[MS ABI] Hook clang up to the new EH instructions

The new EH instructions make it possible for LLVM to generate .xdata
tables that the MSVC personality routines will be happy about.  Because
this is experimental, hide it behind a -cc1 flag (-fnew-ms-eh).

Differential Revision: http://reviews.llvm.org/D11405

llvm-svn: 243767

1 files changed, 19 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CGCleanup.cpp b/clang/lib/CodeGen/CGCleanup.cpp
index 3d4c4850f60..ef5a98ead98 100644
--- a/clang/lib/CodeGen/CGCleanup.cpp
+++ b/clang/lib/CodeGen/CGCleanup.cpp
@@ -247,6 +247,13 @@ void EHScopeStack::pushTerminate() {
   InnermostEHScope = stable_begin();
 }
 
+void EHScopeStack::pushCatchEnd(llvm::BasicBlock *CatchEndBlockBB) {
+  char *Buffer = allocate(EHCatchEndScope::getSize());
+  auto *CES = new (Buffer) EHCatchEndScope(InnermostEHScope);
+  CES->setCachedEHDispatchBlock(CatchEndBlockBB);
+  InnermostEHScope = stable_begin();
+}
+
 /// Remove any 'null' fixups on the stack.  However, we can't pop more
 /// fixups than the fixup depth on the innermost normal cleanup, or
 /// else fixups that we try to add to that cleanup will end up in the
@@ -896,6 +903,14 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
     CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
 
     EmitBlock(EHEntry);
+    llvm::BasicBlock *NextAction = getEHDispatchBlock(EHParent);
+    if (CGM.getCodeGenOpts().NewMSEH &&
+        EHPersonality::get(*this).isMSVCPersonality()) {
+      if (NextAction)
+        Builder.CreateCleanupPad(VoidTy, NextAction);
+      else
+        Builder.CreateCleanupPad(VoidTy, {});
+    }
 
     // We only actually emit the cleanup code if the cleanup is either
     // active or was used before it was deactivated.
@@ -905,7 +920,10 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
       EmitCleanup(*this, Fn, cleanupFlags, EHActiveFlag);
     }
 
-    Builder.CreateBr(getEHDispatchBlock(EHParent));
+    if (CGM.getCodeGenOpts().NewMSEH && EHPersonality::get(*this).isMSVCPersonality())
+      Builder.CreateCleanupRet(NextAction);
+    else
+      Builder.CreateBr(NextAction);
 
     Builder.restoreIP(SavedIP);