Fix T102845: GPU python crash in background mode

`BPYGPU_IS_INIT_OR_ERROR_OBJ` is not implemented in all pygpu functions.

Instead of copying and pasting that call across the API when it has no
gpu context, override the methods with one that always reports error.

source/blender/python/gpu/gpu_py.c

@@ -51,16 +51,72 @@ struct PyC_StringEnumItems bpygpu_dataformat_items[] = {
 /** \name Utilities
  * \{ */
 
-bool bpygpu_is_init_or_error(void)
+static const char g_error[] = "GPU API is not available in background mode";
-{
-  if (!GPU_is_init()) {
-    PyErr_SetString(PyExc_SystemError,
-                    "GPU functions for drawing are not available in background mode");
 
-    return false;
+static PyObject *py_error__ml_meth(PyObject *UNUSED(self), PyObject *UNUSED(args))
+{
+  PyErr_SetString(PyExc_SystemError, g_error);
+  Py_RETURN_NONE;
+}
+
+static PyObject *py_error__getter(PyObject *UNUSED(self), void *UNUSED(type))
+{
+  PyErr_SetString(PyExc_SystemError, g_error);
+  Py_RETURN_NONE;
+}
+
+static int py_error__setter(PyObject *UNUSED(self), PyObject *value, void *UNUSED(type))
+{
+  PyErr_SetString(PyExc_SystemError, g_error);
+  return -1;
+}
+
+static PyObject *py_error__tp_new(PyTypeObject *UNUSED(type),
+                                  PyObject *UNUSED(args),
+                                  PyObject *UNUSED(kwds))
+{
+  PyErr_SetString(PyExc_SystemError, g_error);
+  return NULL;
+}
+
+PyObject *bpygpu_create_module(PyModuleDef *module_type)
+{
+  if (!GPU_is_init() && module_type->m_methods) {
+    /* Replace all methods with an error method.
+     * That way when the method is called, an error will appear instead. */
+    for (PyMethodDef *meth = module_type->m_methods; meth->ml_name; meth++) {
+      meth->ml_meth = py_error__ml_meth;
+    }
   }
 
-  return true;
+  PyObject *module = PyModule_Create(module_type);
+
+  return module;
+}
+
+int bpygpu_finalize_type(PyTypeObject *py_type)
+{
+  if (!GPU_is_init()) {
+    if (py_type->tp_methods) {
+      /* Replace all methods with an error method. */
+      for (PyMethodDef *meth = py_type->tp_methods; meth->ml_name; meth++) {
+        meth->ml_meth = py_error__ml_meth;
+      }
+    }
+    if (py_type->tp_getset) {
+      /* Replace all getters and setter with a functions that always returns error. */
+      for (PyGetSetDef *getset = py_type->tp_getset; getset->name; getset++) {
+        getset->get = py_error__getter;
+        getset->set = py_error__setter;
+      }
+    }
+    if (py_type->tp_new) {
+      /* If initialized, return error. */
+      py_type->tp_new = py_error__tp_new;
+    }
+  }
+
+  return PyType_Ready(py_type);
 }
 
 /** \} */

source/blender/python/gpu/gpu_py.h

@@ -9,15 +9,5 @@
 extern struct PyC_StringEnumItems bpygpu_primtype_items[];
 extern struct PyC_StringEnumItems bpygpu_dataformat_items[];
 
-bool bpygpu_is_init_or_error(void);
+PyObject *bpygpu_create_module(PyModuleDef *module_type);
-
+int bpygpu_finalize_type(PyTypeObject *py_type);
-#define BPYGPU_IS_INIT_OR_ERROR_OBJ \
-  if (UNLIKELY(!bpygpu_is_init_or_error())) { \
-    return NULL; \
-  } \
-  ((void)0)
-#define BPYGPU_IS_INIT_OR_ERROR_INT \
-  if (UNLIKELY(!bpygpu_is_init_or_error())) { \
-    return -1; \
-  } \
-  ((void)0)

source/blender/python/gpu/gpu_py_api.c

@@ -21,6 +21,7 @@
 #include "gpu_py_state.h"
 #include "gpu_py_types.h"
 
