xref: /petsc/src/sys/python/pythonsys.c (revision 21e3ffae2f3b73c0bd738cf6d0a809700fc04bb0)
1 #include <petsc/private/petscimpl.h> /*I "petscsys.h" I*/
2 
3 /* ---------------------------------------------------------------- */
4 
5 #if !defined(PETSC_PYTHON_EXE)
6   #define PETSC_PYTHON_EXE "python"
7 #endif
8 
9 static PetscErrorCode PetscPythonFindExecutable(char pythonexe[], size_t len)
10 {
11   PetscBool flag;
12 
13   PetscFunctionBegin;
14   /* get the path for the Python interpreter executable */
15   PetscCall(PetscStrncpy(pythonexe, PETSC_PYTHON_EXE, len));
16   PetscCall(PetscOptionsGetString(NULL, NULL, "-python", pythonexe, len, &flag));
17   if (!flag || pythonexe[0] == 0) PetscCall(PetscStrncpy(pythonexe, PETSC_PYTHON_EXE, len));
18   PetscFunctionReturn(PETSC_SUCCESS);
19 }
20 
21 /*
22     Python does not appear to have a universal way to indicate the location of Python dynamic library so try several possibilities
23 */
24 static PetscErrorCode PetscPythonFindLibraryName(const char pythonexe[], const char attempt[], char pythonlib[], size_t pl, PetscBool *found)
25 {
26   char  command[2 * PETSC_MAX_PATH_LEN];
27   FILE *fp  = NULL;
28   char *eol = NULL;
29 
30   PetscFunctionBegin;
31   /* call Python to find out the name of the Python dynamic library */
32   PetscCall(PetscStrncpy(command, pythonexe, sizeof(command)));
33   PetscCall(PetscStrlcat(command, " ", sizeof(command)));
34   PetscCall(PetscStrlcat(command, attempt, sizeof(command)));
35 #if defined(PETSC_HAVE_POPEN)
36   PetscCall(PetscPOpen(PETSC_COMM_SELF, NULL, command, "r", &fp));
37   PetscCheck(fgets(pythonlib, pl, fp), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Python: bad output from executable: %s\nRunning: %s", pythonexe, command);
38   PetscCall(PetscPClose(PETSC_COMM_SELF, fp));
39 #else
40   SETERRQ(PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: Aborted due to missing popen()");
41 #endif
42   /* remove newlines */
43   PetscCall(PetscStrchr(pythonlib, '\n', &eol));
44   if (eol) eol[0] = 0;
45   PetscCall(PetscTestFile(pythonlib, 'r', found));
46   PetscFunctionReturn(PETSC_SUCCESS);
47 }
48 
49 static PetscErrorCode PetscPythonFindLibrary(const char pythonexe[], char pythonlib[], size_t pl)
50 {
51   const char cmdline1[] = "-c 'import os, sysconfig; print(os.path.join(sysconfig.get_config_var(\"LIBDIR\"),sysconfig.get_config_var(\"LDLIBRARY\")))'";
52   const char cmdline2[] = "-c 'import os, sysconfig; print(os.path.join(sysconfig.get_path(\"stdlib\"),os.path.pardir,\"libpython\"+sysconfig.get_python_version()+\".dylib\"))'";
53   const char cmdline3[] = "-c 'import os, sysconfig; print(os.path.join(sysconfig.get_config_var(\"LIBPL\"),sysconfig.get_config_var(\"LDLIBRARY\")))'";
54   const char cmdline4[] = "-c 'import sysconfig; print(sysconfig.get_config_var(\"LIBPYTHON\"))'";
55   const char cmdline5[] = "-c 'import os, sysconfig; import sys;print(os.path.join(sysconfig.get_config_var(\"LIBDIR\"),\"libpython\"+sys.version[:3]+\".so\"))'";
56 
57   PetscBool found = PETSC_FALSE;
58 
59   PetscFunctionBegin;
60 #if defined(PETSC_PYTHON_LIB)
61   PetscCall(PetscStrncpy(pythonlib, PETSC_PYTHON_LIB, pl));
62   PetscFunctionReturn(PETSC_SUCCESS);
63 #endif
64 
65   PetscCall(PetscPythonFindLibraryName(pythonexe, cmdline1, pythonlib, pl, &found));
66   if (!found) PetscCall(PetscPythonFindLibraryName(pythonexe, cmdline2, pythonlib, pl, &found));
