Support: Use Expected<T>::moveInto() in a few places

These are some usage examples for `Expected<T>::moveInto()`.

Differential Revision: https://reviews.llvm.org/D112280

Author: dexonsmith

clang/lib/CodeGen/BackendUtil.cpp

@@ -1657,16 +1657,17 @@ void clang::EmitBackendOutput(DiagnosticsEngine &Diags,
     // If we are performing a ThinLTO importing compile, load the function index
     // into memory and pass it into runThinLTOBackend, which will run the
     // function importer and invoke LTO passes.
-    Expected<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
-        llvm::getModuleSummaryIndexForFile(CGOpts.ThinLTOIndexFile,
-                                           /*IgnoreEmptyThinLTOIndexFile*/true);
-    if (!IndexOrErr) {
-      logAllUnhandledErrors(IndexOrErr.takeError(), errs(),
+    std::unique_ptr<ModuleSummaryIndex> CombinedIndex;
+    if (Error E = llvm::getModuleSummaryIndexForFile(
+                      CGOpts.ThinLTOIndexFile,
+                      /*IgnoreEmptyThinLTOIndexFile*/ true)
+                      .moveInto(CombinedIndex)) {
+      logAllUnhandledErrors(std::move(E), errs(),
                             "Error loading index file '" +
                             CGOpts.ThinLTOIndexFile + "': ");
       return;
     }
-    std::unique_ptr<ModuleSummaryIndex> CombinedIndex = std::move(*IndexOrErr);
+
     // A null CombinedIndex means we should skip ThinLTO compilation
     // (LLVM will optionally ignore empty index files, returning null instead
     // of an error).

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -179,10 +179,8 @@ static Expected<std::string> readIdentificationBlock(BitstreamCursor &Stream) {
 
   while (true) {
     BitstreamEntry Entry;
-    if (Expected<BitstreamEntry> Res = Stream.advance())
-      Entry = Res.get();
-    else
-      return Res.takeError();
+    if (Error E = Stream.advance().moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     default:
@@ -226,10 +224,8 @@ static Expected<std::string> readIdentificationCode(BitstreamCursor &Stream) {
       return "";
 
     BitstreamEntry Entry;
-    if (Expected<BitstreamEntry> Res = Stream.advance())
-      Entry = std::move(Res.get());
-    else
-      return Res.takeError();
+    if (Error E = Stream.advance().moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::EndBlock:
@@ -305,10 +301,8 @@ static Expected<bool> hasObjCCategory(BitstreamCursor &Stream) {
   // need to understand them all.
   while (true) {
     BitstreamEntry Entry;
-    if (Expected<BitstreamEntry> Res = Stream.advance())
-      Entry = std::move(Res.get());
-    else
-      return Res.takeError();
+    if (Error E = Stream.advance().moveInto(Entry))
+      return std::move(E);
 
     switch (Entry.Kind) {
     case BitstreamEntry::Error:

llvm/lib/DebugInfo/Symbolize/Symbolize.cpp

@@ -280,10 +280,7 @@ bool getGNUDebuglinkContents(const ObjectFile *Obj, std::string &DebugName,
     return false;
   for (const SectionRef &Section : Obj->sections()) {
     StringRef Name;
-    if (Expected<StringRef> NameOrErr = Section.getName())
-      Name = *NameOrErr;
-    else
-      consumeError(NameOrErr.takeError());
+    consumeError(Section.getName().moveInto(Name));
 
     Name = Name.substr(Name.find_first_not_of("._"));
     if (Name == "gnu_debuglink") {

llvm/lib/Object/ObjectFile.cpp

@@ -55,14 +55,15 @@ bool SectionRef::containsSymbol(SymbolRef S) const {
 }
 
 Expected<uint64_t> ObjectFile::getSymbolValue(DataRefImpl Ref) const {
-  if (Expected<uint32_t> FlagsOrErr = getSymbolFlags(Ref)) {
-    if (*FlagsOrErr & SymbolRef::SF_Undefined)
-      return 0;
-    if (*FlagsOrErr & SymbolRef::SF_Common)
-      return getCommonSymbolSize(Ref);
-  } else
+  uint32_t Flags;
+  if (Error E = getSymbolFlags(Ref).moveInto(Flags))
     // TODO: Test this error.
-    return FlagsOrErr.takeError();
+    return std::move(E);
+
+  if (Flags & SymbolRef::SF_Undefined)
+    return 0;
+  if (Flags & SymbolRef::SF_Common)
+    return getCommonSymbolSize(Ref);
   return getSymbolValueImpl(Ref);
 }
 

llvm/lib/XRay/InstrumentationMap.cpp

@@ -86,10 +86,8 @@ 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 (Error E = I->getContents().moveInto(Contents))
+    return E;
 
   RelocMap Relocs;
   if (ObjFile.getBinary()->isELF()) {