[Dependency Scanning] Modernize and revive the module dependencies cache serialization format

This format has gotten stale and been not in use for many months. This commit restores primary functionality of the format.

Author: artemcm

include/swift-c/DependencyScan/DependencyScan.h

@@ -475,17 +475,6 @@ swiftscan_source_location_get_line_number(swiftscan_source_location_t source_loc
 SWIFTSCAN_PUBLIC int64_t
 swiftscan_source_location_get_column_number(swiftscan_source_location_t source_location);
 
-//=== Scanner Cache Operations --------------------------------------------===//
-// The following operations expose an implementation detail of the dependency
-// scanner: its module dependencies cache. This is done in order
-// to allow clients to perform incremental dependency scans by having the
-// scanner's state be serializable and re-usable.
-
-/// For the specified \c scanner instance, reset its internal state, ensuring subsequent
-/// scanning queries are done "from-scratch".
-SWIFTSCAN_PUBLIC void
-swiftscan_scanner_cache_reset(swiftscan_scanner_t scanner);
-
 /// An entry point to invoke the compiler via a library call.
 SWIFTSCAN_PUBLIC int invoke_swift_compiler(int argc, const char **argv);
 

include/swift/AST/ModuleDependencies.h

@@ -769,6 +769,15 @@ class ModuleDependencyInfo {
   setLinkLibraries(const ArrayRef<LinkLibrary> linkLibraries) {
     storage->linkLibraries.assign(linkLibraries.begin(), linkLibraries.end());
   }
+  
+  const ArrayRef<std::string> getAuxiliaryFiles() const {
+    return storage->auxiliaryFiles;
+  }
+  
+  void
+  setAuxiliaryFiles(const ArrayRef<std::string> auxiliaryFiles) {
+    storage->auxiliaryFiles.assign(auxiliaryFiles.begin(), auxiliaryFiles.end());
+  }
 
   bool isStaticLibrary() const {
     if (auto *detail = getAsSwiftInterfaceModule())

include/swift/DependencyScan/DependencyScanningTool.h

@@ -108,8 +108,6 @@ class DependencyScanningTool {
                   const llvm::StringSet<> &PlaceholderModules,
                   StringRef WorkingDirectory);
 
-  /// Discard the tool's current `SharedCache` and start anew.
-  void resetCache();
   /// Query diagnostics consumed so far.
   std::vector<DependencyScanDiagnosticCollector::ScannerDiagnosticInfo> getDiagnostics();
   /// Discared the collection of diagnostics encountered so far.

include/swift/DependencyScan/SerializedModuleDependencyCacheFormat.h

@@ -57,6 +57,12 @@ using IsFrameworkField = BCFixed<1>;
 using IsSystemField = BCFixed<1>;
 /// A bit that indicates whether or not a module is that of a static archive
 using IsStaticField = BCFixed<1>;
+/// A bit taht indicates whether or not a link library is a force-load one
+using IsForceLoadField = BCFixed<1>;
+
+/// Source location fields
+using LineNumberField = BCFixed<32>;
+using ColumnNumberField = BCFixed<32>;
 
 /// Arrays of various identifiers, distinguished for readability
 using IdentifierIDArryField = llvm::BCArray<IdentifierIDField>;
@@ -65,9 +71,12 @@ using ModuleIDArryField = llvm::BCArray<IdentifierIDField>;
 /// Identifiers used to refer to the above arrays
 using FileIDArrayIDField = IdentifierIDField;
 using ContextHashIDField = IdentifierIDField;
+using ModuleCacheKeyIDField = IdentifierIDField;
 using ImportArrayIDField = IdentifierIDField;
 using FlagIDArrayIDField = IdentifierIDField;
 using DependencyIDArrayIDField = IdentifierIDField;
+using AuxiliaryFilesArrayIDField = IdentifierIDField;
+using SourceLocationIDArrayIDField = IdentifierIDField;
 
 /// The ID of the top-level block containing the dependency graph
 const unsigned GRAPH_BLOCK_ID = llvm::bitc::FIRST_APPLICATION_BLOCKID;
@@ -81,6 +90,9 @@ namespace graph_block {
 enum {
   METADATA = 1,
   MODULE_NODE,
+  LINK_LIBRARY_NODE,
+  SOURCE_LOCATION_NODE,
+  IMPORT_STATEMENT_NODE,
   SWIFT_INTERFACE_MODULE_DETAILS_NODE,
   SWIFT_SOURCE_MODULE_DETAILS_NODE,
   SWIFT_PLACEHOLDER_MODULE_DETAILS_NODE,
@@ -117,6 +129,26 @@ using IdentifierNodeLayout = BCRecordLayout<IDENTIFIER_NODE, BCBlob>;
 using IdentifierArrayLayout =
     BCRecordLayout<IDENTIFIER_ARRAY_NODE, IdentifierIDArryField>;
 