+#include "gpu_py.h"
 #include "gpu_py_api.h" /* Own include. */
 
 /* -------------------------------------------------------------------- */
@@ -48,7 +49,7 @@ PyObject *BPyInit_gpu(void)
   PyObject *submodule;
   PyObject *mod;
 
-  mod = PyModule_Create(&pygpu_module_def);
+  mod = bpygpu_create_module(&pygpu_module_def);
 
   PyModule_AddObject(mod, "types", (submodule = bpygpu_types_init()));
   PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);

source/blender/python/gpu/gpu_py_batch.c

@@ -47,8 +47,6 @@ static bool pygpu_batch_is_program_or_error(BPyGPUBatch *self)
 
 static PyObject *pygpu_batch__tp_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   const char *exc_str_missing_arg = "GPUBatch.__new__() missing required argument '%s' (pos %d)";
 
   struct PyC_StringEnum prim_type = {bpygpu_primtype_items, GPU_PRIM_NONE};

source/blender/python/gpu/gpu_py_capabilities.c

@@ -13,6 +13,7 @@
 
 #include "GPU_capabilities.h"
 
+#include "gpu_py.h"
 #include "gpu_py_capabilities.h" /* own include */
 
 /* -------------------------------------------------------------------- */
@@ -315,7 +316,7 @@ PyObject *bpygpu_capabilities_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_capabilities_module_def);
+  submodule = bpygpu_create_module(&pygpu_capabilities_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_element.c

@@ -26,8 +26,6 @@
 
 static PyObject *pygpu_IndexBuf__tp_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   const char *error_prefix = "IndexBuf.__new__";
   bool ok = true;
 

source/blender/python/gpu/gpu_py_framebuffer.c

@@ -267,7 +267,6 @@ static PyObject *pygpu_framebuffer__tp_new(PyTypeObject *UNUSED(self),
                                            PyObject *args,
                                            PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
   if (!GPU_context_active_get()) {
     PyErr_SetString(PyExc_RuntimeError, "No active GPU context found");
     return NULL;

source/blender/python/gpu/gpu_py_matrix.c

@@ -24,6 +24,7 @@
 #include "GPU_matrix.h"
 #undef USE_GPU_PY_MATRIX_API
 
+#include "gpu_py.h"
 #include "gpu_py_matrix.h" /* own include */
 
 /* -------------------------------------------------------------------- */
@@ -542,9 +543,9 @@ PyObject *bpygpu_matrix_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_matrix_module_def);
+  submodule = bpygpu_create_module(&pygpu_matrix_module_def);
 
-  if (PyType_Ready(&PyGPUMatrixStackContext_Type) < 0) {
+  if (bpygpu_finalize_type(&PyGPUMatrixStackContext_Type) < 0) {
     return NULL;
   }
 

source/blender/python/gpu/gpu_py_offscreen.c

@@ -211,8 +211,6 @@ static PyObject *pygpu_offscreen__tp_new(PyTypeObject *UNUSED(self),
                                          PyObject *args,
                                          PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   GPUOffScreen *ofs = NULL;
   int width, height;
   struct PyC_StringEnum pygpu_textureformat = {pygpu_framebuffer_color_texture_formats, GPU_RGBA8};

source/blender/python/gpu/gpu_py_platform.c

@@ -14,6 +14,7 @@
 #include "GPU_context.h"
 #include "GPU_platform.h"
 
+#include "gpu_py.h"
 #include "gpu_py_platform.h" /* Own include. */
 
 /* -------------------------------------------------------------------- */
@@ -155,7 +156,7 @@ PyObject *bpygpu_platform_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_platform_module_def);
+  submodule = bpygpu_create_module(&pygpu_platform_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_select.c

@@ -20,6 +20,7 @@
 
 #include "GPU_select.h"
 
+#include "gpu_py.h"
 #include "gpu_py_select.h" /* Own include. */
 
 /* -------------------------------------------------------------------- */
@@ -72,7 +73,7 @@ PyObject *bpygpu_select_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_select_module_def);
+  submodule = bpygpu_create_module(&pygpu_select_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_shader.c

