[MACHO] Replaced calls to getStruct with getStructOrErr in functions returning Error or Expected or similar

[Bigcheese]

It would be nice to get tests for these cases, although I realize that can be difficult as it requires malformed inputs.

[jakehehrlich]

Might label as NFC.

[jakehehrlich]

In D62711#1525409, @Bigcheese wrote:

It would be nice to get tests for these cases, although I realize that can be difficult as it requires malformed inputs.

This is an NFC. The error messages will change slightly but I don't think we should add the burden of adding all of those tests (which as you say are not easy) onto someone making a strict improvement.

[abrachet]

Removed inconsistent spacing

[jhenderson]

llvm/lib/Object/MachOObjectFile.cpp

935–939

This line needs clang-formatting.

[abrachet]

fixed formatting issues

[jhenderson]

LGTM.

[steven_wu]

LGTM.

llvm/lib/Object/MachOObjectFile.cpp

if (auto SegOrErr = getStructOrErr<Segment>(Obj, Load.Ptr)) {
     if (S.nsects > std::numeric_limits<uint32_t>::max() / SectionSize ||
         S.nsects * SectionSize > Load.C.cmdsize - SegmentLoadSize)
       return malformedError("load command " + Twine(LoadCommandIndex) +
                             " inconsistent cmdsize in " + CmdName +
                             " for the number of sections");
     for (unsigned J = 0; J < S.nsects; ++J) {
       const char *Sec = getSectionPtr(Obj, Load, J);
       Sections.push_back(Sec);
-      Section s = getStruct<Section>(Obj, Sec);
+      auto SectionOrErr = getStructOrErr<Section>(Obj, Sec);
+      if (!SectionOrErr)
+        return SectionOrErr.takeError();
+      Section s = SectionOrErr.get();
       if (Obj.getHeader().filetype != MachO::MH_DYLIB_STUB &&
           Obj.getHeader().filetype != MachO::MH_DSYM &&
           s.flags != MachO::S_ZEROFILL &&
           s.flags != MachO::S_THREAD_LOCAL_ZEROFILL &&
           s.offset > FileSize)
         return malformedError("offset field of section " + Twine(J) + " in " +
                               CmdName + " command " + Twine(LoadCommandIndex) +
                               " extends past the end of the file");
static Error checkSymtabCommand(const MachOObjectFile &Obj,
                                 uint32_t LoadCommandIndex,
                                 const char **SymtabLoadCmd,
                                 std::list<MachOElement> &Elements) {
   if (Load.C.cmdsize < sizeof(MachO::symtab_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_SYMTAB cmdsize too small");
   if (*SymtabLoadCmd != nullptr)
     return malformedError("more than one LC_SYMTAB command");
-  MachO::symtab_command Symtab =
-    getStruct<MachO::symtab_command>(Obj, Load.Ptr);
+  auto SymtabOrErr = getStructOrErr<MachO::symtab_command>(Obj, Load.Ptr);
+  if (!SymtabOrErr)
+    return SymtabOrErr.takeError();
+  MachO::symtab_command Symtab = SymtabOrErr.get();
   if (Symtab.cmdsize != sizeof(MachO::symtab_command))
     return malformedError("LC_SYMTAB command " + Twine(LoadCommandIndex) +
                           " has incorrect cmdsize");
   uint64_t FileSize = Obj.getData().size();
   if (Symtab.symoff > FileSize)
     return malformedError("symoff field of LC_SYMTAB command " +
                           Twine(LoadCommandIndex) + " extends past the end "
                           "of the file");
static Error checkDysymtabCommand(const MachOObjectFile &Obj,
                                   uint32_t LoadCommandIndex,
                                   const char **DysymtabLoadCmd,
                                   std::list<MachOElement> &Elements) {
   if (Load.C.cmdsize < sizeof(MachO::dysymtab_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_DYSYMTAB cmdsize too small");
   if (*DysymtabLoadCmd != nullptr)
     return malformedError("more than one LC_DYSYMTAB command");
-  MachO::dysymtab_command Dysymtab =
-    getStruct<MachO::dysymtab_command>(Obj, Load.Ptr);
+  auto DysymtabOrErr = 
+    getStructOrErr<MachO::dysymtab_command>(Obj, Load.Ptr);
+  if (!DysymtabOrErr)
+    return DysymtabOrErr.takeError();
