Revert r360876 "[Object] Change object::SectionRef::getContents() to …

…return Expected<StringRef>"

It broke the Clang build, see llvm-commits thread.

> Expected<ArrayRef<uint8_t>> may be better but use Expected<StringRef> for now.
>
> Follow-up of D61781.

llvm-svn: 360878

llvm/include/llvm/Object/ObjectFile.h

@@ -98,7 +98,7 @@ class SectionRef {
   uint64_t getAddress() const;
   uint64_t getIndex() const;
   uint64_t getSize() const;
-  Expected<StringRef> getContents() const;
+  std::error_code getContents(StringRef &Result) const;
 
   /// Get the alignment of this section as the actual value (not log 2).
   uint64_t getAlignment() const;
@@ -454,12 +454,13 @@ inline uint64_t SectionRef::getSize() const {
   return OwningObject->getSectionSize(SectionPimpl);
 }
 
-inline Expected<StringRef> SectionRef::getContents() const {
+inline std::error_code SectionRef::getContents(StringRef &Result) const {
   Expected<ArrayRef<uint8_t>> Res =
       OwningObject->getSectionContents(SectionPimpl);
   if (!Res)
-    return Res.takeError();
-  return StringRef(reinterpret_cast<const char *>(Res->data()), Res->size());
+    return errorToErrorCode(Res.takeError());
+  Result = StringRef(reinterpret_cast<const char *>(Res->data()), Res->size());
+  return std::error_code();
 }
 
 inline uint64_t SectionRef::getAlignment() const {

llvm/lib/DebugInfo/DWARF/DWARFContext.cpp

@@ -1410,14 +1410,8 @@ class DWARFObjInMemory final : public DWARFObject {
       // Try to obtain an already relocated version of this section.
       // Else use the unrelocated section from the object file. We'll have to
       // apply relocations ourselves later.
-      if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data)) {
-        Expected<StringRef> E = Section.getContents();
-        if (E)
-          Data = *E;
-        else
-          // maybeDecompress below will error.
-          consumeError(E.takeError());
-      }
+      if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data))
+        Section.getContents(Data);
 
       if (auto Err = maybeDecompress(Section, Name, Data)) {
         ErrorPolicy EP = HandleError(createError(

llvm/lib/DebugInfo/Symbolize/SymbolizableObjectFile.cpp

@@ -53,13 +53,13 @@ SymbolizableObjectFile::create(object::ObjectFile *Obj,
   if (Obj->getArch() == Triple::ppc64) {
     for (section_iterator Section : Obj->sections()) {
       StringRef Name;
+      StringRef Data;
       if (auto EC = Section->getName(Name))
         return EC;
       if (Name == ".opd") {
-        Expected<StringRef> E = Section->getContents();
-        if (!E)
-          return errorToErrorCode(E.takeError());
-        OpdExtractor.reset(new DataExtractor(*E, Obj->isLittleEndian(),
+        if (auto EC = Section->getContents(Data))
+          return EC;
+        OpdExtractor.reset(new DataExtractor(Data, Obj->isLittleEndian(),
                                              Obj->getBytesInAddress()));
         OpdAddress = Section->getAddress();
         break;

llvm/lib/DebugInfo/Symbolize/Symbolize.cpp

@@ -221,12 +221,9 @@ bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName,
     Section.getName(Name);
     Name = Name.substr(Name.find_first_not_of("._"));
     if (Name == "gnu_debuglink") {
-      Expected<StringRef> ContentsOrErr = Section.getContents();
-      if (!ContentsOrErr) {
-        consumeError(ContentsOrErr.takeError());
-        return false;
-      }
-      DataExtractor DE(*ContentsOrErr, Obj->isLittleEndian(), 0);
+      StringRef Data;
+      Section.getContents(Data);
+      DataExtractor DE(Data, Obj->isLittleEndian(), 0);
       uint32_t Offset = 0;
       if (const char *DebugNameStr = DE.getCStr(&Offset)) {
         // 4-byte align the offset.

