xref: /petsc/src/sys/python/pythonsys.c (revision c6db04a5321582041def2b1e244c75985478b3ef)
1 
2 #include <petscsys.h>       /*I "petscsys.h" I*/
3 
4 /* ---------------------------------------------------------------- */
5 
6 #if !defined(PETSC_PYTHON_EXE)
7 #define PETSC_PYTHON_EXE "python"
8 #endif
9 
10 #undef __FUNCT__
11 #define __FUNCT__ "PetscPythonFindExecutable"
12 static PetscErrorCode PetscPythonFindExecutable(char pythonexe[PETSC_MAX_PATH_LEN])
13 {
14   PetscBool      flag;
15   PetscErrorCode ierr;
16   PetscFunctionBegin;
17   /* get the path for the Python interpreter executable */
18   ierr = PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
19   ierr = PetscOptionsGetString(PETSC_NULL,"-python",pythonexe,PETSC_MAX_PATH_LEN,&flag);CHKERRQ(ierr);
20   if (!flag || pythonexe[0]==0) {
21     ierr = PetscStrncpy(pythonexe,PETSC_PYTHON_EXE,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
22   }
23   PetscFunctionReturn(0);
24 }
25 
26 #undef __FUNCT__
27 #define __FUNCT__ "PetscPythonFindLibrary"
28 static PetscErrorCode PetscPythonFindLibrary(char pythonexe[PETSC_MAX_PATH_LEN],
29 					     char pythonlib[PETSC_MAX_PATH_LEN])
30 {
31   const char cmdline[] = "-c 'import sys; print(sys.exec_prefix); print(sys.version[:3])'";
32   char command[PETSC_MAX_PATH_LEN+1+sizeof(cmdline)+1];
33   char prefix[PETSC_MAX_PATH_LEN],version[8],sep[2]={PETSC_DIR_SEPARATOR, 0},*eol;
34   FILE* fp = NULL;
35   char path[PETSC_MAX_PATH_LEN+1];
36   PetscBool  found = PETSC_FALSE;
37   PetscErrorCode ierr;
38   PetscFunctionBegin;
39 
40 #if defined(PETSC_PYTHON_LIB)
41   ierr = PetscStrcpy(pythonlib,PETSC_PYTHON_LIB);CHKERRQ(ierr);
42   PetscFunctionReturn(0);
43 #endif
44 
45   /* call Python to find out the name of the Python dynamic library */
46   ierr = PetscStrncpy(command,pythonexe,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
47   ierr = PetscStrcat(command," ");CHKERRQ(ierr);
48   ierr = PetscStrcat(command,cmdline);CHKERRQ(ierr);
49 #if defined(PETSC_HAVE_POPEN)
50   ierr = PetscPOpen(PETSC_COMM_SELF,PETSC_NULL,command,"r",&fp);CHKERRQ(ierr);
51   if (!fgets(prefix,sizeof(prefix),fp))
52     { SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: bad output from executable: %s",pythonexe); }
53   if (!fgets(version,sizeof(version),fp))
54     { SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: bad output from executable: %s",pythonexe); }
55   ierr = PetscPClose(PETSC_COMM_SELF,fp);CHKERRQ(ierr);
56 #else
57   SETERRQ(PETSC_COMM_SELF,1,"Python: Aborted due to missing popen()");
58 #endif
59   /* remove newlines */
60   ierr = PetscStrchr(prefix,'\n',&eol);CHKERRQ(ierr);
61   if (eol) eol[0] = 0;
62   ierr = PetscStrchr(version,'\n',&eol);CHKERRQ(ierr);
63   if (eol) eol[0] = 0;
64 
65   /* test for $prefix/lib64/libpythonX.X[.so]*/
66   ierr = PetscStrcpy(pythonlib,prefix);CHKERRQ(ierr);
67   ierr = PetscStrcat(pythonlib,sep);CHKERRQ(ierr);
68   ierr = PetscStrcat(pythonlib,"lib64");CHKERRQ(ierr);
69   ierr = PetscTestDirectory(pythonlib,'r',&found);CHKERRQ(ierr);
