Emit swift5 reflection section data in dsym bundle generated by dsymutil in the Dwarf section.

Add support for Swift reflection metadata to dsymutil.

This patch adds support for copying Swift reflection metadata (__swift5_.* sections) from .o files to into the symbol-rich binary in the output .dSYM. The functionality is automatically enabled only if a .o file has reflection metadata sections and the binary doesn't. When copying dsymutil moves the section from the __TEXT segment to the __DWARF segment.

rdar://76973336

Differential Revision: https://reviews.llvm.org/D115007

Author: rastogishubham

llvm/include/llvm/BinaryFormat/Swift.def

@@ -0,0 +1,26 @@
+//===- llvm/BinaryFormat/Swift.def - Swift definitions ---------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Macros for running through Swift enumerators.
+//
+//===----------------------------------------------------------------------===//
+
+#if !(defined HANDLE_SWIFT_SECTION)
+#error "Missing macro definition of HANDLE_SWIFT_SECTION"
+#endif
+
+#ifndef HANDLE_SWIFT_SECTION
+#define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF)
+#endif
+
+HANDLE_SWIFT_SECTION(fieldmd, "__swift5_fieldmd", "swift5_fieldmd", ".sw5flmd")
+HANDLE_SWIFT_SECTION(assocty, "__swift5_assocty", "swift5_assocty", ".sw5asty")
+HANDLE_SWIFT_SECTION(builtin, "__swift5_builtin", "swift5_builtin", ".sw5bltn")
+HANDLE_SWIFT_SECTION(capture, "__swift5_capture", "swift5_capture", ".sw5cptr")
+HANDLE_SWIFT_SECTION(typeref, "__swift5_typeref", "swift5_typeref", ".sw5tyrf")
+HANDLE_SWIFT_SECTION(reflstr, "__swift5_reflstr", "swift5_reflstr", ".sw5rfst")

llvm/include/llvm/BinaryFormat/Swift.h

@@ -0,0 +1,24 @@
+//===-- llvm/BinaryFormat/Swift.h ---Swift Constants-------------*- 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_BINARYFORMAT_SWIFT_H
+#define LLVM_BINARYFORMAT_SWIFT_H
+
+namespace llvm {
+namespace swift {
+
+enum Swift5ReflectionSectionKind {
+#define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF) KIND,
+#include "llvm/BinaryFormat/Swift.def"
+#undef HANDLE_SWIFT_SECTION
+  unknown,
+  last = unknown
+};
+} // end of namespace swift
+} // end of namespace llvm
+
+#endif

llvm/include/llvm/DWARFLinker/DWARFStreamer.h

@@ -9,6 +9,7 @@
 #ifndef LLVM_DWARFLINKER_DWARFSTREAMER_H
 #define LLVM_DWARFLINKER_DWARFSTREAMER_H
 
+#include "llvm/BinaryFormat/Swift.h"
 #include "llvm/CodeGen/AccelTable.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/DWARFLinker/DWARFLinker.h"
@@ -48,7 +49,7 @@ class DwarfStreamer : public DwarfEmitter {
       : OutFile(OutFile), OutFileType(OutFileType), Translator(Translator),
         ErrorHandler(Error), WarningHandler(Warning) {}
 
-  bool init(Triple TheTriple);
+  bool init(Triple TheTriple, StringRef Swift5ReflectionSegmentName);
 
   /// Dump the file to the disk.
   void finish();
@@ -85,6 +86,11 @@ class DwarfStreamer : public DwarfEmitter {
   /// Emit the swift_ast section stored in \p Buffer.
   void emitSwiftAST(StringRef Buffer);
 
+  /// Emit the swift reflection section stored in \p Buffer.
+  void emitSwiftReflectionSection(
+      llvm::swift::Swift5ReflectionSectionKind ReflSectionKind,
+      StringRef Buffer, uint32_t Alignment, uint32_t Size);
+
   /// Emit debug_ranges for \p FuncRange by translating the
   /// original \p Entries.
   void emitRangesEntries(

llvm/include/llvm/MC/MCContext.h

@@ -80,6 +80,10 @@ namespace llvm {
   private:
     Environment Env;
 
+    /// The name of the Segment where Swift5 Reflection Section data will be
+    /// outputted
+    StringRef Swift5ReflectionSegmentName;
+
     /// The triple for this object.
     Triple TT;
 