67   if (!found) PetscCall(PetscPythonFindLibraryName(pythonexe, cmdline3, pythonlib, pl, &found));
68   if (!found) PetscCall(PetscPythonFindLibraryName(pythonexe, cmdline4, pythonlib, pl, &found));
69   if (!found) PetscCall(PetscPythonFindLibraryName(pythonexe, cmdline5, pythonlib, pl, &found));
70   PetscCall(PetscInfo(NULL, "Python library  %s found %d\n", pythonlib, found));
71   PetscFunctionReturn(PETSC_SUCCESS);
72 }
73 
74 /* ---------------------------------------------------------------- */
75 
76 typedef struct _Py_object_t PyObject; /* fake definition */
77 
78 static PyObject *Py_None = NULL;
79 
80 static const char *(*Py_GetVersion)(void);
81 
82 static int (*Py_IsInitialized)(void);
83 static void (*Py_InitializeEx)(int);
84 static void (*Py_Finalize)(void);
85 
86 static void (*PySys_SetArgv)(int, void *);
87 static PyObject *(*PySys_GetObject)(const char *);
88 static PyObject *(*PyObject_CallMethod)(PyObject *, const char *, const char *, ...);
89 static PyObject *(*PyImport_ImportModule)(const char *);
90 
91 static void (*Py_IncRef)(PyObject *);
92 static void (*Py_DecRef)(PyObject *);
93 
94 static void (*PyErr_Clear)(void);
95 static PyObject *(*PyErr_Occurred)(void);
96 static void (*PyErr_Fetch)(PyObject **, PyObject **, PyObject **);
97 static void (*PyErr_NormalizeException)(PyObject **, PyObject **, PyObject **);
98 static void (*PyErr_Display)(PyObject *, PyObject *, PyObject *);
99 static void (*PyErr_Restore)(PyObject *, PyObject *, PyObject *);
100 
101 #define PetscDLPyLibOpen(libname)      PetscDLLibraryAppend(PETSC_COMM_SELF, &PetscDLLibrariesLoaded, libname)
102 #define PetscDLPyLibSym(symbol, value) PetscDLLibrarySym(PETSC_COMM_SELF, &PetscDLLibrariesLoaded, NULL, symbol, (void **)value)
103 #define PetscDLPyLibClose(comm) \
104   do { \
105   } while (0)
106 
107 static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
108 {
109   PetscFunctionBegin;
110   /* open the Python dynamic library */
111   PetscCall(PetscDLPyLibOpen(pythonlib));
112   PetscCall(PetscInfo(NULL, "Python: loaded dynamic library %s\n", pythonlib));
113   /* look required symbols from the Python C-API */
114   PetscCall(PetscDLPyLibSym("_Py_NoneStruct", &Py_None));
115   PetscCall(PetscDLPyLibSym("Py_GetVersion", &Py_GetVersion));
116   PetscCall(PetscDLPyLibSym("Py_IsInitialized", &Py_IsInitialized));
117   PetscCall(PetscDLPyLibSym("Py_InitializeEx", &Py_InitializeEx));
118   PetscCall(PetscDLPyLibSym("Py_Finalize", &Py_Finalize));
119   PetscCall(PetscDLPyLibSym("PySys_GetObject", &PySys_GetObject));
120   PetscCall(PetscDLPyLibSym("PySys_SetArgv", &PySys_SetArgv));
121   PetscCall(PetscDLPyLibSym("PyObject_CallMethod", &PyObject_CallMethod));
122   PetscCall(PetscDLPyLibSym("PyImport_ImportModule", &PyImport_ImportModule));
123   PetscCall(PetscDLPyLibSym("Py_IncRef", &Py_IncRef));
124   PetscCall(PetscDLPyLibSym("Py_DecRef", &Py_DecRef));
125   PetscCall(PetscDLPyLibSym("PyErr_Clear", &PyErr_Clear));
126   PetscCall(PetscDLPyLibSym("PyErr_Occurred", &PyErr_Occurred));
127   PetscCall(PetscDLPyLibSym("PyErr_Fetch", &PyErr_Fetch));
128   PetscCall(PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException));
129   PetscCall(PetscDLPyLibSym("PyErr_Display", &PyErr_Display));
130   PetscCall(PetscDLPyLibSym("PyErr_Restore", &PyErr_Restore));
131   /* XXX TODO: check that ALL symbols were there !!! */
132   PetscCheck(Py_None, PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: failed to load symbols from Python dynamic library %s", pythonlib);
