bpo-36763: Add PyMemAllocatorName (GH-13387)

* Add PyMemAllocatorName enum
* _PyPreConfig.allocator type becomes PyMemAllocatorName, instead of
  char*
* Remove _PyPreConfig_Clear()
* Add _PyMem_GetAllocatorName()
* Rename _PyMem_GetAllocatorsName() to
  _PyMem_GetCurrentAllocatorName()
* Remove _PyPreConfig_SetAllocator(): just call
  _PyMem_SetupAllocators() directly, we don't have do reallocate the
  configuration with the new allocator anymore!
* _PyPreConfig_Write() parameter becomes const, as it should be in
  the first place!

4 files changed, 28 insertions, 9 deletions

diff --git a/Include/cpython/coreconfig.h b/Include/cpython/coreconfig.h
index 1ba2663..dca4134 100644
--- a/Include/cpython/coreconfig.h
+++ b/Include/cpython/coreconfig.h
@@ -120,7 +120,9 @@ typedef struct {
     int utf8_mode;
 
     int dev_mode;           /* Development mode. PYTHONDEVMODE, -X dev */
-    char *allocator;        /* Memory allocator: PYTHONMALLOC */
+
+    /* Memory allocator: PYTHONMALLOC env var */
+    PyMemAllocatorName allocator;
 } _PyPreConfig;
 
 #ifdef MS_WINDOWS
@@ -137,7 +139,7 @@ typedef struct {
         .isolated = -1, \
         .use_environment = -1, \
         .dev_mode = -1, \
-        .allocator = NULL}
+        .allocator = PYMEM_ALLOCATOR_NOT_SET}
 
 
 /* --- _PyCoreConfig ---------------------------------------------- */
diff --git a/Include/cpython/pymem.h b/Include/cpython/pymem.h
index bd66506..79f063b 100644
--- a/Include/cpython/pymem.h
+++ b/Include/cpython/pymem.h
@@ -11,12 +11,8 @@ PyAPI_FUNC(void *) PyMem_RawCalloc(size_t nelem, size_t elsize);
 PyAPI_FUNC(void *) PyMem_RawRealloc(void *ptr, size_t new_size);
 PyAPI_FUNC(void) PyMem_RawFree(void *ptr);
 
-/* Configure the Python memory allocators. Pass NULL to use default
-   allocators. */
-PyAPI_FUNC(int) _PyMem_SetupAllocators(const char *opt);
-
 /* Try to get the allocators name set by _PyMem_SetupAllocators(). */
-PyAPI_FUNC(const char*) _PyMem_GetAllocatorsName(void);
+PyAPI_FUNC(const char*) _PyMem_GetCurrentAllocatorName(void);
 
 PyAPI_FUNC(void *) PyMem_Calloc(size_t nelem, size_t elsize);
 
@@ -41,6 +37,19 @@ typedef enum {
     PYMEM_DOMAIN_OBJ
 } PyMemAllocatorDomain;
 
+typedef enum {
+    PYMEM_ALLOCATOR_NOT_SET = 0,
+    PYMEM_ALLOCATOR_DEFAULT = 1,
+    PYMEM_ALLOCATOR_DEBUG = 2,
+    PYMEM_ALLOCATOR_MALLOC = 3,
+    PYMEM_ALLOCATOR_MALLOC_DEBUG = 4,
+#ifdef WITH_PYMALLOC
+    PYMEM_ALLOCATOR_PYMALLOC = 5,
+    PYMEM_ALLOCATOR_PYMALLOC_DEBUG = 6,
+#endif
+} PyMemAllocatorName;
+
+
 typedef struct {
     /* user context passed as the first argument to the 4 functions */
     void *ctx;
diff --git a/Include/internal/pycore_coreconfig.h b/Include/internal/pycore_coreconfig.h
index d48904e..ccb7948 100644
--- a/Include/internal/pycore_coreconfig.h
+++ b/Include/internal/pycore_coreconfig.h
@@ -88,7 +88,6 @@ PyAPI_FUNC(_PyInitError) _PyPreCmdline_Read(_PyPreCmdline *cmdline,
 
 /* --- _PyPreConfig ----------------------------------------------- */
 
-PyAPI_FUNC(void) _PyPreConfig_Clear(_PyPreConfig *config);
 PyAPI_FUNC(int) _PyPreConfig_Copy(_PyPreConfig *config,
     const _PyPreConfig *config2);
 PyAPI_FUNC(PyObject*) _PyPreConfig_AsDict(const _PyPreConfig *config);
@@ -96,7 +95,7 @@ PyAPI_FUNC(void) _PyCoreConfig_GetCoreConfig(_PyPreConfig *config,
     const _PyCoreConfig *core_config);
 PyAPI_FUNC(_PyInitError) _PyPreConfig_Read(_PyPreConfig *config,
     const _PyArgv *args);
-PyAPI_FUNC(_PyInitError) _PyPreConfig_Write(_PyPreConfig *config);
+PyAPI_FUNC(_PyInitError) _PyPreConfig_Write(const _PyPreConfig *config);
 
 
 /* --- _PyCoreConfig ---------------------------------------------- */
diff --git a/Include/internal/pycore_pymem.h b/Include/internal/pycore_pymem.h
index 20f3b5e..dcc492a 100644
--- a/Include/internal/pycore_pymem.h
+++ b/Include/internal/pycore_pymem.h
@@ -179,6 +179,15 @@ static inline int _PyMem_IsPtrFreed(void *ptr)
 #endif
 }
 
+PyAPI_FUNC(int) _PyMem_GetAllocatorName(
+    const char *name,
+    PyMemAllocatorName *allocator);
+
+/* Configure the Python memory allocators.
+   Pass PYMEM_ALLOCATOR_DEFAULT to use default allocators.
+   PYMEM_ALLOCATOR_NOT_SET does nothing. */
+PyAPI_FUNC(int) _PyMem_SetupAllocators(PyMemAllocatorName allocator);
+
 #ifdef __cplusplus
 }
 #endif