swiftlang · jansvoboda11 · Nov 12, 2025 · Nov 12, 2025 · Nov 12, 2025 · Nov 13, 2025
diff --git a/clang-tools-extra/clangd/ScanningProjectModules.cpp b/clang-tools-extra/clangd/ScanningProjectModules.cpp
@@ -38,7 +38,7 @@ class ModuleDependencyScanner {
       : CDB(CDB), TFS(TFS),
         Service(tooling::dependencies::ScanningMode::CanonicalPreprocessing,
                 tooling::dependencies::ScanningOutputFormat::P1689,
-                CASOptions(), nullptr, nullptr, nullptr) {}
+                CASOptions(), nullptr, nullptr) {}
 
   /// The scanned modules dependency information for a specific source file.
   struct ModuleDependencyInfo {

diff --git a/clang/include/clang/Basic/DiagnosticCASKinds.td b/clang/include/clang/Basic/DiagnosticCASKinds.td
@@ -11,8 +11,9 @@ let Component = "CAS" in {
 def err_cas_cannot_be_initialized : Error<
   "CAS cannot be initialized from the specified '-fcas-*' options: %0">,
   DefaultFatal;
-def err_cas_cannot_parse_root_id : Error<
-  "CAS cannot parse root-id '%0' specified by -fcas-fs">, DefaultFatal;
+def err_cas_cannot_parse_root_id
+    : Error<"CAS cannot parse root-id '%0' specified by '-fcas-*' options">,
+      DefaultFatal;
 def err_cas_filesystem_cannot_be_initialized : Error<
   "CAS filesystem cannot be initialized from root-id '%0': %1">, DefaultFatal;
 def err_cas_filesystem_cannot_set_working_directory : Error<

diff --git a/clang/include/clang/Basic/FileSystemOptions.h b/clang/include/clang/Basic/FileSystemOptions.h
@@ -24,14 +24,6 @@ class FileSystemOptions {
   /// If set, paths are resolved as if the working directory was
   /// set to the value of WorkingDir.
   std::string WorkingDir;
-
-  /// If set, uses this root ID with \a CASFileSystem.
-  std::string CASFileSystemRootID;
-
-  /// If set, used as the working directory for -fcas-fs.
-  ///
-  /// FIXME: Merge with WorkingDir?
-  std::string CASFileSystemWorkingDirectory;
 };
 
 } // end namespace clang

diff --git a/clang/include/clang/Frontend/CompileJobCacheKey.h b/clang/include/clang/Frontend/CompileJobCacheKey.h
@@ -33,7 +33,6 @@ class DiagnosticsEngine;
 
 enum class CachingInputKind {
   IncludeTree,
-  FileSystemRoot,
   CachedCompilation,
   Object,
 };

diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
@@ -2513,23 +2513,12 @@ class Preprocessor {
   /// See \c FrontendOptions::CASIncludeTreeID.
   std::optional<std::string> CASIncludeTreeID;
 
-  /// The cas-fs tree that is being built, if any.
-  /// See \c FileSystemOptions::CASFileSystemRootID.
-  std::optional<std::string> CASFileSystemRootID;
-
 public:
   std::optional<std::string> getCASIncludeTreeID() const {
     return CASIncludeTreeID;
   }
   void setCASIncludeTreeID(std::string ID) { CASIncludeTreeID = std::move(ID); }
 
-  std::optional<std::string> getCASFileSystemRootID() const {
-    return CASFileSystemRootID;
-  }
-  void setCASFileSystemRootID(std::string ID) {
-    CASFileSystemRootID = std::move(ID);
-  }
-
   /// Allocate a new MacroInfo object with the provided SourceLocation.
   MacroInfo *AllocateMacroInfo(SourceLocation L);
 

diff --git a/clang/include/clang/Options/Options.td b/clang/include/clang/Options/Options.td
@@ -9065,40 +9065,6 @@ def fsycl_is_host : Flag<["-"], "fsycl-is-host">,
 // CAS Options
 //===----------------------------------------------------------------------===//
 
