lint: Check Cython code

.github/workflows/ci-check.yml

@@ -113,6 +113,9 @@ jobs:
     - name: codespell
       run:  codespell
 
+    - name: cython
+      run:  conf/cythonize.sh -Wextra -Werror
+
   type:
     runs-on: ubuntu-latest
 

conf/requirements-lint.txt

@@ -1,4 +1,5 @@
 codespell
+cython
 flake8
 flake8-assertive
 flake8-bandit

src/mpi4py/MPI.pyx

@@ -12,6 +12,6 @@
 #cython: binding=True
 
 from __future__ import annotations
-cimport cython
+cimport cython  # no-cython-lint
 
 include "MPI/MPI.pyx"

src/mpi4py/MPI/Comm.pyx

@@ -2535,12 +2535,12 @@ cdef class Intracomm(Comm):
         #
         cdef int rank = MPI_UNDEFINED
         CHKERR( MPI_Comm_rank(self.ob_mpi, &rank) )
-        cdef tmp1, tmp2, tmp3
+        cdef object unused1, unused2, unused3
         if root == rank:
-            tmp1 = asmpistr(command, &cmd)
-            tmp2 = asarray_argv(args, &argv)
+            unused1 = asmpistr(command, &cmd)
+            unused2 = asarray_argv(args, &argv)
         if errcodes is not None:
-            tmp3 = newarray(maxprocs, &ierrcodes)
+            unused3 = newarray(maxprocs, &ierrcodes)
         #
         cdef Intercomm comm = <Intercomm>New(Intercomm)
         with nogil: CHKERR( MPI_Comm_spawn(
@@ -2574,20 +2574,20 @@ cdef class Intracomm(Comm):
         #
         cdef int rank = MPI_UNDEFINED
         CHKERR( MPI_Comm_rank(self.ob_mpi, &rank) )
-        cdef tmp1, tmp2, tmp3, tmp4, tmp5
+        cdef object unused1, unused2, unused3, unused4, unused5
         if root == rank:
-            tmp1 = asarray_cmds(command, &count, &cmds)
-            tmp2 = asarray_argvs(args, count, &argvs)
-            tmp3 = asarray_nprocs(maxprocs, count, &imaxprocs)
-            tmp4 = asarray_Info(info, count, &infos)
+            unused1 = asarray_cmds(command, &count, &cmds)
+            unused2 = asarray_argvs(args, count, &argvs)
+            unused3 = asarray_nprocs(maxprocs, count, &imaxprocs)
+            unused4 = asarray_Info(info, count, &infos)
         cdef int np = 0
         if errcodes is not None:
             if root != rank:
                 count = <int>len(maxprocs)
-                tmp3 = asarray_nprocs(maxprocs, count, &imaxprocs)
+                unused3 = asarray_nprocs(maxprocs, count, &imaxprocs)
             for i in range(count):
                 np += imaxprocs[i]
-            tmp5 = newarray(np, &ierrcodes)
+            unused5 = newarray(np, &ierrcodes)
         #
         cdef Intercomm comm = <Intercomm>New(Intercomm)
         with nogil: CHKERR( MPI_Comm_spawn_multiple(
@@ -3046,11 +3046,11 @@ cdef class Cartcomm(Topocomm):
         cdef int ndim = 0
         CHKERR( MPI_Cartdim_get(self.ob_mpi, &ndim) )
         cdef int *idims = NULL
-        cdef tmp1 = newarray(ndim, &idims)
+        cdef unused1 = newarray(ndim, &idims)
         cdef int *iperiods = NULL
-        cdef tmp2 = newarray(ndim, &iperiods)
+        cdef unused2 = newarray(ndim, &iperiods)
         cdef int *icoords = NULL
-        cdef tmp3 = newarray(ndim, &icoords)
+        cdef unused3 = newarray(ndim, &icoords)
