[C++20] [Modules] Deprecate to load C++20 Named Modules eagerly

[ChuanqiXu]

Summary

Close https://github.com/llvm/llvm-project/issues/60824

The form -fmodule-file=<path-to-BMI> will load modules eagerly and the form -fmodule-file=<module-name>=<path-to-BMI> will load modules lazily. The inconsistency adds many additional burdens to the implementations. And the inconsistency looks not helpful and necessary neither. So I want to deprecate the form -fmodule-file=<path-to-BMI> for named modules. This is pretty helpful for us (the developers).

Does this change make any regression from the perspective of the users?

To be honest, yes. But I think such regression is acceptable. Here is the example:

// M.cppm
export module M;
export int m = 5;

// N.cpp
// import M; // woops, we forgot to import M.
int n = m;

In the original version, the compiler can diagnose the users to import M since the compiler have already imported M. But in the later style, the compiler can only say "unknown identifier m".

But I think such regression doesn't make a deal since it only works if the user put -fmodule-file=M.pcm in the command line. But how can the user put -fmodule-file=M.pcm in the command line without import M;? Especially currently such options are generated by build systems. And the build systems will only generate the command line from the source file.

So I think this change is pretty pretty helpful for developers and almost innocent for users and we should accept this one.

I'll add the release notes and edit the document after we land this.

[ChuanqiXu]

For example, the issue (https://github.com/llvm/llvm-project/issues/60085) disappears after we change the eagerly loading to lazily loading.

[ChuanqiXu]

Don't emit the warning if we're compiling a .pcm file directly.

clang/include/clang/Basic/DiagnosticSerializationKinds.td

 def warn_duplicate_module_file_extension : Warning<
   "duplicate module file extension block name '%0'">,
   InGroup<ModuleFileExtension>;
 
 def warn_module_system_bit_conflict : Warning<
   "module file '%0' was validated as a system module and is now being imported "
   "as a non-system module; any difference in diagnostic options will be ignored">,
   InGroup<ModuleConflict>;
+
+def warn_eagerly_load_for_standard_cplusplus_modules : Warning<
+  "the form '-fmodule-file=<BMI-path>' is deprecated for standard C++ named modules;"
+  "consider to use '-fmodule-file=<module-name>=<BMI-path>' instead">,
+  InGroup<DiagGroup<"eager-load-cxx-named-modules">>;
 } // let CategoryName
 
 let CategoryName = "AST Serialization Issue" in {
 def warn_module_uses_date_time : Warning<
   "%select{precompiled header|module}0 uses __DATE__ or __TIME__">,
   InGroup<DiagGroup<"pch-date-time">>;
 def err_module_no_size_mtime_for_header : Error<
   "cannot emit module %0: %select{size|mtime}1 must be explicitly specified "
   "for missing header file \"%2\"">;
 def err_module_unable_to_hash_content : Error<
   "failed to hash content for '%0' because memory buffer cannot be retrieved">;
 } // let CategoryName
 } // let Component
 

clang/lib/Serialization/ASTReader.cpp

case SUBMODULE_DEFINITION: {
       CurrentModule->InferSubmodules = InferSubmodules;
       CurrentModule->InferExplicitSubmodules = InferExplicitSubmodules;
       CurrentModule->InferExportWildcard = InferExportWildcard;
       CurrentModule->ConfigMacrosExhaustive = ConfigMacrosExhaustive;
       CurrentModule->ModuleMapIsPrivate = ModuleMapIsPrivate;
       if (DeserializationListener)
         DeserializationListener->ModuleRead(GlobalID, CurrentModule);
 
+      // If we're loading a module before we initialize the sema, it implies
+      // we're performing eagerly loading.
+      if (!getSema() && CurrentModule->isModulePurview() &&
+          !getContext().getLangOpts().isCompilingModule())
+        Diag(clang::diag::warn_eagerly_load_for_standard_cplusplus_modules);
+
       SubmodulesLoaded[GlobalIndex] = CurrentModule;
 
       // Clear out data that will be replaced by what is in the module file.
       CurrentModule->LinkLibraries.clear();
       CurrentModule->ConfigMacros.clear();
       CurrentModule->UnresolvedConflicts.clear();
       CurrentModule->Conflicts.clear();
 

clang/test/CXX/basic/basic.link/p10-ex2.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 // RUN: cd %t
 //
 // RUN: %clang_cc1 -std=c++20 M.cpp -fsyntax-only -DTEST_INTERFACE -verify
 // RUN: %clang_cc1 -std=c++20 M.cpp -emit-module-interface -o M.pcm
-// RUN: %clang_cc1 -std=c++20 useM.cpp -fsyntax-only -fmodule-file=M.pcm -verify
+// RUN: %clang_cc1 -std=c++20 useM.cpp -fsyntax-only -fmodule-file=M=M.pcm -verify
 
 //--- decls.h
 int f(); // #1, attached to the global module
 int g(); // #2, attached to the global module
 
 //--- M.cpp
 module;
 #include "decls.h"

clang/test/CXX/basic/basic.link/p2.cpp

 // RUN: %clang_cc1 -std=c++2a -DEXPORT %s -verify
 // RUN: %clang_cc1 -std=c++2a -DEXPORT %s -emit-module-interface -o %t.pcm
-// RUN: %clang_cc1 -std=c++2a -UEXPORT %s -verify -fmodule-file=%t.pcm
+// RUN: %clang_cc1 -std=c++2a -UEXPORT %s -verify -fmodule-file=M=%t.pcm
 
 #ifdef EXPORT
 // expected-no-diagnostics
 export
 #else
 // expected-note@+2 {{add 'export' here}}
 #endif
 module M;
 
