bpo-41078: Add pycore_list.h internal header file (GH-21057)

* Move _PyList_ITEMS() to pycore_list.h.
* The C extension "_heapq" is now built with Py_BUILD_CORE_MODULE
  macro defined to access the internal C API.

Include/cpython/listobject.h

@@ -32,4 +32,3 @@ PyAPI_FUNC(void) _PyList_DebugMallocStats(FILE *out);
 #define PyList_GET_ITEM(op, i) (_PyList_CAST(op)->ob_item[i])
 #define PyList_SET_ITEM(op, i, v) (_PyList_CAST(op)->ob_item[i] = (v))
 #define PyList_GET_SIZE(op)    Py_SIZE(_PyList_CAST(op))
-#define _PyList_ITEMS(op)      (_PyList_CAST(op)->ob_item)

Include/internal/pycore_list.h

@@ -0,0 +1,20 @@
+#ifndef Py_INTERNAL_LIST_H
+#define Py_INTERNAL_LIST_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+#include "listobject.h"           // _PyList_CAST()
+
+
+#define _PyList_ITEMS(op) (_PyList_CAST(op)->ob_item)
+
+
+#ifdef __cplusplus
+}
+#endif
+#endif   /* !Py_INTERNAL_LIST_H */

Makefile.pre.in

@@ -1110,6 +1110,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_import.h \
 		$(srcdir)/Include/internal/pycore_initconfig.h \
 		$(srcdir)/Include/internal/pycore_interp.h \
+		$(srcdir)/Include/internal/pycore_list.h \
 		$(srcdir)/Include/internal/pycore_object.h \
 		$(srcdir)/Include/internal/pycore_pathconfig.h \
 		$(srcdir)/Include/internal/pycore_pyerrors.h \

Modules/Setup

@@ -180,7 +180,7 @@ _symtable symtablemodule.c
 #_datetime _datetimemodule.c	# datetime accelerator
 #_zoneinfo _zoneinfo.c	# zoneinfo accelerator
 #_bisect _bisectmodule.c	# Bisection algorithms
-#_heapq _heapqmodule.c	# Heap queue algorithm
+#_heapq _heapqmodule.c -DPy_BUILD_CORE_MODULE	# Heap queue algorithm
 #_asyncio _asynciomodule.c  # Fast asyncio Future
 #_json -I$(srcdir)/Include/internal -DPy_BUILD_CORE_BUILTIN _json.c	# _json speedups
 #_statistics _statisticsmodule.c # statistics accelerator

Modules/_heapqmodule.c

@@ -7,9 +7,11 @@ annotated by François Pinard, and converted to C by Raymond Hettinger.
 */
 
 #include "Python.h"
+#include "pycore_list.h"          // _PyList_ITEMS()
 
 #include "clinic/_heapqmodule.c.h"
 
+
 /*[clinic input]
 module _heapq
 [clinic start generated code]*/

PCbuild/pythoncore.vcxproj

@@ -165,8 +165,8 @@
     <ClInclude Include="..\Include\internal\pycore_abstract.h" />
     <ClInclude Include="..\Include\internal\pycore_accu.h" />
     <ClInclude Include="..\Include\internal\pycore_atomic.h" />
-    <ClInclude Include="..\Include\internal\pycore_bytes_methods.h" />
     <ClInclude Include="..\Include\internal\pycore_bitutils.h" />
+    <ClInclude Include="..\Include\internal\pycore_bytes_methods.h" />
     <ClInclude Include="..\Include\internal\pycore_call.h" />
     <ClInclude Include="..\Include\internal\pycore_ceval.h" />
     <ClInclude Include="..\Include\internal\pycore_code.h" />
@@ -181,6 +181,7 @@
     <ClInclude Include="..\Include\internal\pycore_import.h" />
     <ClInclude Include="..\Include\internal\pycore_initconfig.h" />
     <ClInclude Include="..\Include\internal\pycore_interp.h" />
+    <ClInclude Include="..\Include\internal\pycore_list.h" />
     <ClInclude Include="..\Include\internal\pycore_object.h" />
     <ClInclude Include="..\Include\internal\pycore_pathconfig.h" />
     <ClInclude Include="..\Include\internal\pycore_pyerrors.h" />

PCbuild/pythoncore.vcxproj.filters

@@ -240,6 +240,9 @@
     <ClInclude Include="..\Include\internal\pycore_interp.h">
       <Filter>Include</Filter>
     </ClInclude>
+    <ClInclude Include="..\Include\internal\pycore_list.h">
+      <Filter>Include</Filter>
+    </ClInclude>
     <ClInclude Include="..\Include\internal\pycore_object.h">
       <Filter>Include</Filter>
     </ClInclude>

setup.py

@@ -863,7 +863,8 @@ class PyBuildExt(build_ext):
         # bisect
         self.add(Extension("_bisect", ["_bisectmodule.c"]))
         # heapq
-        self.add(Extension("_heapq", ["_heapqmodule.c"]))
+        self.add(Extension("_heapq", ["_heapqmodule.c"],
+                           extra_compile_args=['-DPy_BUILD_CORE_MODULE']))
         # C-optimized pickle replacement
         self.add(Extension("_pickle", ["_pickle.c"],
                            extra_compile_args=['-DPy_BUILD_CORE_MODULE']))