-// Example command-lines we expect:
-//
-// For building against some pre-ingested, CAS-based filesystem in the builtin
-// on-disk CAS:
-// ```
-// % clang -fcas-path=auto -fcas-fs=llvmcas://1af12fa2afa1af2a1fa
-// % clang -fcas-path=path/to/cas -fcas-fs=llvmcas://1af12fa2afa1af2a1fa
-// ```
-//
-// For building against some pre-ingested, CAS-based filesystem using a plugin:
-// ```
-// % clang -fcas-plugin=path/to/some/cas-plugind \
-//         -fcas-plugin-args=-X,-Y,-Z            \
-//         -fcas-fs=llvmcas://1af12fa2afa1af2a1fa
-// ```
-//
-// For automatically ingesting from the live filesystem into a CAS,
-// canonicalizing the paths, and running the `-cc1` against the CAS tree:
-// ```
-// % clang -fdepscan                              \
-//         -fdepscan-prefix-map=/my/sources=/^src \
-//         -fdepscan-prefix-map=/my/build/dir=/^build
-// ```
-//
-// For pruning and canonicalizing even when starting from a pre-ingested,
-// CAS-based filesystem:
-// ```
-// % clang -fcas-path=path/to/the/cas             \
-//         -fcas-fs=llvmcas://1af12fa2afa1af2a1fa \
-//         -fdepscan                              \
-//         -fdepscan-prefix-map=/my/sources=/^src \
-//         -fdepscan-prefix-map=/my/build/dir=/^build
-// ```
-
 // Driver CAS options.
 def fdepscan_EQ : Joined<["-"], "fdepscan=">,
     Group<f_Group>,
@@ -9155,10 +9121,6 @@ def fdepscan_daemon_EQ : Joined<["-"], "fdepscan-daemon=">, Group<f_Group>,
              " daemon specified, rather than try to spawn its own based on"
              " parent processes.">;
 
-def fdepscan_include_tree : Flag<["-"], "fdepscan-include-tree">,
-    Visibility<[ClangOption, CLOption]>,
-    Group<f_Group>, HelpText<"Set dep-scanner to produce the include tree">;
-
 // CAS prefix map options.
 //
 // FIXME: Add DepscanOption flag.
@@ -9219,20 +9181,6 @@ def fcas_plugin_option : Separate<["-"], "fcas-plugin-option">,
     HelpText<"Option to pass to the CAS plugin.">,
     MarshallingInfoStringPairVector<CASOpts<"PluginOptions">>;
 
-// FIXME: Add to driver once it's supported by -fdepscan.
-def fcas_fs : Separate<["-"], "fcas-fs">,
-    Group<f_Group>, MetaVarName<"<tree>">,
-    HelpText<"Configure the filesystem to read from the provided CAS tree."
-             " See also -fcas-builtin-path for loading a tree.">,
-    MarshallingInfoString<FileSystemOpts<"CASFileSystemRootID">>;
-
-// FIXME: Remove / merge with -fworking-directory?
-def fcas_fs_working_directory : Separate<["-"], "fcas-fs-working-directory">,
-    Group<f_Group>, MetaVarName<"<dir>">,
-    HelpText<"Working directory for -fcas-fs (if not the root).">,
-    ShouldParseIf<!strconcat("!", fcas_fs.KeyPath, ".empty()")>,
-    MarshallingInfoString<FileSystemOpts<"CASFileSystemWorkingDirectory">>;
-
 def fcas_include_tree : Separate<["-"], "fcas-include-tree">,
     Group<f_Group>, MetaVarName<"<tree>">,
     HelpText<"Configure the frontend to use a CAS include tree.">,

diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -379,10 +379,6 @@ enum ControlRecordTypes {
   /// Record code for the (optional) \c ActionCache  key for this module.
   MODULE_CACHE_KEY,
 
-  /// Record code for the (optional) CAS filesystem root ID for implicit modules
-  /// built with the dependency scanner.
-  CASFS_ROOT_ID,
-
   /// Record code for the (optional) include-tree ID for implicit modules
   /// built with the dependency scanner.
   CAS_INCLUDE_TREE_ID,

diff --git a/clang/include/clang/Serialization/ModuleFile.h b/clang/include/clang/Serialization/ModuleFile.h
@@ -150,10 +150,6 @@ class ModuleFile {
   /// The \c CASID for the module, or empty.
   std::string CASID;
 