133   PetscCheck(Py_GetVersion, PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: failed to load symbols from Python dynamic library %s", pythonlib);
134   PetscCheck(Py_IsInitialized, PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: failed to load symbols from Python dynamic library %s", pythonlib);
135   PetscCheck(Py_InitializeEx, PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: failed to load symbols from Python dynamic library %s", pythonlib);
136   PetscCheck(Py_Finalize, PETSC_COMM_SELF, PETSC_ERR_LIB, "Python: failed to load symbols from Python dynamic library %s", pythonlib);
137   PetscCall(PetscInfo(NULL, "Python: all required symbols loaded from Python dynamic library %s\n", pythonlib));
138   PetscFunctionReturn(PETSC_SUCCESS);
139 }
140 
141 /* ---------------------------------------------------------------- */
142 
143 static char      PetscPythonExe[PETSC_MAX_PATH_LEN] = {0};
144 static char      PetscPythonLib[PETSC_MAX_PATH_LEN] = {0};
145 static PetscBool PetscBeganPython                   = PETSC_FALSE;
146 
147 /*@C
148   PetscPythonFinalize - Finalize PETSc for use with Python.
149 
150   Level: intermediate
151 
152 .seealso: `PetscPythonInitialize()`, `PetscPythonPrintError()`
153 @*/
154 PetscErrorCode PetscPythonFinalize(void)
155 {
156   PetscFunctionBegin;
157   if (PetscBeganPython) {
158     if (Py_IsInitialized()) Py_Finalize();
159   }
160   PetscBeganPython = PETSC_FALSE;
161   PetscFunctionReturn(PETSC_SUCCESS);
162 }
163 
164 /*@C
165   PetscPythonInitialize - Initialize Python for use with PETSc and import petsc4py.
166 
167    Input Parameters:
168 +  pyexe - path to the Python interpreter executable, or NULL.
169 -  pylib - full path to the Python dynamic library, or NULL.
170 
171   Level: intermediate
172 
173 .seealso: `PetscPythonFinalize()`, `PetscPythonPrintError()`
174 @*/
175 PetscErrorCode PetscPythonInitialize(const char pyexe[], const char pylib[])
176 {
177   PyObject *module = NULL;
178 
179   PetscFunctionBegin;
180   if (PetscBeganPython) PetscFunctionReturn(PETSC_SUCCESS);
181   /* Python executable */
182   if (pyexe && pyexe[0] != 0) {
183     PetscCall(PetscStrncpy(PetscPythonExe, pyexe, sizeof(PetscPythonExe)));
184   } else {
185     PetscCall(PetscPythonFindExecutable(PetscPythonExe, sizeof(PetscPythonExe)));
186   }
187   /* Python dynamic library */
188   if (pylib && pylib[0] != 0) {
189     PetscCall(PetscStrncpy(PetscPythonLib, pylib, sizeof(PetscPythonLib)));
190   } else {
191     PetscCall(PetscPythonFindLibrary(PetscPythonExe, PetscPythonLib, sizeof(PetscPythonLib)));
192   }
193   /* dynamically load Python library */
194   PetscCall(PetscPythonLoadLibrary(PetscPythonLib));
195   /* initialize Python */
196   PetscBeganPython = PETSC_FALSE;
197   if (!Py_IsInitialized()) {
198     static PetscBool registered = PETSC_FALSE;
199     const char      *py_version;
200     PyObject        *sys_path;
201     char             path[PETSC_MAX_PATH_LEN] = {0};
202 
203     /* initialize Python. Py_InitializeEx() prints an error and EXITS the program if it is not successful! */
204     PetscCall(PetscInfo(NULL, "Calling Py_InitializeEx(0);\n"));
205     Py_InitializeEx(0); /* 0: do not install signal handlers */
206     PetscCall(PetscInfo(NULL, "Py_InitializeEx(0) called successfully;\n"));
207 
208     /*  build 'sys.argv' list */
209     py_version = Py_GetVersion();
