[WinEH] Add cleanupendpad instruction

Summary:
Add a `cleanupendpad` instruction, used to mark exceptional exits out of
cleanups (for languages/targets that can abort a cleanup with another
exception).  The `cleanupendpad` instruction is similar to the `catchendpad`
instruction in that it is an EH pad which is the target of unwind edges in
the handler and which itself has an unwind edge to the next EH action.
The `cleanupendpad` instruction, similar to `cleanupret` has a `cleanuppad`
argument indicating which cleanup it exits.  The unwind successors of a
`cleanuppad`'s `cleanupendpad`s must agree with each other and with its
`cleanupret`s.

Update WinEHPrepare (and docs/tests) to accomodate `cleanupendpad`.

Reviewers: rnk, andrew.w.kaylor, majnemer

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D12433

llvm-svn: 246751

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index b9604af..be39b88 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -3999,6 +3999,25 @@ std::error_code BitcodeReader::parseFunctionBody(Function *F) {
       InstructionList.push_back(I);
       break;
     }
+    case bitc::FUNC_CODE_INST_CLEANUPENDPAD: { // CLEANUPENDPADINST: [val] or [val,bb#]
+      if (Record.size() != 1 && Record.size() != 2)
+        return error("Invalid record");
+      unsigned Idx = 0;
+      Value *CleanupPad = getValue(Record, Idx++, NextValueNo,
+                                   Type::getTokenTy(Context), OC_CleanupPad);
+      if (!CleanupPad)
+        return error("Invalid record");
+
+      BasicBlock *BB = nullptr;
+      if (Record.size() == 2) {
+        BB = getBasicBlock(Record[Idx++]);
+        if (!BB)
+          return error("Invalid record");
+      }
+      I = CleanupEndPadInst::Create(cast<CleanupPadInst>(CleanupPad), BB);
+      InstructionList.push_back(I);
+      break;
+    }
     case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
       // Check magic
       if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {