gh-143253: Add libabigail suppression file for internal types (#143254)

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: pablogsal

.github/CODEOWNERS

@@ -143,6 +143,9 @@ Misc/externals.spdx.json      @sethmlarson
 Misc/sbom.spdx.json           @sethmlarson
 Tools/build/generate_sbom.py  @sethmlarson
 
+# ABI check
+Misc/libabigail.abignore      @encukou
+
 
 # ----------------------------------------------------------------------------
 # Platform Support

Makefile.pre.in

@@ -1883,7 +1883,7 @@ regen-abidump: all
 
 .PHONY: check-abidump
 check-abidump: all
-	abidiff $(srcdir)/Doc/data/python$(LDVERSION).abi "libpython$(LDVERSION).so" --drop-private-types --no-architecture --no-added-syms
+	abidiff $(srcdir)/Doc/data/python$(LDVERSION).abi "libpython$(LDVERSION).so" --drop-private-types --no-architecture --no-added-syms --suppressions $(srcdir)/Misc/libabigail.abignore
 
 .PHONY: regen-limited-abi
 regen-limited-abi: all

Misc/libabigail.abignore

@@ -0,0 +1,25 @@
+# libabigail suppression file for CPython ABI checks
+#
+# Suppress types defined directly in internal headers (pycore_*.h)
+# Regex matches filenames NOT starting with "pycore_", so pycore_* types are suppressed.
+[suppress_type]
+  source_location_not_regexp = ^([^p]|p[^y]|py[^c]|pyc[^o]|pyco[^r]|pycor[^e]|pycore[^_])
+  accessed_through = pointer
+
+# Suppress public typedefs that alias internal structs.
+# These are public names but their underlying struct layout is internal.
+[suppress_type]
+  name = PyInterpreterState
+  accessed_through = pointer
+
+[suppress_type]
+  name = _PyRuntimeState
+  accessed_through = pointer
+
+[suppress_type]
+  name = PyThreadState
+  accessed_through = pointer
+
+[suppress_variable]
+  name = _PyRuntime
+  type_name = _PyRuntimeState