 #ifndef EXPORT
 // expected-error@+2 {{private module fragment in module implementation unit}}
 #endif
 module :private;

clang/test/CXX/basic/basic.lookup/basic.lookup.argdep/p5-ex2.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 // RUN: cd %t
 //
 // RUN: %clang_cc1 -std=c++20 M.cpp -emit-module-interface -o M.pcm
 // RUN: %clang_cc1 -std=c++20 N.cpp -emit-module-interface -o N.pcm \
-// RUN:   -fmodule-file=M.pcm
+// RUN:   -fmodule-file=M=M.pcm
 // RUN: %clang_cc1 -std=c++20 Q.cpp -emit-module-interface -o Q.pcm
-// RUN: %clang_cc1 -std=c++20 Q-impl.cpp -fsyntax-only -fmodule-file=Q.pcm \
-// RUN:   -fmodule-file=N.pcm -verify
+// RUN: %clang_cc1 -std=c++20 Q-impl.cpp -fsyntax-only -fmodule-file=Q=Q.pcm \
+// RUN:   -fmodule-file=N=N.pcm -verify
 
 //--- M.cpp
 export module M;
 namespace R {
 export struct X {};
 export void f(X);
 } // namespace R
 namespace S {

clang/test/CXX/basic/basic.scope/basic.scope.namespace/p2.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: echo '#ifndef FOO_H' > %t/foo.h
 // RUN: echo '#define FOO_H' >> %t/foo.h
 // RUN: echo 'extern int in_header;' >> %t/foo.h
 // RUN: echo '#endif' >> %t/foo.h
 // RUN: %clang_cc1 -std=c++2a -I%t -emit-module-interface -DINTERFACE %s -o %t.pcm
-// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=%t.pcm -DIMPLEMENTATION %s -verify -fno-modules-error-recovery
-// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=%t.pcm %s -verify -fno-modules-error-recovery
+// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=A=%t.pcm -DIMPLEMENTATION %s -verify -fno-modules-error-recovery
+// RUN: %clang_cc1 -std=c++2a -I%t -fmodule-file=A=%t.pcm %s -verify -fno-modules-error-recovery
 
 #ifdef INTERFACE
 module;
 #include "foo.h"
 // FIXME: The following need to be moved to a header file. The global module
 // fragment is only permitted to contain preprocessor directives.
 int global_module_fragment;
 export module A;
 export int exported;
 int not_exported;
 static int internal;
 
 module :private;
 int not_exported_private;
 static int internal_private;
 #else
 
 #ifdef IMPLEMENTATION
 module;
 #endif
 
 void test_early() {
-  in_header = 1; // expected-error {{missing '#include "foo.h"'; 'in_header' must be declared before it is used}}
+  in_header = 1; // expected-error {{use of undeclared identifier 'in_header'}}
   // expected-note@* {{not visible}}
 
-  global_module_fragment = 1; // expected-error {{missing '#include'; 'global_module_fragment' must be declared before it is used}}
-                              // [e-mail]:16 {{not visible}}
+  global_module_fragment = 1; // expected-error {{use of undeclared identifier 'global_module_fragment'}}
 
-  exported = 1; // expected-error {{must be imported from module 'A'}}
-                // [e-mail]:18 {{declaration here is not visible}}
+  exported = 1; // expected-error {{use of undeclared identifier 'exported'}}
 
-  not_exported = 1; // expected-error {{declaration of 'not_exported' must be imported from module 'A' before it is required}}
-                    // [e-mail]:19 {{declaration here is not visible}}
+  not_exported = 1; // expected-error {{use of undeclared identifier 'not_exported'}}
 
   // FIXME: We need better diagnostic message for static variable.
-  internal = 1; // expected-error {{declaration of 'internal' must be imported from module 'A' before it is required}}
-                // [e-mail]:20 {{declaration here is not visible}}
+  internal = 1; // expected-error {{use of undeclared identifier 'internal'}}
 
   not_exported_private = 1; // expected-error {{undeclared identifier}}
 
   internal_private = 1; // expected-error {{undeclared identifier}}
 }
 
 #ifdef IMPLEMENTATION
 module A;
 #else
 import A;
 #endif
 
 void test_late() {
   in_header = 1; // expected-error {{missing '#include "foo.h"'; 'in_header' must be declared before it is used}}
   // expected-note@* {{not visible}}
 
   global_module_fragment = 1; // expected-error {{missing '#include'; 'global_module_fragment' must be declared before it is used}}
-  // [e-mail]:16 {{not visible}}
 
   exported = 1;
 
   not_exported = 1;
 #ifndef IMPLEMENTATION
   // expected-error@-2 {{declaration of 'not_exported' must be imported from module 'A' before it is required}}
   // [e-mail]:19 {{declaration here is not visible}}
 #endif

clang/test/CXX/module/basic/basic.def.odr/p6.cppm

 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: split-file %s %t
 //
 // RUN: %clang_cc1 -std=c++20 -verify %t/global-vs-module.cppm 
 // RUN: %clang_cc1 -std=c++20 -verify %t/global-vs-module.cppm -DEXPORT
 // RUN: %clang_cc1 -std=c++20 -verify %t/global-vs-module.cppm -DUSING
 //
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/global-vs-module.cppm -o %t/M.pcm -DNO_GLOBAL -DEXPORT
-// RUN: %clang_cc1 -std=c++20 -verify %t/module-vs-global.cpp -fmodule-file=%t/M.pcm
+// RUN: %clang_cc1 -std=c++20 -verify %t/module-vs-global.cpp -fmodule-file=M=%t/M.pcm
 //
 // Some of the following tests intentionally have no -verify in their RUN
 // lines; we are testing that those cases do not produce errors.
 //
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/M.pcm -DMODULE_INTERFACE -verify
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/M.pcm -DMODULE_INTERFACE -DNO_IMPORT
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -DMODULE_INTERFACE -verify
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -DMODULE_INTERFACE -DNO_IMPORT
 //
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/M.pcm -emit-module-interface -o %t/N.pcm -DMODULE_INTERFACE -DNO_ERRORS
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/N.pcm -verify
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -emit-module-interface -o %t/N.pcm -DMODULE_INTERFACE -DNO_ERRORS
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -fmodule-file=N=%t/N.pcm -verify
 // FIXME: Once we start importing "import" declarations properly, this should
 // be rejected (-verify should be added to the following line).
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/N.pcm -DNO_IMPORT
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -fmodule-file=N=%t/N.pcm -DNO_IMPORT
 //
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/M.pcm -emit-module-interface -o %t/N-no-M.pcm -DMODULE_INTERFACE -DNO_ERRORS -DNO_IMPORT
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/N-no-M.pcm -verify
-// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=%t/N-no-M.pcm -DNO_IMPORT
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -emit-module-interface -o %t/N-no-M.pcm -DMODULE_INTERFACE -DNO_ERRORS -DNO_IMPORT
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=M=%t/M.pcm -fmodule-file=N=%t/N-no-M.pcm -verify
+// RUN: %clang_cc1 -std=c++20 %t/module-vs-module.cpp -fmodule-file=N=%t/N-no-M.pcm -DNO_IMPORT
 
