Merge pull request swiftlang#36111 from CodaFi/cross-over-episode

Add Real Enable/Disable Flags for Cross-Module Incremental Builds

Author: CodaFi

include/swift/Frontend/FrontendOptions.h

@@ -298,7 +298,7 @@ class FrontendOptions {
   ///
   /// This flag is currently only propagated from the driver to
   /// any merge-modules jobs.
-  bool EnableExperimentalCrossModuleIncrementalBuild = false;
+  bool DisableCrossModuleIncrementalBuild = false;
 
   /// Best effort to output a .swiftmodule regardless of any compilation
   /// errors. SIL generation and serialization is skipped entirely when there

include/swift/Option/Options.td

@@ -1111,6 +1111,18 @@ def emit_supported_features : Flag<["-"], "emit-supported-features">,
   HelpText<"Emit a JSON file including all supported compiler features">, ModeOpt,
   Flags<[FrontendOption, NoInteractiveOption, DoesNotAffectIncrementalBuild]>;
 
+def enable_incremental_imports :
+  Flag<["-"], "enable-incremental-imports">,
+  Flags<[FrontendOption]>,
+  HelpText<"Enable cross-module incremental build metadata and "
+           "driver scheduling for Swift modules">;
+
+def disable_incremental_imports :
+  Flag<["-"], "disable-incremental-imports">,
+  Flags<[FrontendOption]>,
+  HelpText<"Disable cross-module incremental build metadata and "
+           "driver scheduling for Swift modules">;
+
 def index_file : Flag<["-"], "index-file">,
   HelpText<"Produce index data for a source file">, ModeOpt,
   Flags<[NoInteractiveOption, DoesNotAffectIncrementalBuild]>;

include/swift/Serialization/SerializationOptions.h

@@ -132,7 +132,7 @@ namespace swift {
     bool SerializeAllSIL = false;
     bool SerializeOptionsForDebugging = false;
     bool IsSIB = false;
-    bool ExperimentalCrossModuleIncrementalInfo = false;
+    bool DisableCrossModuleIncrementalInfo = false;
   };
 
 } // end namespace swift

lib/Driver/Driver.cpp

@@ -1008,8 +1008,9 @@ Driver::buildCompilation(const ToolChain &TC,
     const bool EmitFineGrainedDependencyDotFileAfterEveryImport = ArgList->hasArg(
         options::
             OPT_driver_emit_fine_grained_dependency_dot_file_after_every_import);
-    const bool EnableCrossModuleDependencies = ArgList->hasArg(
-        options::OPT_enable_experimental_cross_module_incremental_build);
+    const bool EnableCrossModuleDependencies
+        = ArgList->hasArg(options::OPT_enable_incremental_imports,
+                          options::OPT_disable_incremental_imports, true);
 
     // clang-format off
     C = std::make_unique<Compilation>(

lib/Driver/ToolChains.cpp

@@ -1050,9 +1050,7 @@ ToolChain::constructInvocation(const MergeModuleJobAction &job,
 
   context.Args.AddLastArg(Arguments, options::OPT_import_objc_header);
 
-  context.Args.AddLastArg(
-      Arguments,
-      options::OPT_enable_experimental_cross_module_incremental_build);
+  context.Args.AddLastArg(Arguments, options::OPT_disable_incremental_imports);
 
   Arguments.push_back("-module-name");
   Arguments.push_back(context.Args.MakeArgString(context.OI.ModuleName));

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -103,8 +103,8 @@ bool ArgsToFrontendOptionsConverter::convert(
 
   Opts.ImportPrescan |= Args.hasArg(OPT_import_prescan);
 
-  Opts.EnableExperimentalCrossModuleIncrementalBuild |=
-      Args.hasArg(OPT_enable_experimental_cross_module_incremental_build);
+  Opts.DisableCrossModuleIncrementalBuild |=
+      Args.hasArg(OPT_disable_incremental_imports);
 
   // Always track system dependencies when scanning dependencies.
   if (const Arg *ModeArg = Args.getLastArg(OPT_modes_Group)) {

lib/Frontend/Frontend.cpp

@@ -178,8 +178,8 @@ SerializationOptions CompilerInvocation::computeSerializationOptions(
       opts.SerializeOptionsForDebugging.getValueOr(
           !isModuleExternallyConsumed(module));
 
-  serializationOpts.ExperimentalCrossModuleIncrementalInfo =
-      opts.EnableExperimentalCrossModuleIncrementalBuild;
+  serializationOpts.DisableCrossModuleIncrementalInfo =
+      opts.DisableCrossModuleIncrementalBuild;
 
   return serializationOpts;
 }

lib/Frontend/ModuleInterfaceBuilder.cpp

@@ -79,10 +79,13 @@ bool ModuleInterfaceBuilder::collectDepsForSerialization(
   path::native(ResourcePath);
 
   auto DTDeps = SubInstance.getDependencyTracker()->getDependencies();
-  SmallVector<StringRef, 16> InitialDepNames(DTDeps.begin(), DTDeps.end());
-  InitialDepNames.push_back(interfacePath);
-  InitialDepNames.insert(InitialDepNames.end(),
-                         extraDependencies.begin(), extraDependencies.end());
+  SmallVector<std::string, 16> InitialDepNames(DTDeps.begin(), DTDeps.end());
+  auto IncDeps = SubInstance.getDependencyTracker()->getIncrementalDependencyPaths();
+  InitialDepNames.append(IncDeps.begin(), IncDeps.end());
+  InitialDepNames.push_back(interfacePath.str());
+  for (const auto &extra : extraDependencies) {
+    InitialDepNames.push_back(extra.str());
+  }
   SmallString<128> Scratch;
 
   for (const auto &InitialDepName : InitialDepNames) {

lib/FrontendTool/FrontendTool.cpp

@@ -1536,7 +1536,11 @@ static bool performCompileStepsPostSILGen(CompilerInstance &Instance,
 
     SerializationOptions serializationOpts =
         Invocation.computeSerializationOptions(outs, Instance.getMainModule());
-    if (serializationOpts.ExperimentalCrossModuleIncrementalInfo) {
+
+    const bool canEmitIncrementalInfoIntoModule =
+        !serializationOpts.DisableCrossModuleIncrementalInfo &&
+        (Action == FrontendOptions::ActionType::MergeModules);
+    if (canEmitIncrementalInfoIntoModule) {
       const auto alsoEmitDotFile =
           Instance.getInvocation()
               .getLangOptions()

lib/FrontendTool/LoadedModuleTrace.cpp

@@ -577,7 +577,11 @@ static void computeSwiftModuleTraceInfo(
     path::replace_extension(modPath, swiftInterfaceExt);
   };
 
-  for (auto &depPath : depTracker.getDependencies()) {
+  auto deps = depTracker.getDependencies();
+  SmallVector<std::string, 16> dependencies{deps.begin(), deps.end()};
+  auto incrDeps = depTracker.getIncrementalDependencyPaths();
+  dependencies.append(incrDeps.begin(), incrDeps.end());
+  for (const auto &depPath : dependencies) {
 
     // Decide if this is a swiftmodule based on the extension of the raw
     // dependency path, as the true file may have a different one.