FindPython: Add support for pydebug ABI flag on Windows

Fixes: #27969

Help/release/4.4.rst

@@ -432,3 +432,14 @@ Other Changes
 * Targets which provide C++ modules may now be consumed by targets with
   different :prop_tgt:`compile features <COMPILE_FEATURES>` and
   :prop_tgt:`options <COMPILE_OPTIONS>` than the provider.
+
+Updates
+=======
+
+Changes made since CMake 4.4.0 include the following.
+
+4.4.1
+-----
+
+* The :module:`FindPython`, :module:`FindPython3` modules learned to manage, on
+  ``Windows`` systems, the ``pydebug`` ABI flag.

Modules/FindPython.cmake

@@ -183,7 +183,7 @@ This module defines the following variables
     * IronPython
     * PyPy
 
-``Python3_FREE_THREADED``
+``Python_FREE_THREADED``
   .. versionadded:: 4.4
 
   Boolean value, which is ``true`` if the python is free threaded (i.e.
@@ -363,6 +363,10 @@ Hints
     threaded python), is added and is optional. If not specified, the value is
     ``OFF``.
 
+  .. versionadded:: 4.4.1
+    The ``pydebug`` flag is now supported on ``Windows`` systems for ``Python``
+    3.14+.
+
   Each element can be set to one of the following:
 
   * ``ON``: Corresponding flag is selected.
@@ -371,8 +375,10 @@ Hints
 
   .. note::
 
-    If ``Python3_FIND_ABI`` is not defined, any ABI, excluding the
-    ``gil_disabled`` flag, will be searched.
+    If ``Python_FIND_ABI`` is not defined, the following default apply:
+
+      * On ``POSIX`` systems: ``ANY``, ``ANY``, ``ANY``, ``OFF``.
+      * On ``Windows`` systems: ``OFF``, ``OFF``, ``OFF``, ``OFF``.
 
   From this 4-tuple, various ABIs will be searched starting from the most
   specialized to the most general. Moreover, when ``ANY`` is specified for
@@ -386,7 +392,10 @@ Hints
     set (Python_FIND_ABI "ON" "ANY" "ANY" "ON")
 
   The following flags combinations will be appended, in that order, to the
-  artifact names: ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+  artifact names:
+
+    * On ``POSIX`` systems: ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+    * On ``Windows`` systems: ``tmu_d``, ``tm_d``, ``tu_d``, and ``t_d``.
 
   And to search any possible ABIs:
 
@@ -394,18 +403,24 @@ Hints
 
     set (Python_FIND_ABI "ANY" "ANY" "ANY" "ANY")
 
-  The following combinations, in that order, will be used: ``mu``, ``m``,
-  ``u``, ``<empty>``, ``dmu``, ``dm``, ``du``, ``d``, ``tmu``, ``tm``, ``tu``,
-  ``t``, ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+  The following combinations, in that order, will be used:
+
+  * On ``POSIX`` systems: ``mu``, ``m``, ``u``, ``<empty>``, ``dmu``, ``dm``,
+    ``du``, ``d``, ``tmu``, ``tm``, ``tu``, ``t``, ``tdmu``, ``tdm``, ``tdu``,
+    and ``td``.
+  * On ``Windows`` systems: ``mu``, ``m``, ``u``, ``<empty>``, ``mu_d``,
+    ``m_d``, ``u_d``, ``_d``, ``tmu``, ``tm``, ``tu``, ``t``, ``tmu_d``, ``tm_d``,
+    ``tu_d``, and ``t_d``.
 
   .. note::
 
-    This hint is useful only on ``POSIX`` systems except for the
-    ``gil_disabled`` flag. So, on ``Windows`` systems,
-    when ``Python_FIND_ABI`` is defined, ``Python`` distributions from
-    `python.org <https://www.python.org/>`_ will be found only if the value for
-    each flag is ``OFF`` or ``ANY`` except for the fourth one
-    (``gil_disabled``).
+    This hint is fully usable on ``POSIX`` systems. On ``Windows`` systems,
+    only the ``gil_disabled`` and ``pydebug`` flags are supported. Moreover,
+    the ``pydebug`` flag is only supported for ``Python`` 3.14+. So, on
+    ``Windows`` systems, when ``Python_FIND_ABI`` is defined, ``Python``
+    distributions from `python.org <https://www.python.org/>`_ will be found
+    only if the value for the flags ``pymalloc`` and ``unicode`` is ``OFF`` or
+    ``ANY``.
 
 ``Python_FIND_STRATEGY``
   .. versionadded:: 3.15
@@ -659,7 +674,7 @@ If the library type is not specified, ``MODULE`` is assumed.
   was introduced. Specifying only major version ``3`` is equivalent to ``3.2``.
 
 .. versionchanged:: 4.4
-  When ``USE_SABI`` is specified, if ``Python3_FREE_THREADED`` is ``true`` and
+  When ``USE_SABI`` is specified, if ``Python_FREE_THREADED`` is ``true`` and
   Python version is ``3.15`` or upper, ``Py_TARGET_ABI3T`` preprocessor
   definition will be defined rather than ``Py_LIMITED_API`` (see :pep:`803` for
   more details).

Modules/FindPython/Support.cmake

@@ -312,18 +312,36 @@ function (_PYTHON_GET_ABIFLAGS _PGA_FIND_ABI _PGABIFLAGS)
   endif()
 
   if (pydebug STREQUAL "ON")
-    if (abiflags)
-      list (TRANSFORM abiflags PREPEND "d")
+    if (WIN32)
+      if (NOT abiflags STREQUAL "<none>")
+        list (TRANSFORM abiflags APPEND "_d")
+      else()
+        set (abiflags "_d")
+      endif()
     else()
-      set (abiflags "d")
+      if (NOT abiflags STREQUAL "<none>")
+        list (TRANSFORM abiflags PREPEND "d")
+      else()
+        set (abiflags "d")
+      endif()
     endif()
   elseif (pydebug STREQUAL "ANY")
-    if (abiflags)
-      set (flags "${abiflags}")
-      list (TRANSFORM flags PREPEND "d")
-      list (APPEND abiflags "${flags}")
+    if (WIN32)
+      if (NOT abiflags STREQUAL "<none>")
+        set (flags "${abiflags}")
+        list (TRANSFORM flags APPEND "_d")
+        list (APPEND abiflags "${flags}")
+      else()
+        set (abiflags "<none>" "_d")
+      endif()
     else()
-      set (abiflags "<none>" "d")
+      if (NOT abiflags STREQUAL "<none>")
+        set (flags "${abiflags}")
+        list (TRANSFORM flags PREPEND "d")
+        list (APPEND abiflags "${flags}")
+      else()
+        set (abiflags "<none>" "d")
+      endif()
     endif()
   endif()
 
@@ -434,12 +452,26 @@ function (_PYTHON_GET_NAMES _PYTHON_PGN_NAMES)
 
