[Bridging PCH] Move dependency-on-bridging-PCH to -emit-bc JobAction itself.

(cherry picked from commit d4ff453)

Author: graydon

lib/Driver/Driver.cpp

@@ -1300,6 +1300,27 @@ void Driver::buildOutputInfo(const ToolChain &TC, const DerivedArgList &Args,
                                          OI.SelectedSanitizer);
 }
 
+static void
+currentDependsOnPCHIfPresent(JobAction *PCH,
+                             std::unique_ptr<Action> &Current,
+                             ActionList &Actions) {
+  if (PCH) {
+    // FIXME: When we have a PCH job, it's officially owned by the Actions
+    // array; but it's also a secondary input to each of the current
+    // JobActions, which means that we need to flip the "owns inputs" bit
+    // on the JobActions so they don't try to free it. That in turn means
+    // we need to transfer ownership of all the JobActions' existing
+    // inputs to the Actions array, since the JobActions either own or
+    // don't own _all_ of their inputs. Ownership can't vary
+    // input-by-input.
+    auto *job = cast<JobAction>(Current.get());
+    auto inputs = job->getInputs();
+    Actions.append(inputs.begin(), inputs.end());
+    job->setOwnsInputs(false);
+    job->addInput(PCH);
+  }
+}
+
 void Driver::buildActions(const ToolChain &TC,
                           const DerivedArgList &Args,
                           const InputFileList &Inputs,
@@ -1364,30 +1385,17 @@ void Driver::buildActions(const ToolChain &TC,
           Current.reset(new CompileJobAction(Current.release(),
                                              types::TY_LLVM_BC,
                                              previousBuildState));
+          currentDependsOnPCHIfPresent(PCH, Current, Actions);
           AllModuleInputs.push_back(Current.get());
           Current.reset(new BackendJobAction(Current.release(),
                                              OI.CompilerOutputType, 0));
         } else {
           Current.reset(new CompileJobAction(Current.release(),
                                              OI.CompilerOutputType,
                                              previousBuildState));
+          currentDependsOnPCHIfPresent(PCH, Current, Actions);
           AllModuleInputs.push_back(Current.get());
         }
-        if (PCH) {
-          // FIXME: When we have a PCH job, it's officially owned by the Actions
-          // array; but it's also a secondary input to each of the current
-          // JobActions, which means that we need to flip the "owns inputs" bit
-          // on the JobActions so they don't try to free it. That in turn means
-          // we need to transfer ownership of all the JobActions' existing
-          // inputs to the Actions array, since the JobActions either own or
-          // don't own _all_ of their inputs. Ownership can't vary
-          // input-by-input.
-          auto *job = cast<JobAction>(Current.get());
-          auto inputs = job->getInputs();
-          Actions.append(inputs.begin(), inputs.end());
-          job->setOwnsInputs(false);
-          job->addInput(PCH);
-        }
         AllLinkerInputs.push_back(Current.release());
         break;
       }

test/Driver/bridging-pch.swift

@@ -32,6 +32,12 @@
 // PERSISTENT-YESPCHACT: 2: input, "{{.*}}bridging-pch.swift", swift
 // PERSISTENT-YESPCHACT: 3: compile, {2, 1}, none
 
+// RUN: %swiftc_driver -c -driver-print-actions -embed-bitcode -import-objc-header %S/Inputs/bridging-header.h -pch-output-dir %t/pch %s 2>&1 | %FileCheck %s -check-prefix=PERSISTENT-YESPCHACTBC
+// PERSISTENT-YESPCHACTBC: 0: input, "{{.*}}Inputs/bridging-header.h", objc-header
+// PERSISTENT-YESPCHACTBC: 1: generate-pch, {0}, none
+// PERSISTENT-YESPCHACTBC: 2: input, "{{.*}}bridging-pch.swift", swift
+// PERSISTENT-YESPCHACTBC: 3: compile, {2, 1}, llvm-bc
+
 // RUN: %swiftc_driver -typecheck -disable-bridging-pch -driver-print-actions -import-objc-header %S/Inputs/bridging-header.h -pch-output-dir %t/pch %s 2>&1 | %FileCheck %s -check-prefix=NOPCHACT
 
 // RUN: %swiftc_driver -typecheck -driver-print-jobs -import-objc-header %S/Inputs/bridging-header.h -pch-output-dir %t/pch -disable-bridging-pch %s 2>&1 | %FileCheck %s -check-prefix=PERSISTENT-DISABLED-YESPCHJOB