Reapply "[ORC] Enable JIT support for the compact-unwind frame..." with fixes.

This reapplies 4f0325873fa (and follow up patches 26fc07d5d88, a001cc0e6cdc,
c9bc242e387, and fd174f0ff3e), which were reverted in 212cdc9a377 to
investigate bot failures (e.g.
https://lab.llvm.org/buildbot/#/builders/108/builds/8502)

The fix to address the bot failures was landed in d0052ebbe2e. This patch also
restricts construction of the UnwindInfoManager object to Apple platforms (as
it won't be used on other platforms).

1 files changed, 0 insertions, 116 deletions

diff --git a/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp b/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
index 3e757f7..179e458c 100644
--- a/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
+++ b/llvm/lib/ExecutionEngine/JITLink/MachOLinkGraphBuilder.cpp
@@ -733,121 +733,5 @@ Error MachOLinkGraphBuilder::graphifyCStringSection(
   return Error::success();
 }
 
-Error CompactUnwindSplitter::operator()(LinkGraph &G) {
-  auto *CUSec = G.findSectionByName(CompactUnwindSectionName);
-  if (!CUSec)
-    return Error::success();
-
-  if (!G.getTargetTriple().isOSBinFormatMachO())
-    return make_error<JITLinkError>(
-        "Error linking " + G.getName() +
-        ": compact unwind splitting not supported on non-macho target " +
-        G.getTargetTriple().str());
-
-  unsigned CURecordSize = 0;
-  unsigned PersonalityEdgeOffset = 0;
-  unsigned LSDAEdgeOffset = 0;
-  switch (G.getTargetTriple().getArch()) {
-  case Triple::aarch64:
-  case Triple::x86_64:
-    // 64-bit compact-unwind record format:
-    // Range start: 8 bytes.
-    // Range size:  4 bytes.
-    // CU encoding: 4 bytes.
-    // Personality: 8 bytes.
-    // LSDA:        8 bytes.
-    CURecordSize = 32;
-    PersonalityEdgeOffset = 16;
-    LSDAEdgeOffset = 24;
-    break;
-  default:
-    return make_error<JITLinkError>(
-        "Error linking " + G.getName() +
-        ": compact unwind splitting not supported on " +
-        G.getTargetTriple().getArchName());
-  }
-
-  std::vector<Block *> OriginalBlocks(CUSec->blocks().begin(),
-                                      CUSec->blocks().end());
-  LLVM_DEBUG({
-    dbgs() << "In " << G.getName() << " splitting compact unwind section "
-           << CompactUnwindSectionName << " containing "
-           << OriginalBlocks.size() << " initial blocks...\n";
-  });
-
-  while (!OriginalBlocks.empty()) {
-    auto *B = OriginalBlocks.back();
-    OriginalBlocks.pop_back();
-
-    if (B->getSize() == 0) {
-      LLVM_DEBUG({
-        dbgs() << "  Skipping empty block at "
-               << formatv("{0:x16}", B->getAddress()) << "\n";
-      });
-      continue;
-    }
-
-    unsigned NumBlocks = B->getSize() / CURecordSize;
-
-    LLVM_DEBUG({
-      dbgs() << "  Splitting block at " << formatv("{0:x16}", B->getAddress())
-             << " into " << NumBlocks << " compact unwind record(s)\n";
-    });
-
-    if (B->getSize() % CURecordSize)
-      return make_error<JITLinkError>(
-          "Error splitting compact unwind record in " + G.getName() +
-          ": block at " + formatv("{0:x}", B->getAddress()) + " has size " +
-          formatv("{0:x}", B->getSize()) +
-          " (not a multiple of CU record size of " +
-          formatv("{0:x}", CURecordSize) + ")");
-
-    auto Blocks =
-        G.splitBlock(*B, map_range(seq(1U, NumBlocks), [=](Edge::OffsetT Idx) {
-          return Idx * CURecordSize;
-        }));
-
-    for (auto *CURec : Blocks) {
-      bool AddedKeepAlive = false;
-
-      for (auto &E : CURec->edges()) {
-        if (E.getOffset() == 0) {
-          LLVM_DEBUG({
-            dbgs() << "    Updating compact unwind record at "
-                   << CURec->getAddress() << " to point to "
-                   << (E.getTarget().hasName() ? *E.getTarget().getName()
-                                               : StringRef())
-                   << " (at " << E.getTarget().getAddress() << ")\n";
-          });
-
-          if (E.getTarget().isExternal())
-            return make_error<JITLinkError>(
-                "Error adding keep-alive edge for compact unwind record at " +
-                formatv("{0:x}", CURec->getAddress()) + ": target " +
-                *E.getTarget().getName() + " is an external symbol");
-          auto &TgtBlock = E.getTarget().getBlock();
-          auto &CURecSym =
-              G.addAnonymousSymbol(*CURec, 0, CURecordSize, false, false);
-          TgtBlock.addEdge(Edge::KeepAlive, 0, CURecSym, 0);
-          AddedKeepAlive = true;
-        } else if (E.getOffset() != PersonalityEdgeOffset &&
-                   E.getOffset() != LSDAEdgeOffset)
-          return make_error<JITLinkError>(
-              "Unexpected edge at offset " + formatv("{0:x}", E.getOffset()) +
-              " in compact unwind record at " +
-              formatv("{0:x}", CURec->getAddress()));
-      }
-
-      if (!AddedKeepAlive)
-        return make_error<JITLinkError>(
-            "Error adding keep-alive edge for compact unwind record at " +
-            formatv("{0:x}", CURec->getAddress()) +
-            ": no outgoing target edge at offset 0");
-    }
-  }
-
-  return Error::success();
-}
-
 } // end namespace jitlink
 } // end namespace llvm