   foreach (implementation IN LISTS _PGN_IMPLEMENTATIONS)
     if (implementation STREQUAL "CPython")
+      set (abi "${_${_PYTHON_PREFIX}_ABIFLAGS}")
+      list (TRANSFORM abi REPLACE "^<none>$" "")
+
+      set (unversionednames python${_${_PYTHON_PREFIX}_REQUIRED_VERSION_MAJOR} python)
+
       if (_PGN_INTERPRETER AND _${_PYTHON_PREFIX}_FIND_UNVERSIONED_NAMES STREQUAL "FIRST")
-        if (_PGN_DEBUG)
-          list (APPEND names python${_${_PYTHON_PREFIX}_REQUIRED_VERSION_MAJOR}_d python_d)
+        if (abi)
+          unset (fullnames)
+          foreach (name IN LISTS unversionednames)
+            set (abinames "${abi}")
+            list (TRANSFORM abinames PREPEND "${name}")
+            list(APPEND fullnames "${abinames}")
+          endforeach()
         else()
-          list (APPEND names python${_${_PYTHON_PREFIX}_REQUIRED_VERSION_MAJOR} python)
+          set (fullnames ${unversionednames})
         endif()
+        if (_PGN_DEBUG AND NOT abi MATCHES "_d")
+          list (TRANSFORM fullnames APPEND "_d")
+        endif()
+        list (APPEND names ${fullnames})
       endif()
       foreach (version IN LISTS _PGN_VERSION)
         if (_PGN_WIN32)
@@ -448,24 +480,19 @@ function (_PYTHON_GET_NAMES _PYTHON_PGN_NAMES)
           else()
             string (REPLACE "." "" name_version ${version})
           endif()
-          set (abi "${_${_PYTHON_PREFIX}_ABIFLAGS}")
-          list (TRANSFORM abi REPLACE "^<none>$" "")
           if (abi)
             set (abinames "${abi}")
             list (TRANSFORM abinames PREPEND "python${name_version}")
           else()
             set (abinames "python${name_version}")
           endif()
-          if (_PGN_DEBUG)
+          if (_PGN_DEBUG AND NOT abi MATCHES "_d")
             list (TRANSFORM abinames APPEND "_d")
           endif()
           list (APPEND names ${abinames})
         endif()
 
         if (_PGN_POSIX)
-          set (abi "${_${_PYTHON_PREFIX}_ABIFLAGS}")
-          list (TRANSFORM abi REPLACE "^<none>$" "")
-
           if (abi)
             if (_PGN_CONFIG AND DEFINED CMAKE_LIBRARY_ARCHITECTURE)
               set (abinames "${abi}")
@@ -493,11 +520,20 @@ function (_PYTHON_GET_NAMES _PYTHON_PGN_NAMES)
         endif()
       endforeach()
       if (_PGN_INTERPRETER AND _${_PYTHON_PREFIX}_FIND_UNVERSIONED_NAMES STREQUAL "LAST")
-        if (_PGN_DEBUG)
-          list (APPEND names python${_${_PYTHON_PREFIX}_REQUIRED_VERSION_MAJOR}_d python_d)
+        if (abi)
+          unset (fullnames)
+          foreach (name IN LISTS unversionednames)
+            set (abinames "${abi}")
+            list (TRANSFORM abinames PREPEND "${name}")
+            list(APPEND fullnames "${abinames}")
+          endforeach()
         else()
-          list (APPEND names python${_${_PYTHON_PREFIX}_REQUIRED_VERSION_MAJOR} python)
+          set (fullnames ${unversionednames})
         endif()
+        if (_PGN_DEBUG AND NOT abi MATCHES "_d")
+          list (TRANSFORM fullnames APPEND "_d")
+        endif()
+        list(APPEND names ${fullnames})
       endif()
     elseif (implementation STREQUAL "IronPython")
       if (_PGN_INTERPRETER)
@@ -831,7 +867,7 @@ function (_PYTHON_GET_VERSION)
     if (_${_PYTHON_PREFIX}_LIBRARY_RELEASE)
       get_filename_component (library_name "${_${_PYTHON_PREFIX}_LIBRARY_RELEASE}" NAME)
       # extract version from library name
-      if (library_name MATCHES "python([23])([0-9]+)([tdmu]*)")
+      if (library_name MATCHES "python([23])([0-9]+)([tdmu_]*)")
         set (${_PGV_PREFIX}VERSION_MAJOR "${CMAKE_MATCH_1}" PARENT_SCOPE)
         set (${_PGV_PREFIX}VERSION_MINOR "${CMAKE_MATCH_2}" PARENT_SCOPE)
         set (${_PGV_PREFIX}VERSION "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}" PARENT_SCOPE)
@@ -867,7 +903,7 @@ function (_PYTHON_GET_VERSION)
     if (_${_PYTHON_PREFIX}_SABI_LIBRARY_RELEASE)
       get_filename_component (library_name "${_${_PYTHON_PREFIX}_SABI_LIBRARY_RELEASE}" NAME)
       # extract version from library name
-      if (library_name MATCHES "python([23])([tdmu]*)")
+      if (library_name MATCHES "python([23])([tdmu_]*)")
         set (${_PGV_PREFIX}VERSION_MAJOR "${CMAKE_MATCH_1}" PARENT_SCOPE)
         set (${_PGV_PREFIX}VERSION "${CMAKE_MATCH_1}" PARENT_SCOPE)
         set (abi "${CMAKE_MATCH_2}")

Modules/FindPython3.cmake

@@ -362,6 +362,10 @@ Hints
     threaded python), is added and is optional. If not specified, the value is
     ``OFF``.
 
