Add alternate version of LiveVariables analysis that does not kill liveness at assignments. This 'relaxed' liveness is useful in path sensitive analysis for situations where the resulting extended liveness allows us to find some bugs.

- Added killAtAssign flag to LiveVariables
- Added relaxed LiveVariables to AnalysisContext with an accessor

llvm-svn: 112306

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/Analysis/AnalysisContext.cpp b/clang/lib/Analysis/AnalysisContext.cpp
index 2c337f07c3c..884cbc65f4b 100644
--- a/clang/lib/Analysis/AnalysisContext.cpp
+++ b/clang/lib/Analysis/AnalysisContext.cpp
@@ -104,6 +104,20 @@ LiveVariables *AnalysisContext::getLiveVariables() {
   return liveness;
 }
 
+LiveVariables *AnalysisContext::getRelaxedLiveVariables() {
+  if (!relaxedLiveness) {
+    CFG *c = getCFG();
+    if (!c)
+      return 0;
+
+    relaxedLiveness = new LiveVariables(*this, false);
+    relaxedLiveness->runOnCFG(*c);
+    relaxedLiveness->runOnAllBlocks(*c, 0, true);
+  }
+
+  return relaxedLiveness;
+}
+
 AnalysisContext *AnalysisContextManager::getContext(const Decl *D,
                                                     idx::TranslationUnit *TU) {
   AnalysisContext *&AC = Contexts[D];