[clang][modules] Don't prevent translation of FW_Private includes when explicitly building FW (#70714)

clang/lib/Basic/Module.cpp

@@ -166,9 +166,10 @@ bool Module::isForBuilding(const LangOptions &LangOpts) const {
   StringRef TopLevelName = getTopLevelModuleName();
   StringRef CurrentModule = LangOpts.CurrentModule;
 
-  // When building framework Foo, we want to make sure that Foo *and*
-  // Foo_Private are textually included and no modules are built for both.
-  if (getTopLevelModule()->IsFramework &&
+  // When building the implementation of framework Foo, we want to make sure
+  // that Foo *and* Foo_Private are textually included and no modules are built
+  // for either.
+  if (!LangOpts.isCompilingModule() && getTopLevelModule()->IsFramework &&
       CurrentModule == LangOpts.ModuleName &&
       !CurrentModule.endswith("_Private") && TopLevelName.endswith("_Private"))
     TopLevelName = TopLevelName.drop_back(8);

clang/test/ClangScanDeps/modules-priv-fw-from-pub.m

@@ -0,0 +1,121 @@
+// This test checks that importing private headers from the public headers of
+// a framework is consistent between the dependency scanner and the explicit build.
+
+// RUN: rm -rf %t
+// RUN: split-file %s %t
+
+//--- frameworks/FW.framework/Modules/module.modulemap
+framework module FW { header "FW.h" }
+//--- frameworks/FW.framework/Modules/module.private.modulemap
+framework module FW_Private { header "FW_Private.h"}
+//--- frameworks/FW.framework/Headers/FW.h
+#include <FW/FW_Private.h>
+//--- frameworks/FW.framework/PrivateHeaders/FW_Private.h
+@import Dependency;
+
+//--- modules/module.modulemap
+module Dependency { header "dependency.h" }
+//--- modules/dependency.h
+// empty
+
+//--- tu.m
+#include <FW/FW.h>
+
+//--- cdb.json.in
+[{
+  "file": "DIR/tu.m",
+  "directory": "DIR",
+  "command": "clang -fmodules -fmodules-cache-path=DIR/cache -fimplicit-module-maps -I DIR/modules -F DIR/frameworks -Wno-framework-include-private-from-public -Wno-atimport-in-framework-header -c DIR/tu.m -o DIR/tu.o"
+}]
+
+// RUN: sed -e "s|DIR|%/t|g" %t/cdb.json.in > %t/cdb.json
+// RUN: clang-scan-deps -compilation-database %t/cdb.json -format experimental-full > %t/deps.json
+
+// Check that FW is reported to depend on FW_Private.
+// RUN: cat %t/deps.json | sed 's:\\\\\?:/:g' | FileCheck %s -DPREFIX=%/t
+// CHECK:      {
+// CHECK-NEXT:   "modules": [
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-module-deps": [],
+// CHECK-NEXT:       "clang-modulemap-file": "[[PREFIX]]/modules/module.modulemap",
+// CHECK-NEXT:       "command-line": [
+// CHECK:            ],
+// CHECK-NEXT:       "context-hash": "{{.*}}",
+// CHECK-NEXT:       "file-deps": [
+// CHECK-NEXT:         "[[PREFIX]]/modules/dependency.h",
+// CHECK-NEXT:         "[[PREFIX]]/modules/module.modulemap"
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "name": "Dependency"
+// CHECK-NEXT:     },
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-module-deps": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:           "context-hash": "{{.*}}",
+// CHECK-NEXT:           "module-name": "FW_Private"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "clang-modulemap-file": "[[PREFIX]]/frameworks/FW.framework/Modules/module.modulemap",
+// CHECK-NEXT:       "command-line": [
+// CHECK:            ],
+// CHECK-NEXT:       "context-hash": "{{.*}}",
+// CHECK-NEXT:       "file-deps": [
+// CHECK-NEXT:         "[[PREFIX]]/frameworks/FW.framework/Headers/FW.h",
+// CHECK-NEXT:         "[[PREFIX]]/frameworks/FW.framework/Modules/module.modulemap",
+// CHECK-NEXT:         "[[PREFIX]]/frameworks/FW.framework/Modules/module.private.modulemap"
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "name": "FW"
+// CHECK-NEXT:     },
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "clang-module-deps": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:           "context-hash": "{{.*}}",
+// CHECK-NEXT:           "module-name": "Dependency"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "clang-modulemap-file": "[[PREFIX]]/frameworks/FW.framework/Modules/module.private.modulemap",
+// CHECK-NEXT:       "command-line": [
+// CHECK:            ],
+// CHECK-NEXT:       "context-hash": "{{.*}}",
+// CHECK-NEXT:       "file-deps": [
+// CHECK-NEXT:         "[[PREFIX]]/frameworks/FW.framework/Modules/module.private.modulemap",
+// CHECK-NEXT:         "[[PREFIX]]/frameworks/FW.framework/PrivateHeaders/FW_Private.h",
+// CHECK-NEXT:         "[[PREFIX]]/modules/module.modulemap"
+// CHECK-NEXT:       ],
+// CHECK-NEXT:       "name": "FW_Private"
+// CHECK-NEXT:     }
+// CHECK-NEXT:   ],
+// CHECK-NEXT:   "translation-units": [
+// CHECK-NEXT:     {
+// CHECK-NEXT:       "commands": [
+// CHECK-NEXT:         {
+// CHECK-NEXT:           "clang-context-hash": "{{.*}}",
+// CHECK-NEXT:           "clang-module-deps": [
+// CHECK-NEXT:             {
+// CHECK-NEXT:               "context-hash": "{{.*}}",
+// CHECK-NEXT:               "module-name": "FW"
+// CHECK-NEXT:             }
+// CHECK-NEXT:           ],
+// CHECK-NEXT:           "command-line": [
+// CHECK:                ],
+// CHECK-NEXT:           "executable": "clang",
+// CHECK-NEXT:           "file-deps": [
+// CHECK-NEXT:             "[[PREFIX]]/tu.m"
+// CHECK-NEXT:           ],
+// CHECK-NEXT:           "input-file": "[[PREFIX]]/tu.m"
+// CHECK-NEXT:         }
+// CHECK-NEXT:       ]
+// CHECK-NEXT:     }
+// CHECK-NEXT:   ]
+// CHECK-NEXT: }
+
+// Check that building FW succeeds. If FW_Private was to be treated textually,
+// building FW would fail due to Dependency not being present on the command line.
+// RUN: %deps-to-rsp %t/deps.json --module-name=Dependency > %t/Dependency.cc1.rsp
+// RUN: %deps-to-rsp %t/deps.json --module-name=FW_Private > %t/FW_Private.cc1.rsp
+// RUN: %deps-to-rsp %t/deps.json --module-name=FW > %t/FW.cc1.rsp
+// RUN: %deps-to-rsp %t/deps.json --tu-index=0 > %t/tu.rsp
+
+// RUN: %clang @%t/Dependency.cc1.rsp
+// RUN: %clang @%t/FW_Private.cc1.rsp
+// RUN: %clang @%t/FW.cc1.rsp
+// RUN: %clang @%t/tu.rsp