Split libAnalysis into two libraries: libAnalysis and libChecker.

(1) libAnalysis is a generic analysis library that can be used by
    Sema.  It defines the CFG, basic dataflow analysis primitives, and
    inexpensive flow-sensitive analyses (e.g. LiveVariables).

(2) libChecker contains the guts of the static analyzer, incuding the
    path-sensitive analysis engine and domain-specific checks.

Now any clients that want to use the frontend to build their own tools
don't need to link in the entire static analyzer.

This change exposes various obvious cleanups that can be made to the
layout of files and headers in libChecker.  More changes pending.  :)

This change also exposed a layering violation between AnalysisContext
and MemRegion.  BlockInvocationContext shouldn't explicitly know about
BlockDataRegions.  For now I've removed the BlockDataRegion* from
BlockInvocationContext (removing context-sensitivity; although this
wasn't used yet).  We need to have a better way to extend
BlockInvocationContext (and any LocationContext) to add
context-sensitivty.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@94406 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 79 insertions, 0 deletions

diff --git a/lib/Checker/NoReturnFunctionChecker.cpp b/lib/Checker/NoReturnFunctionChecker.cpp
new file mode 100644
index 0000000000..1455d87665
--- /dev/null
+++ b/lib/Checker/NoReturnFunctionChecker.cpp
@@ -0,0 +1,79 @@
+//=== 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 "GRExprEngineInternalChecks.h"
+#include "clang/Checker/PathSensitive/Checker.h"
+#include "llvm/ADT/StringSwitch.h"
+
+using namespace clang;
+
+namespace {
+
+class NoReturnFunctionChecker : public Checker {
+public:
+  static void *getTag() { static int tag = 0; return &tag; }
+  virtual bool EvalCallExpr(CheckerContext &C, const CallExpr *CE);
+};
+
+}
+
+void clang::RegisterNoReturnFunctionChecker(GRExprEngine &Eng) {
+  Eng.registerCheck(new NoReturnFunctionChecker());
+}
+
+bool NoReturnFunctionChecker::EvalCallExpr(CheckerContext &C, 
+                                           const CallExpr *CE) {
+  const GRState *state = C.getState();
+  const Expr *Callee = CE->getCallee();
+  SVal L = state->getSVal(Callee);
+  const FunctionDecl *FD = L.getAsFunctionDecl();
+  if (!FD)
+    return false;
+
+  bool BuildSinks = false;
+
+  if (FD->getAttr<NoReturnAttr>() || 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>(llvm::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)
+    return false;
+
+  C.GenerateSink(CE);
+  return true;
+}