Fix DeleteDeadVarargs not to crash on functions referenced by BlockAddresses
This pass was assuming that if hasAddressTaken() returns false for a
function, the function's only uses are call sites. That's not true
because there can be references by BlockAddresses too.
Fix the pass to handle this case. Fix
BlockAddress::replaceUsesOfWithOnConstant() to allow a function's type
to be changed by RAUW'ing the function with a bitcast of the recreated
function.
Patch by Mark Seaborn.
llvm-svn: 183933
diff --git a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
index 3fdb5f0..70d0317 100644
--- a/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
+++ b/llvm/lib/Transforms/IPO/DeadArgumentElimination.cpp
@@ -263,8 +263,10 @@
// to pass in a smaller number of arguments into the new function.
//
std::vector<Value*> Args;
- while (!Fn.use_empty()) {
- CallSite CS(Fn.use_back());
+ for (Value::use_iterator I = Fn.use_begin(), E = Fn.use_end(); I != E; ) {
+ CallSite CS(*I++);
+ if (!CS)
+ continue;
Instruction *Call = CS.getInstruction();
// Pass all the same arguments.
@@ -330,6 +332,11 @@
if (DI != FunctionDIs.end())
DI->second.replaceFunction(NF);
+ // Fix up any BlockAddresses that refer to the function.
+ Fn.replaceAllUsesWith(ConstantExpr::getBitCast(NF, Fn.getType()));
+ // Delete the bitcast that we just created, so that NF does not
+ // appear to be address-taken.
+ NF->removeDeadConstantUsers();
// Finally, nuke the old function.
Fn.eraseFromParent();
return true;