Make blockaddress(@func, null) be valid, and make 'deleting a basic

block with a blockaddress still referring to it' replace the invalid 
blockaddress with a new blockaddress(@func, null) instead of a 
inttoptr(1).

This changes the bitcode encoding format, and still needs codegen 
support (this should produce a non-zero value, referring to the entry
block of the function would also be quite reasonable).

llvm-svn: 85678

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index 68527e3..749f16f 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -2274,11 +2274,12 @@ bool BitcodeReader::ParseFunctionBody(Function *F) {
     std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
     for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
       unsigned BlockIdx = RefList[i].first;
-      if (BlockIdx >= FunctionBBs.size())
+      if (BlockIdx > FunctionBBs.size())
         return Error("Invalid blockaddress block #");
     
       GlobalVariable *FwdRef = RefList[i].second;
-      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
+      BasicBlock *BB = BlockIdx == 0 ? 0 : FunctionBBs[BlockIdx-1];
+      FwdRef->replaceAllUsesWith(BlockAddress::get(F, BB));
       FwdRef->eraseFromParent();
     }