building on the new CallGraphSCC abstraction, teach CallGraphSCCPassManager
to keep the node entries in scc_iterator up to date instead of dangling as
the SCC mutates.
This is a really terrible problem which was causing -g to affect codegen
because it would permute the memory image of the compiler process.
Thanks to Dale for expertly hunting it down.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101565 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/llvm/ADT/SCCIterator.h b/include/llvm/ADT/SCCIterator.h
index 3159406..80eb8c5 100644
--- a/include/llvm/ADT/SCCIterator.h
+++ b/include/llvm/ADT/SCCIterator.h
@@ -183,6 +183,15 @@
return true;
return false;
}
+
+ /// ReplaceNode - This informs the scc_iterator that the specified Old node
+ /// has been deleted, and New is to be used in its place.
+ void ReplaceNode(NodeType *Old, NodeType *New) {
+ assert(!nodeVisitNumbers.count(New) && "New already in scc_iterator?");
+ assert(nodeVisitNumbers.count(Old) && "Old not in scc_iterator?");
+ nodeVisitNumbers[New] = nodeVisitNumbers[Old];
+ nodeVisitNumbers.erase(Old);
+ }
};
diff --git a/lib/Analysis/IPA/CallGraphSCCPass.cpp b/lib/Analysis/IPA/CallGraphSCCPass.cpp
index f5d24f0..7b73c5d 100644
--- a/lib/Analysis/IPA/CallGraphSCCPass.cpp
+++ b/lib/Analysis/IPA/CallGraphSCCPass.cpp
@@ -417,6 +417,11 @@
Nodes[i] = New;
break;
}
+
+ // Update the active scc_iterator so that it doesn't contain dangling
+ // pointers to the old CallGraphNode.
+ scc_iterator<CallGraph*> *CGI = (scc_iterator<CallGraph*>*)Context;
+ CGI->ReplaceNode(Old, New);
}