llvm/lib/ExecutionEngine/JITLink/MachOAtomGraphBuilder.cpp

@@ -136,14 +136,14 @@ Error MachOAtomGraphBuilder::parseSections() {
 
     if (!SecRef.isVirtual()) {
       // If this section has content then record it.
-      Expected<StringRef> Content = SecRef.getContents();
-      if (!Content)
-        return Content.takeError();
-      if (Content->size() != SecRef.getSize())
+      StringRef Content;
+      if (auto EC = SecRef.getContents(Content))
+        return errorCodeToError(EC);
+      if (Content.size() != SecRef.getSize())
         return make_error<JITLinkError>("Section content size does not match "
                                         "declared size for " +
                                         Name);
-      MachOSec.setContent(*Content);
+      MachOSec.setContent(Content);
     } else {
       // If this is a zero-fill section then just record the size.
       MachOSec.setZeroFill(SecRef.getSize());

llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

@@ -792,10 +792,8 @@ RuntimeDyldImpl::emitSection(const ObjectFile &Obj,
   if (!IsVirtual && !IsZeroInit) {
     // In either case, set the location of the unrelocated section in memory,
     // since we still process relocations for it even if we're not applying them.
-    if (Expected<StringRef> E = Section.getContents())
-      data = *E;
-    else
-      return E.takeError();
+    if (auto EC = Section.getContents(data))
+      return errorCodeToError(EC);
     pData = data.data();
   }
 

llvm/lib/Object/ELFObjectFile.cpp

@@ -377,13 +377,12 @@ ELFObjectFileBase::getPltAddresses() const {
   }
   if (!Plt || !RelaPlt || !GotPlt)
     return {};
-  Expected<StringRef> PltContents = Plt->getContents();
-  if (!PltContents) {
-    consumeError(PltContents.takeError());
+  StringRef PltContents;
+  if (Plt->getContents(PltContents))
     return {};
-  }
-  auto PltEntries = MIA->findPltEntries(Plt->getAddress(),
-                                        arrayRefFromStringRef(*PltContents),
+  ArrayRef<uint8_t> PltBytes((const uint8_t *)PltContents.data(),
+                             Plt->getSize());
+  auto PltEntries = MIA->findPltEntries(Plt->getAddress(), PltBytes,
                                         GotPlt->getAddress(), Triple);
   // Build a map from GOT entry virtual address to PLT entry virtual address.
   DenseMap<uint64_t, uint64_t> GotToPlt;

llvm/lib/Object/IRObjectFile.cpp

@@ -74,12 +74,12 @@ Expected<MemoryBufferRef>
 IRObjectFile::findBitcodeInObject(const ObjectFile &Obj) {
   for (const SectionRef &Sec : Obj.sections()) {
     if (Sec.isBitcode()) {
-      Expected<StringRef> Contents = Sec.getContents();
-      if (!Contents)
-        return Contents.takeError();
-      if (Contents->size() <= 1)
+      StringRef SecContents;
+      if (std::error_code EC = Sec.getContents(SecContents))
+        return errorCodeToError(EC);
+      if (SecContents.size() <= 1)
         return errorCodeToError(object_error::bitcode_section_not_found);
-      return MemoryBufferRef(*Contents, Obj.getFileName());
+      return MemoryBufferRef(SecContents, Obj.getFileName());
     }
   }
 

llvm/lib/Object/Object.cpp

@@ -247,10 +247,10 @@ uint64_t LLVMGetSectionSize(LLVMSectionIteratorRef SI) {
 }
 
 const char *LLVMGetSectionContents(LLVMSectionIteratorRef SI) {
-  if (Expected<StringRef> E = (*unwrap(SI))->getContents())
-    return E->data();
-  else
-    report_fatal_error(E.takeError());
+  StringRef ret;
+  if (std::error_code ec = (*unwrap(SI))->getContents(ret))
+    report_fatal_error(ec.message());
+  return ret.data();
 }
 
 uint64_t LLVMGetSectionAddress(LLVMSectionIteratorRef SI) {

llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp

@@ -348,10 +348,8 @@ Expected<bool> RawCoverageMappingDummyChecker::isDummy() {
 }
 
