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.

llvm-svn: 94406

1 files changed, 79 insertions, 0 deletions

diff --git a/clang/lib/Checker/UndefinedAssignmentChecker.cpp b/clang/lib/Checker/UndefinedAssignmentChecker.cpp
new file mode 100644
index 00000000000..6edc3d8150a
--- /dev/null
+++ b/clang/lib/Checker/UndefinedAssignmentChecker.cpp
@@ -0,0 +1,79 @@
+//===--- UndefinedAssignmentChecker.h ---------------------------*- C++ -*--==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines UndefinedAssginmentChecker, a builtin check in GRExprEngine that
+// checks for assigning undefined values.
+//
+//===----------------------------------------------------------------------===//
+
+#include "GRExprEngineInternalChecks.h"
+#include "clang/Checker/PathSensitive/CheckerVisitor.h"
+#include "clang/Checker/PathSensitive/BugReporter.h"
+
+using namespace clang;
+
+namespace {
+class UndefinedAssignmentChecker
+  : public CheckerVisitor<UndefinedAssignmentChecker> {
+  BugType *BT;
+public:
+  UndefinedAssignmentChecker() : BT(0) {}
+  static void *getTag();
+  virtual void PreVisitBind(CheckerContext &C, const Stmt *AssignE,
+                            const Stmt *StoreE, SVal location,
+                            SVal val);
+};
+}
+
+void clang::RegisterUndefinedAssignmentChecker(GRExprEngine &Eng){
+  Eng.registerCheck(new UndefinedAssignmentChecker());
+}
+
+void *UndefinedAssignmentChecker::getTag() {
+  static int x = 0;
+  return &x;
+}
+
+void UndefinedAssignmentChecker::PreVisitBind(CheckerContext &C,
+                                              const Stmt *AssignE,
+                                              const Stmt *StoreE,
+                                              SVal location,
+                                              SVal val) {
+  if (!val.isUndef())
+    return;
+
+  ExplodedNode *N = C.GenerateSink();
+
+  if (!N)
+    return;
+
+  if (!BT)
+    BT = new BuiltinBug("Assigned value is garbage or undefined");
+
+  // Generate a report for this bug.
+  EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getName(), N);
+
+  if (AssignE) {
+    const Expr *ex = 0;
+
+    if (const BinaryOperator *B = dyn_cast<BinaryOperator>(AssignE))
+      ex = B->getRHS();
+    else if (const DeclStmt *DS = dyn_cast<DeclStmt>(AssignE)) {
+      const VarDecl* VD = dyn_cast<VarDecl>(DS->getSingleDecl());
+      ex = VD->getInit();
+    }
+    if (ex) {
+      R->addRange(ex->getSourceRange());
+      R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, ex);
+    }
+  }
+
+  C.EmitReport(R);
+}  
+