+  MachO::dysymtab_command Dysymtab = DysymtabOrErr.get();
   if (Dysymtab.cmdsize != sizeof(MachO::dysymtab_command))
     return malformedError("LC_DYSYMTAB command " + Twine(LoadCommandIndex) +
                           " has incorrect cmdsize");
   uint64_t FileSize = Obj.getData().size();
   if (Dysymtab.tocoff > FileSize)
     return malformedError("tocoff field of LC_DYSYMTAB command " +
                           Twine(LoadCommandIndex) + " extends past the end of "
                           "the file");
static Error checkLinkeditDataCommand(const MachOObjectFile &Obj,
                                  const char **LoadCmd, const char *CmdName,
                                  std::list<MachOElement> &Elements,
                                  const char *ElementName) {
   if (Load.C.cmdsize < sizeof(MachO::linkedit_data_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " cmdsize too small");
   if (*LoadCmd != nullptr)
     return malformedError("more than one " + Twine(CmdName) + " command");
-  MachO::linkedit_data_command LinkData =
-    getStruct<MachO::linkedit_data_command>(Obj, Load.Ptr);
+  auto LinkDataOrError = 
+    getStructOrErr<MachO::linkedit_data_command>(Obj, Load.Ptr);
+  if (!LinkDataOrError)
+    return LinkDataOrError.takeError();
+  MachO::linkedit_data_command LinkData = LinkDataOrError.get();
   if (LinkData.cmdsize != sizeof(MachO::linkedit_data_command))
     return malformedError(Twine(CmdName) + " command " +
                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
   uint64_t FileSize = Obj.getData().size();
   if (LinkData.dataoff > FileSize)
     return malformedError("dataoff field of " + Twine(CmdName) + " command " +
                           Twine(LoadCommandIndex) + " extends past the end of "
                           "the file");
static Error checkDyldInfoCommand(const MachOObjectFile &Obj,
                                   const char **LoadCmd, const char *CmdName,
                                   std::list<MachOElement> &Elements) {
   if (Load.C.cmdsize < sizeof(MachO::dyld_info_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " cmdsize too small");
   if (*LoadCmd != nullptr)
     return malformedError("more than one LC_DYLD_INFO and or LC_DYLD_INFO_ONLY "
                           "command");
-  MachO::dyld_info_command DyldInfo =
-    getStruct<MachO::dyld_info_command>(Obj, Load.Ptr);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(Obj, Load.Ptr);
+  if (!DyldInfoOrErr)
+    return DyldInfoOrErr.takeError();
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   if (DyldInfo.cmdsize != sizeof(MachO::dyld_info_command))
     return malformedError(Twine(CmdName) + " command " +
                           Twine(LoadCommandIndex) + " has incorrect cmdsize");
   uint64_t FileSize = Obj.getData().size();
   if (DyldInfo.rebase_off > FileSize)
     return malformedError("rebase_off field of " + Twine(CmdName) +
                           " command " + Twine(LoadCommandIndex) + " extends "
                           "past the end of the file");

 }
 
 static Error checkDylibCommand(const MachOObjectFile &Obj,
                                const MachOObjectFile::LoadCommandInfo &Load,
                                uint32_t LoadCommandIndex, const char *CmdName) {
   if (Load.C.cmdsize < sizeof(MachO::dylib_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " cmdsize too small");
-  MachO::dylib_command D = getStruct<MachO::dylib_command>(Obj, Load.Ptr);
+  auto CommandOrErr = getStructOrErr<MachO::dylib_command>(Obj, Load.Ptr);
+  if (!CommandOrErr)
+    return CommandOrErr.takeError();
+  MachO::dylib_command D = CommandOrErr.get();
   if (D.dylib.name < sizeof(MachO::dylib_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " name.offset field too small, not past "
                           "the end of the dylib_command struct");
   if (D.dylib.name >= D.cmdsize)
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " name.offset field extends past the end "
                           "of the load command");

