[analyzer] Refactor conditional expression evaluating code
Summary:
Instead of digging through the ExplodedGraph, to figure out which edge brought
us here, I compute the value of conditional expression by looking at the
sub-expression values.
To do this, I needed to change the liveness algorithm a bit -- now, the full
conditional expression also depends on all atomic sub-expressions, not only the
outermost ones.
Reviewers: jordan_rose
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1340
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@189090 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/LiveVariables.cpp b/lib/Analysis/LiveVariables.cpp
index b43892a..1583fcb 100644
--- a/lib/Analysis/LiveVariables.cpp
+++ b/lib/Analysis/LiveVariables.cpp
@@ -212,6 +212,8 @@
LiveVariables::LivenessValues &val;
LiveVariables::Observer *observer;
const CFGBlock *currentBlock;
+
+ void markLogicalExprLeaves(const Expr *E);
public:
TransferFunctions(LiveVariablesImpl &im,
LiveVariables::LivenessValues &Val,
@@ -368,9 +370,25 @@
if (observer)
observer->observerKill(DR);
}
+ } else if (B->isLogicalOp()) {
+ // Leaf expressions in the logical operator tree are live until we reach the
+ // outermost logical operator. Static analyzer relies on this behaviour.
+ markLogicalExprLeaves(B->getLHS()->IgnoreParens());
+ markLogicalExprLeaves(B->getRHS()->IgnoreParens());
}
}
+void TransferFunctions::markLogicalExprLeaves(const Expr *E) {
+ const BinaryOperator *B = dyn_cast<BinaryOperator>(E);
+ if (!B || !B->isLogicalOp()) {
+ val.liveStmts = LV.SSetFact.add(val.liveStmts, E);
+ return;
+ }
+
+ markLogicalExprLeaves(B->getLHS()->IgnoreParens());
+ markLogicalExprLeaves(B->getRHS()->IgnoreParens());
+}
+
void TransferFunctions::VisitBlockExpr(BlockExpr *BE) {
AnalysisDeclContext::referenced_decls_iterator I, E;
llvm::tie(I, E) =