) |
| .Case("yy_fatal_error", true) |
| .Case("_XCAssertionFailureHandler", true) |
| .Case("_DTAssertionFailureHandler", true) |
| .Case("_TSAssertionFailureHandler", true) |
| .Default(false); |
| } |
| } |
| |
| if (BuildSinks) |
| C.generateSink(C.getState(), C.getPredecessor()); |
| } |
| |
| void NoReturnFunctionChecker::checkPostObjCMessage(const ObjCMethodCall &Msg, |
| CheckerContext &C) const { |
| // Check if the method is annotated with analyzer_noreturn. |
| if (const ObjCMethodDecl *MD = Msg.getDecl()) { |
| MD = MD->getCanonicalDecl(); |
| if (MD->hasAttr<AnalyzerNoReturnAttr>()) { |
| C.generateSink(C.getState(), C.getPredecessor()); |
| return; |
| } |
| } |
| |
| // HACK: This entire check is to handle two messages in the Cocoa frameworks: |
| // -[NSAssertionHandler |
| // handleFailureInMethod:object:file:lineNumber:description:] |
| // -[NSAssertionHandler |
| // handleFailureInFunction:file:lineNumber:description:] |
| // Eventually these should be annotated with __attribute__((noreturn)). |
| // Because ObjC messages use dynamic dispatch, it is not generally safe to |
| // assume certain methods can't return. In cases where it is definitely valid, |
| // see if you can mark the methods noreturn or analyzer_noreturn instead of |
| // adding more explicit checks to this method. |
| |
| if (!Msg.isInstanceMessage()) |
| return; |
| |
| const ObjCInterfaceDecl *Receiver = Msg.getReceiverInterface(); |
| if (!Receiver) |
| return; |
| if (!Receiver->getIdentifier()->isStr("NSAssertionHandler")) |
| return; |
| |
| Selector Sel = Msg.getSelector(); |
| switch (Sel.getNumArgs()) { |
| default: |
| return; |
| case 4: |
| lazyInitKeywordSelector(HandleFailureInFunctionSel, C.getASTContext(), |
| "handleFailureInFunction", "file", "lineNumber", |
| "description"); |
| if (Sel != HandleFailureInFunctionSel) |
| return; |
| break; |
| case 5: |
| lazyInitKeywordSelector(HandleFailureInMethodSel, C.getASTContext(), |
| "handleFailureInMethod", "object", "file", |
| "lineNumber", "description"); |
| if (Sel != HandleFailureInMethodSel) |
| return; |
| break; |
| } |
| |
| // If we got here, it's one of the messages we care about. |
| C.generateSink(C.getState(), C.getPredecessor()); |
| } |
| |
| void ento::registerNoReturnFunctionChecker(CheckerManager &mgr) { |
| mgr.registerChecker<NoReturnFunctionChecker>(); |
| } |
| |
| bool ento::shouldRegisterNoReturnFunctionChecker(const CheckerManager &mgr) { |
| return true; |
| } |