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, 112 insertions, 0 deletions

diff --git a/lib/Checker/AttrNonNullChecker.cpp b/lib/Checker/AttrNonNullChecker.cpp
new file mode 100644
index 0000000000..c9e0e40af7
--- /dev/null
+++ b/lib/Checker/AttrNonNullChecker.cpp
@@ -0,0 +1,112 @@
+//===--- AttrNonNullChecker.h - Undefined arguments checker ----*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines AttrNonNullChecker, a builtin check in GRExprEngine that 
+// performs checks for arguments declared to have nonnull attribute.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Checker/PathSensitive/CheckerVisitor.h"
+#include "clang/Checker/PathSensitive/BugReporter.h"
+#include "GRExprEngineInternalChecks.h"
+
+using namespace clang;
+
+namespace {
+class AttrNonNullChecker
+  : public CheckerVisitor<AttrNonNullChecker> {
+  BugType *BT;
+public:
+  AttrNonNullChecker() : BT(0) {}
+  static void *getTag() {
+    static int x = 0;
+    return &x;
+  }
+  void PreVisitCallExpr(CheckerContext &C, const CallExpr *CE);
+};
+} // end anonymous namespace
+
+void clang::RegisterAttrNonNullChecker(GRExprEngine &Eng) {
+  Eng.registerCheck(new AttrNonNullChecker());
+}
+
+void AttrNonNullChecker::PreVisitCallExpr(CheckerContext &C, 
+                                          const CallExpr *CE) {
+  const GRState *state = C.getState();
+
+  // Check if the callee has a 'nonnull' attribute.
+  SVal X = state->getSVal(CE->getCallee());
+
+  const FunctionDecl* FD = X.getAsFunctionDecl();
+  if (!FD)
+    return;
+
+  const NonNullAttr* Att = FD->getAttr<NonNullAttr>();
+  if (!Att)
+    return;
+
+  // Iterate through the arguments of CE and check them for null.
+  unsigned idx = 0;
+
+  for (CallExpr::const_arg_iterator I=CE->arg_begin(), E=CE->arg_end(); I!=E;
+       ++I, ++idx) {
+
+    if (!Att->isNonNull(idx))
+      continue;
+
+    const SVal &V = state->getSVal(*I);
+    const DefinedSVal *DV = dyn_cast<DefinedSVal>(&V);
+
+    if (!DV)
+      continue;
+
+    ConstraintManager &CM = C.getConstraintManager();
+    const GRState *stateNotNull, *stateNull;
+    llvm::tie(stateNotNull, stateNull) = CM.AssumeDual(state, *DV);
+
+    if (stateNull && !stateNotNull) {
+      // Generate an error node.  Check for a null node in case
+      // we cache out.
+      if (ExplodedNode *errorNode = C.GenerateSink(stateNull)) {
+
+        // Lazily allocate the BugType object if it hasn't already been
+        // created. Ownership is transferred to the BugReporter object once
+        // the BugReport is passed to 'EmitWarning'.
+        if (!BT)
+          BT = new BugType("Argument with 'nonnull' attribute passed null",
+                           "API");
+
+        EnhancedBugReport *R =
+          new EnhancedBugReport(*BT,
+                                "Null pointer passed as an argument to a "
+                                "'nonnull' parameter", errorNode);
+
+        // Highlight the range of the argument that was null.
+        const Expr *arg = *I;
+        R->addRange(arg->getSourceRange());
+        R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, arg);
+
+        // Emit the bug report.
+        C.EmitReport(R);
+      }
+
+      // Always return.  Either we cached out or we just emitted an error.
+      return;
+    }
+
+    // If a pointer value passed the check we should assume that it is
+    // indeed not null from this point forward.
+    assert(stateNotNull);
+    state = stateNotNull;
+  }
+
+  // If we reach here all of the arguments passed the nonnull check.
+  // If 'state' has been updated generated a new node.
+  C.addTransition(state);
+}