@@ -95,8 +95,6 @@ static int pygpu_shader_uniform_location_get(GPUShader *shader,
 
 static PyObject *pygpu_shader__tp_new(PyTypeObject *UNUSED(type), PyObject *args, PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   struct {
     const char *vertexcode;
     const char *fragcode;
@@ -835,8 +833,6 @@ PyDoc_STRVAR(
     "   :rtype: :class:`bpy.types.GPUShader`\n");
 static PyObject *pygpu_shader_from_builtin(PyObject *UNUSED(self), PyObject *args, PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   struct PyC_StringEnum pygpu_bultinshader = {pygpu_shader_builtin_items};
   struct PyC_StringEnum pygpu_config = {pygpu_shader_config_items, GPU_SHADER_CFG_DEFAULT};
 
@@ -954,7 +950,7 @@ PyObject *bpygpu_shader_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_shader_module_def);
+  submodule = bpygpu_create_module(&pygpu_shader_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_state.c

@@ -17,6 +17,7 @@
 #include "../generic/py_capi_utils.h"
 #include "../generic/python_utildefines.h"
 
+#include "gpu_py.h"
 #include "gpu_py_framebuffer.h"
 #include "gpu_py_state.h" /* own include */
 
@@ -445,7 +446,7 @@ PyObject *bpygpu_state_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_state_module_def);
+  submodule = bpygpu_create_module(&pygpu_state_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_texture.c

@@ -111,8 +111,6 @@ static int pygpu_texture_valid_check(BPyGPUTexture *bpygpu_tex)
 
 static PyObject *pygpu_texture__tp_new(PyTypeObject *UNUSED(self), PyObject *args, PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   PyObject *py_size;
   int size[3] = {1, 1, 1};
   int layers = 0;
@@ -605,7 +603,7 @@ int bpygpu_ParseTexture(PyObject *o, void *p)
 PyObject *bpygpu_texture_init(void)
 {
   PyObject *submodule;
-  submodule = PyModule_Create(&pygpu_texture_module_def);
+  submodule = bpygpu_create_module(&pygpu_texture_module_def);
 
   return submodule;
 }

source/blender/python/gpu/gpu_py_types.c

@@ -11,6 +11,7 @@
 
 #include "../generic/py_capi_utils.h"
 
+#include "gpu_py.h"
 #include "gpu_py_types.h" /* own include */
 
 /* -------------------------------------------------------------------- */
@@ -33,42 +34,42 @@ PyObject *bpygpu_types_init(void)
 {
   PyObject *submodule;
 
-  submodule = PyModule_Create(&pygpu_types_module_def);
+  submodule = bpygpu_create_module(&pygpu_types_module_def);
 
-  if (PyType_Ready(&BPyGPU_BufferType) < 0) {
+  if (bpygpu_finalize_type(&BPyGPU_BufferType) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUVertFormat_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUVertFormat_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUVertBuf_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUVertBuf_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUIndexBuf_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUIndexBuf_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUBatch_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUBatch_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUOffScreen_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUOffScreen_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUShader_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUShader_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUTexture_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUTexture_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUFrameBuffer_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUFrameBuffer_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUUniformBuf_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUUniformBuf_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUShaderCreateInfo_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUShaderCreateInfo_Type) < 0) {
     return NULL;
   }
-  if (PyType_Ready(&BPyGPUStageInterfaceInfo_Type) < 0) {
+  if (bpygpu_finalize_type(&BPyGPUStageInterfaceInfo_Type) < 0) {
     return NULL;
   }
 

source/blender/python/gpu/gpu_py_uniformbuffer.c

@@ -59,8 +59,6 @@ static PyObject *pygpu_uniformbuffer__tp_new(PyTypeObject *UNUSED(self),
                                              PyObject *args,
                                              PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   GPUUniformBuf *ubo = NULL;
   PyObject *pybuffer_obj;
   char err_out[256] = "unknown error. See console";