[ModuleInterface] Address more review comments.

Author: graydon

lib/Frontend/ParseableInterfaceSupport.cpp

@@ -121,12 +121,7 @@ ParseableInterfaceModuleLoader::configureSubInvocationAndOutputPaths(
   SubInvocation.setInputKind(InputFileKind::SwiftModuleInterface);
   SubInvocation.setRuntimeResourcePath(SearchPathOpts.RuntimeResourcePath);
   SubInvocation.setTargetTriple(LangOpts.Target);
-
-  if (auto ClangLoader = Ctx.getClangModuleLoader()) {
-    auto const &Clang = ClangLoader->getClangInstance();
-    std::string ModuleCachePath = getModuleCachePathFromClang(Clang);
-    SubInvocation.setClangModuleCachePath(ModuleCachePath);
-  }
+  SubInvocation.setClangModuleCachePath(CacheDir);
 
   // Calculate an output filename that includes a hash of relevant key data, and
   // wire up the SubInvocation's InputsAndOutputs to contain both input and
@@ -152,7 +147,9 @@ ParseableInterfaceModuleLoader::configureSubInvocationAndOutputPaths(
 // Check that the output .swiftmodule file is at least as new as all the
 // dependencies it read when it was built last time.
 static bool
-swiftModuleIsUpToDate(clang::vfs::FileSystem &FS, StringRef OutPath) {
+swiftModuleIsUpToDate(clang::vfs::FileSystem &FS,
+                      StringRef ModuleCachePath,
+                      StringRef OutPath) {
 
   if (!FS.exists(OutPath))
     return false;
@@ -183,11 +180,12 @@ swiftModuleIsUpToDate(clang::vfs::FileSystem &FS, StringRef OutPath) {
                  << " is directly out of date\n");
       return false;
     }
-    // Recursively probe any .swiftmodules for up-to-date-ness.
+    // Recursively check freshness of any .swiftmodules in the module cache.
     auto Ext = llvm::sys::path::extension(In.Path);
     auto Ty = file_types::lookupTypeForExtension(Ext);
     if (Ty == file_types::TY_SwiftModuleFile &&
-        !swiftModuleIsUpToDate(FS, In.Path)) {
+        In.Path.startswith(ModuleCachePath) &&
+        !swiftModuleIsUpToDate(FS, ModuleCachePath, In.Path)) {
       LLVM_DEBUG(llvm::dbgs() << "Dep " << In.Path
                  << " is indirectly out of date\n");
       return false;
@@ -312,7 +310,7 @@ std::error_code ParseableInterfaceModuleLoader::openModuleFiles(
   configureSubInvocationAndOutputPaths(SubInvocation, InPath, OutPath);
 
   // Evaluate if we need to run this sub-invocation, and if so run it.
-  if (!swiftModuleIsUpToDate(FS, OutPath)) {
+  if (!swiftModuleIsUpToDate(FS, CacheDir, OutPath)) {
     if (buildSwiftModuleFromSwiftInterface(FS, Diags, SubInvocation, InPath,
                                            OutPath))
       return std::make_error_code(std::errc::invalid_argument);