 }
 
 static Error checkDyldCommand(const MachOObjectFile &Obj,
                               const MachOObjectFile::LoadCommandInfo &Load,
                               uint32_t LoadCommandIndex, const char *CmdName) {
   if (Load.C.cmdsize < sizeof(MachO::dylinker_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " cmdsize too small");
-  MachO::dylinker_command D = getStruct<MachO::dylinker_command>(Obj, Load.Ptr);
+  auto CommandOrErr = getStructOrErr<MachO::dylinker_command>(Obj, Load.Ptr);
+  if (!CommandOrErr)
+    return CommandOrErr.takeError();
+  MachO::dylinker_command D = CommandOrErr.get();
   if (D.name < sizeof(MachO::dylinker_command))
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " name.offset field too small, not past "
                           "the end of the dylinker_command struct");
   if (D.name >= D.cmdsize)
     return malformedError("load command " + Twine(LoadCommandIndex) + " " +
                           CmdName + " name.offset field extends past the end "
                           "of the load command");

 
 static Error checkNoteCommand(const MachOObjectFile &Obj,
                               const MachOObjectFile::LoadCommandInfo &Load,
                               uint32_t LoadCommandIndex,
                               std::list<MachOElement> &Elements) {
   if (Load.C.cmdsize != sizeof(MachO::note_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_NOTE has incorrect cmdsize");
-  MachO::note_command Nt = getStruct<MachO::note_command>(Obj, Load.Ptr);
+  auto NoteCmdOrErr = getStructOrErr<MachO::note_command>(Obj, Load.Ptr);
+  if (!NoteCmdOrErr)
+    return NoteCmdOrErr.takeError();
+  MachO::note_command Nt = NoteCmdOrErr.get();
   uint64_t FileSize = Obj.getData().size();
   if (Nt.offset > FileSize)
     return malformedError("offset field of LC_NOTE command " +
                           Twine(LoadCommandIndex) + " extends "
                           "past the end of the file");
   uint64_t BigSize = Nt.offset;
   BigSize += Nt.size;
   if (BigSize > FileSize)
     return malformedError("size field plus offset field of LC_NOTE command " +
                           Twine(LoadCommandIndex) + " extends past the end of "
                           "the file");
   if (Error Err = checkOverlappingElement(Elements, Nt.offset, Nt.size,
                                           "LC_NOTE data"))
     return Err;
   return Error::success();
 }
 
 static Error
 parseBuildVersionCommand(const MachOObjectFile &Obj,
                          const MachOObjectFile::LoadCommandInfo &Load,
                          SmallVectorImpl<const char*> &BuildTools,
                          uint32_t LoadCommandIndex) {
-  MachO::build_version_command BVC =
-      getStruct<MachO::build_version_command>(Obj, Load.Ptr);
+  auto BVCOrErr = 
+    getStructOrErr<MachO::build_version_command>(Obj, Load.Ptr);
+  if (!BVCOrErr)
+    return BVCOrErr.takeError();
+  MachO::build_version_command BVC = BVCOrErr.get();
   if (Load.C.cmdsize !=
       sizeof(MachO::build_version_command) +
           BVC.ntools * sizeof(MachO::build_tool_version))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_BUILD_VERSION_COMMAND has incorrect cmdsize");
 
   auto Start = Load.Ptr + sizeof(MachO::build_version_command);
   BuildTools.resize(BVC.ntools);
   for (unsigned i = 0; i < BVC.ntools; ++i)
     BuildTools[i] = Start + i * sizeof(MachO::build_tool_version);
 
