Revert "[dsymutil] Remove support for obfuscated bitcode" (#85826)

Reverts #85713 Since it is breaking Linux x64 builds.

Author: Andres Villegas

llvm/docs/CommandGuide/dsymutil.rst

@@ -140,6 +140,10 @@ OPTIONS
  (in bytes) to the linked dSYM. The table is sorted by the output size listing
  the object files with the largest contribution first.
 
+.. option:: --symbol-map <bcsymbolmap>
+
+ Update the existing dSYMs inplace using symbol map specified.
+
 .. option:: -s, --symtab
 
  Dumps the symbol table found in *executable* or object file(s) and exits.

llvm/include/llvm/CodeGen/NonRelocatableStringpool.h

@@ -27,7 +27,10 @@ class NonRelocatableStringpool {
   /// order.
   using MapTy = StringMap<DwarfStringPoolEntry, BumpPtrAllocator>;
 
-  NonRelocatableStringpool(bool PutEmptyString = false) {
+  NonRelocatableStringpool(
+      std::function<StringRef(StringRef Input)> Translator = nullptr,
+      bool PutEmptyString = false)
+      : Translator(Translator) {
     if (PutEmptyString)
       getEntry("");
   }
@@ -56,6 +59,7 @@ class NonRelocatableStringpool {
   MapTy Strings;
   uint64_t CurrentEndOffset = 0;
   unsigned NumEntries = 0;
+  std::function<StringRef(StringRef Input)> Translator;
 };
 
 /// Helper for making strong types.

llvm/include/llvm/DWARFLinker/Classic/DWARFStreamer.h

@@ -45,13 +45,16 @@ class DwarfStreamer : public DwarfEmitter {
 public:
   DwarfStreamer(DWARFLinkerBase::OutputFileType OutFileType,
                 raw_pwrite_stream &OutFile,
+                DWARFLinkerBase::TranslatorFuncTy Translator,
                 DWARFLinkerBase::MessageHandlerTy Warning)
-      : OutFile(OutFile), OutFileType(OutFileType), WarningHandler(Warning) {}
+      : OutFile(OutFile), OutFileType(OutFileType), Translator(Translator),
+        WarningHandler(Warning) {}
   virtual ~DwarfStreamer() = default;
 
   static Expected<std::unique_ptr<DwarfStreamer>> createStreamer(
       const Triple &TheTriple, DWARFLinkerBase::OutputFileType FileType,
-      raw_pwrite_stream &OutFile, DWARFLinkerBase::MessageHandlerTy Warning);
+      raw_pwrite_stream &OutFile, DWARFLinkerBase::TranslatorFuncTy Translator,
+      DWARFLinkerBase::MessageHandlerTy Warning);
 
   Error init(Triple TheTriple, StringRef Swift5ReflectionSegmentName);
 
@@ -292,6 +295,7 @@ class DwarfStreamer : public DwarfEmitter {
   /// The output file we stream the linked Dwarf to.
   raw_pwrite_stream &OutFile;
   DWARFLinker::OutputFileType OutFileType = DWARFLinker::OutputFileType::Object;
+  std::function<StringRef(StringRef Input)> Translator;
 
   uint64_t RangesSectionSize = 0;
   uint64_t RngListsSectionSize = 0;

llvm/include/llvm/DWARFLinker/DWARFLinkerBase.h

@@ -82,6 +82,7 @@ class DWARFLinkerBase {
       std::function<void(const DWARFFile &File, llvm::StringRef Output)>;
   using ObjectPrefixMapTy = std::map<std::string, std::string>;
   using CompileUnitHandlerTy = function_ref<void(const DWARFUnit &Unit)>;
+  using TranslatorFuncTy = std::function<StringRef(StringRef)>;
   using SwiftInterfacesMapTy = std::map<std::string, std::string>;
   /// Type of output file.
   enum class OutputFileType : uint8_t {

llvm/include/llvm/DWARFLinker/Parallel/DWARFLinker.h

@@ -123,7 +123,8 @@ class DWARFLinker : public DWARFLinkerBase {
 
   /// Creates dwarf linker instance.
   static std::unique_ptr<DWARFLinker>
-  createLinker(MessageHandlerTy ErrorHandler, MessageHandlerTy WarningHandler);
+  createLinker(MessageHandlerTy ErrorHandler, MessageHandlerTy WarningHandler,
+               TranslatorFuncTy StringsTranslator = nullptr);
 