         CHKERR( MPI_Cart_get(self.ob_mpi, ndim, idims, iperiods, icoords) )
         cdef object dims    = [idims[i]    for i in range(ndim)]
         cdef object periods = [iperiods[i] for i in range(ndim)]
@@ -3098,7 +3098,7 @@ cdef class Cartcomm(Topocomm):
         """
         cdef int ndim = 0, *icoords = NULL
         CHKERR( MPI_Cartdim_get(self.ob_mpi, &ndim) )
-        cdef tmp = newarray(ndim, &icoords)
+        cdef unused = newarray(ndim, &icoords)
         CHKERR( MPI_Cart_coords(self.ob_mpi, rank, ndim, icoords) )
         cdef object coords = [icoords[i] for i in range(ndim)]
         return coords
@@ -3142,7 +3142,7 @@ def Compute_dims(int nnodes: int, dims: int | Sequence[int]) -> list[int]:
     except:
         ndims = dims
         dims = [0] * ndims
-    cdef tmp = chkarray(dims, ndims, &idims)
+    cdef unused = chkarray(dims, ndims, &idims)
     CHKERR( MPI_Dims_create(nnodes, ndims, idims) )
     dims = [idims[i] for i in range(ndims)]
     return dims
@@ -3194,9 +3194,9 @@ cdef class Graphcomm(Topocomm):
         cdef int nindex = 0, nedges = 0
         CHKERR( MPI_Graphdims_get( self.ob_mpi, &nindex, &nedges) )
         cdef int *iindex = NULL
-        cdef tmp1 = newarray(nindex, &iindex)
+        cdef unused1 = newarray(nindex, &iindex)
         cdef int *iedges = NULL
-        cdef tmp2 = newarray(nedges, &iedges)
+        cdef unused2 = newarray(nedges, &iedges)
         CHKERR( MPI_Graph_get(self.ob_mpi, nindex, nedges, iindex, iedges) )
         cdef object index = [iindex[i] for i in range(nindex)]
         cdef object edges = [iedges[i] for i in range(nedges)]
@@ -3241,7 +3241,7 @@ cdef class Graphcomm(Topocomm):
         cdef int nneighbors = 0, *ineighbors = NULL
         CHKERR( MPI_Graph_neighbors_count(
                 self.ob_mpi, rank, &nneighbors) )
-        cdef tmp = newarray(nneighbors, &ineighbors)
+        cdef unused = newarray(nneighbors, &ineighbors)
         CHKERR( MPI_Graph_neighbors(
                 self.ob_mpi, rank, nneighbors, ineighbors) )
         cdef object neighbors = [ineighbors[i] for i in range(nneighbors)]
@@ -3293,14 +3293,14 @@ cdef class Distgraphcomm(Topocomm):
         cdef int *sources = NULL, *destinations = NULL
         cdef int *sourceweights = MPI_UNWEIGHTED
         cdef int *destweights   = MPI_UNWEIGHTED
-        cdef tmp1, tmp2, tmp3, tmp4
-        tmp1 = newarray(maxindegree,  &sources)
-        tmp2 = newarray(maxoutdegree, &destinations)
+        cdef object unused1, unused2, unused3, unused4
+        unused1 = newarray(maxindegree,  &sources)
+        unused2 = newarray(maxoutdegree, &destinations)
         if weighted:
-            tmp3 = newarray(maxindegree, &sourceweights)
+            unused3 = newarray(maxindegree, &sourceweights)
             for i in range(maxindegree):
                 sourceweights[i] = 1
-            tmp4 = newarray(maxoutdegree, &destweights)
+            unused4 = newarray(maxoutdegree, &destweights)
             for i in range(maxoutdegree):
                 destweights[i]   = 1
         #