 //--- global-vs-module.cppm
 #ifndef NO_GLOBAL
 module;
 extern int var; // expected-note {{previous declaration is here}}
 int func(); // expected-note {{previous declaration is here}}
 struct str; // expected-note {{previous declaration is here}}
 using type = int;

clang/test/CXX/module/basic/basic.link/module-declaration.cpp

 // Tests for module-declaration syntax.
 //
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: split-file %s %t
 //
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/x.cppm -o %t/x.pcm
-// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=%t/x.pcm %t/x.y.cppm -o %t/x.y.pcm
+// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=x=%t/x.pcm %t/x.y.cppm -o %t/x.y.pcm
 //
 // Module implementation for unknown and known module. (The former is ill-formed.)
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify -x c++ %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify -x c++ %t/M.cpp \
 // RUN:            -DTEST=1 -DEXPORT= -DMODULE_NAME=z
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify -x c++ %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x=%t/x.pcm -fmodule-file=x.y=%t/x.y.pcm -verify -x c++ %t/M.cpp \
 // RUN:            -DTEST=2 -DEXPORT= -DMODULE_NAME=x
 //
 // Module interface for unknown and known module. (The latter is ill-formed due to
 // redefinition.)
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=3 -DEXPORT=export -DMODULE_NAME=z
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=4 -DEXPORT=export -DMODULE_NAME=x
 //
 // Miscellaneous syntax.
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=7 -DEXPORT=export -DMODULE_NAME='z elderberry'
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=8 -DEXPORT=export -DMODULE_NAME='z [[]]'
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=9 -DEXPORT=export -DMODULE_NAME='z [[fancy]]'
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -verify %t/M.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -verify %t/M.cpp \
 // RUN:            -DTEST=10 -DEXPORT=export -DMODULE_NAME='z [[maybe_unused]]'
 
 //--- x.cppm
 export module x;
 int a, b;
 
 //--- x.y.cppm
 export module x.y;
 int c;
 
 //--- M.cpp
 
 EXPORT module MODULE_NAME;
-#if TEST == 4
-// expected-error@-2 {{redefinition of module 'x'}}
-// expected-note-re@* {{loaded from '{{.*[/\\]}}x.pcm'}}
-#elif TEST == 7
-// expected-error@-5 {{expected ';'}} expected-error@-5 {{a type specifier is required}}
+#if TEST == 7
+// expected-error@-2 {{expected ';'}} expected-error@-2 {{a type specifier is required}}
 #elif TEST == 9
-// expected-warning@-7 {{unknown attribute 'fancy' ignored}}
+// expected-warning@-4 {{unknown attribute 'fancy' ignored}}
 #elif TEST == 10
-// expected-error-re@-9 {{'maybe_unused' attribute cannot be applied to a module{{$}}}}
+// expected-error-re@-6 {{'maybe_unused' attribute cannot be applied to a module{{$}}}}
 #elif TEST == 1
-// expected-error@-11 {{module 'z' not found}}
+// expected-error@-8 {{module 'z' not found}}
 #else
 // expected-no-diagnostics
 #endif

clang/test/CXX/module/basic/basic.link/p2.cppm

 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 %t/M.cppm -verify
 // RUN: %clang_cc1 -std=c++20 %t/M.cppm -emit-module-interface -o %t/M.pcm
-// RUN: %clang_cc1 -std=c++20 -fmodule-file=%t/M.pcm %t/M.cpp -verify
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=M=%t/M.pcm %t/M.cpp -verify
 //
-// RUN: %clang_cc1 -std=c++20 -fmodule-file=%t/M.pcm %t/user.cpp -verify
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=M=%t/M.pcm %t/user.cpp -verify
 
 //--- M.cppm
 // expected-no-diagnostics
 export module M;
 
 export int external_linkage_var;
 int module_linkage_var;
 static int internal_linkage_var;

clang/test/CXX/module/basic/basic.search/module-import.cppm

 // Tests for imported module search.
 //
 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: split-file %s %t
 //
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/x.cppm -o %t/x.pcm
-// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=%t/x.pcm %t/y.cppm -o %t/y.pcm
-//
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.pcm -verify %t/use.cpp \
-// RUN:            -DMODULE_NAME=x
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/y.pcm -verify %t/use.cpp \
-// RUN:            -DMODULE_NAME=y
+// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=x=%t/x.pcm %t/y.cppm -o %t/y.pcm
 //
 // RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x=%t/x.pcm -verify %t/use.cpp \
 // RUN:            -DMODULE_NAME=x
 // RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=y=%t/y.pcm -verify %t/use.cpp \
 // RUN:            -DMODULE_NAME=y
 //
 // RUN: mv %t/x.pcm %t/a.pcm
 //
 // RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x=%t/a.pcm -verify %t/use.cpp \
 // RUN:            -DMODULE_NAME=x
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/y.pcm -fmodule-file=x=%t/a.pcm -verify %t/use.cpp \
-// RUN:            -DMODULE_NAME=y
 // RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=y=%t/y.pcm -fmodule-file=x=%t/a.pcm -verify %t/use.cpp \
 // RUN:            -DMODULE_NAME=y
 //
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=y=%t/y.pcm -fmodule-file=x=%t/a.pcm %t/z.cppm -o %t/z.pcm
 //
 // RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=z=%t/z.pcm -fmodule-file=y=%t/y.pcm -fmodule-file=x=%t/a.pcm -verify %t/use.cpp \
 // RUN:            -DMODULE_NAME=z
 //

