[c++20] Parsing support for module-declarations, import-declarations,

and the global and private module fragment.

For now, the private module fragment introducer is ignored, but use of
the global module fragment introducer should be properly enforced.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@358353 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 107 insertions, 21 deletions

diff --git a/test/CXX/basic/basic.link/p1.cpp b/test/CXX/basic/basic.link/p1.cpp
new file mode 100644
index 0000000000..b94e57017f
--- /dev/null
+++ b/test/CXX/basic/basic.link/p1.cpp
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -std=c++2a -verify %s
+// RUN: %clang_cc1 -std=c++2a -verify -DNO_GLOBAL_FRAG %s
+// RUN: %clang_cc1 -std=c++2a -verify -DNO_MODULE_DECL %s
+// RUN: %clang_cc1 -std=c++2a -verify -DEXPORT_FRAGS %s
+
+#ifdef NO_GLOBAL_FRAG
+// expected-error@#mod-decl {{module declaration must occur at the start of the translation unit}}
+// expected-note@1 {{add 'module;' to the start of the file to introduce a global module fragment}}
+#else
+#ifdef EXPORT_FRAGS
+export // expected-error {{global module fragment cannot be exported}}
+#endif
+module; // #glob-frag
+#endif
+
+extern int a; // #a1
+
+#ifdef NO_MODULE_DECL
+// expected-error@#glob-frag {{missing 'module' declaration at end of global module fragment introduced here}}
+#else
+export module Foo; // #mod-decl
+
+// expected-error@#a2 {{declaration of 'a' in module Foo follows declaration in the global module}}
+// expected-note@#a1 {{previous decl}}
+#endif
+
+int a; // #a2
+extern int b;
+
+module; // expected-error {{'module;' introducing a global module fragment can appear only at the start of the translation unit}}
+
+#ifdef EXPORT_FRAGS
+export // expected-error {{private module fragment cannot be exported}}
+#endif
+module :private;
+
+int b; // ok
diff --git a/test/CXX/basic/basic.link/p3.cpp b/test/CXX/basic/basic.link/p3.cpp
new file mode 100644
index 0000000000..23f39d11b6
--- /dev/null
+++ b/test/CXX/basic/basic.link/p3.cpp
@@ -0,0 +1,53 @@
+// RUN: %clang_cc1 -std=c++2a -verify %s
+// RUN: %clang_cc1 -std=c++2a -verify %s -DIMPORT_ERROR=1
+// RUN: %clang_cc1 -std=c++2a -verify %s -DIMPORT_ERROR=2
+
+module;
+
+#if IMPORT_ERROR != 2
+struct import { struct inner {}; };
+#endif
+struct module { struct inner {}; };
+
+constexpr int n = 123;
+
+export module m; // #1
+
+// Import errors are fatal, so we test them in isolation.
+#if IMPORT_ERROR == 1
+import x = {}; // expected-error {{module 'x' not found}}
+
+#elif IMPORT_ERROR == 2
+struct X;
+template<int> struct import;
+template<> struct import<n> {
+  static X y;
+};
+
+// This is not valid because the 'import <n>' is a pp-import, even though it
+// grammatically can't possibly be an import declaration.
+struct X {} import<n>::y; // expected-error {{'n' file not found}}
+
+#else
+module y = {}; // expected-error {{multiple module declarations}} expected-error 2{{}}
+// expected-note@#1 {{previous module declaration}}
+
+::import x = {};
+::module y = {};
+
+import::inner xi = {};
+module::inner yi = {};
+
+namespace N {
+  module a;
+  import b;
+}
+
+extern "C++" module cxxm;
+extern "C++" import cxxi;
+
+template<typename T> module module_var_template;
+
+// This is a variable named 'import' that shadows the type 'import' above.
+struct X {} import;
+#endif
diff --git a/test/CXX/module/module.unit/p3.cpp b/test/CXX/module/module.unit/p3.cpp
new file mode 100644
index 0000000000..2e08f4a9a8
--- /dev/null
+++ b/test/CXX/module/module.unit/p3.cpp
@@ -0,0 +1,4 @@
+// RUN: %clang_cc1 -std=c++2a -verify %s
+
+export module foo:bar; // expected-error {{sorry, module partitions are not yet supported}}
+import :baz; // expected-error {{sorry, module partitions are not yet supported}}
diff --git a/test/CXX/modules-ts/basic/basic.link/module-declaration.cpp b/test/CXX/modules-ts/basic/basic.link/module-declaration.cpp
index feb0afdda0..7615536b81 100644
--- a/test/CXX/modules-ts/basic/basic.link/module-declaration.cpp
+++ b/test/CXX/modules-ts/basic/basic.link/module-declaration.cpp
@@ -10,47 +10,39 @@
 //
 // Module implementation for unknown and known module. (The former is ill-formed.)
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=1 -DEXPORT= -DPARTITION= -DMODULE_NAME=z
+// RUN:            -DTEST=1 -DEXPORT= -DMODULE_NAME=z
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=2 -DEXPORT= -DPARTITION= -DMODULE_NAME=x
+// 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++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=3 -DEXPORT=export -DPARTITION= -DMODULE_NAME=z
+// RUN:            -DTEST=3 -DEXPORT=export -DMODULE_NAME=z
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=4 -DEXPORT=export -DPARTITION= -DMODULE_NAME=x
-//
-// Defining a module partition.
-// RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=5 -DEXPORT=export -DPARTITION=partition -DMODULE_NAME=z
-// RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=6 -DEXPORT= -DPARTITION=partition -DMODULE_NAME=z
+// RUN:            -DTEST=4 -DEXPORT=export -DMODULE_NAME=x
 //
 // Miscellaneous syntax.
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=7 -DEXPORT= -DPARTITION=elderberry -DMODULE_NAME=z
+// RUN:            -DTEST=7 -DEXPORT=export -DMODULE_NAME='z elderberry'
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=8 -DEXPORT=export -DPARTITION= -DMODULE_NAME='z [[]]'
+// RUN:            -DTEST=8 -DEXPORT=export -DMODULE_NAME='z [[]]'
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=9 -DEXPORT=export -DPARTITION= -DMODULE_NAME='z [[fancy]]'
+// RUN:            -DTEST=9 -DEXPORT=export -DMODULE_NAME='z [[fancy]]'
 // RUN: %clang_cc1 -std=c++1z -fmodules-ts -I%t -fmodule-file=%t/x.y.pcm -verify %s \
-// RUN:            -DTEST=10 -DEXPORT=export -DPARTITION= -DMODULE_NAME='z [[maybe_unused]]'
+// RUN:            -DTEST=10 -DEXPORT=export -DMODULE_NAME='z [[maybe_unused]]'
 