70   if (found) {
71     ierr = PetscStrcat(pythonlib,sep);CHKERRQ(ierr);
72     ierr = PetscStrcat(pythonlib,"libpython");CHKERRQ(ierr);
73     ierr = PetscStrcat(pythonlib,version);CHKERRQ(ierr);
74     ierr = PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);CHKERRQ(ierr);
75     if (found) PetscFunctionReturn(0);
76   }
77 
78   /* test for $prefix/lib/libpythonX.X[.so]*/
79   ierr = PetscStrcpy(pythonlib,prefix);CHKERRQ(ierr);
80   ierr = PetscStrcat(pythonlib,sep);CHKERRQ(ierr);
81   ierr = PetscStrcat(pythonlib,"lib");CHKERRQ(ierr);
82   ierr = PetscTestDirectory(pythonlib,'r',&found);CHKERRQ(ierr);
83   if (found) {
84     ierr = PetscStrcat(pythonlib,sep);CHKERRQ(ierr);
85     ierr = PetscStrcat(pythonlib,"libpython");CHKERRQ(ierr);
86     ierr = PetscStrcat(pythonlib,version);CHKERRQ(ierr);
87     ierr = PetscDLLibraryRetrieve(PETSC_COMM_SELF,pythonlib,path,PETSC_MAX_PATH_LEN,&found);CHKERRQ(ierr);
88     if (found) PetscFunctionReturn(0);
89   }
90 
91   /* nothing good found */
92   ierr = PetscMemzero(pythonlib,PETSC_MAX_PATH_LEN);CHKERRQ(ierr);
93   ierr = PetscInfo(0,"Python dynamic library not found\n");CHKERRQ(ierr);
94 
95   PetscFunctionReturn(0);
96 }
97 
98 /* ---------------------------------------------------------------- */
99 
100 typedef struct _Py_object_t PyObject; /* fake definition */
101 
102 static PyObject* Py_None = 0;
103 
104 static const char* (*Py_GetVersion)(void);
105 
106 static int   	 (*Py_IsInitialized)(void);
107 static void  	 (*Py_InitializeEx)(int);
108 static void  	 (*Py_Finalize)(void);
109 
110 static void      (*PySys_SetArgv)(int, char **);
111 static PyObject* (*PyImport_ImportModule)(const char *);
112 
113 static void      (*Py_IncRef)(PyObject *);
114 static void      (*Py_DecRef)(PyObject *);
115 
116 static void      (*PyErr_Clear)(void);
117 static PyObject* (*PyErr_Occurred)(void);
118 static void      (*PyErr_Fetch)(PyObject **, PyObject **, PyObject **);
119 static void      (*PyErr_NormalizeException)(PyObject **, PyObject **, PyObject **);
120 static void      (*PyErr_Display)(PyObject *, PyObject *, PyObject *);
121 static void      (*PyErr_Restore)(PyObject *, PyObject *, PyObject *);
122 
123 
124 #define PetscDLPyLibOpen(libname) \
125   PetscDLLibraryAppend(PETSC_COMM_SELF,&DLLibrariesLoaded,libname)
126 #define PetscDLPyLibSym(symbol, value) \
127   PetscDLLibrarySym(PETSC_COMM_SELF,&DLLibrariesLoaded,PETSC_NULL,symbol,(void**)value)
128 #define PetscDLPyLibClose(comm) \
129   do { } while(0)
130 
131 #undef __FUNCT__
132 #define __FUNCT__ "PetscPythonLoadLibrary"
133 static PetscErrorCode PetscPythonLoadLibrary(const char pythonlib[])
134 {
135   PetscErrorCode ierr;
136   PetscFunctionBegin;
137 
138   /* open the Python dynamic library */
139   ierr = PetscDLPyLibOpen(pythonlib);CHKERRQ(ierr);
140   ierr = PetscInfo1(0,"Python: loaded dynamic library %s\n", pythonlib);CHKERRQ(ierr);
141   /* look required symbols from the Python C-API */