   return Error::success();
 }
 
 static Error checkRpathCommand(const MachOObjectFile &Obj,
                                const MachOObjectFile::LoadCommandInfo &Load,
                                uint32_t LoadCommandIndex) {
   if (Load.C.cmdsize < sizeof(MachO::rpath_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_RPATH cmdsize too small");
-  MachO::rpath_command R = getStruct<MachO::rpath_command>(Obj, Load.Ptr);
+  auto ROrErr = getStructOrErr<MachO::rpath_command>(Obj, Load.Ptr);
+  if (!ROrErr)
+    return ROrErr.takeError();
+  MachO::rpath_command R = ROrErr.get();
   if (R.path < sizeof(MachO::rpath_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_RPATH path.offset field too small, not past "
                           "the end of the rpath_command struct");
   if (R.path >= R.cmdsize)
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_RPATH path.offset field extends past the end "
                           "of the load command");

 }
 
 static Error checkLinkerOptCommand(const MachOObjectFile &Obj,
                                    const MachOObjectFile::LoadCommandInfo &Load,
                                    uint32_t LoadCommandIndex) {
   if (Load.C.cmdsize < sizeof(MachO::linker_option_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_LINKER_OPTION cmdsize too small");
-  MachO::linker_option_command L =
-    getStruct<MachO::linker_option_command>(Obj, Load.Ptr);
+  auto LinkOptionOrErr = 
+    getStructOrErr<MachO::linker_option_command>(Obj, Load.Ptr);
+  if (!LinkOptionOrErr)
+    return LinkOptionOrErr.takeError();
+  MachO::linker_option_command L = LinkOptionOrErr.get(); 
   // Make sure the count of strings is correct.
   const char *string = (const char *)Load.Ptr +
                        sizeof(struct MachO::linker_option_command);
   uint32_t left = L.cmdsize - sizeof(struct MachO::linker_option_command);
   uint32_t i = 0;
   while (left > 0) {
     while (*string == '\0' && left > 0) {
       string++;

 
 static Error checkThreadCommand(const MachOObjectFile &Obj,
                                 const MachOObjectFile::LoadCommandInfo &Load,
                                 uint32_t LoadCommandIndex,
                                 const char *CmdName) {
   if (Load.C.cmdsize < sizeof(MachO::thread_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           CmdName + " cmdsize too small");
-  MachO::thread_command T =
-    getStruct<MachO::thread_command>(Obj, Load.Ptr);
+  auto ThreadCommandOrErr = 
+    getStructOrErr<MachO::thread_command>(Obj, Load.Ptr);
+  if (!ThreadCommandOrErr)
+    return ThreadCommandOrErr.takeError();
+  MachO::thread_command T = ThreadCommandOrErr.get();
   const char *state = Load.Ptr + sizeof(MachO::thread_command);
   const char *end = Load.Ptr + T.cmdsize;
   uint32_t nflavor = 0;
   uint32_t cputype = getCPUType(Obj);
   while (state < end) {
     if(state + sizeof(uint32_t) > end)
       return malformedError("load command " + Twine(LoadCommandIndex) +
                             "flavor in " + CmdName + " extends past end of "
static Error checkTwoLevelHintsCommand(const MachOObjectFile &Obj,
                                        uint32_t LoadCommandIndex,
                                        const char **LoadCmd,
                                        std::list<MachOElement> &Elements) {
   if (Load.C.cmdsize != sizeof(MachO::twolevel_hints_command))
     return malformedError("load command " + Twine(LoadCommandIndex) +
                           " LC_TWOLEVEL_HINTS has incorrect cmdsize");
   if (*LoadCmd != nullptr)
     return malformedError("more than one LC_TWOLEVEL_HINTS command");
-  MachO::twolevel_hints_command Hints =
-    getStruct<MachO::twolevel_hints_command>(Obj, Load.Ptr);
+  auto HintsOrErr = getStructOrErr<MachO::twolevel_hints_command>(Obj, Load.Ptr);
+  if(!HintsOrErr)
+    return HintsOrErr.takeError();
+  MachO::twolevel_hints_command Hints = HintsOrErr.get();
   uint64_t FileSize = Obj.getData().size();
   if (Hints.offset > FileSize)
     return malformedError("offset field of LC_TWOLEVEL_HINTS command " +
                           Twine(LoadCommandIndex) + " extends past the end of "
                           "the file");
   uint64_t BigSize = Hints.nhints;
   BigSize *= sizeof(MachO::twolevel_hint);
   BigSize += Hints.offset;
std::error_code MachOObjectFile::getLibraryShortNameByIndex(unsigned Index,
                                                          StringRef &Res) const {
   if (Index >= Libraries.size())
     return object_error::parse_failed;
 