clang/test/CXX/module/dcl.dcl/dcl.module/dcl.module.import/p1.cppm

 // RUN: rm -rf %t
 // RUN: mkdir %t
 // RUN: split-file %s %t
 //
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/x.cppm -o %t/x.pcm
-// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=%t/x.pcm %t/x.y.cppm -o %t/x.y.pcm
+// RUN: %clang_cc1 -std=c++20 -emit-module-interface -fmodule-file=x=%t/x.pcm %t/x.y.cppm -o %t/x.y.pcm
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/a.b.cppm -o %t/a.b.pcm
 //
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -fmodule-file=%t/a.b.pcm -verify %t/test.cpp \
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -fmodule-file=x=%t/x.pcm -verify %t/test.cpp \
 // RUN:            -DMODULE_NAME=z -DINTERFACE
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -fmodule-file=%t/a.b.pcm -verify %t/test.cpp \
-// RUN:            -DMODULE_NAME=a.b
-// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=%t/x.y.pcm -fmodule-file=%t/a.b.pcm -verify %t/test.x.cpp
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -fmodule-file=x=%t/x.pcm \
+// RUN:            -fmodule-file=a.b=%t/a.b.pcm -verify %t/test.cpp -DMODULE_NAME=a.b
+// RUN: %clang_cc1 -std=c++20 -I%t -fmodule-file=x.y=%t/x.y.pcm -fmodule-file=x=%t/x.pcm -verify %t/test.x.cpp
 
 //--- x.cppm
 export module x;
 export int a, b;
 
 //--- x.y.cppm
 export module x.y;
 export int c;
 
 //--- a.b.cppm
 export module a.b;
 export int d;
 
 //--- test.x.cpp
 module x;
 int use_1 = a; // ok
 
 int use_2 = b; // ok
 
 // There is no relation between module x and module x.y.
-int use_3 = c; // expected-error {{declaration of 'c' must be imported from module 'x.y'}}
-               // [e-mail]:2 {{not visible}}
+int use_3 = c; // expected-error {{use of undeclared identifier 'c'}}
 
 //--- test.cpp
 #ifdef INTERFACE
 export module MODULE_NAME;
 #else
 module MODULE_NAME;
 #endif
 

clang/test/CXX/module/dcl.dcl/dcl.module/dcl.module.interface/p1.cppm

 // RUN: %clang_cc1 -std=c++20 %s -verify -o /dev/null
 // RUN: %clang_cc1 -std=c++20 %s -DINTERFACE -verify -emit-module-interface -o %t
-// RUN: %clang_cc1 -std=c++20 %s -DIMPLEMENTATION -verify -fmodule-file=%t -o /dev/null
+// RUN: %clang_cc1 -std=c++20 %s -DIMPLEMENTATION -verify -fmodule-file=A=%t -o /dev/null
 //
 // RUN: %clang_cc1 -std=c++20 %s -DBUILT_AS_INTERFACE -emit-module-interface -verify -o /dev/null
 // RUN: %clang_cc1 -std=c++20 %s -DINTERFACE -DBUILT_AS_INTERFACE -emit-module-interface -verify -o /dev/null
 // RUN: %clang_cc1 -std=c++20 %s -DIMPLEMENTATION -DBUILT_AS_INTERFACE -emit-module-interface -verify -o /dev/null
 
 #if INTERFACE
 // expected-no-diagnostics
 export module A;

clang/test/CXX/module/dcl.dcl/dcl.module/p1.cpp

 // RUN: %clang_cc1 -std=c++20 -verify %s -DFOO=export -DBAR=export
 // RUN: %clang_cc1 -std=c++20 -verify %s -DFOO=export -DBAR=
 // RUN: %clang_cc1 -std=c++20 %s -DFOO=export -emit-module-interface -o %t
-// RUN: %clang_cc1 -std=c++20 %s -fmodule-file=%t -DFOO=
-// RUN: %clang_cc1 -std=c++20 %s -fmodule-file=%t -DBAR=export
-// RUN: %clang_cc1 -std=c++20 -verify %s -fmodule-file=%t -DFOO= -DBAR=export
+// RUN: %clang_cc1 -std=c++20 %s -fmodule-file=foo=%t -DFOO=
+// RUN: %clang_cc1 -std=c++20 %s -fmodule-file=foo=%t -DBAR=export
+// RUN: %clang_cc1 -std=c++20 -verify %s -fmodule-file=foo=%t -DFOO= -DBAR=export
 
 #ifdef FOO
 FOO module foo; // expected-note {{previous module declaration is here}}
 #endif
 
 #ifdef BAR
 BAR module bar; // expected-error {{translation unit contains multiple module declarations}}
 #endif

clang/test/CXX/module/dcl.dcl/dcl.module/p5.cpp

 // RUN: rm -rf %t
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %s -o %t -DINTERFACE
-// RUN: %clang_cc1 -std=c++20 -fmodule-file=%t %s -verify -DIMPLEMENTATION
-// RUN: %clang_cc1 -std=c++20 -fmodule-file=%t %s -verify -DEARLY_IMPLEMENTATION
-// RUN: %clang_cc1 -std=c++20 -fmodule-file=%t %s -verify -DUSER
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=Foo=%t %s -verify -DIMPLEMENTATION
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=Foo=%t %s -verify -DEARLY_IMPLEMENTATION
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=Foo=%t %s -verify -DUSER
 
 // expected-no-diagnostics
 
 #if defined(INTERFACE) || defined(EARLY_IMPLEMENTATION) || defined(IMPLEMENTATION)
 module;
 #endif
 
