Clean up the Checker API a little more, resolving some hidden bugs

along the way.  Important changes:

1) To generate a sink node, use GenerateSink(); GenerateNode() is for
generating regular transitions.  This makes the API clearer and also
allows us to use the 'bool' option to GenerateNode() for a different
purpose.

2) GenerateNode() now automatically adds the generated node to the
destination ExplodedNodeSet (autotransition) unless the client
specifies otherwise with a bool flag.  Several checkers did not call
'addTransition()' after calling 'GenerateNode()', causing the
simulation path to be prematurely culled when a non-fail stop bug was
encountered.

3) Add variants of GenerateNode()/GenerateSink() that take neither a
Stmt* or a GRState*; most callers of GenerateNode() just pass in the
same Stmt* as provided when the CheckerContext object is created; we
can just use that the majority of the time.  This cleanup also allows
us to potentially coelesce the APIs for evaluating branches and
end-of-paths (which currently directly use builders).

4) addTransition() no longer needs to be called except for a few
cases.  We now have a variant of addTransition() that takes a
GRState*; this allows one to propagate the updated state without
caring about generating a new node explicitly.  This nicely cleaned up
a bunch of cases that called autoTransition() with a bunch of
conditional logic surround the call (that common logic has now been
swallowed up by addTransition() itself).

llvm-svn: 89707

1 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/Analysis/Checker.cpp b/clang/lib/Analysis/Checker.cpp
index 985b1e0a1d7..0d907e50168 100644
--- a/clang/lib/Analysis/Checker.cpp
+++ b/clang/lib/Analysis/Checker.cpp
@@ -16,3 +16,20 @@
 using namespace clang;
 
 Checker::~Checker() {}
+
+CheckerContext::~CheckerContext() {
+  // Do we need to autotransition?  'Dst' can get populated in a variety of
+  // ways, including 'addTransition()' adding the predecessor node to Dst
+  // without actually generated a new node.  We also shouldn't autotransition
+  // if we are building sinks or we generated a node and decided to not
+  // add it as a transition.
+  if (Dst.size() == size && !B.BuildSinks && !B.HasGeneratedNode) {
+    if (state && state != B.GetState(Pred)) {
+      static int autoTransitionTag = 0;
+      B.Tag = &autoTransitionTag;
+      addTransition(state);
+    }
+    else
+      Dst.Add(Pred);
+  }
+}