lib/GR/Checkers/NoReturnFunctionChecker.cpp

   1 //=== NoReturnFunctionChecker.cpp -------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This defines NoReturnFunctionChecker, which evaluates functions that do not
  11 // return to the caller.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "GRExprEngineInternalChecks.h"
  16 #include "clang/GR/PathSensitive/CheckerVisitor.h"
  17 #include "llvm/ADT/StringSwitch.h"
  18
  19 using namespace clang;
  20 using namespace GR;
  21
  22 namespace {
  23
  24 class NoReturnFunctionChecker : public CheckerVisitor<NoReturnFunctionChecker> {
  25 public:
  26   static void *getTag() { static int tag = 0; return &tag; }
  27   void PostVisitCallExpr(CheckerContext &C, const CallExpr *CE);
  28 };
  29
  30 }
  31
  32 void GR::RegisterNoReturnFunctionChecker(GRExprEngine &Eng) {
  33   Eng.registerCheck(new NoReturnFunctionChecker());
  34 }
  35
  36 void NoReturnFunctionChecker::PostVisitCallExpr(CheckerContext &C,
  37                                                 const CallExpr *CE) {
  38   const GRState *state = C.getState();
  39   const Expr *Callee = CE->getCallee();
  40
  41   bool BuildSinks = getFunctionExtInfo(Callee->getType()).getNoReturn();
  42
  43   if (!BuildSinks) {
  44     SVal L = state->getSVal(Callee);
  45     const FunctionDecl *FD = L.getAsFunctionDecl();
  46     if (!FD)
  47       return;
  48
  49     if (FD->getAttr<AnalyzerNoReturnAttr>())
  50       BuildSinks = true;
  51     else if (const IdentifierInfo *II = FD->getIdentifier()) {
  52       // HACK: Some functions are not marked noreturn, and don't return.
  53       //  Here are a few hardwired ones.  If this takes too long, we can
  54       //  potentially cache these results.
  55       BuildSinks
  56         = llvm::StringSwitch<bool>(llvm::StringRef(II->getName()))
  57             .Case("exit", true)
  58             .Case("panic", true)
  59             .Case("error", true)
  60             .Case("Assert", true)
  61             // FIXME: This is just a wrapper around throwing an exception.
  62             //  Eventually inter-procedural analysis should handle this easily.
  63             .Case("ziperr", true)
  64             .Case("assfail", true)
  65             .Case("db_error", true)
  66             .Case("__assert", true)
  67             .Case("__assert_rtn", true)
  68             .Case("__assert_fail", true)
  69             .Case("dtrace_assfail", true)
  70             .Case("yy_fatal_error", true)
  71             .Case("_XCAssertionFailureHandler", true)
  72             .Case("_DTAssertionFailureHandler", true)
  73             .Case("_TSAssertionFailureHandler", true)
  74             .Default(false);
  75     }
  76   }
  77
  78   if (BuildSinks)
  79     C.generateSink(CE);
  80 }