test/ParseableInterface/client.swift

@@ -58,34 +58,64 @@
 //
 //
 // Phase 4: Same command as in phase 3, but check that none of the cached modules are rebuilt.
+// (The initial touch commands here are redundant, but are repeated to remind the reader of context.)
+// RUN: touch -t 201401240006 %t/LeafModule.swiftinterface
+// RUN: touch -t 201401240007 %t/OtherModule.swiftinterface
+// RUN: touch -t 201401240007 %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch -t 201401240008 %t/TestModule.swiftmodule
+// RUN: touch -t 201401240008 %t/modulecache/OtherModule-*.swiftmodule
 // RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -enable-parseable-module-interface -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// (Reset TestModule to where it was moments ago)
 // RUN: touch -t 201401240008 %t/TestModule.swiftmodule
+// (Check that TestModule -- at minute 08 -- is still not-older than the two cached modules, which should still be at minutes 08 and 07.)
 // RUN: test ! %t/TestModule.swiftmodule -ot %t/modulecache/OtherModule-*.swiftmodule
 // RUN: test ! %t/TestModule.swiftmodule -ot %t/modulecache/LeafModule-*.swiftmodule
 //
 //
 // Phase 5: change the mtime on LeafModule.swiftinterface and watch LeafModule-*.swiftmodule and OtherModule-*.swiftmodule recompile.
+// (The initial touch commands here are redundant, but are repeated to remind the reader of context.)
+// RUN: touch -t 201401240006 %t/LeafModule.swiftinterface
+// RUN: touch -t 201401240007 %t/OtherModule.swiftinterface
+// RUN: touch -t 201401240007 %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch -t 201401240008 %t/TestModule.swiftmodule
+// RUN: touch -t 201401240008 %t/modulecache/OtherModule-*.swiftmodule
+// (Push LeafModule's interface forward 10 minutes from the minute 06 timestamp stored in both cached modules, invalidating them)
 // RUN: touch -t 201401240016 %t/LeafModule.swiftinterface
 // RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -enable-parseable-module-interface -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// (Check that the two cached modules were rebuit -- that the LeafModule.swiftinterface at minute 16 is older than them.)
 // RUN: test %t/LeafModule.swiftinterface -ot %t/modulecache/LeafModule-*.swiftmodule
 // RUN: test %t/LeafModule.swiftinterface -ot %t/modulecache/OtherModule-*.swiftmodule
 //
 //
 // Phase 6: change the mtimes on LeafModule-*.swiftmodule and OtherModule.swiftinterface, and watch just OtherModule-*.swiftmodule recompile, leaving LeafModule-*.swiftmodule alone.
+// (The initial touch commands here are redundant, but are repeated to remind the reader of context.)
+// RUN: touch -t 201401240016 %t/LeafModule.swiftinterface
+// RUN: touch -t 201401240007 %t/OtherModule.swiftinterface
+// RUN: touch %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch %t/modulecache/OtherModule-*.swiftmodule
+// (Perturb LeafModule's cached module and OtherModule's interface mtimes, so they do not match values stored in OtherModule's cached module.)
 // RUN: touch -t 201401240016 %t/modulecache/LeafModule-*.swiftmodule
 // RUN: touch -t 201401240017 %t/OtherModule.swiftinterface
 // RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -enable-parseable-module-interface -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// (Check that Othermodule.swiftinterface at minute 17 is not older than the LeafModule's cached module which should still be at minute 16.)
 // RUN: test ! %t/OtherModule.swiftinterface -ot %t/modulecache/LeafModule-*.swiftmodule
+// (Check that Othermodule.swiftinterface at minute 17 _is_ older than the OtherModule's cached module, which was just rebuilt.)
 // RUN: test %t/OtherModule.swiftinterface -ot %t/modulecache/OtherModule-*.swiftmodule
 //
 //
-// Phase 7: change the size on LeafModule.swiftinterface (keeping mtime fixed) and watch LeafModule-*.swiftmodule and OtherModule-*.swiftmodule recompile.
+// Phase 7: change the _size_ on LeafModule.swiftinterface (keeping mtime fixed) and watch LeafModule-*.swiftmodule and OtherModule-*.swiftmodule recompile.
+// (The initial touch commands here are redundant, but are repeated to remind the reader of context.)
+// RUN: touch -t 201401240016 %t/LeafModule.swiftinterface
+// RUN: touch -t 201401240016 %t/modulecache/LeafModule-*.swiftmodule
+// RUN: touch -t 201401240017 %t/OtherModule.swiftinterface
 // RUN: touch -t 201401240017 %t/modulecache/OtherModule-*.swiftmodule
+// (Perturb the size of the LeafModule interface while keeping its mtime fixed.)
 // RUN: echo '// size change' >>%t/LeafModule.swiftinterface
 // RUN: touch -t 201401240016 %t/LeafModule.swiftinterface
 // RUN: %target-swift-frontend -I %t -module-cache-path %t/modulecache -enable-parseable-module-interface -emit-module -o %t/TestModule.swiftmodule -module-name TestModule %s
+// (Check that both of the cached modules were rebuilt and are now newer than their respective interfaces.)
 // RUN: test %t/LeafModule.swiftinterface -ot %t/modulecache/LeafModule-*.swiftmodule
-// RUN: test %t/LeafModule.swiftinterface -ot %t/modulecache/OtherModule-*.swiftmodule
+// RUN: test %t/OtherModule.swiftinterface -ot %t/modulecache/OtherModule-*.swiftmodule
 
 import OtherModule