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[analyzer] Refactor conditional expression evaluating code

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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

llvm-svn: 189090
This commit is contained in:
Pavel Labath
2013-08-23 07:19:22 +00:00
parent a9debbfb01
commit 02b64d46a0
4 changed files with 99 additions and 63 deletions
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18
clang/lib/Analysis/LiveVariables.cpp
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@@ -212,6 +212,8 @@ class TransferFunctions : public StmtVisitor<TransferFunctions> {
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 @@ void TransferFunctions::VisitBinaryOperator(BinaryOperator *B) {
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) =