1 files changed, 189 insertions, 11 deletions

diff --git a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
index 6d586e7d73f1..4578d0bb75d4 100644
--- a/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/MachOObjcopy.cpp
@@ -18,31 +18,209 @@ namespace objcopy {
 namespace macho {
 
 using namespace object;
+using SectionPred = std::function<bool(const Section &Sec)>;
+
+static void removeSections(const CopyConfig &Config, Object &Obj) {
+  SectionPred RemovePred = [](const Section &) { return false; };
+
+  if (!Config.ToRemove.empty()) {
+    RemovePred = [&Config, RemovePred](const Section &Sec) {
+      return Config.ToRemove.matches(Sec.CanonicalName);
+    };
+  }
+
+  if (Config.StripAll || Config.StripDebug) {
+    // Remove all debug sections.
+    RemovePred = [RemovePred](const Section &Sec) {
+      if (Sec.Segname == "__DWARF")
+        return true;
+
+      return RemovePred(Sec);
+    };
+  }
+
+  if (!Config.OnlySection.empty()) {
+    // Overwrite RemovePred because --only-section takes priority.
+    RemovePred = [&Config](const Section &Sec) {
+      return !Config.OnlySection.matches(Sec.CanonicalName);
+    };
+  }
+
+  return Obj.removeSections(RemovePred);
+}
+
+static void markSymbols(const CopyConfig &Config, Object &Obj) {
+  // Symbols referenced from the indirect symbol table must not be removed.
+  for (IndirectSymbolEntry &ISE : Obj.IndirectSymTable.Symbols)
+    if (ISE.Symbol)
+      (*ISE.Symbol)->Referenced = true;
+}
+
+static void updateAndRemoveSymbols(const CopyConfig &Config, Object &Obj) {
+  for (SymbolEntry &Sym : Obj.SymTable) {
+    auto I = Config.SymbolsToRename.find(Sym.Name);
+    if (I != Config.SymbolsToRename.end())
+      Sym.Name = I->getValue();
+  }
+
+  auto RemovePred = [Config](const std::unique_ptr<SymbolEntry> &N) {
+    if (N->Referenced)
+      return false;
+    return Config.StripAll;
+  };
+
+  Obj.SymTable.removeSymbols(RemovePred);
+}
+
+static LoadCommand buildRPathLoadCommand(StringRef Path) {
+  LoadCommand LC;
+  MachO::rpath_command RPathLC;
+  RPathLC.cmd = MachO::LC_RPATH;
+  RPathLC.path = sizeof(MachO::rpath_command);
+  RPathLC.cmdsize = alignTo(sizeof(MachO::rpath_command) + Path.size(), 8);
+  LC.MachOLoadCommand.rpath_command_data = RPathLC;
+  LC.Payload.assign(RPathLC.cmdsize - sizeof(MachO::rpath_command), 0);
+  std::copy(Path.begin(), Path.end(), LC.Payload.begin());
+  return LC;
+}
+
+static Error dumpSectionToFile(StringRef SecName, StringRef Filename,
+                               Object &Obj) {
+  for (LoadCommand &LC : Obj.LoadCommands)
+    for (Section &Sec : LC.Sections) {
+      if (Sec.CanonicalName == SecName) {
+        Expected<std::unique_ptr<FileOutputBuffer>> BufferOrErr =
+            FileOutputBuffer::create(Filename, Sec.Content.size());
+        if (!BufferOrErr)
+          return BufferOrErr.takeError();
+        std::unique_ptr<FileOutputBuffer> Buf = std::move(*BufferOrErr);
+        llvm::copy(Sec.Content, Buf->getBufferStart());
+
+        if (Error E = Buf->commit())
+          return E;
+        return Error::success();
+      }
+    }
+
+  return createStringError(object_error::parse_failed, "section '%s' not found",
+                           SecName.str().c_str());
+}
+
+static Error addSection(StringRef SecName, StringRef Filename, Object &Obj) {
+  ErrorOr<std::unique_ptr<MemoryBuffer>> BufOrErr =
+      MemoryBuffer::getFile(Filename);
+  if (!BufOrErr)
+    return createFileError(Filename, errorCodeToError(BufOrErr.getError()));
+  std::unique_ptr<MemoryBuffer> Buf = std::move(*BufOrErr);
+
+  std::pair<StringRef, StringRef> Pair = SecName.split(',');
+  StringRef TargetSegName = Pair.first;
+  Section Sec(TargetSegName, Pair.second);
+  Sec.Content = Obj.NewSectionsContents.save(Buf->getBuffer());
+
+  // Add the a section into an existing segment.
+  for (LoadCommand &LC : Obj.LoadCommands) {
+    Optional<StringRef> SegName = LC.getSegmentName();
+    if (SegName && SegName == TargetSegName) {
+      LC.Sections.push_back(Sec);
+      return Error::success();
+    }
+  }
+
+  // There's no segment named TargetSegName. Create a new load command and
+  // Insert a new section into it.
+  LoadCommand &NewSegment = Obj.addSegment(TargetSegName);
+  NewSegment.Sections.push_back(Sec);
+  return Error::success();
+}
+
+// isValidMachOCannonicalName returns success if Name is a MachO cannonical name
+// ("<segment>,<section>") and lengths of both segment and section names are
+// valid.
+Error isValidMachOCannonicalName(StringRef Name) {
+  if (Name.count(',') != 1)
+    return createStringError(errc::invalid_argument,
+                             "invalid section name '%s' (should be formatted "
+                             "as '<segment name>,<section name>')",
+                             Name.str().c_str());
+
+  std::pair<StringRef, StringRef> Pair = Name.split(',');
+  if (Pair.first.size() > 16)
+    return createStringError(errc::invalid_argument,
+                             "too long segment name: '%s'",
+                             Pair.first.str().c_str());
+  if (Pair.second.size() > 16)
+    return createStringError(errc::invalid_argument,
+                             "too long section name: '%s'",
+                             Pair.second.str().c_str());
+  return Error::success();
+}
 
