[libcxx-commits] [libcxx] b8456e2 - [libc++][AIX] Fixup problems with ABI list checking (#155643)

[via libcxx-commits]

Author: David Tenty
Date: 2025-08-27T18:28:26-04:00
New Revision: b8456e2a9698aa927d7b3f9c38213f3219aa0498

URL: https://github.com/llvm/llvm-project/commit/b8456e2a9698aa927d7b3f9c38213f3219aa0498
DIFF: https://github.com/llvm/llvm-project/commit/b8456e2a9698aa927d7b3f9c38213f3219aa0498.diff

LOG: [libc++][AIX] Fixup problems with ABI list checking (#155643)

There are some problems with our ABI list checking exposed by recent
compiler/cmake upgrades.

- For symcheck, there are typos in how XCOFF magic are defined, we
intended the second two digits to be a hex value, but our syntax doesn't
say that. Thus this will never match a valid XCOFF file.
- AIX triples can have version numbers. Those need to be discarded when
looking for an libc++ ABI list, like we do for other targets.

Added: 
    

Modified: 
    libcxx/lib/abi/CMakeLists.txt
    libcxx/utils/libcxx/sym_check/util.py

Removed: 
    


################################################################################
diff  --git a/libcxx/lib/abi/CMakeLists.txt b/libcxx/lib/abi/CMakeLists.txt
index 7c08bd06c50b2..8f277aad2dcd5 100644
--- a/libcxx/lib/abi/CMakeLists.txt
+++ b/libcxx/lib/abi/CMakeLists.txt
@@ -16,6 +16,9 @@ function(cxx_abi_list_identifier result triple abi_library abi_version unstable
   elseif("${triple}" MATCHES "freebsd")
     # Ignore the major and minor versions of freebsd targets.
     string(REGEX REPLACE "freebsd[0-9]+\\.[0-9]+" "freebsd" triple "${triple}")
+  elseif("${triple}" MATCHES "aix")
+    # Ignore the V.R.M.F version string of aix targets.
+    string(REGEX REPLACE "aix[0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+" "aix" triple "${triple}")
   endif()
   list(APPEND abi_properties "${triple}")
   list(APPEND abi_properties "${abi_library}")

diff  --git a/libcxx/utils/libcxx/sym_check/util.py b/libcxx/utils/libcxx/sym_check/util.py
index fc7ba4244ab5a..dbc886f29ddea 100644
--- a/libcxx/utils/libcxx/sym_check/util.py
+++ b/libcxx/utils/libcxx/sym_check/util.py
@@ -95,7 +95,7 @@ def is_xcoff_or_big_ar(filename):
     with open(filename, "rb") as f:
         magic_bytes = f.read(7)
     return (
-        magic_bytes[:4] in [b"\x01DF", b"\x01F7"]  # XCOFF32  # XCOFF64
+        magic_bytes[:2] in [b"\x01\xDF", b"\x01\xF7"]  # XCOFF32  # XCOFF64
         or magic_bytes == b"<bigaf>"
     )