[libc][annex_k] Add Annex K support macros.

[bassiounix]

RFC https://discourse.llvm.org/t/rfc-bounds-checking-interfaces-for-llvm-libc/87685

Add internal support macros required by Annex K interface in LLVM libc.

[bassiounix]

• [libc][annex_k] Add constraint_handler_t. #163239 : 3 dependent PRs (#163309 , #163869 , #164089 )
• [libc][annex_k] Add rsize_t. #163238
• [libc][annex_k] Add errno_t. #163094
• [libc][annex_k] Add Annex K support macros. #163100 👈 (View in Graphite)
• main

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[llvmbot]

@llvm/pr-subscribers-libc

Author: Muhammad Bassiouni (bassiounix)

Changes

RFC https://discourse.llvm.org/t/rfc-bounds-checking-interfaces-for-llvm-libc/87685

Add internal support macros required by Annex K interface in LLVM libc.

---

Full diff: https://github.com/llvm/llvm-project/pull/163100.diff

2 Files Affected:

• (modified) libc/include/llvm-libc-macros/CMakeLists.txt (+6)
• (added) libc/include/llvm-libc-macros/annex-k-macros.h (+26)

diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index 76c03d913ee12..f41da94e1d726 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -31,6 +31,12 @@ if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
   add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
 endif()
 
+add_macro_header(
+  annex_k_macros
+  HDR
+    annex-k-macros.h
+)
+
 add_macro_header(
   assert_macros
   HDR
diff --git a/libc/include/llvm-libc-macros/annex-k-macros.h b/libc/include/llvm-libc-macros/annex-k-macros.h
new file mode 100644
index 0000000000000..c3f845cd77574
--- /dev/null
+++ b/libc/include/llvm-libc-macros/annex-k-macros.h
@@ -0,0 +1,26 @@
+//===-- Definition of macros to be used with Annex K functions ------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_INCLUDE_LLVM_LIBC_MACROS_ANNEX_K_MACROS_H
+#define LLVM_LIBC_INCLUDE_LLVM_LIBC_MACROS_ANNEX_K_MACROS_H
+
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) ||              \
+    (defined(__cplusplus) && __cplusplus >= 201703L)
+
+// TODO(bassiounix): Who should def this macro (clang vs libc)? Where?
+#define __STDC_LIB_EXT1__ 201112L
+
+#if defined(__STDC_WANT_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__ == 1
+
+#define LIBC_HAS_ANNEX_K
+
+#endif // defined(__STDC_WANT_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__ == 1
+
+#endif // (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) ||
+       // (defined(__cplusplus) && __cplusplus >= 201703L)
+#endif // LLVM_LIBC_INCLUDE_LLVM_LIBC_MACROS_ANNEX_K_MACROS_H

[frederick-vs-ja]

Per C23/N3220 6.10.10 Predefined macro names, __STDC_LIB_EXT1__ is (conditionally) predefined. So perhaps Clang should define it while libc should not.

[bassiounix]

I am commenting this define for now. The standard specifies that any implementation that adheres to the standard should conditionally define __STDC_LIB_EXT1__.
We haven't fully implemented Annex K yet, so no need to introduce it now.

[michaelrj-google]

Looks good to me once the question of if the compiler or the library should define the macro is resolved.

[bassiounix]

Looks good to me once the question of if the compiler or the library should define the macro is resolved.

I am commenting this define for now. The standard specifies that any implementation that adheres to the standard should conditionally define __STDC_LIB_EXT1__.
We haven't fully implemented Annex K yet, so no need to introduce it now.

[bassiounix]

Merge activity

• Oct 22, 6:23 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Oct 22, 6:25 PM UTC: @bassiounix merged this pull request with Graphite.