Move DWARFRecordSectionSplitter code to its own file

[rastogishubham]

Summary

With 229d576b31f4071ab68c85ac4fabb78cfa502b04 the class EHFrameSplitter was renamed to DWARFRecordSectionSplitter. This change merely moves it to it's own .cpp/.h file

[rastogishubham]

Add newlines to the ends of DWARFRecordSectionSplitter.h/.cpp

[aprantl]

This is generally fine, I have a few nitpicks inline :-)

llvm/include/llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h

2

typo: Splittert

13

I don't think this is needed. All the types could be forward-declared (they are just used as references here).

14

what is this needed for?

[rastogishubham]

llvm/include/llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h

13

This include is also here because of the cpp file which requires this include, should I move this to the cpp file?

14

This is needed because in the cpp file it creates a BinaryStreamReader, should I move the include to the cpp file instead?

llvm/lib/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.cpp:76

BinaryStreamReader BlockReader(
      StringRef(B.getContent().data(), B.getContent().size()),
      G.getEndianness());

[rastogishubham]

llvm/include/llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h

13

Hmm, I was wrong, but the forward declaration will not work here because it also uses a nested class which I do not think can be forward declared

[rastogishubham]

Made changes as pointed out by Adrian

llvm/include/llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h

+//===--------- DWARFRecordSectionSplitter.h - JITLink -----------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_EXECUTIONENGINE_JITLINK_DWARFRECORDSECTIONSPLITTER_H
+#define LLVM_EXECUTIONENGINE_JITLINK_DWARFRECORDSECTIONSPLITTER_H
+
+#include "llvm/ExecutionEngine/JITLink/JITLink.h"
+
+namespace llvm {
+namespace jitlink {
+
+/// A LinkGraph pass that splits blocks in a section that follows the DWARF
+/// Record format into sub-blocks where each header gets its own block.
+/// When splitting EHFrames, DWARFRecordSectionSplitter should not be run
+/// without EHFrameEdgeFixer, which is responsible for adding FDE-to-CIE edges.
+class DWARFRecordSectionSplitter {
+public:
+  DWARFRecordSectionSplitter(StringRef SectionName);
+  Error operator()(LinkGraph &G);
+
+private:
+  Error processBlock(LinkGraph &G, Block &B, LinkGraph::SplitBlockCache &Cache);
+
+  StringRef SectionName;
+};
+
+} // namespace jitlink
+} // namespace llvm
+
+#endif // LLVM_EXECUTIONENGINE_JITLINK_DWARFRECORDSECTIONSPLITTER_H

llvm/lib/ExecutionEngine/JITLink/CMakeLists.txt

 add_llvm_component_library(LLVMJITLink
+  DWARFRecordSectionSplitter.cpp
   EHFrameSupport.cpp
   JITLink.cpp
   JITLinkGeneric.cpp
   JITLinkMemoryManager.cpp
   MemoryFlags.cpp
 
   # Formats:
 

llvm/lib/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.cpp

+//===-------- JITLink_DWARFRecordSectionSplitter.cpp - JITLink-------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
+#include "llvm/Support/BinaryStreamReader.h"
+
+#define DEBUG_TYPE "jitlink"
+
+namespace llvm {
+namespace jitlink {
+
+DWARFRecordSectionSplitter::DWARFRecordSectionSplitter(StringRef SectionName)
+    : SectionName(SectionName) {}
+
+Error DWARFRecordSectionSplitter::operator()(LinkGraph &G) {
+  auto *Section = G.findSectionByName(SectionName);
+
+  if (!Section) {
+    LLVM_DEBUG({
+      dbgs() << "DWARFRecordSectionSplitter: No " << SectionName
+             << " section. Nothing to do\n";
+    });
+    return Error::success();
+  }
+
+  LLVM_DEBUG({
+    dbgs() << "DWARFRecordSectionSplitter: Processing " << SectionName
+           << "...\n";
+  });
+
+  DenseMap<Block *, LinkGraph::SplitBlockCache> Caches;
+
+  {
+    // Pre-build the split caches.
+    for (auto *B : Section->blocks())
+      Caches[B] = LinkGraph::SplitBlockCache::value_type();
+    for (auto *Sym : Section->symbols())
+      Caches[&Sym->getBlock()]->push_back(Sym);
+    for (auto *B : Section->blocks())
+      llvm::sort(*Caches[B], [](const Symbol *LHS, const Symbol *RHS) {
+        return LHS->getOffset() > RHS->getOffset();
+      });
+  }
+
+  // Iterate over blocks (we do this by iterating over Caches entries rather
+  // than Section->blocks() as we will be inserting new blocks along the way,
+  // which would invalidate iterators in the latter sequence.
+  for (auto &KV : Caches) {
+    auto &B = *KV.first;
+    auto &BCache = KV.second;
+    if (auto Err = processBlock(G, B, BCache))
+      return Err;
+  }
+
+  return Error::success();
+}
+
+Error DWARFRecordSectionSplitter::processBlock(
+    LinkGraph &G, Block &B, LinkGraph::SplitBlockCache &Cache) {
+  LLVM_DEBUG(dbgs() << "  Processing block at " << B.getAddress() << "\n");
+
+  // Section should not contain zero-fill blocks.
+  if (B.isZeroFill())
+    return make_error<JITLinkError>("Unexpected zero-fill block in " +
+                                    SectionName + " section");
+
+  if (B.getSize() == 0) {
+    LLVM_DEBUG(dbgs() << "    Block is empty. Skipping.\n");
+    return Error::success();
+  }
+
+  BinaryStreamReader BlockReader(
+      StringRef(B.getContent().data(), B.getContent().size()),
+      G.getEndianness());
+
+  while (true) {
+    uint64_t RecordStartOffset = BlockReader.getOffset();
+
+    LLVM_DEBUG({
+      dbgs() << "    Processing CFI record at "
+             << formatv("{0:x16}", B.getAddress()) << "\n";
+    });
+
+    uint32_t Length;
+    if (auto Err = BlockReader.readInteger(Length))
+      return Err;
+    if (Length != 0xffffffff) {
+      if (auto Err = BlockReader.skip(Length))
+        return Err;
+    } else {
+      uint64_t ExtendedLength;
+      if (auto Err = BlockReader.readInteger(ExtendedLength))
+        return Err;
+      if (auto Err = BlockReader.skip(ExtendedLength))
+        return Err;
+    }
+
+    // If this was the last block then there's nothing to split
+    if (BlockReader.empty()) {
+      LLVM_DEBUG(dbgs() << "      Extracted " << B << "\n");
+      return Error::success();
+    }
+
+    uint64_t BlockSize = BlockReader.getOffset() - RecordStartOffset;
+    auto &NewBlock = G.splitBlock(B, BlockSize);
+    (void)NewBlock;
+    LLVM_DEBUG(dbgs() << "      Extracted " << NewBlock << "\n");
+  }
+}
+
+} // namespace jitlink
+} // namespace llvm