 #ifdef USER

clang/test/CXX/module/module.context/p7.cpp

 // RUN: rm -rf %t
 // RUN: split-file %s %t
 // RUN: cd %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-header-unit -xc++-header-unit-header std-10-6-ex1-decl.h \
 // RUN: -o decl.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-header-unit -xc++-header-unit-header std-10-6-ex1-defn.h \
 // RUN: -o defn.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface std-10-6-ex1-stuff.cpp \
 // RUN: -o stuff.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface std-10-6-ex1-M1.cpp \
-// RUN: -fmodule-file=stuff.pcm -o M1.pcm  -fmodule-file=defn.pcm
+// RUN: -fmodule-file=stuff=stuff.pcm -o M1.pcm  -fmodule-file=defn.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface std-10-6-ex1-M2.cpp \
-// RUN: -fmodule-file=stuff.pcm -o M2.pcm  -fmodule-file=decl.pcm
+// RUN: -fmodule-file=stuff=stuff.pcm -o M2.pcm  -fmodule-file=decl.pcm
 
 // RUN: %clang_cc1 -std=c++20 std-10-6-ex1-use.cpp \
-// RUN: -fmodule-file=M1.pcm -fmodule-file=M2.pcm  -fsyntax-only -verify
+// RUN: -fmodule-file=M1=M1.pcm -fmodule-file=M2=M2.pcm  -fsyntax-only -verify
 
 //--- std-10-6-ex1-decl.h
 struct X;
 
 //--- std-10-6-ex1-defn.h
 struct X {};
 
 //--- std-10-6-ex1-stuff.cpp

clang/test/CXX/module/module.interface/p1.cpp

 // RUN: %clang_cc1 -std=c++2a %s -DERRORS -verify
 // RUN: %clang_cc1 -std=c++2a %s -emit-module-interface -o %t.pcm
-// RUN: %clang_cc1 -std=c++2a %s -fmodule-file=%t.pcm -DIMPLEMENTATION -verify -Db=b2 -Dc=c2
+// RUN: %clang_cc1 -std=c++2a %s -fmodule-file=M=%t.pcm -DIMPLEMENTATION -verify -Db=b2 -Dc=c2
 
 module;
 
 #ifdef ERRORS
 export int a; // expected-error {{export declaration can only be used within a module purview}}
 #endif
 
 #ifndef IMPLEMENTATION

clang/test/CXX/module/module.interface/p2.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: %clang_cc1 -std=c++20 -x c++-header %S/Inputs/header.h -emit-header-unit -o %t/h.pcm
 // RUN: %clang_cc1 -std=c++20 %s -DX_INTERFACE -emit-module-interface -o %t/x.pcm
 // RUN: %clang_cc1 -std=c++20 %s -DY_INTERFACE -emit-module-interface -o %t/y.pcm
-// RUN: %clang_cc1 -std=c++20 %s -DINTERFACE -fmodule-file=%t/x.pcm -fmodule-file=%t/y.pcm -emit-module-interface -o %t/m.pcm
-// RUN: %clang_cc1 -std=c++20 %s -DIMPLEMENTATION -I%S/Inputs -fmodule-file=%t/h.pcm -fmodule-file=%t/m.pcm -verify
-// RUN: %clang_cc1 -std=c++20 %s -DUSER -I%S/Inputs -fmodule-file=%t/h.pcm -fmodule-file=%t/m.pcm -verify
+// RUN: %clang_cc1 -std=c++20 %s -DINTERFACE -fmodule-file=X=%t/x.pcm -fmodule-file=Y=%t/y.pcm -emit-module-interface -o %t/m.pcm
+// RUN: %clang_cc1 -std=c++20 %s -DIMPLEMENTATION -I%S/Inputs -fmodule-file=%t/h.pcm -fmodule-file=p2=%t/m.pcm -verify
+// RUN: %clang_cc1 -std=c++20 %s -DUSER -I%S/Inputs -fmodule-file=%t/h.pcm -fmodule-file=p2=%t/m.pcm -verify
 
 #if defined(X_INTERFACE)
 export module X;
 export int x;
 
 #elif defined(Y_INTERFACE)
 export module Y;
 export int y;

clang/test/CXX/module/module.unit/p8.cpp

 // RUN: echo 'export module foo; export int n;' > %t.cppm
 // RUN: %clang_cc1 -std=c++2a %t.cppm -emit-module-interface -o %t.pcm
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=0 %s
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=1 %s
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=2 %s
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=3 %s
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=4 %s
-// RUN: %clang_cc1 -std=c++2a -fmodule-file=%t.pcm -verify -DMODE=5 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=0 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=1 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=2 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=3 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=4 %s
+// RUN: %clang_cc1 -std=c++2a -fmodule-file=foo=%t.pcm -verify -DMODE=5 %s
 
 #if MODE == 0
 // no module declaration
 
 #elif MODE == 1
 // expected-no-diagnostics
 module foo; // Implementation, implicitly imports foo.
 #define IMPORTED
 
 #elif MODE == 2
-export module foo; // expected-error {{redefinition of module 'foo'}}
-// expected-note-re@* {{module loaded from '{{.*}}.pcm'}}
-#define IMPORTED
+export module foo;
 
 #elif MODE == 3
 export module bar; // A different module
 
 #elif MODE == 4
 module foo:bar; // Partition implementation
 //#define IMPORTED (we don't import foo here)
 
 #elif MODE == 5
 export module foo:bar; // Partition interface
 //#define IMPORTED  (we don't import foo here)
 
 #endif
 
 int k = n;
 #ifndef IMPORTED
-// expected-error@-2 {{declaration of 'n' must be imported from module 'foo' before it is required}}
-// expected-note@* {{not visible}}
+// expected-error@-2 {{use of undeclared identifier 'n'}}
 #endif

clang/test/Modules/cxx20-10-1-ex2.cpp

 
 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-1-ex2-tu1.cpp \
 // RUN:  -o %t/B_Y.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-1-ex2-tu2.cpp \
-// RUN:  -fmodule-file=%t/B_Y.pcm -o %t/B.pcm
+// RUN:  -fmodule-file=B:Y=%t/B_Y.pcm -o %t/B.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-1-ex2-tu3.cpp \
 // RUN:   -o %t/B_X1.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-1-ex2-tu4.cpp \
-// RUN:-fmodule-file=%t/B.pcm  -o %t/B_X2.pcm
+// RUN:-fmodule-file=B=%t/B.pcm  -o %t/B_X2.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/std10-1-ex2-tu5.cpp \
-// RUN:  -fmodule-file=%t/B.pcm  -o %t/b_tu5.o
+// RUN:  -fmodule-file=B=%t/B.pcm  -o %t/b_tu5.o
 
