[WebAssembly] Add functions for EHScopes

Summary:
There are functions using the term 'funclet' to refer to both
1. an EH scopes, the structure of BBs that starts with
catchpad/cleanuppad and ends with catchret/cleanupret, and
2. a small function that gets outlined in AsmPrinter, which is the
original meaning of 'funclet'.

So far the two have been the same thing; EH scopes are always outlined
in AsmPrinter as funclets at the end of the compilation pipeline. But
now wasm also uses scope-based EH but does not outline those, so we now
need to correctly distinguish those two use cases in functions.

This patch splits `MachineBasicBlock::isFuncletEntry` into
`isFuncletEntry` and `isEHScopeEntry`, and
`MachineFunction::hasFunclets` into `hasFunclets` and `hasEHScopes`, in
order to distinguish the two different use cases. And this also changes
some uses of the term 'funclet' to 'scope' in `getFuncletMembership` and
change the function name to `getEHScopeMembership` because this function
is not about outlined funclets but about EH scope memberships.

This change is in the same vein as D45559.

Reviewers: majnemer, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D47005

llvm-svn: 333045

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 798b924..a3a6d43 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -226,9 +226,10 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
       const Instruction *PadInst = BB.getFirstNonPHI();
       // If this is a non-landingpad EH pad, mark this function as using
       // funclets.
-      // FIXME: SEH catchpads do not create funclets, so we could avoid setting
-      // this in such cases in order to improve frame layout.
+      // FIXME: SEH catchpads do not create EH scope/funclets, so we could avoid
+      // setting this in such cases in order to improve frame layout.
       if (!isa<LandingPadInst>(PadInst)) {
+        MF->setHasEHScopes(true);
         MF->setHasEHFunclets(true);
         MF->getFrameInfo().setHasOpaqueSPAdjustment(true);
       }