@@ -399,13 +403,17 @@ namespace llvm {
                        const MCRegisterInfo *MRI, const MCSubtargetInfo *MSTI,
                        const SourceMgr *Mgr = nullptr,
                        MCTargetOptions const *TargetOpts = nullptr,
-                       bool DoAutoReset = true);
+                       bool DoAutoReset = true,
+                       StringRef Swift5ReflSegmentName = {});
     MCContext(const MCContext &) = delete;
     MCContext &operator=(const MCContext &) = delete;
     ~MCContext();
 
     Environment getObjectFileType() const { return Env; }
 
+    const StringRef &getSwift5ReflectionSegmentName() const {
+      return Swift5ReflectionSegmentName;
+    }
     const Triple &getTargetTriple() const { return TT; }
     const SourceMgr *getSourceManager() const { return SrcMgr; }
 

llvm/include/llvm/MC/MCObjectFileInfo.h

@@ -15,6 +15,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/BinaryFormat/Swift.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/CodeGen.h"
 #include "llvm/Support/VersionTuple.h"
@@ -228,6 +229,10 @@ class MCObjectFileInfo {
   MCSection *ReadOnly8Section = nullptr;
   MCSection *ReadOnly16Section = nullptr;
 
+  // Swift5 Reflection Data Sections
+  std::array<MCSection *, swift::Swift5ReflectionSectionKind::last>
+      Swift5ReflectionSections = {};
+
 public:
   void initMCObjectFileInfo(MCContext &MCCtx, bool PIC,
                             bool LargeCodeModel = false);
@@ -423,6 +428,14 @@ class MCObjectFileInfo {
 
   bool isPositionIndependent() const { return PositionIndependent; }
 
+  // Swift5 Reflection Data Sections
+  MCSection *getSwift5ReflectionSection(
+      llvm::swift::Swift5ReflectionSectionKind ReflSectionKind) {
+    return ReflSectionKind != llvm::swift::Swift5ReflectionSectionKind::unknown
+               ? Swift5ReflectionSections[ReflSectionKind]
+               : nullptr;
+  }
+
 private:
   bool PositionIndependent = false;
   MCContext *Ctx = nullptr;

llvm/include/llvm/Object/MachO.h

@@ -22,6 +22,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/BinaryFormat/MachO.h"
+#include "llvm/BinaryFormat/Swift.h"
 #include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Object/Binary.h"
 #include "llvm/Object/ObjectFile.h"
@@ -583,6 +584,9 @@ class MachOObjectFile : public ObjectFile {
 
   StringRef mapDebugSectionName(StringRef Name) const override;
 
+  llvm::swift::Swift5ReflectionSectionKind
+  mapReflectionSectionNameToEnumValue(StringRef SectionName) const override;
+
   bool hasPageZeroSegment() const { return HasPageZeroSegment; }
 
   static bool classof(const Binary *v) {

llvm/include/llvm/Object/ObjectFile.h

@@ -18,6 +18,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/BinaryFormat/Magic.h"
+#include "llvm/BinaryFormat/Swift.h"
 #include "llvm/Object/Binary.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Object/SymbolicFile.h"
@@ -290,6 +291,11 @@ class ObjectFile : public SymbolicFile {
   virtual void getRelocationTypeName(DataRefImpl Rel,
                                      SmallVectorImpl<char> &Result) const = 0;
 
+  virtual llvm::swift::Swift5ReflectionSectionKind
+  mapReflectionSectionNameToEnumValue(StringRef SectionName) const {
+    return llvm::swift::Swift5ReflectionSectionKind::unknown;
+  };
+
   Expected<uint64_t> getSymbolValue(DataRefImpl Symb) const;
 
 public:

llvm/lib/DWARFLinker/DWARFStreamer.cpp

@@ -27,7 +27,8 @@
 
 namespace llvm {
 
-bool DwarfStreamer::init(Triple TheTriple) {
+bool DwarfStreamer::init(Triple TheTriple,
+                         StringRef Swift5ReflectionSegmentName) {
   std::string ErrorStr;
   std::string TripleName;
   StringRef Context = "dwarf streamer init";
@@ -54,8 +55,9 @@ bool DwarfStreamer::init(Triple TheTriple) {
   if (!MSTI)
     return error("no subtarget info for target " + TripleName, Context), false;
 
-  MC.reset(new MCContext(TheTriple, MAI.get(), MRI.get(), MSTI.get()));
-  MOFI.reset(TheTarget->createMCObjectFileInfo(*MC, /*PIC=*/false));
+  MC.reset(new MCContext(TheTriple, MAI.get(), MRI.get(), MSTI.get(), nullptr,
+                         nullptr, true, Swift5ReflectionSegmentName));
+  MOFI.reset(TheTarget->createMCObjectFileInfo(*MC, /*PIC=*/false, false));
   MC->setObjectFileInfo(MOFI.get());
 