210     if (py_version[0] == '2') {
211       int   argc    = 0;
212       char *argv[1] = {NULL};
213       PySys_SetArgv(argc, argv);
214     }
215     if (py_version[0] == '3') {
216       int      argc    = 0;
217       wchar_t *argv[1] = {NULL};
218       PySys_SetArgv(argc, argv);
219     }
220     /* add PETSC_LIB_DIR in front of 'sys.path' */
221     sys_path = PySys_GetObject("path");
222     if (sys_path) {
223       PetscCall(PetscStrreplace(PETSC_COMM_SELF, "${PETSC_LIB_DIR}", path, sizeof(path)));
224       Py_DecRef(PyObject_CallMethod(sys_path, "insert", "is", (int)0, (char *)path));
225 #if defined(PETSC_PETSC4PY_INSTALL_PATH)
226       {
227         char *rpath;
228         PetscCall(PetscStrallocpy(PETSC_PETSC4PY_INSTALL_PATH, &rpath));
229         Py_DecRef(PyObject_CallMethod(sys_path, "insert", "is", (int)0, rpath));
230         PetscCall(PetscFree(rpath));
231       }
232 #endif
233     }
234     /* register finalizer */
235     if (!registered) {
236       PetscCall(PetscRegisterFinalize(PetscPythonFinalize));
237       registered = PETSC_TRUE;
238     }
239     PetscBeganPython = PETSC_TRUE;
240     PetscCall(PetscInfo(NULL, "Python initialize completed.\n"));
241   }
242   /* import 'petsc4py.PETSc' module */
243   module = PyImport_ImportModule("petsc4py.PETSc");
244   if (module) {
245     PetscCall(PetscInfo(NULL, "Python: successfully imported  module 'petsc4py.PETSc'\n"));
246     Py_DecRef(module);
247     module = NULL;
248   } else {
249     PetscCall(PetscPythonPrintError());
250     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it");
251   }
252   PetscFunctionReturn(PETSC_SUCCESS);
253 }
254 
255 /*@C
256   PetscPythonPrintError - Print any current Python errors.
257 
258   Level: developer
259 
260 .seealso: `PetscPythonInitialize()`, `PetscPythonFinalize()`
261 @*/
262 PetscErrorCode PetscPythonPrintError(void)
263 {
264   PyObject *exc = NULL, *val = NULL, *tb = NULL;
265 
266   PetscFunctionBegin;
267   if (!PetscBeganPython) PetscFunctionReturn(PETSC_SUCCESS);
268   if (!PyErr_Occurred()) PetscFunctionReturn(PETSC_SUCCESS);
269   PyErr_Fetch(&exc, &val, &tb);
270   PyErr_NormalizeException(&exc, &val, &tb);
271   PyErr_Display(exc ? exc : Py_None, val ? val : Py_None, tb ? tb : Py_None);
272   PyErr_Restore(exc, val, tb);
273   PetscFunctionReturn(PETSC_SUCCESS);
274 }
275 
276 /* ---------------------------------------------------------------- */
277 
278 PETSC_EXTERN PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject, const char[]);
279 PetscErrorCode (*PetscPythonMonitorSet_C)(PetscObject, const char[]) = NULL;
280 
281 /*@C
282   PetscPythonMonitorSet - Set a Python monitor for a `PetscObject`
283 
284   Level: developer
285 
286 .seealso: `PetscPythonInitialize()`, `PetscPythonFinalize()`, `PetscPythonPrintError()`
287 @*/
288 PetscErrorCode PetscPythonMonitorSet(PetscObject obj, const char url[])
289 {
290   PetscFunctionBegin;
291   PetscValidHeader(obj, 1);
292   PetscValidCharPointer(url, 2);
293   if (!PetscPythonMonitorSet_C) {
294     PetscCall(PetscPythonInitialize(NULL, NULL));
295     PetscCheck(PetscPythonMonitorSet_C, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Couldn't initialize Python support for monitors");
296   }
297   PetscCall(PetscPythonMonitorSet_C(obj, url));
298   PetscFunctionReturn(PETSC_SUCCESS);
299 }
300 
301 /* ---------------------------------------------------------------- */
302