llvm/lib/ExecutionEngine/JITLink/EHFrameSupport.cpp

 //===-------- JITLink_EHFrameSupport.cpp - JITLink eh-frame utils ---------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "EHFrameSupportImpl.h"
 
 #include "llvm/BinaryFormat/Dwarf.h"
 #include "llvm/Config/config.h"
+#include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 #include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h"
 #include "llvm/Support/DynamicLibrary.h"
 
 #define DEBUG_TYPE "jitlink"
 
 namespace llvm {
 namespace jitlink {
 
-DWARFRecordSectionSplitter::DWARFRecordSectionSplitter(StringRef SectionName)
-    : SectionName(SectionName) {}
-
-Error DWARFRecordSectionSplitter::operator()(LinkGraph &G) {
-  auto *Section = G.findSectionByName(SectionName);
-
-  if (!Section) {
-    LLVM_DEBUG({
-      dbgs() << "DWARFRecordSectionSplitter: No " << SectionName
-             << " section. Nothing to do\n";
-    });
-    return Error::success();
-  }
-
-  LLVM_DEBUG({
-    dbgs() << "DWARFRecordSectionSplitter: Processing " << SectionName
-           << "...\n";
-  });
-
-  DenseMap<Block *, LinkGraph::SplitBlockCache> Caches;
-
-  {
-    // Pre-build the split caches.
-    for (auto *B : Section->blocks())
-      Caches[B] = LinkGraph::SplitBlockCache::value_type();
-    for (auto *Sym : Section->symbols())
-      Caches[&Sym->getBlock()]->push_back(Sym);
-    for (auto *B : Section->blocks())
-      llvm::sort(*Caches[B], [](const Symbol *LHS, const Symbol *RHS) {
-        return LHS->getOffset() > RHS->getOffset();
-      });
-  }
-
-  // Iterate over blocks (we do this by iterating over Caches entries rather
-  // than Section->blocks() as we will be inserting new blocks along the way,
-  // which would invalidate iterators in the latter sequence.
-  for (auto &KV : Caches) {
-    auto &B = *KV.first;
-    auto &BCache = KV.second;
-    if (auto Err = processBlock(G, B, BCache))
-      return Err;
-  }
-
-  return Error::success();
-}
-
-Error DWARFRecordSectionSplitter::processBlock(
-    LinkGraph &G, Block &B, LinkGraph::SplitBlockCache &Cache) {
-  LLVM_DEBUG(dbgs() << "  Processing block at " << B.getAddress() << "\n");
-
-  // Section should not contain zero-fill blocks.
-  if (B.isZeroFill())
-    return make_error<JITLinkError>("Unexpected zero-fill block in " +
-                                    SectionName + " section");
-
-  if (B.getSize() == 0) {
-    LLVM_DEBUG(dbgs() << "    Block is empty. Skipping.\n");
-    return Error::success();
-  }
-
-  BinaryStreamReader BlockReader(
-      StringRef(B.getContent().data(), B.getContent().size()),
-      G.getEndianness());
-
-  while (true) {
-    uint64_t RecordStartOffset = BlockReader.getOffset();
-
-    LLVM_DEBUG({
-      dbgs() << "    Processing CFI record at "
-             << formatv("{0:x16}", B.getAddress()) << "\n";
-    });
-
-    uint32_t Length;
-    if (auto Err = BlockReader.readInteger(Length))
-      return Err;
-    if (Length != 0xffffffff) {
-      if (auto Err = BlockReader.skip(Length))
-        return Err;
-    } else {
-      uint64_t ExtendedLength;
-      if (auto Err = BlockReader.readInteger(ExtendedLength))
-        return Err;
-      if (auto Err = BlockReader.skip(ExtendedLength))
-        return Err;
-    }
-
-    // If this was the last block then there's nothing to split
-    if (BlockReader.empty()) {
-      LLVM_DEBUG(dbgs() << "      Extracted " << B << "\n");
-      return Error::success();
-    }
-
-    uint64_t BlockSize = BlockReader.getOffset() - RecordStartOffset;
-    auto &NewBlock = G.splitBlock(B, BlockSize);
-    (void)NewBlock;
-    LLVM_DEBUG(dbgs() << "      Extracted " << NewBlock << "\n");
-  }
-}
-
 EHFrameEdgeFixer::EHFrameEdgeFixer(StringRef EHFrameSectionName,
                                    unsigned PointerSize, Edge::Kind Delta64,
                                    Edge::Kind Delta32, Edge::Kind NegDelta32)
     : EHFrameSectionName(EHFrameSectionName), PointerSize(PointerSize),
       Delta64(Delta64), Delta32(Delta32), NegDelta32(NegDelta32) {}
 
