--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/Modules/extensions.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,44 @@
+// Test creation of modules that include extension blocks.
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -ftest-module-file-extension=clang.testA:1:5:0:user_info_for_A -ftest-module-file-extension=clang.testB:2:3:0:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s
+
+// Make sure the extension blocks are actually there.
+// RUN: llvm-bcanalyzer %t/ExtensionTestA.pcm | FileCheck -check-prefix=CHECK-BCANALYZER %s
+// RUN: %clang_cc1 -module-file-info %t/ExtensionTestA.pcm | FileCheck -check-prefix=CHECK-INFO %s
+
+// Make sure that the readers are able to check the metadata.
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -ftest-module-file-extension=clang.testA:1:5:0:user_info_for_A -ftest-module-file-extension=clang.testB:2:3:0:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -ftest-module-file-extension=clang.testA:1:3:0:user_info_for_A -ftest-module-file-extension=clang.testB:3:2:0:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s -verify
+
+// Make sure that extension blocks can be part of the module hash.
+// We test this in an obscure way, by making sure we don't get conflicts when
+// using different "versions" of the extensions. Above, the "-verify" test
+// checks that such conflicts produce errors.
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -ftest-module-file-extension=clang.testA:1:5:1:user_info_for_A -ftest-module-file-extension=clang.testB:2:3:1:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -ftest-module-file-extension=clang.testA:1:3:1:user_info_for_A -ftest-module-file-extension=clang.testB:3:2:1:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -ftest-module-file-extension=clang.testA:2:5:0:user_info_for_A -ftest-module-file-extension=clang.testB:7:3:0:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s
+
+// Make sure we can read the message back.
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -ftest-module-file-extension=clang.testA:1:5:0:user_info_for_A -ftest-module-file-extension=clang.testB:2:3:0:user_info_for_B -fmodules-cache-path=%t -I %S/Inputs %s > %t.log 2>&1
+// RUN: FileCheck -check-prefix=CHECK-MESSAGE %s < %t.log
+
+// Make sure we diagnose duplicate module file extensions.
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fdisable-module-hash -ftest-module-file-extension=clang.testA:1:5:0:user_info_for_A -ftest-module-file-extension=clang.testA:1:5:0:user_info_for_A -fmodules-cache-path=%t -I %S/Inputs %s > %t.log 2>&1
+// RUN: FileCheck -check-prefix=CHECK-DUPLICATE %s < %t.log
+
+#include "ExtensionTestA.h"
+// expected-error@-1{{test module file extension 'clang.testA' has different version (1.5) than expected (1.3)}}
+// expected-error@-2{{test module file extension 'clang.testB' has different version (2.3) than expected (3.2)}}
+
+// CHECK-BCANALYZER: {{Block ID.*EXTENSION_BLOCK}}
+// CHECK-BCANALYZER: {{100.00.*EXTENSION_METADATA}}
+
+// CHECK-INFO: Module file extension 'clang.testA' 1.5: user_info_for_A
+// CHECK-INFO: Module file extension 'clang.testB' 2.3: user_info_for_B
+
+// CHECK-MESSAGE: Read extension block message: Hello from clang.testA v1.5
+// CHECK-MESSAGE: Read extension block message: Hello from clang.testB v2.3
+
+// CHECK-DUPLICATE: warning: duplicate module file extension block name 'clang.testA'