 static Error handleArgs(const CopyConfig &Config, Object &Obj) {
   if (Config.AllowBrokenLinks || !Config.BuildIdLinkDir.empty() ||
       Config.BuildIdLinkInput || Config.BuildIdLinkOutput ||
       !Config.SplitDWO.empty() || !Config.SymbolsPrefix.empty() ||
-      !Config.AllocSectionsPrefix.empty() || !Config.AddSection.empty() ||
-      !Config.DumpSection.empty() || !Config.KeepSection.empty() ||
-      Config.NewSymbolVisibility || !Config.OnlySection.empty() ||
-      !Config.SymbolsToGlobalize.empty() || !Config.SymbolsToKeep.empty() ||
-      !Config.SymbolsToLocalize.empty() || !Config.SymbolsToWeaken.empty() ||
-      !Config.SymbolsToKeepGlobal.empty() || !Config.SectionsToRename.empty() ||
-      !Config.SymbolsToRename.empty() ||
+      !Config.AllocSectionsPrefix.empty() || !Config.KeepSection.empty() ||
+      Config.NewSymbolVisibility || !Config.SymbolsToGlobalize.empty() ||
+      !Config.SymbolsToKeep.empty() || !Config.SymbolsToLocalize.empty() ||
+      !Config.SymbolsToWeaken.empty() || !Config.SymbolsToKeepGlobal.empty() ||
+      !Config.SectionsToRename.empty() ||
       !Config.UnneededSymbolsToRemove.empty() ||
       !Config.SetSectionAlignment.empty() || !Config.SetSectionFlags.empty() ||
-      !Config.ToRemove.empty() || Config.ExtractDWO || Config.KeepFileSymbols ||
-      Config.LocalizeHidden || Config.PreserveDates || Config.StripDWO ||
+      Config.ExtractDWO || Config.KeepFileSymbols || Config.LocalizeHidden ||
+      Config.PreserveDates || Config.StripAllGNU || Config.StripDWO ||
       Config.StripNonAlloc || Config.StripSections || Config.Weaken ||
-      Config.DecompressDebugSections || Config.StripDebug ||
-      Config.StripNonAlloc || Config.StripSections || Config.StripUnneeded ||
+      Config.DecompressDebugSections || Config.StripNonAlloc ||
+      Config.StripSections || Config.StripUnneeded ||
       Config.DiscardMode != DiscardType::None || !Config.SymbolsToAdd.empty() ||
       Config.EntryExpr) {
     return createStringError(llvm::errc::invalid_argument,
                              "option not supported by llvm-objcopy for MachO");
   }
+  removeSections(Config, Obj);
+
+  // Mark symbols to determine which symbols are still needed.
+  if (Config.StripAll)
+    markSymbols(Config, Obj);
+
+  updateAndRemoveSymbols(Config, Obj);
+
+  if (Config.StripAll)
+    for (LoadCommand &LC : Obj.LoadCommands)
+      for (Section &Sec : LC.Sections)
+        Sec.Relocations.clear();
+
+  for (const StringRef &Flag : Config.DumpSection) {
+    std::pair<StringRef, StringRef> SecPair = Flag.split("=");
+    StringRef SecName = SecPair.first;
+    StringRef File = SecPair.second;
+    if (Error E = dumpSectionToFile(SecName, File, Obj))
+      return E;
+  }
 
+  for (const auto &Flag : Config.AddSection) {
+    std::pair<StringRef, StringRef> SecPair = Flag.split("=");
+    StringRef SecName = SecPair.first;
+    StringRef File = SecPair.second;
+    if (Error E = isValidMachOCannonicalName(SecName))
+      return E;
+    if (Error E = addSection(SecName, File, Obj))
+      return E;
+  }
+
+  for (StringRef RPath : Config.RPathToAdd) {
+    for (LoadCommand &LC : Obj.LoadCommands) {
+      if (LC.MachOLoadCommand.load_command_data.cmd == MachO::LC_RPATH &&
+          RPath == StringRef(reinterpret_cast<char *>(LC.Payload.data()),
+                             LC.Payload.size())
+                       .trim(0)) {
+        return createStringError(errc::invalid_argument,
+                                 "rpath " + RPath +
+                                     " would create a duplicate load command");
+      }
+    }
+    Obj.addLoadCommand(buildRPathLoadCommand(RPath));
+  }
   return Error::success();
 }