 Error EHFrameEdgeFixer::operator()(LinkGraph &G) {
   auto *EHFrame = G.findSectionByName(EHFrameSectionName);

llvm/lib/ExecutionEngine/JITLink/EHFrameSupportImpl.h

 #include "llvm/ExecutionEngine/JITLink/EHFrameSupport.h"
 
 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
 #include "llvm/Support/BinaryStreamReader.h"
 
 namespace llvm {
 namespace jitlink {
 
-/// A LinkGraph pass that splits blocks in a section that follows the DWARF
-/// Record format into sub-blocks where each header gets its own block.
-/// When splitting EHFrames, DWARFRecordSectionSplitter should not be run
-/// without EHFrameEdgeFixer, which is responsible for adding FDE-to-CIE edges.
-class DWARFRecordSectionSplitter {
-public:
-  DWARFRecordSectionSplitter(StringRef SectionName);
-  Error operator()(LinkGraph &G);
-
-private:
-  Error processBlock(LinkGraph &G, Block &B, LinkGraph::SplitBlockCache &Cache);
-
-  StringRef SectionName;
-};
-
 /// A LinkGraph pass that adds missing FDE-to-CIE, FDE-to-PC and FDE-to-LSDA
 /// edges.
 class EHFrameEdgeFixer {
 public:
   EHFrameEdgeFixer(StringRef EHFrameSectionName, unsigned PointerSize,
                    Edge::Kind Delta64, Edge::Kind Delta32,
                    Edge::Kind NegDelta32);
   Error operator()(LinkGraph &G);

llvm/lib/ExecutionEngine/JITLink/ELF_x86_64.cpp

 //===---- ELF_x86_64.cpp -JIT linker implementation for ELF/x86-64 ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // ELF/x86-64 jit-link implementation.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ExecutionEngine/JITLink/ELF_x86_64.h"
+#include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 #include "llvm/ExecutionEngine/JITLink/JITLink.h"
 #include "llvm/ExecutionEngine/JITLink/TableManager.h"
 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
 #include "llvm/Object/ELFObjectFile.h"
 #include "llvm/Support/Endian.h"
 
 #include "DefineExternalSectionStartAndEndSymbols.h"
 #include "EHFrameSupportImpl.h"

llvm/lib/ExecutionEngine/JITLink/MachO_arm64.cpp

 //===---- MachO_arm64.cpp - JIT linker implementation for MachO/arm64 -----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // MachO/arm64 jit-link implementation.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ExecutionEngine/JITLink/MachO_arm64.h"
+#include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 
 #include "MachOLinkGraphBuilder.h"
 #include "PerGraphGOTAndPLTStubsBuilder.h"
 
 #define DEBUG_TYPE "jitlink"
 
 using namespace llvm;
 using namespace llvm::jitlink;

llvm/lib/ExecutionEngine/JITLink/MachO_x86_64.cpp

 //===---- MachO_x86_64.cpp -JIT linker implementation for MachO/x86-64 ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // MachO/x86-64 jit-link implementation.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ExecutionEngine/JITLink/MachO_x86_64.h"
+#include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h"
 #include "llvm/ExecutionEngine/JITLink/x86_64.h"
 
 #include "MachOLinkGraphBuilder.h"
 #include "PerGraphGOTAndPLTStubsBuilder.h"
 
 #define DEBUG_TYPE "jitlink"
 
 using namespace llvm;