| //=== NoReturnFunctionChecker.cpp -------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This defines NoReturnFunctionChecker, which evaluates functions that do not |
| // return to the caller. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ClangSACheckers.h" |
| #include "clang/StaticAnalyzer/Core/Checker.h" |
| #include "clang/StaticAnalyzer/Core/CheckerManager.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h" |
| #include "clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include <cstdarg> |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| |
| class NoReturnFunctionChecker : public Checker< check::PostStmt<CallExpr>, |
| check::PostObjCMessage > { |
| public: |
| void checkPostStmt(const CallExpr *CE, CheckerContext &C) const; |
| void checkPostObjCMessage(const ObjCMessage &msg, CheckerContext &C) const; |
| }; |
| |
| } |
| |
| void NoReturnFunctionChecker::checkPostStmt(const CallExpr *CE, |
| CheckerContext &C) const { |
| ProgramStateRef state = C.getState(); |
| const Expr *Callee = CE->getCallee(); |
| |
| bool BuildSinks = getFunctionExtInfo(Callee->getType()).getNoReturn(); |
| |
| if (!BuildSinks) { |
| SVal L = state->getSVal(Callee, C.getLocationContext()); |
| const FunctionDecl *FD = L.getAsFunctionDecl(); |
| if (!FD) |
| return; |
| |
| if (FD->getAttr<AnalyzerNoReturnAttr>()) |
| BuildSinks = true; |
| else if (const IdentifierInfo *II = FD->getIdentifier()) { |
| // 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("__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(); |
| } |
| |
| static bool END_WITH_NULL isMultiArgSelector(const Selector *Sel, ...) { |
| va_list argp; |
| va_start(argp, Sel); |
| |
| unsigned Slot = 0; |
| const char *Arg; |
| while ((Arg = va_arg(argp, const char *))) { |
| if (!Sel->getNameForSlot(Slot).equals(Arg)) |
| break; // still need to va_end! |
| ++Slot; |
| } |
| |
| va_end(argp); |
| |
| // We only succeeded if we made it to the end of the argument list. |
| return (Arg == NULL); |
| } |
| |
| void NoReturnFunctionChecker::checkPostObjCMessage(const ObjCMessage &Msg, |
| CheckerContext &C) const { |
| // 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: |
| if (!isMultiArgSelector(&Sel, "handleFailureInFunction", "file", |
| "lineNumber", "description", NULL)) |
| return; |
| break; |
| case 5: |
| if (!isMultiArgSelector(&Sel, "handleFailureInMethod", "object", "file", |
| "lineNumber", "description", NULL)) |
| return; |
| break; |
| } |
| |
| // If we got here, it's one of the messages we care about. |
| C.generateSink(); |
| } |
| |
| |
| void ento::registerNoReturnFunctionChecker(CheckerManager &mgr) { |
| mgr.registerChecker<NoReturnFunctionChecker>(); |
| } |