Modified the notion of "Block-level expressions" in CFGs to include Stmt*. This
is because GNU-style Statement-expressions cause the last statement in the
statement-expression to act like an expression.
We now have two notions: block-level statements and block-level expressions.
The former are all Stmt* that appear in the list of statements in CFGBlocks. The
latter is the subset of the former; these block-level statements are used as
subexpressions somewhere in the AST. CFG::isBlockExpr() returns true for the
latter, not the former (previously isBlockExpr() always returned true for
non-Expr Stmt*).
Modified the LiveVariables analysis to also track liveness state for block-level
expressions (using the updated definition of block-level expressions).
Modified the dataflow solver so that when it records values for block-level
statements, it records the dataflow value *before* the transfer function for a
Stmt* is evaluated (not after). This is more in sync in what clients will want.
Modified CFGStmtVisitor to record the current block-level statement.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46143 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Analysis/LiveVariables.cpp b/Analysis/LiveVariables.cpp
index ff4224a..5bd72b4 100644
--- a/Analysis/LiveVariables.cpp
+++ b/Analysis/LiveVariables.cpp
@@ -77,7 +77,16 @@
if (AD.Observer)
AD.Observer->ObserveStmt(S,AD,LiveState);
- static_cast<CFGStmtVisitor<TransferFuncs>*>(this)->Visit(S);
+
+ if (S == getCurrentBlkStmt()) {
+ StmtVisitor<TransferFuncs,void>::Visit(S);
+ if (getCFG().isBlkExpr(S)) LiveState(S,AD) = Dead;
+ }
+ else if (!getCFG().isBlkExpr(S))
+ StmtVisitor<TransferFuncs,void>::Visit(S);
+ else
+ // For block-level expressions, mark that they are live.
+ LiveState(S,AD) = Alive;
}
void TransferFuncs::VisitDeclRefExpr(DeclRefExpr* DR) {
@@ -186,6 +195,10 @@
return Live(D,getAnalysisData());
}
+bool LiveVariables::isLive(const Stmt* Loc, const Stmt* StmtVal) const {
+ return getStmtData(Loc)(StmtVal,getAnalysisData());
+}
+
//===----------------------------------------------------------------------===//
// printing liveness state for debugging
//