move <meta> out of include_c++/experimental and define __cpp_lib_reflection, fix for [GH #36]

dev_tools/bin/edg-pack-cpfe-ce

@@ -192,8 +192,7 @@ def _add_experimental_headers_to_base(tar: tarfile.TarFile,
   '''
   header_dir = source_dir / 'include_c++' / 'experimental'
   if not header_dir.exists():
-    eprint(f"{header_dir} does not exist")
-    sys.exit(1)
+    return
 
   edgpack.add_header_files_to_tar(
     tar,

include_c++/Changes

@@ -1,3 +1,15 @@
+Version 7.1
+
+10/22/26 [GH #36]
+<meta> is no longer in the experimental subdirectory
+
+The <meta> header (meta.stdh) has been moved out of the experimental
+subdirectory, so it is now found in the same way as the other headers in
+this directory.  It also defines the library feature-test macro
+__cpp_lib_reflection, with the value 202603L that GCC 16 uses.
+
+
+-------------------------------------------------------------------------------
 Version 7.0, September 28, 2026
 
 No changes.

include_c++/experimental/meta.stdh → include_c++/meta.stdh

@@ -8,12 +8,18 @@ SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 /*
 meta -- Include file for std::meta facilities
 
-This is an experimental header approximating support for facilities as
-described in the C++ committee's paper P2996.
+This header approximates support for facilities as described in the C++
+committee's paper P2996.
 */
 #ifndef __META_STDH
 #define __META_STDH
 
+/* The library feature-test macro for reflection, with the value GCC 16
+   uses.  As in GCC, it is defined only when reflection is enabled. */
+#if defined(__cpp_impl_reflection) && !defined(__cpp_lib_reflection)
+#define __cpp_lib_reflection 202603L
+#endif /* defined(__cpp_impl_reflection) && ... */
+
 #include <concepts>
 #include <initializer_list>
 #include <memory>

src/interpret.c

@@ -20597,7 +20597,7 @@ See do_constexpr_intrinsic_call for the meaning of the parameters.
 
 /*
 The enumerators of std::meta::operators, in the order in which
-<experimental/meta> declares them, each paired with the operator-name kind
+<meta> declares them, each paired with the operator-name kind
 that denotes the same operator in the front end.  An enumerator's value is its
 position in this list, counting from one, and its symbol is the spelling that
 opname_names records for the operator-name kind, so both directions of the
@@ -20720,7 +20720,7 @@ Implement std::meta::operator_of(info): the std::meta::operators enumerator for
 the operator function represented by the argument (which may be an operator
 function or operator function template).  The result is stored as the value of
 that enumerator, whose ordinal matches the enumerator sequence declared in
-<experimental/meta> (the enumeration has an integer underlying type, so the
+<meta> (the enumeration has an integer underlying type, so the
 value is written in integer form).  The evaluation fails if the reflection does
 not designate an operator function.
 

src/macro.c

@@ -12465,7 +12465,7 @@ command line -D options.
     }  /* if */
     if (injection_enabled) {
       /* Likewise for token injection, which the EDG-provided
-         <experimental/meta.stdh> header uses to write token sequences. */
+         meta.stdh header uses to write token sequences. */
       (void)enter_predef_macro("1", "__EDG_INJECTION_ENABLED__",
                                /*cannot_be_redefined=*/TRUE,
                                /*ref_suppresses_pch_file=*/FALSE);

tests/expectations/edg_x86_32/changes.log

@@ -7,4 +7,5 @@ EDGcpfe28436.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[6.8] GNU/clang compatibility: larg
 EDGcpfe28794.sft.cpp:fp:-DTEST_NUMBER=1:REQUIREMENTS NOT MET:Abort on __builtin_bit_cast in dependent context
 EDGcpfe8330.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[4.1] Microsoft compatibility: Calling conventions and pointer-to-member-function
 EDGcpfe9522.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[4.1] Microsoft compatibility: __ptr64 on 64-bit targets
+GH36.sft.cpp:fp:-DTEST_NUMBER=1 --c++26 --set_flag reflection:REQUIREMENTS NOT MET:[GH #36] <meta> defines __cpp_lib_reflection
 GH38.sft.cpp:fn:-DTEST_NUMBER=1 --gnu_version 150200:REQUIREMENTS NOT MET:[GH #38] Integer value limits for a 128-bit host integer representation