142   ierr = PetscDLPyLibSym("_Py_NoneStruct"        , &Py_None               );CHKERRQ(ierr);
143   ierr = PetscDLPyLibSym("Py_GetVersion"         , &Py_GetVersion         );CHKERRQ(ierr);
144   ierr = PetscDLPyLibSym("Py_IsInitialized"      , &Py_IsInitialized      );CHKERRQ(ierr);
145   ierr = PetscDLPyLibSym("Py_InitializeEx"       , &Py_InitializeEx       );CHKERRQ(ierr);
146   ierr = PetscDLPyLibSym("Py_Finalize"           , &Py_Finalize           );CHKERRQ(ierr);
147   ierr = PetscDLPyLibSym("PySys_SetArgv"         , &PySys_SetArgv         );CHKERRQ(ierr);
148   ierr = PetscDLPyLibSym("PyImport_ImportModule" , &PyImport_ImportModule );CHKERRQ(ierr);
149   ierr = PetscDLPyLibSym("Py_IncRef"             , &Py_IncRef             );CHKERRQ(ierr);
150   ierr = PetscDLPyLibSym("Py_DecRef"             , &Py_DecRef             );CHKERRQ(ierr);
151   ierr = PetscDLPyLibSym("PyErr_Clear"           , &PyErr_Clear           );CHKERRQ(ierr);
152   ierr = PetscDLPyLibSym("PyErr_Occurred"        , &PyErr_Occurred        );CHKERRQ(ierr);
153   ierr = PetscDLPyLibSym("PyErr_Fetch"             , &PyErr_Fetch             );CHKERRQ(ierr);
154   ierr = PetscDLPyLibSym("PyErr_NormalizeException", &PyErr_NormalizeException);CHKERRQ(ierr);
155   ierr = PetscDLPyLibSym("PyErr_Display",            &PyErr_Display           );CHKERRQ(ierr);
156   ierr = PetscDLPyLibSym("PyErr_Restore",            &PyErr_Restore           );CHKERRQ(ierr);
157   /* XXX TODO: check that ALL symbols were there !!! */
158   if (!Py_None)          SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
159   if (!Py_GetVersion)    SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
160   if (!Py_IsInitialized) SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
161   if (!Py_InitializeEx)  SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
162   if (!Py_Finalize)      SETERRQ(PETSC_COMM_SELF,1,"Python: failed to load symbols from dynamic library");
163   ierr = PetscInfo(0,"Python: all required symbols loaded from Python dynamic library\n");CHKERRQ(ierr);
164 
165   PetscFunctionReturn(0);
166 }
167 
168 /* ---------------------------------------------------------------- */
169 
170 static char       PetscPythonExe[PETSC_MAX_PATH_LEN] = { 0 };
171 static char       PetscPythonLib[PETSC_MAX_PATH_LEN] = { 0 };
172 static PetscBool  PetscBeganPython = PETSC_FALSE;
173 
174 #undef __FUNCT__
175 #define __FUNCT__ "PetscPythonFinalize"
176 /*@C
177   PetscPythonFinalize - Finalize Python.
178 
179   Level: intermediate
180 
181 .keywords: Python
182 @*/
183 PetscErrorCode  PetscPythonFinalize(void)
184 {
185   PetscFunctionBegin;
186   if (PetscBeganPython) { if (Py_IsInitialized()) Py_Finalize(); }
187   PetscBeganPython = PETSC_FALSE;
188   PetscFunctionReturn(0);
189 }
190 
191 #undef __FUNCT__
192 #define __FUNCT__ "PetscPythonInitialize"
193 /*@C
194   PetscPythonInitialize - Initialize Python and import petsc4py.
195 
196    Input Parameter:
197 +  pyexe - path to the Python interpreter executable, or PETSC_NULL.
