[clang] [InstallAPI] Collect frontend attributes & ObjCInterface decls (PR #83378)

[Cyndy Ishida via cfe-commits]

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@@ -16,6 +16,74 @@ using namespace llvm::MachO;
 
 namespace clang::installapi {
 
+GlobalRecord *FrontendRecordsSlice::addGlobal(
+    StringRef Name, RecordLinkage Linkage, GlobalRecord::Kind GV,
+    const clang::AvailabilityInfo Avail, const Decl *D, const HeaderType Access,
+    SymbolFlags Flags) {
+
+  auto *GR = llvm::MachO::RecordsSlice::addGlobal(Name, Linkage, GV, Flags);
+  if (!FrontendRecords.contains(GR))
+    FrontendRecords.insert({GR, FrontendAttrs{Avail, D, Access}});
+  return GR;
+}
+
+ObjCInterfaceRecord *FrontendRecordsSlice::addObjCInterface(
+    StringRef Name, RecordLinkage Linkage, const clang::AvailabilityInfo Avail,
+    const Decl *D, HeaderType Access, bool IsEHType) {
+  ObjCIFSymbolKind SymType =
+      ObjCIFSymbolKind::Class | ObjCIFSymbolKind::MetaClass;
+  if (IsEHType)
+    SymType |= ObjCIFSymbolKind::EHType;
+  auto *ObjCR =
+      llvm::MachO::RecordsSlice::addObjCInterface(Name, Linkage, SymType);
+  if (!FrontendRecords.contains(ObjCR))
+    FrontendRecords.insert({ObjCR, FrontendAttrs{Avail, D, Access}});
+  return ObjCR;
+}
+
+std::optional<HeaderType>
+InstallAPIContext::findAndRecordFile(const FileEntry *FE,
+                                     const Preprocessor &PP) {
+  if (!FE)
+    return std::nullopt;
+
+  // Check if header has been looked up already and whether it is something
+  // installapi should use.
+  auto It = KnownFiles.find(FE);
----------------
cyndyishida wrote:

Which sets do you suggest? `KnownFiles` + `UnusedFiles`, wouldn't the lookup be roughly equivalent since there are no duplicates between those disjoint sets? 

https://github.com/llvm/llvm-project/pull/83378