-EXPORT module PARTITION MODULE_NAME;
+EXPORT module MODULE_NAME;
 #if TEST == 4
 // expected-error@-2 {{redefinition of module 'x'}}
 // expected-note-re@module-declaration.cpp:* {{loaded from '{{.*[/\\]}}x.pcm'}}
-#elif TEST == 6
-// expected-error@-5 {{module partition must be declared 'export'}}
 #elif TEST == 7
-// expected-error@-7 {{expected ';'}} expected-error@-7 {{requires a type specifier}} expected-error@-7 {{definition of module 'elderberry' is not available}}
+// expected-error@-5 {{expected ';'}} expected-error@-5 {{requires a type specifier}}
 #elif TEST == 9
-// expected-warning@-9 {{unknown attribute 'fancy' ignored}}
+// expected-warning@-7 {{unknown attribute 'fancy' ignored}}
 #elif TEST == 10
-// expected-error-re@-11 {{'maybe_unused' attribute cannot be applied to a module{{$}}}}
+// expected-error-re@-9 {{'maybe_unused' attribute cannot be applied to a module{{$}}}}
 #elif TEST == 1
-// expected-error@-13 {{definition of module 'z' is not available}}
+// expected-error@-11 {{definition of module 'z' is not available}}
 #else
 // expected-no-diagnostics
 #endif