   MAB = TheTarget->createMCAsmBackend(*MSTI, *MRI, MCOptions);
@@ -302,6 +304,18 @@ void DwarfStreamer::emitSwiftAST(StringRef Buffer) {
   MS->emitBytes(Buffer);
 }
 
+void DwarfStreamer::emitSwiftReflectionSection(
+    llvm::swift::Swift5ReflectionSectionKind ReflSectionKind, StringRef Buffer,
+    uint32_t Alignment, uint32_t Size) {
+  MCSection *ReflectionSection =
+      MOFI->getSwift5ReflectionSection(ReflSectionKind);
+  if (ReflectionSection == nullptr)
+    return;
+  ReflectionSection->setAlignment(Align(Alignment));
+  MS->SwitchSection(ReflectionSection);
+  MS->emitBytes(Buffer);
+}
+
 /// Emit the debug_range section contents for \p FuncRange by
 /// translating the original \p Entries. The debug_range section
 /// format is totally trivial, consisting just of pairs of address

llvm/lib/MC/MCContext.cpp

@@ -67,10 +67,10 @@ static void defaultDiagHandler(const SMDiagnostic &SMD, bool, const SourceMgr &,
 MCContext::MCContext(const Triple &TheTriple, const MCAsmInfo *mai,
                      const MCRegisterInfo *mri, const MCSubtargetInfo *msti,
                      const SourceMgr *mgr, MCTargetOptions const *TargetOpts,
-                     bool DoAutoReset)
-    : TT(TheTriple), SrcMgr(mgr), InlineSrcMgr(nullptr),
-      DiagHandler(defaultDiagHandler), MAI(mai), MRI(mri), MSTI(msti),
-      Symbols(Allocator), UsedNames(Allocator),
+                     bool DoAutoReset, StringRef Swift5ReflSegmentName)
+    : Swift5ReflectionSegmentName(Swift5ReflSegmentName), TT(TheTriple),
+      SrcMgr(mgr), InlineSrcMgr(nullptr), DiagHandler(defaultDiagHandler),
+      MAI(mai), MRI(mri), MSTI(msti), Symbols(Allocator), UsedNames(Allocator),
       InlineAsmUsedLabelNames(Allocator),
       CurrentDwarfLoc(0, 0, 0, DWARF2_FLAG_IS_STMT, 0, 0),
       AutoReset(DoAutoReset), TargetOptions(TargetOpts) {

llvm/lib/MC/MCObjectFileInfo.cpp

@@ -299,6 +299,17 @@ void MCObjectFileInfo::initMachOMCObjectFileInfo(const Triple &T) {
   RemarksSection = Ctx->getMachOSection(
       "__LLVM", "__remarks", MachO::S_ATTR_DEBUG, SectionKind::getMetadata());
 
+  // The architecture of dsymutil makes it very difficult to copy the Swift
+  // reflection metadata sections into the __TEXT segment, so dsymutil creates
+  // these sections in the __DWARF segment instead.
+  if (!Ctx->getSwift5ReflectionSegmentName().empty()) {
+#define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF)                           \
+  Swift5ReflectionSections[llvm::swift::Swift5ReflectionSectionKind::KIND] =   \
+      Ctx->getMachOSection(Ctx->getSwift5ReflectionSegmentName().data(),       \
+                           MACHO, 0, SectionKind::getMetadata());
+#include "llvm/BinaryFormat/Swift.def"
+  }
+
   TLSExtraDataSection = TLSTLVSection;
 }
 

llvm/lib/Object/MachOObjectFile.cpp

@@ -20,6 +20,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/BinaryFormat/MachO.h"
+#include "llvm/BinaryFormat/Swift.h"
 #include "llvm/Object/Error.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Object/ObjectFile.h"
@@ -4765,3 +4766,14 @@ MachOObjectFile::findDsymObjectMembers(StringRef Path) {
                              Path.str().c_str());
   return ObjectPaths;
 }
+
+llvm::swift::Swift5ReflectionSectionKind
+MachOObjectFile::mapReflectionSectionNameToEnumValue(
+    StringRef SectionName) const {
+#define HANDLE_SWIFT_SECTION(KIND, MACHO, ELF, COFF)                           \
+  .Case(MACHO, llvm::swift::Swift5ReflectionSectionKind::KIND)
+  return StringSwitch<llvm::swift::Swift5ReflectionSectionKind>(SectionName)
+#include "llvm/BinaryFormat/Swift.def"
+      .Default(llvm::swift::Swift5ReflectionSectionKind::unknown);
+#undef HANDLE_SWIFT_SECTION
+}