+  .. versionadded:: 4.4.1
+    The ``pydebug`` flag is now supported on ``Windows`` systems for ``Python``
+    3.14+.
+
   Each element can be set to one of the following:
 
   * ``ON``: Corresponding flag is selected.
@@ -370,8 +374,10 @@ Hints
 
   .. note::
 
-    If ``Python3_FIND_ABI`` is not defined, any ABI, excluding the
-    ``gil_disabled`` flag, will be searched.
+    If ``Python3_FIND_ABI`` is not defined, the following default apply:
+
+      * On ``POSIX`` systems: ``ANY``, ``ANY``, ``ANY``, ``OFF``.
+      * On ``Windows`` systems: ``OFF``, ``OFF``, ``OFF``, ``OFF``.
 
   From this 4-tuple, various ABIs will be searched starting from the most
   specialized to the most general. Moreover, when ``ANY`` is specified for
@@ -385,7 +391,10 @@ Hints
     set (Python3_FIND_ABI "ON" "ANY" "ANY" "ON")
 
   The following flags combinations will be appended, in that order, to the
-  artifact names: ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+  artifact names:
+
+    * On ``POSIX`` systems: ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+    * On ``Windows`` systems: ``tmu_d``, ``tm_d``, ``tu_d``, and ``t_d``.
 
   And to search any possible ABIs:
 
@@ -393,18 +402,24 @@ Hints
 
     set (Python3_FIND_ABI "ANY" "ANY" "ANY" "ANY")
 
-  The following combinations, in that order, will be used: ``mu``, ``m``,
-  ``u``, ``<empty>``, ``dmu``, ``dm``, ``du``, ``d``, ``tmu``, ``tm``, ``tu``,
-  ``t``, ``tdmu``, ``tdm``, ``tdu``, and ``td``.
+  The following combinations, in that order, will be used:
+
+  * On ``POSIX`` systems: ``mu``, ``m``, ``u``, ``<empty>``, ``dmu``, ``dm``,
+    ``du``, ``d``, ``tmu``, ``tm``, ``tu``, ``t``, ``tdmu``, ``tdm``, ``tdu``,
+    and ``td``.
+  * On ``Windows`` systems: ``mu``, ``m``, ``u``, ``<empty>``, ``mu_d``,
+    ``m_d``, ``u_d``, ``_d``, ``tmu``, ``tm``, ``tu``, ``t``, ``tmu_d``, ``tm_d``,
+    ``tu_d``, and ``t_d``.
 
   .. note::
 
-    This hint is useful only on ``POSIX`` systems except for the
-    ``gil_disabled`` flag. So, on ``Windows`` systems,
-    when ``Python_FIND_ABI`` is defined, ``Python`` distributions from
-    `python.org <https://www.python.org/>`_ will be found only if the value for
-    each flag is ``OFF`` or ``ANY`` except for the fourth one
-    (``gil_disabled``).
+    This hint is fully usable on ``POSIX`` systems. On ``Windows`` systems,
+    only the ``gil_disabled`` and ``pydebug`` flags are supported. Moreover,
+    the ``pydebug`` flag is only supported for ``Python`` 3.14+. So, on
+    ``Windows`` systems, when ``Python3_FIND_ABI`` is defined, ``Python``
+    distributions from `python.org <https://www.python.org/>`_ will be found
+    only if the value for the flags ``pymalloc`` and ``unicode`` is ``OFF`` or
+    ``ANY``.
 
 ``Python3_FIND_STRATEGY``
   .. versionadded:: 3.15