 // RUN: %clang_cc1 -std=c++20 -S %t/std10-1-ex2-tu6.cpp \
-// RUN:  -fmodule-file=%t/B.pcm  -o %t/b_tu6.s -verify
+// RUN:  -fmodule-file=B=%t/B.pcm  -o %t/b_tu6.s -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-1-ex2-tu7.cpp \
-// RUN: -fmodule-file=%t/B_X2.pcm  -o %t/B_X3.pcm -verify
+// RUN: -fmodule-file=B:X2=%t/B_X2.pcm  -o %t/B_X3.pcm -verify
 
 //--- std10-1-ex2-tu1.cpp
 module B:Y;
 int y();
 // expected-no-diagnostics
 
 //--- std10-1-ex2-tu2.cpp
 export module B;

clang/test/Modules/cxx20-10-2-ex2.cpp

 // Based on C++20 10.2 example 2.
 
 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-header-unit -I %t \
 // RUN: -xc++-user-header std-10-2-ex2-c.h -o %t/std-10-2-ex2-c.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std-10-2-ex2-tu1.cpp \
 // RUN:  -o  %t/X.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std-10-2-ex2-tu2.cpp \
-// RUN: -fmodule-file=%t/std-10-2-ex2-c.pcm -fmodule-file=%t/X.pcm \
+// RUN: -fmodule-file=%t/std-10-2-ex2-c.pcm -fmodule-file=X=%t/X.pcm \
 // RUN: -pedantic-errors -verify -o  %t/M.pcm
 
 //--- std-10-2-ex2-b.h
 int f();
 
 //--- std-10-2-ex2-c.h
 int g();
 

clang/test/Modules/cxx20-10-2-ex5.cpp

 // Based on C++20 10.2 example 5.
 
 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std-10-2-ex5-tu1.cpp \
 // RUN:  -o  %t/M.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/std-10-2-ex5-tu2.cpp \
-// RUN:  -fmodule-file=%t/M.pcm -o  %t/tu-2.o
+// RUN:  -fmodule-file=M=%t/M.pcm -o  %t/tu-2.o
 
 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/std-10-2-ex5-tu3.cpp \
-// RUN:  -fmodule-file=%t/M.pcm -verify -o %t/main.o
+// RUN:  -fmodule-file=M=%t/M.pcm -verify -o %t/main.o
 
 //--- std-10-2-ex5-tu1.cpp
 export module M;
 export struct X {
   static void f();
   struct Y {};
 };
 namespace {

clang/test/Modules/cxx20-10-3-ex1.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex1-tu1.cpp \
 // RUN:  -o %t/M_PartImpl.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex1-tu2.cpp \
-// RUN:  -fmodule-file=%t/M_PartImpl.pcm -o %t/M.pcm -verify
+// RUN:  -fmodule-file=M:PartImpl=%t/M_PartImpl.pcm -o %t/M.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex1-tu3.cpp \
 // RUN:  -o %t/M_Part.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex1-tu4.cpp \
-// RUN:  -fmodule-file=%t/M_Part.pcm -o %t/M.pcm
+// RUN:  -fmodule-file=M:Part=%t/M_Part.pcm -o %t/M.pcm
 
 //--- std10-3-ex1-tu1.cpp
 module M:PartImpl;
 
 // expected-no-diagnostics
 
 //--- std10-3-ex1-tu2.cpp
 export module M;

clang/test/Modules/cxx20-10-3-ex2.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex2-tu1.cpp \
 // RUN:  -o %t/M.pcm
 
 // RUN: %clang_cc1 -std=c++20 -S %t/std10-3-ex2-tu2.cpp \
-// RUN:  -fmodule-file=%t/M.pcm -o %t/tu_8.s -verify
+// RUN:  -fmodule-file=M=%t/M.pcm -o %t/tu_8.s -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/std10-3-ex2-tu3.cpp \
 // RUN:  -o %t/M.pcm -verify
 
 //--- std10-3-ex2-tu1.cpp
 export module M;
 
 //--- std10-3-ex2-tu2.cpp
 module M;
           // error: cannot import M in its own unit
 import M; // expected-error {{import of module 'M' appears within its own implementation}}
 
 //--- std10-3-ex2-tu3.cpp
 export module M;
           // error: cannot import M in its own unit
 import M; // expected-error {{import of module 'M' appears within its own interface}}

clang/test/Modules/cxx20-10-5-ex1.cpp

 // RUN: rm -rf %t
 // RUN: split-file %s %t
 // RUN: cd %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface std-10-5-ex1-interface.cpp \
 // RUN: -DBAD_FWD_DECL  -fsyntax-only -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface std-10-5-ex1-interface.cpp \
 // RUN: -o A.pcm
 
-// RUN: %clang_cc1 -std=c++20 std-10-5-ex1-use.cpp  -fmodule-file=A.pcm \
+// RUN: %clang_cc1 -std=c++20 std-10-5-ex1-use.cpp  -fmodule-file=A=A.pcm \
 // RUN:    -fsyntax-only -verify
 
 //--- std-10-5-ex1-interface.cpp
 
 export module A;
 #ifdef BAD_FWD_DECL
 export inline void fn_e(); // expected-error {{inline function not defined before the private module fragment}}
                            // [e-mail]:21 {{private module fragment begins here}}

clang/test/Modules/cxx20-import-diagnostics-a.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu1.cpp \
 // RUN:  -o %t/B.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu2.cpp \
 // RUN:  -o %t/C.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu3.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -fmodule-file=%t/C.pcm -o %t/AOK1.pcm
+// RUN:  -fmodule-file=B=%t/B.pcm -fmodule-file=C=%t/C.pcm -o %t/AOK1.pcm
 