+using LinkLibraryLayout =
+    BCRecordLayout<LINK_LIBRARY_NODE,            // ID
+                   IdentifierIDField,            // libraryName
+                   IsFrameworkField,             // isFramework
+                   IsForceLoadField              // forceLoad
+                   >;
+
+using SourceLocationLayout =
+    BCRecordLayout<LINK_LIBRARY_NODE,            // ID
+                   IdentifierIDField,            // bufferIdentifier
+                   LineNumberField,              // lineNumber
+                   ColumnNumberField             // columnNumber
+                   >;
+
+using ImportStatementLayout =
+    BCRecordLayout<LINK_LIBRARY_NODE,            // ID
+                   IdentifierIDField,            // importIdentifier
+                   SourceLocationIDArrayIDField  // importLocations
+                   >;
+
 // After the array records, we have a sequence of Module info
 // records, each of which is followed by one of:
 // - SwiftInterfaceModuleDetails
@@ -130,7 +162,14 @@ using ModuleInfoLayout =
                    ContextHashIDField,           // contextHash
                    ImportArrayIDField,           // moduleImports
                    ImportArrayIDField,           // optionalModuleImports
-                   DependencyIDArrayIDField      // resolvedDirectModuleDependencies
+                   // ACTODO: LinkLibrariesArrayIDField,           // linkLibraries
+                   DependencyIDArrayIDField,       // importedSwiftModules
+                   DependencyIDArrayIDField,       // importedClangModules
+                   DependencyIDArrayIDField,       // crossImportOverlayModules
+                   DependencyIDArrayIDField,       // swiftOverlayDependencies
+                   ModuleCacheKeyIDField,          // moduleCacheKey
+                   AuxiliaryFilesArrayIDField      // auxiliaryFiles
+                   // ACTODO: MacroDependenciesArrayIDField,           // macroDependencies
                    >;
 
 using SwiftInterfaceModuleDetailsLayout =
@@ -147,7 +186,6 @@ using SwiftInterfaceModuleDetailsLayout =
                    FileIDArrayIDField,                  // sourceFiles
                    FileIDArrayIDField,                  // bridgingSourceFiles
                    IdentifierIDField,                   // bridgingModuleDependencies
-                   DependencyIDArrayIDField,            // swiftOverlayDependencies
                    IdentifierIDField,                   // CASFileSystemRootID
                    IdentifierIDField,                   // bridgingHeaderIncludeTree
                    IdentifierIDField,                   // moduleCacheKey
@@ -161,7 +199,6 @@ using SwiftSourceModuleDetailsLayout =
                    FileIDArrayIDField,               // sourceFiles
                    FileIDArrayIDField,               // bridgingSourceFiles
                    FileIDArrayIDField,               // bridgingModuleDependencies
-                   DependencyIDArrayIDField,         // swiftOverlayDependencies
                    IdentifierIDField,                // CASFileSystemRootID
                    IdentifierIDField,                // bridgingHeaderIncludeTree
                    FlagIDArrayIDField,               // buildCommandLine
@@ -173,7 +210,6 @@ using SwiftBinaryModuleDetailsLayout =
                    FileIDField,                      // compiledModulePath
                    FileIDField,                      // moduleDocPath
                    FileIDField,                      // moduleSourceInfoPath
-                   DependencyIDArrayIDField,         // swiftOverlayDependencies
                    FileIDField,                      // headerImport
                    IdentifierIDField,                // headerModuleDependencies
                    FileIDArrayIDField,               // headerSourceFiles
@@ -220,7 +256,7 @@ bool readInterModuleDependenciesCache(llvm::StringRef path,
 /// Returns true if there was an error.
 bool writeInterModuleDependenciesCache(DiagnosticEngine &diags,
                                        llvm::vfs::OutputBackend &backend,
-                                       llvm::StringRef path,
+                                       llvm::StringRef outputPath,
                                        const ModuleDependenciesCache &cache);
 
 /// Tries to write out the given dependency cache with the given

lib/DependencyScan/DependencyScanningTool.cpp

@@ -356,11 +356,6 @@ DependencyScanningTool::getDependencies(
   return BatchScanResults;
 }
 
-void DependencyScanningTool::resetCache() {
-  llvm::sys::SmartScopedLock<true> Lock(DependencyScanningToolStateLock);
-  ScanningService.reset(new SwiftDependencyScanningService());
-}
-
 std::vector<
     DependencyScanDiagnosticCollector::ScannerDiagnosticInfo>
 DependencyScanningTool::getDiagnostics() {