198 -  pylib - full path to the Python dynamic library, or PETSC_NULL.
199 
200   Level: intermediate
201 
202 .keywords: Python
203 
204 @*/
205 PetscErrorCode  PetscPythonInitialize(const char pyexe[],const char pylib[])
206 {
207   PyObject          *module    = 0;
208   static PetscBool  registered = PETSC_FALSE;
209   PetscErrorCode    ierr;
210   PetscFunctionBegin;
211   if (PetscBeganPython) PetscFunctionReturn(0);
212   /* Python executable */
213   if (pyexe && pyexe[0] != 0) {
214     ierr = PetscStrncpy(PetscPythonExe,pyexe,sizeof(PetscPythonExe));CHKERRQ(ierr);
215   } else {
216     ierr = PetscPythonFindExecutable(PetscPythonExe);CHKERRQ(ierr);
217   }
218   /* Python dynamic library */
219   if (pylib && pylib[0] != 0) {
220     ierr = PetscStrncpy(PetscPythonLib,pylib,sizeof(PetscPythonLib));CHKERRQ(ierr);
221   } else {
222     ierr = PetscPythonFindLibrary(PetscPythonExe,PetscPythonLib);CHKERRQ(ierr);
223   }
224   /* dynamically load Python library */
225   ierr = PetscPythonLoadLibrary(PetscPythonLib);CHKERRQ(ierr);
226   /* initialize Python */
227   PetscBeganPython = PETSC_FALSE;
228   if (!Py_IsInitialized()) {
229     const char *py_version = Py_GetVersion();
230     /* call below does not install signal handlers */
231     Py_InitializeEx(0);
232     /* call below required to build 'sys.argv' list */
233     if (py_version[0] == '2') {
234       int  argc   = 0;
235       char **argv = 0;
236       ierr = PetscGetArgs(&argc,&argv);CHKERRQ(ierr);
237       if (argc && argv) PySys_SetArgv(argc,argv);
238     }
239     /* register finalizer */
240     if (!registered) {
241       ierr = PetscRegisterFinalize(PetscPythonFinalize);CHKERRQ(ierr);
242       registered = PETSC_TRUE;
243     }
244     PetscBeganPython = PETSC_TRUE;
245   }
246   /* import 'petsc4py.PETSc' module */
247   module = PyImport_ImportModule("petsc4py.PETSc");
248   if (module) {
249     ierr = PetscInfo(0,"Python: successfully imported  module 'petsc4py.PETSc'\n");CHKERRQ(ierr);
250     Py_DecRef(module); module = 0;
251   } else {
252     PetscPythonPrintError();
253     SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Python: could not import module 'petsc4py.PETSc', perhaps your PYTHONPATH does not contain it\n");
254   }
255   PetscFunctionReturn(0);
256 }
257 
258 #undef __FUNCT__
259 #define __FUNCT__ "PetscPythonPrintError"
260 /*@C
261   PetscPythonPrintError - Print Python errors.
262 
263   Level: developer
264 
265 .keywords: Python
266 
267 @*/
268 PetscErrorCode  PetscPythonPrintError(void)
269 {
270   PyObject *exc=0, *val=0, *tb=0;
271   PetscFunctionBegin;
272   if (!PetscBeganPython) PetscFunctionReturn(0);
273   if (!PyErr_Occurred()) PetscFunctionReturn(0);
274   PyErr_Fetch(&exc,&val,&tb);
275   PyErr_NormalizeException(&exc,&val,&tb);
276   PyErr_Display(exc ? exc : Py_None,
277                 val ? val : Py_None,
278                 tb  ? tb  : Py_None);
279   PyErr_Restore(exc,val,tb);
280   PetscFunctionReturn(0);
281 }
282 
283 /* ---------------------------------------------------------------- */
284