 Error InstrProfSymtab::create(SectionRef &Section) {
-  Expected<StringRef> DataOrErr = Section.getContents();
-  if (!DataOrErr)
-    return DataOrErr.takeError();
-  Data = *DataOrErr;
+  if (auto EC = Section.getContents(Data))
+    return errorCodeToError(EC);
   Address = Section.getAddress();
 
   // If this is a linked PE/COFF file, then we have to skip over the null byte
@@ -689,11 +687,8 @@ static Error loadBinaryFormat(MemoryBufferRef ObjectBuffer,
     return E;
 
   // Get the contents of the given sections.
-  if (Expected<StringRef> E = CoverageSection->getContents())
-    CoverageMapping = *E;
-  else
-    return E.takeError();
-
+  if (auto EC = CoverageSection->getContents(CoverageMapping))
+    return errorCodeToError(EC);
   if (Error E = ProfileNames.create(*NamesSection))
     return E;
 

llvm/lib/XRay/InstrumentationMap.cpp

@@ -78,10 +78,9 @@ loadObj(StringRef Filename, object::OwningBinary<object::ObjectFile> &ObjFile,
         "Failed to find XRay instrumentation map.",
         std::make_error_code(std::errc::executable_format_error));
 
-  if (Expected<StringRef> E = I->getContents())
-    Contents = *E;
-  else
-    return E.takeError();
+  if (I->getContents(Contents))
+    return errorCodeToError(
+        std::make_error_code(std::errc::executable_format_error));
 
   RelocMap Relocs;
   if (ObjFile.getBinary()->isELF()) {

llvm/tools/dsymutil/DwarfLinker.cpp

@@ -436,13 +436,9 @@ static bool isMachOPairedReloc(uint64_t RelocType, uint64_t Arch) {
 void DwarfLinker::RelocationManager::findValidRelocsMachO(
     const object::SectionRef &Section, const object::MachOObjectFile &Obj,
     const DebugMapObject &DMO) {
-  Expected<StringRef> ContentsOrErr = Section.getContents();
-  if (!ContentsOrErr) {
-    consumeError(ContentsOrErr.takeError());
-    Linker.reportWarning("error reading section", DMO);
-    return;
-  }
-  DataExtractor Data(*ContentsOrErr, Obj.isLittleEndian(), 0);
+  StringRef Contents;
+  Section.getContents(Contents);
+  DataExtractor Data(Contents, Obj.isLittleEndian(), 0);
   bool SkipNext = false;
 
   for (const object::RelocationRef &Reloc : Section.relocations()) {

llvm/tools/dsymutil/DwarfStreamer.cpp

@@ -667,12 +667,10 @@ void DwarfStreamer::translateLineTable(DataExtractor Data, uint32_t Offset,
 
 static void emitSectionContents(const object::ObjectFile &Obj,
                                 StringRef SecName, MCStreamer *MS) {
-  if (auto Sec = getSectionByName(Obj, SecName)) {
-    if (Expected<StringRef> E = Sec->getContents())
-      MS->EmitBytes(*E);
-    else
-      consumeError(E.takeError());
-  }
+  StringRef Contents;
+  if (auto Sec = getSectionByName(Obj, SecName))
+    if (!Sec->getContents(Contents))
+      MS->EmitBytes(Contents);
 }
 
 void DwarfStreamer::copyInvariantDebugSection(const object::ObjectFile &Obj) {

llvm/tools/llvm-cfi-verify/lib/FileAnalysis.cpp

@@ -453,11 +453,13 @@ Error FileAnalysis::parseCodeSections() {
     if (!Section.getName(SectionName) && SectionName == ".plt")
       continue;
 