-  /// The CAS filesystem root ID for implicit modules built with the dependency
-  /// scanner, or empty.
-  std::string CASFileSystemRootID;
-
   /// The include-tree root ID for implicit modules built with the dependency
   /// scanner, or empty.
   std::string IncludeTreeID;

diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningCASFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningCASFilesystem.h
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningService.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningService.h
@@ -10,12 +10,10 @@
 #define LLVM_CLANG_TOOLING_DEPENDENCYSCANNING_DEPENDENCYSCANNINGSERVICE_H
 
 #include "clang/CAS/CASOptions.h"
-#include "clang/Tooling/DependencyScanning/DependencyScanningCASFilesystem.h"
 #include "clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h"
 #include "clang/Tooling/DependencyScanning/InProcessModuleCache.h"
 #include "llvm/ADT/BitmaskEnum.h"
 #include "llvm/CAS/ActionCache.h"
-#include "llvm/CAS/CachingOnDiskFileSystem.h"
 #include "llvm/Support/Chrono.h"
 
 namespace clang {
@@ -46,13 +44,6 @@ enum class ScanningOutputFormat {
   /// explicitly building modules.
   Full,
 
-  /// This emits the CAS ID of the scanned files.
-  Tree,
-
-  /// This emits the full dependency graph but with CAS tree embedded as file
-  /// dependency.
-  FullTree,
-
   /// This emits the CAS ID of the include tree.
   IncludeTree,
 
@@ -111,7 +102,6 @@ class DependencyScanningService {
       ScanningMode Mode, ScanningOutputFormat Format, CASOptions CASOpts,
       std::shared_ptr<llvm::cas::ObjectStore> CAS,
       std::shared_ptr<llvm::cas::ActionCache> Cache,
-      IntrusiveRefCntPtr<llvm::cas::CachingOnDiskFileSystem> SharedFS,
       ScanningOptimizations OptimizeArgs = ScanningOptimizations::Default,
       bool EagerLoadModules = false, bool TraceVFS = false,
       std::time_t BuildSessionTimestamp =
@@ -131,20 +121,14 @@ class DependencyScanningService {
   bool shouldCacheNegativeStats() const { return CacheNegativeStats; }
 
   DependencyScanningFilesystemSharedCache &getSharedCache() {
-    assert(!SharedFS && "Expected not to have a CASFS");
-    assert(SharedCache && "Expected a shared cache");
-    return *SharedCache;
+    return SharedCache;
   }
 
   const CASOptions &getCASOpts() const { return CASOpts; }
 
   std::shared_ptr<llvm::cas::ObjectStore> getCAS() const { return CAS; }
   std::shared_ptr<llvm::cas::ActionCache> getCache() const { return Cache; }
 
-  llvm::cas::CachingOnDiskFileSystem &getSharedFS() { return *SharedFS; }
-
-  bool useCASFS() const { return (bool)SharedFS; }
-
   ModuleCacheEntries &getModuleCacheEntries() { return ModCacheEntries; }
 
   std::time_t getBuildSessionTimestamp() const { return BuildSessionTimestamp; }
@@ -162,11 +146,8 @@ class DependencyScanningService {
   /// Whether to trace VFS accesses.
   const bool TraceVFS;
   const bool CacheNegativeStats;
-  /// Shared CachingOnDiskFileSystem. Set to nullptr to not use CAS dependency
-  /// scanning.
-  IntrusiveRefCntPtr<llvm::cas::CachingOnDiskFileSystem> SharedFS;
   /// The global file system cache.
-  std::optional<DependencyScanningFilesystemSharedCache> SharedCache;
+  DependencyScanningFilesystemSharedCache SharedCache;
   /// The global module cache entries.
   ModuleCacheEntries ModCacheEntries;
   /// The build session timestamp.