Revert "[clang] Convert OptionalFileEntryRefDegradesToFileEntryPtr to std::optional"

This reverts commit 8f0df9f3bbc6d7f3d5cbfd955c5ee4404c53a75d.

The Optional*RefDegradesTo*EntryPtr types want to keep the same size as
the underlying type, which std::optional doesn't guarantee. For use with
llvm::Optional, they define their own storage class, and there is no way
to do that in std::optional.

On top of that, that commit broke builds with older GCCs, where
std::optional was not trivially copyable (static_assert in the clang
sources was failing).

1 files changed, 12 insertions, 13 deletions

diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index ffb2780..1ce6df4 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -25,11 +25,11 @@
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/APInt.h"
 #include "llvm/ADT/Hashing.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Capacity.h"
 #include "llvm/Support/Errc.h"
@@ -42,7 +42,6 @@
 #include <cstddef>
 #include <cstdio>
 #include <cstring>
-#include <optional>
 #include <string>
 #include <system_error>
 #include <utility>
@@ -172,7 +171,7 @@ void HeaderSearch::getHeaderMapFileNames(
 }
 
 std::string HeaderSearch::getCachedModuleFileName(Module *Module) {
-  std::optional<FileEntryRef> ModuleMap =
+  Optional<FileEntryRef> ModuleMap =
       getModuleMap().getModuleMapFileForUniquing(Module);
   // The ModuleMap maybe a nullptr, when we load a cached C++ module without
   // *.modulemap file. In this case, just return an empty string.
@@ -213,7 +212,7 @@ std::string HeaderSearch::getPrebuiltModuleFileName(StringRef ModuleName,
 }
 
 std::string HeaderSearch::getPrebuiltImplicitModuleFileName(Module *Module) {
-  std::optional<FileEntryRef> ModuleMap =
+  Optional<FileEntryRef> ModuleMap =
       getModuleMap().getModuleMapFileForUniquing(Module);
   StringRef ModuleName = Module->Name;
   StringRef ModuleMapPath = ModuleMap->getName();
@@ -416,7 +415,7 @@ StringRef DirectoryLookup::getName() const {
   return getHeaderMap()->getFileName();
 }
 
-std::optional<FileEntryRef> HeaderSearch::getFileAndSuggestModule(
+Optional<FileEntryRef> HeaderSearch::getFileAndSuggestModule(
     StringRef FileName, SourceLocation IncludeLoc, const DirectoryEntry *Dir,
     bool IsSystemHeaderDir, Module *RequestingModule,
     ModuleMap::KnownHeader *SuggestedModule, bool OpenFile /*=true*/,
@@ -448,7 +447,7 @@ std::optional<FileEntryRef> HeaderSearch::getFileAndSuggestModule(
 
 /// LookupFile - Lookup the specified file in this search path, returning it
 /// if it exists or returning null if not.
-std::optional<FileEntryRef> DirectoryLookup::LookupFile(
+Optional<FileEntryRef> DirectoryLookup::LookupFile(
     StringRef &Filename, HeaderSearch &HS, SourceLocation IncludeLoc,
     SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
     Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule,
@@ -587,7 +586,7 @@ static bool needModuleLookup(Module *RequestingModule,
 
 /// DoFrameworkLookup - Do a lookup of the specified file in the current
 /// DirectoryLookup, which is a framework directory.
-std::optional<FileEntryRef> DirectoryLookup::DoFrameworkLookup(
+Optional<FileEntryRef> DirectoryLookup::DoFrameworkLookup(
     StringRef Filename, HeaderSearch &HS, SmallVectorImpl<char> *SearchPath,
     SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
     ModuleMap::KnownHeader *SuggestedModule,
@@ -856,7 +855,7 @@ diagnoseFrameworkInclude(DiagnosticsEngine &Diags, SourceLocation IncludeLoc,
 /// for system \#include's or not (i.e. using <> instead of ""). Includers, if
 /// non-empty, indicates where the \#including file(s) are, in case a relative
 /// search is needed. Microsoft mode will pass all \#including files.
-std::optional<FileEntryRef> HeaderSearch::LookupFile(
+Optional<FileEntryRef> HeaderSearch::LookupFile(
     StringRef Filename, SourceLocation IncludeLoc, bool isAngled,
     ConstSearchDirIterator FromDir, ConstSearchDirIterator *CurDirArg,
     ArrayRef<std::pair<const FileEntry *, const DirectoryEntry *>> Includers,
@@ -899,7 +898,7 @@ std::optional<FileEntryRef> HeaderSearch::LookupFile(
 
   // This is the header that MSVC's header search would have found.
   ModuleMap::KnownHeader MSSuggestedModule;
-  std::optional<FileEntryRef> MSFE;
+  Optional<FileEntryRef> MSFE;
 
   // Unless disabled, check to see if the file is in the #includer's
   // directory.  This cannot be based on CurDir, because each includer could be
@@ -928,7 +927,7 @@ std::optional<FileEntryRef> HeaderSearch::LookupFile(
       bool IncluderIsSystemHeader =
           Includer ? getFileInfo(Includer).DirInfo != SrcMgr::C_User :
           BuildSystemModule;
-      if (std::optional<FileEntryRef> FE = getFileAndSuggestModule(
+      if (Optional<FileEntryRef> FE = getFileAndSuggestModule(
               TmpDir, IncludeLoc, IncluderAndDir.second, IncluderIsSystemHeader,
               RequestingModule, SuggestedModule)) {
         if (!Includer) {
@@ -1044,7 +1043,7 @@ std::optional<FileEntryRef> HeaderSearch::LookupFile(
     bool InUserSpecifiedSystemFramework = false;
     bool IsInHeaderMap = false;
     bool IsFrameworkFoundInDir = false;
-    std::optional<FileEntryRef> File = It->LookupFile(
+    Optional<FileEntryRef> File = It->LookupFile(
         Filename, *this, IncludeLoc, SearchPath, RelativePath, RequestingModule,
         SuggestedModule, InUserSpecifiedSystemFramework, IsFrameworkFoundInDir,
         IsInHeaderMap, MappedName, OpenFile);
@@ -1139,7 +1138,7 @@ std::optional<FileEntryRef> HeaderSearch::LookupFile(
       ScratchFilename += '/';
       ScratchFilename += Filename;
 
-      std::optional<FileEntryRef> File = LookupFile(
+      Optional<FileEntryRef> File = LookupFile(
           ScratchFilename, IncludeLoc, /*isAngled=*/true, FromDir, &CurDir,
           Includers.front(), SearchPath, RelativePath, RequestingModule,
           SuggestedModule, IsMapped, /*IsFrameworkFound=*/nullptr);
@@ -1176,7 +1175,7 @@ std::optional<FileEntryRef> HeaderSearch::LookupFile(
 /// within ".../Carbon.framework/Headers/Carbon.h", check to see if HIToolbox
 /// is a subframework within Carbon.framework.  If so, return the FileEntry
 /// for the designated file, otherwise return null.
-std::optional<FileEntryRef> HeaderSearch::LookupSubframeworkHeader(
+Optional<FileEntryRef> HeaderSearch::LookupSubframeworkHeader(
     StringRef Filename, const FileEntry *ContextFileEnt,
     SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
     Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule) {