   /// Set output DWARF handler. Result of linking DWARF is set of sections
   /// containing final debug info. DWARFLinkerBase::link() pass generated

llvm/lib/CodeGen/NonRelocatableStringpool.cpp

@@ -12,6 +12,8 @@
 namespace llvm {
 
 DwarfStringPoolEntryRef NonRelocatableStringpool::getEntry(StringRef S) {
+  if (Translator)
+    S = Translator(S);
   auto I = Strings.insert({S, DwarfStringPoolEntry()});
   auto &Entry = I.first->second;
   if (I.second || !Entry.isIndexed()) {
@@ -26,6 +28,9 @@ DwarfStringPoolEntryRef NonRelocatableStringpool::getEntry(StringRef S) {
 StringRef NonRelocatableStringpool::internString(StringRef S) {
   DwarfStringPoolEntry Entry{nullptr, 0, DwarfStringPoolEntry::NotIndexed};
 
+  if (Translator)
+    S = Translator(S);
+
   auto InsertResult = Strings.insert({S, Entry});
   return InsertResult.first->getKey();
 }

llvm/lib/DWARFLinker/Classic/DWARFLinker.cpp

@@ -2701,8 +2701,8 @@ Error DWARFLinker::link() {
   // This Dwarf string pool which is used for emission. It must be used
   // serially as the order of calling getStringOffset matters for
   // reproducibility.
-  OffsetsStringPool DebugStrPool(true);
-  OffsetsStringPool DebugLineStrPool(false);
+  OffsetsStringPool DebugStrPool(StringsTranslator, true);
+  OffsetsStringPool DebugLineStrPool(StringsTranslator, false);
   DebugDieValuePool StringOffsetPool;
 
   // ODR Contexts for the optimize.

llvm/lib/DWARFLinker/Classic/DWARFStreamer.cpp

@@ -32,9 +32,10 @@ using namespace dwarf_linker::classic;
 
 Expected<std::unique_ptr<DwarfStreamer>> DwarfStreamer::createStreamer(
     const Triple &TheTriple, DWARFLinkerBase::OutputFileType FileType,
-    raw_pwrite_stream &OutFile, DWARFLinkerBase::MessageHandlerTy Warning) {
+    raw_pwrite_stream &OutFile, DWARFLinkerBase::TranslatorFuncTy Translator,
+    DWARFLinkerBase::MessageHandlerTy Warning) {
   std::unique_ptr<DwarfStreamer> Streamer =
-      std::make_unique<DwarfStreamer>(FileType, OutFile, Warning);
+      std::make_unique<DwarfStreamer>(FileType, OutFile, Translator, Warning);
   if (Error Err = Streamer->init(TheTriple, "__DWARF"))
     return std::move(Err);
 
@@ -976,10 +977,11 @@ void DwarfStreamer::emitLineTableString(const DWARFDebugLine::Prologue &P,
 
   switch (String.getForm()) {
   case dwarf::DW_FORM_string: {
-    StringRef Str = *StringVal;
-    Asm->OutStreamer->emitBytes(Str.data());
+    StringRef TranslatedString =
+        (Translator) ? Translator(*StringVal) : *StringVal;
+    Asm->OutStreamer->emitBytes(TranslatedString.data());
     Asm->emitInt8(0);
-    LineSectionSize += Str.size() + 1;
+    LineSectionSize += TranslatedString.size() + 1;
   } break;
   case dwarf::DW_FORM_strp:
   case dwarf::DW_FORM_line_strp: {

llvm/lib/DWARFLinker/Parallel/DWARFLinker.cpp

@@ -15,6 +15,8 @@ using namespace dwarf_linker::parallel;
 
 std::unique_ptr<DWARFLinker>
 DWARFLinker::createLinker(MessageHandlerTy ErrorHandler,
-                          MessageHandlerTy WarningHandler) {
-  return std::make_unique<DWARFLinkerImpl>(ErrorHandler, WarningHandler);
+                          MessageHandlerTy WarningHandler,
+                          TranslatorFuncTy StringsTranslator) {
+  return std::make_unique<DWARFLinkerImpl>(ErrorHandler, WarningHandler,
+                                           StringsTranslator);
 }

llvm/lib/DWARFLinker/Parallel/DWARFLinkerGlobalData.h

@@ -21,6 +21,7 @@ class DWARFDie;
 namespace dwarf_linker {
 namespace parallel {
 