 // RUN: %clang_cc1 -std=c++20 -S %t/import-diags-tu4.cpp \
-// RUN:  -fmodule-file=%t/AOK1.pcm -o %t/tu_3.s -verify
+// RUN:  -fmodule-file=AOK1=%t/AOK1.pcm -fmodule-file=C=%t/C.pcm -o %t/tu_3.s -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu5.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -fmodule-file=%t/C.pcm -o %t/BC.pcm -verify
+// RUN:  -fmodule-file=B=%t/B.pcm -fmodule-file=C=%t/C.pcm -o %t/BC.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -S %t/import-diags-tu6.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -fmodule-file=%t/C.pcm -o %t/tu_5.s -verify
+// RUN:  -fmodule-file=B=%t/B.pcm -fmodule-file=C=%t/C.pcm -o %t/tu_5.s -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu7.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -o %t/D.pcm -verify
+// RUN:  -fmodule-file=B=%t/B.pcm -o %t/D.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu8.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -o %t/D.pcm -verify
+// RUN:  -fmodule-file=B=%t/B.pcm -o %t/D.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -S %t/import-diags-tu9.cpp \
-// RUN:  -fmodule-file=%t/B.pcm -o %t/tu_8.s -verify
+// RUN:  -fmodule-file=B=%t/B.pcm -o %t/tu_8.s -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface %t/import-diags-tu10.cpp \
 // RUN:  -o %t/B.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-obj %t/import-diags-tu11.cpp \
-// RUN:  -fmodule-file=%t/C.pcm  -o %t/impl.o
+// RUN:  -fmodule-file=C=%t/C.pcm  -o %t/impl.o
 
 // Test diagnostics for incorrect module import sequences.
 
 //--- import-diags-tu1.cpp
 
 export module B;
 
 int foo ();

clang/test/Modules/cxx20-import-diagnostics-b.cpp

 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/a.cpp -o %t/a.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/c.cpp \
-// RUN: -fmodule-file=%t/a.pcm -o %t/c.pcm
+// RUN: -fmodule-file=a=%t/a.pcm -o %t/c.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/d.cpp \
-// RUN: -fmodule-file=%t/a.pcm -o %t/d.pcm
+// RUN: -fmodule-file=a=%t/a.pcm -o %t/d.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/e.cpp \
-// RUN: -fmodule-file=%t/a.pcm -o %t/e.pcm
+// RUN: -fmodule-file=a=%t/a.pcm -o %t/e.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/a-part.cpp \
 // RUN: -o %t/a-part.pcm
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/f.cpp \
-// RUN: -fmodule-file=%t/a.pcm -o %t/f.pcm -verify
+// RUN: -fmodule-file=a=%t/a.pcm -o %t/f.pcm -verify
 
 // RUN: %clang_cc1 -std=c++20 -emit-module-interface  %t/g.cpp \
-// RUN: -fmodule-file=%t/a.pcm -o %t/g.pcm -verify
+// RUN: -fmodule-file=a=%t/a.pcm -o %t/g.pcm -verify
 
 //--- a.cpp
 export module a;
 
 //--- b.hpp
 import a;
 
 //--- c.cpp

clang/test/Modules/eagerly-load-cxx-named-modules.cppm

+// RUN: rm -rf %t
+// RUN: mkdir %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
+// RUN: %clang_cc1 -std=c++20 %t/user.cpp -fmodule-file=%t/a.pcm -fsyntax-only \
+// RUN:    2>&1 | FileCheck %t/user.cpp
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -emit-module-interface -o %t/b.pcm \
+// RUN:    -fprebuilt-module-path=%t
+// RUN: %clang_cc1 -std=c++20 %t/b.pcm -S -emit-llvm 2>&1 -o - | FileCheck %t/b.cppm
+
+//--- a.cppm
+export module a;
+
+//--- b.cppm
+export module b;
+import a;
+
+// CHECK-NOT: warning
+
+//--- user.cpp
+import a;
+
+// CHECK: the form '-fmodule-file=<BMI-path>' is deprecated for standard C++ named modules;consider to use '-fmodule-file=<module-name>=<BMI-path>' instead

clang/test/Modules/named-modules-adl-2.cppm

 // RUN: rm -rf %t
 // RUN: split-file %s %t
 // RUN: cd %t
 //
 // RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
-// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=%t/a.pcm -emit-module-interface -o %t/b.pcm
-// RUN: %clang_cc1 -std=c++20 %t/c.cppm -fmodule-file=%t/b.pcm -fsyntax-only -verify
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=a=%t/a.pcm -emit-module-interface -o %t/b.pcm
+// RUN: %clang_cc1 -std=c++20 %t/c.cppm -fmodule-file=b=%t/b.pcm -fsyntax-only -verify
 
 //--- a.cppm
 export module a;
 
 export template<typename T>
 void a(T x) {
   +x;
 }

clang/test/Modules/named-modules-adl.cppm

 // RUN: rm -rf %t
 // RUN: split-file %s %t
 // RUN: cd %t
 //
 // RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
-// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=%t/a.pcm -fsyntax-only -verify
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -fmodule-file=a=%t/a.pcm -fsyntax-only -verify
 