   // If the cache of LibrariesShortNames is not built up do that first for
   // all the Libraries.
   if (LibrariesShortNames.size() == 0) {
     for (unsigned i = 0; i < Libraries.size(); i++) {
-      MachO::dylib_command D =
-        getStruct<MachO::dylib_command>(*this, Libraries[i]);
+      auto CommandOrErr =
+        getStructOrErr<MachO::dylib_command>(*this, Libraries[i]);
+      if (!CommandOrErr)
+        return object_error::parse_failed;
+      MachO::dylib_command D = CommandOrErr.get();
       if (D.dylib.name >= D.cmdsize)
         return object_error::parse_failed;
       const char *P = (const char *)(Libraries[i]) + D.dylib.name;
       StringRef Name = StringRef(P);
       if (D.dylib.name+Name.size() >= D.cmdsize)
         return object_error::parse_failed;
       StringRef Suffix;
       bool isFramework;
MachOObjectFile::getLinkOptHintsLoadCommand() const {
   Cmd.datasize = 0;
   return Cmd;
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoRebaseOpcodes() const {
   if (!DyldInfoLoadCmd)
     return None;
 
-  MachO::dyld_info_command DyldInfo =
-      getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  if (!DyldInfoOrErr)
+    return None;
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   const uint8_t *Ptr =
       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.rebase_off));
   return makeArrayRef(Ptr, DyldInfo.rebase_size);
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoBindOpcodes() const {
   if (!DyldInfoLoadCmd)
     return None;
 
-  MachO::dyld_info_command DyldInfo =
-      getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  if (!DyldInfoOrErr)
+    return None;
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   const uint8_t *Ptr =
       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.bind_off));
   return makeArrayRef(Ptr, DyldInfo.bind_size);
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoWeakBindOpcodes() const {
   if (!DyldInfoLoadCmd)
     return None;
 
-  MachO::dyld_info_command DyldInfo =
-      getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  if (!DyldInfoOrErr)
+    return None;
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   const uint8_t *Ptr =
       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.weak_bind_off));
   return makeArrayRef(Ptr, DyldInfo.weak_bind_size);
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoLazyBindOpcodes() const {
   if (!DyldInfoLoadCmd)
     return None;
 
-  MachO::dyld_info_command DyldInfo =
-      getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  if (!DyldInfoOrErr)
+    return None;
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   const uint8_t *Ptr =
       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.lazy_bind_off));
   return makeArrayRef(Ptr, DyldInfo.lazy_bind_size);
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getDyldInfoExportsTrie() const {
   if (!DyldInfoLoadCmd)
     return None;
 
-  MachO::dyld_info_command DyldInfo =
-      getStruct<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  auto DyldInfoOrErr =
+    getStructOrErr<MachO::dyld_info_command>(*this, DyldInfoLoadCmd);
+  if (!DyldInfoOrErr)
+    return None;
+  MachO::dyld_info_command DyldInfo = DyldInfoOrErr.get();
   const uint8_t *Ptr =
       reinterpret_cast<const uint8_t *>(getPtr(*this, DyldInfo.export_off));
   return makeArrayRef(Ptr, DyldInfo.export_size);
 }
 
 ArrayRef<uint8_t> MachOObjectFile::getUuid() const {
   if (!UuidLoadCmd)
     return None;