+using TranslatorFuncTy = std::function<StringRef(StringRef)>;
 using MessageHandlerTy = std::function<void(
     const Twine &Warning, StringRef Context, const DWARFDie *DIE)>;
 
@@ -94,6 +95,19 @@ class LinkingGlobalData {
   /// Returns global string pool.
   StringPool &getStringPool() { return Strings; }
 
+  /// Set translation function.
+  void setTranslator(TranslatorFuncTy Translator) {
+    this->Translator = Translator;
+  }
+
+  /// Translate specified string.
+  StringRef translateString(StringRef String) {
+    if (Translator)
+      return Translator(String);
+
+    return String;
+  }
+
   /// Returns linking options.
   const DWARFLinkerOptions &getOptions() const { return Options; }
 
@@ -147,6 +161,7 @@ class LinkingGlobalData {
 protected:
   llvm::parallel::PerThreadBumpPtrAllocator Allocator;
   StringPool Strings;
+  TranslatorFuncTy Translator;
   DWARFLinkerOptions Options;
   MessageHandlerTy WarningHandler;
   MessageHandlerTy ErrorHandler;

llvm/lib/DWARFLinker/Parallel/DWARFLinkerImpl.cpp

@@ -20,9 +20,11 @@ using namespace dwarf_linker;
 using namespace dwarf_linker::parallel;
 
 DWARFLinkerImpl::DWARFLinkerImpl(MessageHandlerTy ErrorHandler,
-                                 MessageHandlerTy WarningHandler)
+                                 MessageHandlerTy WarningHandler,
+                                 TranslatorFuncTy StringsTranslator)
     : UniqueUnitID(0), DebugStrStrings(GlobalData),
       DebugLineStrStrings(GlobalData), CommonSections(GlobalData) {
+  GlobalData.setTranslator(StringsTranslator);
   GlobalData.setErrorHandler(ErrorHandler);
   GlobalData.setWarningHandler(WarningHandler);
 }

llvm/lib/DWARFLinker/Parallel/DWARFLinkerImpl.h

@@ -26,7 +26,8 @@ namespace parallel {
 class DWARFLinkerImpl : public DWARFLinker {
 public:
   DWARFLinkerImpl(MessageHandlerTy ErrorHandler,
-                  MessageHandlerTy WarningHandler);
+                  MessageHandlerTy WarningHandler,
+                  TranslatorFuncTy StringsTranslator);
 
   /// Add object file to be linked. Pre-load compile unit die. Call
   /// \p OnCUDieLoaded for each compile unit die. If specified \p File

llvm/lib/DWARFLinker/Parallel/OutputSections.h

@@ -253,7 +253,7 @@ struct SectionDescriptor : SectionDescriptorBase {
 
   /// Emit specified inplace string value into the current section contents.
   void emitInplaceString(StringRef String) {
-    OS << String;
+    OS << GlobalData.translateString(String);
     emitIntVal(0, 1);
   }
 

llvm/lib/DWARFLinker/Parallel/StringEntryToDwarfStringPoolEntryMap.h

@@ -33,7 +33,7 @@ class StringEntryToDwarfStringPoolEntryMap {
       DwarfStringPoolEntryWithExtString *DataPtr =
           GlobalData.getAllocator()
               .Allocate<DwarfStringPoolEntryWithExtString>();
-      DataPtr->String = String->getKey();
+      DataPtr->String = GlobalData.translateString(String->getKey());
       DataPtr->Index = DwarfStringPoolEntry::NotIndexed;
       DataPtr->Offset = 0;
       DataPtr->Symbol = nullptr;