ModuleInterface: teach module interface building to use explicitly built PCMs

Author: nkcsgexi

include/swift/ClangImporter/ClangImporterOptions.h

@@ -103,6 +103,10 @@ class ClangImporterOptions {
   /// DWARFImporter delegate.
   bool DisableSourceImport = false;
 
+  /// When set, use ExtraArgs alone to configure clang instance because ExtraArgs
+  /// contains the full option set.
+  bool ExtraArgsOnly = false;
+
   /// Return a hash code of any components from these options that should
   /// contribute to a Swift Bridging PCH hash.
   llvm::hash_code getPCHHashComponents() const {

include/swift/Option/FrontendOptions.td

@@ -717,4 +717,6 @@ def target_sdk_version : Separate<["-"], "target-sdk-version">,
 def target_variant_sdk_version : Separate<["-"], "target-variant-sdk-version">,
   HelpText<"The version of target variant SDK used for compilation">;
 
+def extra_clang_options_only : Flag<["-"], "only-use-extra-clang-opts">,
+  HelpText<"Options passed via -Xcc are sufficient for Clang configuration">;
 } // end let Flags = [FrontendOption, NoDriverOption, HelpHidden]

lib/ClangImporter/ClangImporter.cpp

@@ -908,6 +908,9 @@ ClangImporter::getOrCreatePCH(const ClangImporterOptions &ImporterOptions,
 std::vector<std::string>
 ClangImporter::getClangArguments(ASTContext &ctx,
                                  const ClangImporterOptions &importerOpts) {
+  if (importerOpts.ExtraArgsOnly) {
+    return importerOpts.ExtraArgs;
+  }
   std::vector<std::string> invocationArgStrs;
   // Clang expects this to be like an actual command line. So we need to pass in
   // "clang" for argv[0]

lib/ClangImporter/ClangModuleDependencyScanner.cpp

@@ -211,30 +211,27 @@ void ClangImporter::recordModuleDependencies(
       fileDeps.push_back(fileDep.getKey().str());
     }
     // Inherit all Clang driver args when creating the clang importer.
-    std::vector<std::string> allArgs = Impl.ClangArgs;
+    ArrayRef<std::string> allArgs = Impl.ClangArgs;
     ClangImporterOptions Opts;
-    std::vector<std::string> cc1Args;
 
-    // Calling this to convert driver args to CC1 args.
-    createClangInvocation(this, Opts, allArgs, &cc1Args);
+    // Ensure the arguments we collected is sufficient to create a Clang
+    // invocation.
+    assert(createClangInvocation(this, Opts, allArgs));
+
     std::vector<std::string> swiftArgs;
     // We are using Swift frontend mode.
     swiftArgs.push_back("-frontend");
+    // We pass the entire argument list via -Xcc, so the invocation should
+    // use extra clang options alone.
+    swiftArgs.push_back("-only-use-extra-clang-opts");
     auto addClangArg = [&](StringRef arg) {
-      swiftArgs.push_back("-Xcc");
-      swiftArgs.push_back("-Xclang");
       swiftArgs.push_back("-Xcc");
       swiftArgs.push_back(arg.str());
     };
     // Add all args inheritted from creating the importer.
-    for (auto arg: cc1Args) {
+    for (auto arg: allArgs) {
       addClangArg(arg);
     }
-    // Add all args reported from the Clang dependencies scanner.
-    for(auto arg: clangModuleDep.NonPathCommandLine) {
-      addClangArg(arg);
-    }
-
     // Swift frontend action: -emit-pcm
     swiftArgs.push_back("-emit-pcm");
     swiftArgs.push_back("-module-name");

lib/Frontend/CompilerInvocation.cpp

@@ -802,6 +802,8 @@ static bool ParseClangImporterArgs(ClangImporterOptions &Opts,
 
   Opts.DisableOverlayModules |= Args.hasArg(OPT_emit_imported_modules);
 
+  Opts.ExtraArgsOnly |= Args.hasArg(OPT_extra_clang_options_only);
+
   if (const Arg *A = Args.getLastArg(OPT_pch_output_dir)) {
     Opts.PrecompiledHeaderOutputDir = A->getValue();
     Opts.PCHDisableValidation |= Args.hasArg(OPT_pch_disable_validation);

test/ScanDependencies/module_deps.swift

@@ -31,6 +31,12 @@
 // RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path C.pcm -o %t/clang-module-cache/C.pcm -Xcc -Xclang -Xcc -fmodule-map-file=%S/Inputs/CHeaders/module.modulemap -Xcc -Xclang -Xcc -fmodule-file=%t/clang-module-cache/B.pcm | %S/Inputs/CommandRunner.py
 // RUN: ls %t/clang-module-cache/C.pcm
 
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path A.swiftmodule -o %t/clang-module-cache/A.swiftmodule -Xcc -Xclang -Xcc -fmodule-map-file=%S/Inputs/CHeaders/module.modulemap -Xcc -Xclang -Xcc -fmodule-file=%t/clang-module-cache/A.pcm -Xcc -Xclang -Xcc -fmodule-file=%t/clang-module-cache/SwiftShims.pcm | %S/Inputs/CommandRunner.py
+// RUN: ls %t/clang-module-cache/A.swiftmodule
+
+// RUN: %target-run %t/ModuleBuilder %t/deps.json %swift-path E.swiftmodule -o %t/clang-module-cache/E.swiftmodule -Xcc -Xclang -Xcc -fmodule-map-file=%S/Inputs/CHeaders/module.modulemap -Xcc -Xclang -Xcc -fmodule-file=%t/clang-module-cache/SwiftShims.pcm | %S/Inputs/CommandRunner.py
+// RUN: ls %t/clang-module-cache/E.swiftmodule
+
 
 // REQUIRES: executable_test
 // REQUIRES: objc_interop
@@ -100,11 +106,10 @@ import G
 
 // CHECK: "commandLine": [
 // CHECK-NEXT: "-frontend"
+// CHECK-NEXT: "-only-use-extra-clang-opts"
 // CHECK-NEXT: "-Xcc"
-// CHECK-NEXT: "-Xclang"
-// CHECK-NEXT: "-Xcc"
-// CHECK-NEXT: "-cc1"
-// CHECK: "-remove-preceeding-explicit-module-build-incompatible-options"
+// CHECK-NEXT: "clang"
+// CHECK: "-fno-implicit-modules"
 
 /// --------Swift module E
 // CHECK: "swift": "E"