Use the input files block instead

Author: jansvoboda11

clang/include/clang/Serialization/ASTBitCodes.h

@@ -54,7 +54,7 @@ const unsigned VERSION_MAJOR = 34;
 /// for the previous version could still support reading the new
 /// version by ignoring new kinds of subblocks), this number
 /// should be increased.
-const unsigned VERSION_MINOR = 1;
+const unsigned VERSION_MINOR = 0;
 
 /// An ID number that refers to an identifier in an AST file.
 ///
@@ -386,10 +386,6 @@ enum ControlRecordTypes {
   /// Record code for the (optional) include-tree ID for implicit modules
   /// built with the dependency scanner.
   CAS_INCLUDE_TREE_ID,
-
-  /// Record code for the (optional) modification timestamp of the
-  /// SDKSettings.json file.
-  SDK_SETTINGS_JSON_TIMESTAMP,
 };
 
 /// Record types that occur within the options block inside

clang/lib/Serialization/ASTReader.cpp

@@ -3134,6 +3134,8 @@ ASTReader::ReadControlBlock(ModuleFile &F,
         for (unsigned I = 0; I < N; ++I) {
           bool IsSystem = I >= NumUserInputs;
           InputFileInfo FI = getInputFileInfo(F, I + 1);
+          if (FI.UnresolvedImportedFilename.ends_with("SDKSettings.json"))
+            continue;
           auto FilenameAsRequested = ResolveImportedPath(
               PathBuf, FI.UnresolvedImportedFilenameAsRequested, F);
           Listener->visitInputFile(
@@ -3507,29 +3509,6 @@ ASTReader::ReadControlBlock(ModuleFile &F,
           return OutOfDate;
       }
       break;
-
-    case SDK_SETTINGS_JSON_TIMESTAMP: {
-      time_t ExpectedModTime = Record[0];
-      time_t ActualModTime = 0;
-      StringRef Sysroot =
-          PP.getHeaderSearchInfo().getHeaderSearchOpts().Sysroot;
-      if (!Sysroot.empty()) {
-        SmallString<128> SDKSettingsJSON = Sysroot;
-        llvm::sys::path::append(SDKSettingsJSON, "SDKSettings.json");
-        if (auto FE = PP.getFileManager().getOptionalFileRef(SDKSettingsJSON))
-          ActualModTime = FE->getModificationTime();
-      }
-      if (ActualModTime && ExpectedModTime &&
-          ActualModTime != ExpectedModTime) {
-        if (!canRecoverFromOutOfDate(F.FileName, ClientLoadCapabilities))
-          Diag(diag::err_fe_ast_file_modified)
-              << "SDKSettings.json" << moduleKindForDiagnostic(F.Kind)
-              << F.FileName << 1 << 1 << llvm::itostr(ExpectedModTime)
-              << llvm::itostr(ActualModTime);
-        return OutOfDate;
-      }
-      break;
-    }
     }
   }
 }
@@ -10369,6 +10348,8 @@ void ASTReader::visitInputFileInfos(
   for (unsigned I = 0; I < N; ++I) {
     bool IsSystem = I >= NumUserInputs;
     InputFileInfo IFI = getInputFileInfo(MF, I+1);
+    if (IFI.UnresolvedImportedFilename.ends_with("SDKSettings.json"))
+      continue;
     Visitor(IFI, IsSystem);
   }
 }
@@ -10384,6 +10365,8 @@ void ASTReader::visitInputFiles(serialization::ModuleFile &MF,
   for (unsigned I = 0; I < N; ++I) {
     bool IsSystem = I >= NumUserInputs;
     InputFile IF = getInputFile(MF, I+1, Complain);
+    if (IF.getFile() && IF.getFile()->getName().ends_with("SDKSettings.json"))
+      continue;
     Visitor(IF, IsSystem);
   }
 }

clang/lib/Serialization/ASTWriter.cpp

@@ -917,7 +917,6 @@ void ASTWriter::WriteBlockInfoBlock() {
   RECORD(MODULE_CACHE_KEY);
   RECORD(CASFS_ROOT_ID);
   RECORD(CAS_INCLUDE_TREE_ID);
-  RECORD(SDK_SETTINGS_JSON_TIMESTAMP);
 
   BLOCK(OPTIONS_BLOCK);
   RECORD(LANGUAGE_OPTIONS);
@@ -1616,20 +1615,6 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, StringRef isysroot) {
     Stream.EmitRecordWithBlob(AbbrevCode, Record, *ID);
   }
 
-  time_t SDKSettingsModTime = 0;
-  StringRef Sysroot = PP.getHeaderSearchInfo().getHeaderSearchOpts().Sysroot;
-  if (!Sysroot.empty()) {
-    SmallString<128> SDKSettingsJSON = Sysroot;
-    llvm::sys::path::append(SDKSettingsJSON, "SDKSettings.json");
-    if (auto FE = PP.getFileManager().getOptionalFileRef(SDKSettingsJSON))
-      SDKSettingsModTime = FE->getModificationTime();
-  }
-  if (SDKSettingsModTime) {
-    Record.clear();
-    Record.push_back(SDKSettingsModTime);
-    Stream.EmitRecord(SDK_SETTINGS_JSON_TIMESTAMP, Record);
-  }
-
   // Imports
   if (Chain) {
     auto Abbrev = std::make_shared<BitCodeAbbrev>();
@@ -5965,6 +5950,18 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema *SemaPtr, StringRef isysroot,
   if (Chain)
     Chain->finalizeForWriting();
 
+  // FIXME: This is here because the include-tree file list refers to this file
+  // and we need to validate it's up-to-date when reading the AST file. Make
+  // this more generic and include the remaining files.
+  StringRef Sysroot = PP->getHeaderSearchInfo().getHeaderSearchOpts().Sysroot;
+  if (!Sysroot.empty()) {
+    SmallString<128> SDKSettingsJSON = Sysroot;
+    llvm::sys::path::append(SDKSettingsJSON, "SDKSettings.json");
+    if (auto FE = PP->getFileManager().getOptionalFileRef(SDKSettingsJSON))
+      PP->getSourceManager().createFileID(*FE, SourceLocation(),
+                                          SrcMgr::C_System);
+  }
+
   // This needs to be done very early, since everything that writes
   // SourceLocations or FileIDs depends on it.
   computeNonAffectingInputFiles();