tests/expectations/edg_x86_32_cp/changes.log

@@ -13,4 +13,5 @@ EDGcpfe28436.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[6.8] GNU/clang compatibility: larg
 EDGcpfe28794.sft.cpp:fp:-DTEST_NUMBER=1:REQUIREMENTS NOT MET:Abort on __builtin_bit_cast in dependent context
 EDGcpfe8330.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[4.1] Microsoft compatibility: Calling conventions and pointer-to-member-function
 EDGcpfe9522.sft.cpp:fp:-DTEST_NUMBER=1:FAIL:[4.1] Microsoft compatibility: __ptr64 on 64-bit targets
+GH36.sft.cpp:fp:-DTEST_NUMBER=1 --c++26 --set_flag reflection:REQUIREMENTS NOT MET:[GH #36] <meta> defines __cpp_lib_reflection
 GH38.sft.cpp:fn:-DTEST_NUMBER=1 --gnu_version 150200:REQUIREMENTS NOT MET:[GH #38] Integer value limits for a 128-bit host integer representation

tests/tests/changes/.GH36.rto/default.1.1.txt

@@ -0,0 +1 @@
+fe_only -DTEST_NUMBER=1 --c++26 --set_flag reflection Test_name.c

tests/tests/changes/.includes/meta/meta.stdh

@@ -0,0 +1 @@
+../../../../../include_c++/meta.stdh

tests/tests/changes/GH36.sft.cpp

@@ -0,0 +1,17 @@
+//type:fp
+//options:--c++26 --set_flag reflection
+//use_system_includes: true
+//edg_header_pack: meta
+//require:TARG_SUPPORTS_X86_64 1
+//remark:[GH #36] <meta> defines __cpp_lib_reflection
+// 10/22/26 [GH #36]
+//
+// The EDG-provided <meta> header defines the library feature-test macro
+// __cpp_lib_reflection, with the value GCC 16 uses.  The GCC system headers
+// that <meta> includes are not accepted for 32-bit targets, so the test
+// requires an x86-64 target.
+
+#include <meta>
+
+static_assert(__cpp_lib_reflection == 202603L, "");
+static_assert(__cpp_lib_reflection == __cpp_impl_reflection, "");

tests/tests/cwg/.cwg3122.rto/default.1.1.txt

@@ -1,7 +1,7 @@
 fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
-"Test_name.c", line 4: catastrophic error: cannot open source file "meta"
-  #include <meta>
-                 ^
+"/edg/workspace/bases/docker/dev-env/gcc/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
 
 1 catastrophic error detected in the compilation of "Test_name.c".
 Compilation terminated.

tests/tests/cwg/.cwg3122.rto/edg_x86_32.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.

tests/tests/cwg/.cwg3122.rto/edg_x86_32_cp.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.

tests/tests/cwg/.cwg3145.rto/default.1.1.txt

@@ -1,7 +1,7 @@
 fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
-"Test_name.c", line 4: catastrophic error: cannot open source file "meta"
-  #include <meta>
-                 ^
+"/edg/workspace/bases/docker/dev-env/gcc/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
 
 1 catastrophic error detected in the compilation of "Test_name.c".
 Compilation terminated.

tests/tests/cwg/.cwg3145.rto/edg_x86_32.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.

tests/tests/cwg/.cwg3145.rto/edg_x86_32_cp.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.

tests/tests/cwg/.cwg3162.rto/default.1.1.txt

@@ -1,7 +1,7 @@
 fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
-"Test_name.c", line 4: catastrophic error: cannot open source file "meta"
-  #include <meta>
-                 ^
+"/edg/workspace/bases/docker/dev-env/gcc/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
 
 1 catastrophic error detected in the compilation of "Test_name.c".
 Compilation terminated.

tests/tests/cwg/.cwg3162.rto/edg_x86_32.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.

tests/tests/cwg/.cwg3162.rto/edg_x86_32_cp.1.1.txt

@@ -0,0 +1,7 @@
+fe_only -DTEST_NUMBER=1 -A --c++26 --set_flag reflection Test_name.c
+"/edg/workspace/bases/docker/dev-env/gcc-i686/include/meta.stdh", line 23: catastrophic error: cannot open source file "concepts"
+  #include <concepts>
+                     ^
+
+1 catastrophic error detected in the compilation of "Test_name.c".
+Compilation terminated.