Merge pull request #31597 from slavapestov/record-dependencies-later

Frontend: Emit reference dependencies at the end of the frontend pipeline

Author: slavapestov

lib/FrontendTool/FrontendTool.cpp

@@ -1290,10 +1290,16 @@ static bool performCompile(CompilerInstance &Instance,
   if (opts.PrintClangStats && Context.getClangModuleLoader())
     Context.getClangModuleLoader()->printStatistics();
 
-  emitReferenceDependenciesForAllPrimaryInputsIfNeeded(Instance);
   emitSwiftRangesForAllPrimaryInputsIfNeeded(Instance);
   emitCompiledSourceForAllPrimaryInputsIfNeeded(Instance);
 
+  SWIFT_DEFER {
+    // We might have freed the ASTContext already, but in that case we must have
+    // emitted the dependencies first.
+    if (Instance.hasASTContext())
+      emitReferenceDependenciesForAllPrimaryInputsIfNeeded(Instance);
+  };
+
   emitIndexData(Instance);
 
   if (Context.hadError())
@@ -1508,6 +1514,11 @@ static void freeDeallocatableResourcesIfPossible(CompilerInstance &Instance) {
     break;
   case DeallocatableResources::SILModuleAndASTContext:
     Instance.freeSILModule();
+
+    // Make sure we emit dependencies now, because we can't do it after the
+    // context is gone.
+    emitReferenceDependenciesForAllPrimaryInputsIfNeeded(Instance);
+
     Instance.freeASTContext();
     break;
   }
@@ -2184,14 +2195,6 @@ int swift::performFrontend(ArrayRef<const char *> Args,
                        Invocation.getFrontendOptions().DumpAPIPath);
   }
 
-  // If we're asked to enable private intransitive dependencies, we need to
-  // write over the dependency files we just emitted because we need to
-  // get the dependencies written post-Sema down on disk.
-  // FIXME: Evaluate the impact turning this on universally has.
-  if (Invocation.getLangOptions().EnableExperientalPrivateIntransitiveDependencies) {
-    emitReferenceDependenciesForAllPrimaryInputsIfNeeded(*Instance);
-  }
-
   // Verify reference dependencies of the current compilation job *before*
   // verifying diagnostics so that the former can be tested via the latter.
   if (Invocation.getFrontendOptions().EnableIncrementalDependencyVerifier) {

test/Incremental/PrivateDependencies/reference-dependencies-dynamic-lookup-fine.swift

@@ -29,10 +29,12 @@ import Foundation
   // CHECK-DAG:  dynamicLookup implementation  '' bar true
   // CHECK-DAG:  dynamicLookup interface  '' bar true
 
+  // DUPLICATE-NOT:  dynamicLookup implementation  '' bar true
   // DUPLICATE:  dynamicLookup implementation  '' bar true
-  // DUPLICATE:  dynamicLookup implementation  '' bar true
-  // DUPLICATE:  dynamicLookup interface  '' bar true
+  // DUPLICATE-NOT:  dynamicLookup implementation  '' bar true
+  // DUPLICATE-NOT:  dynamicLookup interface  '' bar true
   // DUPLICATE:  dynamicLookup interface  '' bar true
+  // DUPLICATE-NOT:  dynamicLookup interface  '' bar true
   func bar(_ x: Int, y: Int) {}
   func bar(_ str: String) {}