 //--- a.h
 namespace n {
 
 struct s { };
 
 void operator+(s, int) {
 }

clang/test/Modules/pr60036.cppm

 // Test case from https://github.com/llvm/llvm-project/issues/60036
 //
 // RUN: rm -rf %t
 // RUN: mkdir -p %t
 // RUN: split-file %s %t
 //
 // RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
 // RUN: %clang_cc1 -std=c++20 %t/b.cppm -emit-module-interface -fprebuilt-module-path=%t -o %t/b.pcm
 // RUN: %clang_cc1 -std=c++20 %t/c.cppm -emit-module-interface -fprebuilt-module-path=%t -o %t/c.pcm
 // RUN: %clang_cc1 -std=c++20 %t/d.cppm -emit-module-interface -fprebuilt-module-path=%t -o %t/d.pcm
 // RUN: %clang_cc1 -std=c++20 %t/e.cppm -emit-module-interface -fprebuilt-module-path=%t -o %t/e.pcm
 // RUN: %clang_cc1 -std=c++20 %t/f.cppm -emit-module-interface -fprebuilt-module-path=%t -o %t/f.pcm
 // RUN: %clang_cc1 -std=c++20 %t/g.cppm -fprebuilt-module-path=%t -verify -fsyntax-only 
 //
 // Tests that the behavior is fine with specifying module file with `-fmodule-file`.
 // RUN: %clang_cc1 -std=c++20 %t/a.cppm -emit-module-interface -o %t/a.pcm
-// RUN: %clang_cc1 -std=c++20 %t/b.cppm -emit-module-interface -fmodule-file=%t/a.pcm -o %t/b.pcm
-// RUN: %clang_cc1 -std=c++20 %t/c.cppm -emit-module-interface -fmodule-file=%t/a.pcm -o %t/c.pcm
+// RUN: %clang_cc1 -std=c++20 %t/b.cppm -emit-module-interface -fmodule-file=a=%t/a.pcm -o %t/b.pcm
+// RUN: %clang_cc1 -std=c++20 %t/c.cppm -emit-module-interface -fmodule-file=a=%t/a.pcm -o %t/c.pcm
 // RUN: %clang_cc1 -std=c++20 %t/d.cppm -emit-module-interface  -o %t/d.pcm
-// RUN: %clang_cc1 -std=c++20 %t/e.cppm -emit-module-interface -fmodule-file=%t/d.pcm -o %t/e.pcm
-// RUN: %clang_cc1 -std=c++20 %t/f.cppm -emit-module-interface -fmodule-file=%t/a.pcm -fmodule-file=%t/b.pcm -fmodule-file=%t/c.pcm -fmodule-file=%t/d.pcm -o %t/f.pcm
-// RUN: %clang_cc1 -std=c++20 %t/g.cppm -fmodule-file=%t/e.pcm -fmodule-file=%t/f.pcm -verify -fsyntax-only 
+// RUN: %clang_cc1 -std=c++20 %t/e.cppm -emit-module-interface -fmodule-file=d=%t/d.pcm -o %t/e.pcm
+// RUN: %clang_cc1 -std=c++20 %t/f.cppm -emit-module-interface -fmodule-file=a=%t/a.pcm -fmodule-file=b=%t/b.pcm -fmodule-file=c=%t/c.pcm -fmodule-file=d=%t/d.pcm -o %t/f.pcm
+// RUN: %clang_cc1 -std=c++20 %t/g.cppm -fmodule-file=e=%t/e.pcm -fmodule-file=f=%t/f.pcm -verify -fsyntax-only 
 
 //--- a.cppm
 export module a;
 
 export template<typename>
 struct a;
 
 template<typename T>

clang/test/SemaCXX/modules.cppm

 // RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -o %t.0.pcm -verify -DTEST=0
 // RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -o %t.1.pcm -verify -DTEST=1
-// RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -fmodule-file=%t.0.pcm -o %t.2.pcm -verify -DTEST=2
-// RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -fmodule-file=%t.0.pcm -o %t.3.pcm -verify -Dfoo=bar -DTEST=3
+// RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -fmodule-file=foo=%t.0.pcm -o %t.2.pcm -verify -DTEST=2
+// RUN:     %clang_cc1 -std=c++20 -emit-module-interface %s -fmodule-file=foo=%t.0.pcm -o %t.3.pcm -verify -Dfoo=bar -DTEST=3
 
-#if TEST == 0
+#if TEST == 0 || TEST == 2
 // expected-no-diagnostics
 #endif
 
 export module foo;
-#if TEST == 2
-// expected-error@-2 {{redefinition of module 'foo'}}
-// [e-mail]:* {{loaded from}}
-#endif
 
 static int m;
-#if TEST == 2
-// expected-error@-2 {{redefinition of '}}
-// expected-note@-3 {{unguarded header; consider using #ifdef guards or #pragma once}}
-// FIXME: We should drop the "header from" in this diagnostic.
-// [e-mail]:1 {{'{{.*}}modules.cppm' included multiple times, additional include site in header from module 'foo'}}
-#endif
+
 int n;
-#if TEST == 2
-// expected-error@-2 {{redefinition of '}}
-// expected-note@-3 {{unguarded header; consider using #ifdef guards or #pragma once}}
-// FIXME: We should drop the "header from" in this diagnostic.
-// [e-mail]:1 {{'{{.*}}modules.cppm' included multiple times, additional include site in header from module 'foo'}}
-#endif
 
 #if TEST == 0
 export {
   int a;
   int b;
   constexpr int *p = &n;
 }
 export int c;
 
 namespace N {
 export void f() {}
 } // namespace N
 
 export struct T {
 } t;
 #elif TEST == 3
-int use_a = a; // expected-error {{declaration of 'a' must be imported from module 'foo' before it is required}}
-// expected-note@-14 {{declaration here is not visible}}
+int use_a = a; // expected-error {{use of undeclared identifier 'a'}}
 
 #undef foo
 import foo; // expected-error {{imports must immediately follow the module declaration}}
 
 export {}
 export {  // expected-note {{begins here}}
   ;       // expected-warning {{ISO C++20 does not permit an empty declaration to appear in an export block}}
 }
 export {               // expected-note {{begins here}}
   static_assert(true); // expected-warning {{ISO C++20 does not permit a static_assert declaration to appear in an export block}}
 }
 
-int use_b = b;
+int use_b = b; // expected-error{{use of undeclared identifier 'b'}}
 int use_n = n; // FIXME: this should not be visible, because it is not exported
 
 extern int n;
-static_assert(&n != p);
+static_assert(&n != p); // expected-error{{use of undeclared identifier 'p'}}
 #endif
 
 #if TEST == 1
 struct S {
   export int n;        // expected-error {{expected member name or ';'}}
   export static int n; // expected-error {{expected member name or ';'}}
 };
 #endif