-    Expected<StringRef> Contents = Section.getContents();
-    if (!Contents)
-      return Contents.takeError();
-    ArrayRef<uint8_t> SectionBytes = arrayRefFromStringRef(*Contents);
+    StringRef SectionContents;
+    if (Section.getContents(SectionContents))
+      return make_error<StringError>("Failed to retrieve section contents",
+                                     inconvertibleErrorCode());
 
+    ArrayRef<uint8_t> SectionBytes((const uint8_t *)SectionContents.data(),
+                                   Section.getSize());
     parseSectionContents(SectionBytes,
                          {Section.getAddress(), Section.getIndex()});
   }

llvm/tools/llvm-cov/TestingSupport.cpp

@@ -69,18 +69,9 @@ int convertForTestingMain(int argc, const char *argv[]) {
   uint64_t ProfileNamesAddress = ProfileNames.getAddress();
   StringRef CoverageMappingData;
   StringRef ProfileNamesData;
-  if (Expected<StringRef> E = CoverageMapping.getContents())
-    CoverageMappingData = *E;
-  else {
-    consumeError(E.takeError());
+  if (CoverageMapping.getContents(CoverageMappingData) ||
+      ProfileNames.getContents(ProfileNamesData))
     return 1;
-  }
-  if (Expected<StringRef> E = ProfileNames.getContents())
-    ProfileNamesData = *E;
-  else {
-    consumeError(E.takeError());
-    return 1;
-  }
 
   int FD;
   if (auto Err = sys::fs::openFileForWrite(OutputFilename, FD)) {

llvm/tools/llvm-cxxdump/llvm-cxxdump.cpp

@@ -48,20 +48,15 @@ static void error(std::error_code EC) {
   exit(1);
 }
 
-LLVM_ATTRIBUTE_NORETURN static void error(Error Err) {
+static void error(Error Err) {
+  if (!Err)
+    return;
   logAllUnhandledErrors(std::move(Err), WithColor::error(outs()),
                         "reading file: ");
   outs().flush();
   exit(1);
 }
 
-template <typename T>
-T unwrapOrError(Expected<T> EO) {
-  if (!EO)
-    error(EO.takeError());
-  return std::move(*EO);
-}
-
 } // namespace llvm
 
 static void reportError(StringRef Input, StringRef Message) {
@@ -200,7 +195,8 @@ static void dumpCXXData(const ObjectFile *Obj) {
     // Skip virtual or BSS sections.
     if (Sec.isBSS() || Sec.isVirtual())
       continue;
-    StringRef SecContents = unwrapOrError(Sec.getContents());
+    StringRef SecContents;
+    error(Sec.getContents(SecContents));
     Expected<uint64_t> SymAddressOrErr = Sym.getAddress();
     error(errorToErrorCode(SymAddressOrErr.takeError()));
     uint64_t SymAddress = *SymAddressOrErr;
@@ -514,8 +510,7 @@ static void dumpArchive(const Archive *Arc) {
     else
       reportError(Arc->getFileName(), cxxdump_error::unrecognized_file_format);
   }
-  if (Err)
-    error(std::move(Err));
+  error(std::move(Err));
 }
 
 static void dumpInput(StringRef File) {

llvm/tools/llvm-dwp/llvm-dwp.cpp

@@ -410,10 +410,9 @@ static Error handleSection(
   if (std::error_code Err = Section.getName(Name))
     return errorCodeToError(Err);
 
-  Expected<StringRef> ContentsOrErr = Section.getContents();
-  if (!ContentsOrErr)
-    return ContentsOrErr.takeError();
-  StringRef Contents = *ContentsOrErr;
+  StringRef Contents;
+  if (auto Err = Section.getContents(Contents))
+    return errorCodeToError(Err);
 
   if (auto Err = handleCompressedSection(UncompressedSections, Name, Contents))
     return Err;