[LCG] Add aliased functions as LCG roots
Current LCG doesn't check aliased functions. So if an internal function has a public alias it will not be added to CG SCC, but it is still reachable from outside through the alias.
So this patch adds aliased functions to SCC.
Differential Revision: https://reviews.llvm.org/D59898
llvm-svn: 357795
diff --git a/llvm/lib/Analysis/LazyCallGraph.cpp b/llvm/lib/Analysis/LazyCallGraph.cpp
index 726f52a..797fcf5 100644
--- a/llvm/lib/Analysis/LazyCallGraph.cpp
+++ b/llvm/lib/Analysis/LazyCallGraph.cpp
@@ -172,6 +172,19 @@
addEdge(EntryEdges.Edges, EntryEdges.EdgeIndexMap, get(F), Edge::Ref);
}
+ // Externally visible aliases of internal functions are also viable entry
+ // edges to the module.
+ for (auto &A : M.aliases()) {
+ if (A.hasLocalLinkage())
+ continue;
+ if (Function* F = dyn_cast<Function>(A.getAliasee())) {
+ LLVM_DEBUG(dbgs() << " Adding '" << F->getName()
+ << "' with alias '" << A.getName()
+ << "' to entry set of the graph.\n");
+ addEdge(EntryEdges.Edges, EntryEdges.EdgeIndexMap, get(*F), Edge::Ref);
+ }
+ }
+
// Now add entry nodes for functions reachable via initializers to globals.
SmallVector<Constant *, 16> Worklist;
SmallPtrSet<Constant *, 16> Visited;