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Slightly simplify tcl/tk load in extension. #23054

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Merged
merged 1 commit into from
May 20, 2022
Merged

Slightly simplify tcl/tk load in extension. #23054

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46 changes: 17 additions & 29 deletions src/_tkagg.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -51,11 +51,9 @@ static int convert_voidptr(PyObject *obj, void *p)
// extension module or loaded Tk libraries at run-time.
static Tk_FindPhoto_t TK_FIND_PHOTO;
static Tk_PhotoPutBlock_t TK_PHOTO_PUT_BLOCK;
#ifdef WIN32_DLL
// Global vars for Tcl functions. We load these symbols from the tkinter
// extension module or loaded Tcl libraries at run-time.
static Tcl_SetVar_t TCL_SETVAR;
#endif

static PyObject *mpl_tk_blit(PyObject *self, PyObject *args)
{
Expand Down Expand Up @@ -225,28 +223,24 @@ static PyMethodDef functions[] = {
// Functions to fill global Tcl/Tk function pointers by dynamic loading.

template <class T>
int load_tk(T lib)
bool load_tcl_tk(T lib)
{
// Try to fill Tk global vars with function pointers. Return the number of
// functions found.
return
!!(TK_FIND_PHOTO =
(Tk_FindPhoto_t)dlsym(lib, "Tk_FindPhoto")) +
!!(TK_PHOTO_PUT_BLOCK =
(Tk_PhotoPutBlock_t)dlsym(lib, "Tk_PhotoPutBlock"));
// Try to fill Tcl/Tk global vars with function pointers. Return whether
// all of them have been filled.
if (void* ptr = dlsym(lib, "Tcl_SetVar")) {
TCL_SETVAR = (Tcl_SetVar_t)ptr;
}
if (void* ptr = dlsym(lib, "Tk_FindPhoto")) {
TK_FIND_PHOTO = (Tk_FindPhoto_t)ptr;
}
if (void* ptr = dlsym(lib, "Tk_PhotoPutBlock")) {
TK_PHOTO_PUT_BLOCK = (Tk_PhotoPutBlock_t)ptr;
}
return TCL_SETVAR && TK_FIND_PHOTO && TK_PHOTO_PUT_BLOCK;
}

#ifdef WIN32_DLL

template <class T>
int load_tcl(T lib)
{
// Try to fill Tcl global vars with function pointers. Return the number of
// functions found.
return
!!(TCL_SETVAR = (Tcl_SetVar_t)dlsym(lib, "Tcl_SetVar"));
}

/* On Windows, we can't load the tkinter module to get the Tcl/Tk symbols,
* because Windows does not load symbols into the library name-space of
* importing modules. So, knowing that tkinter has already been imported by
Expand All @@ -259,7 +253,6 @@ void load_tkinter_funcs(void)
HANDLE process = GetCurrentProcess(); // Pseudo-handle, doesn't need closing.
HMODULE* modules = NULL;
DWORD size;
bool tcl_ok = false, tk_ok = false;
if (!EnumProcessModules(process, NULL, 0, &size)) {
PyErr_SetFromWindowsErr(0);
goto exit;
Expand All @@ -273,11 +266,8 @@ void load_tkinter_funcs(void)
goto exit;
}
for (unsigned i = 0; i < size / sizeof(HMODULE); ++i) {
if (!tcl_ok) {
tcl_ok = load_tcl(modules[i]);
}
if (!tk_ok) {
tk_ok = load_tk(modules[i]);
if (load_tcl_tk(modules[i])) {
return;
}
}
exit:
Expand All @@ -301,7 +291,7 @@ void load_tkinter_funcs(void)

// Try loading from the main program namespace first.
main_program = dlopen(NULL, RTLD_LAZY);
if (load_tk(main_program)) {
if (load_tcl_tk(main_program)) {
goto exit;
}
// Clear exception triggered when we didn't find symbols above.
Expand All @@ -324,7 +314,7 @@ void load_tkinter_funcs(void)
PyErr_SetString(PyExc_RuntimeError, dlerror());
goto exit;
}
if (load_tk(tkinter_lib)) {
if (load_tcl_tk(tkinter_lib)) {
goto exit;
}

Expand Down Expand Up @@ -353,11 +343,9 @@ PyMODINIT_FUNC PyInit__tkagg(void)
load_tkinter_funcs();
if (PyErr_Occurred()) {
return NULL;
#ifdef WIN32_DLL
} else if (!TCL_SETVAR) {
PyErr_SetString(PyExc_RuntimeError, "Failed to load Tcl_SetVar");
return NULL;
#endif
} else if (!TK_FIND_PHOTO) {
PyErr_SetString(PyExc_RuntimeError, "Failed to load Tk_FindPhoto");
return NULL;
Expand Down
3 changes: 1 addition & 2 deletions src/_tkmini.h
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Original file line number Diff line number Diff line change
Expand Up @@ -100,11 +100,10 @@ typedef int (*Tk_PhotoPutBlock_t) (Tcl_Interp *interp, Tk_PhotoHandle handle,
Tk_PhotoImageBlock *blockPtr, int x, int y,
int width, int height, int compRule);

#ifdef WIN32_DLL
/* Typedefs derived from function signatures in Tcl header */
/* Tcl_SetVar typedef */
typedef const char *(*Tcl_SetVar_t)(Tcl_Interp *interp, const char *varName,
const char *newValue, int flags);
#endif

#ifdef __cplusplus
}
Expand Down