src/mpi4py/MPI/Datatype.pyx

@@ -551,10 +551,10 @@ cdef class Datatype:
         cdef MPI_Aint *a = NULL
         cdef MPI_Count *c = NULL
         cdef MPI_Datatype *d = NULL
-        cdef tmp1 = allocate(ni, sizeof(int), &i)
-        cdef tmp2 = allocate(na, sizeof(MPI_Aint), &a)
-        cdef tmp3 = allocate(nc, sizeof(MPI_Count), &c)
-        cdef tmp4 = allocate(nd, sizeof(MPI_Datatype), &d)
+        cdef unused1 = allocate(ni, sizeof(int), &i)
+        cdef unused2 = allocate(na, sizeof(MPI_Aint), &a)
+        cdef unused3 = allocate(nc, sizeof(MPI_Count), &c)
+        cdef unused4 = allocate(nd, sizeof(MPI_Datatype), &d)
         CHKERR( MPI_Type_get_contents_c(
             self.ob_mpi, ni, na, nc, nd, i, a, c, d) )
         cdef object integers  = [i[k] for k in range(ni)]
@@ -616,8 +616,8 @@ cdef class Datatype:
         #
         cdef void *ibptr = NULL, *obptr = NULL
         cdef MPI_Aint iblen = 0, oblen = 0
-        cdef tmp1 = asbuffer_r(inbuf,  &ibptr, &iblen)
-        cdef tmp2 = asbuffer_w(outbuf, &obptr, &oblen)
+        cdef unused1 = asbuffer_r(inbuf,  &ibptr, &iblen)
+        cdef unused2 = asbuffer_w(outbuf, &obptr, &oblen)
         cdef MPI_Count icount = iblen // extent
         cdef MPI_Count ocount = oblen
         #
@@ -642,8 +642,8 @@ cdef class Datatype:
         #
         cdef void *ibptr = NULL, *obptr = NULL
         cdef MPI_Aint iblen = 0, oblen = 0
-        cdef tmp1 = asbuffer_r(inbuf,  &ibptr, &iblen)
-        cdef tmp2 = asbuffer_w(outbuf, &obptr, &oblen)
+        cdef unused1 = asbuffer_r(inbuf,  &ibptr, &iblen)
+        cdef unused2 = asbuffer_w(outbuf, &obptr, &oblen)
         cdef MPI_Count icount = iblen
         cdef MPI_Count ocount = oblen // extent
         #
@@ -691,8 +691,8 @@ cdef class Datatype:
         #
         cdef void *ibptr = NULL, *obptr = NULL
         cdef MPI_Aint iblen = 0, oblen = 0
-        cdef tmp1 = asbuffer_r(inbuf,  &ibptr, &iblen)
-        cdef tmp2 = asbuffer_w(outbuf, &obptr, &oblen)
+        cdef unused1 = asbuffer_r(inbuf,  &ibptr, &iblen)
+        cdef unused2 = asbuffer_w(outbuf, &obptr, &oblen)
         cdef MPI_Count icount = iblen // extent
         cdef MPI_Count ocount = oblen
         #
@@ -721,8 +721,8 @@ cdef class Datatype:
         #
         cdef void *ibptr = NULL, *obptr = NULL
         cdef MPI_Aint iblen = 0, oblen = 0
-        cdef tmp1 = asbuffer_r(inbuf,  &ibptr, &iblen)
-        cdef tmp2 = asbuffer_w(outbuf, &obptr, &oblen)
+        cdef unused1 = asbuffer_r(inbuf,  &ibptr, &iblen)
+        cdef unused2 = asbuffer_w(outbuf, &obptr, &oblen)
         cdef MPI_Count icount = iblen
         cdef MPI_Count ocount = oblen // extent
         #
@@ -856,7 +856,7 @@ cdef class Datatype:
         """
         cdef const char *s = DatatypeCode(self.ob_mpi)
         if s != NULL: return pystr(s)
-        raise ValueError(f"cannot map to character code or type string")
+        raise ValueError("cannot map to character code or type string")
 
     @classmethod
     def fromcode(cls, code: str) -> Datatype:

src/mpi4py/MPI/Group.pyx

@@ -72,14 +72,14 @@ cdef class Group:
         cdef MPI_Group group2 = MPI_GROUP_NULL
         cdef int n = 0, *iranks1 = NULL, *iranks2 = NULL
         #
-        cdef tmp1 = None
+        cdef unused1 = None
         if ranks is not None:
-            tmp1 = getarray(ranks, &n, &iranks1)
+            unused1 = getarray(ranks, &n, &iranks1)
         else:
             CHKERR( MPI_Group_size(self.ob_mpi, &n) )
-            tmp1 = newarray(n, &iranks1)
+            unused1 = newarray(n, &iranks1)
             for i in range(n): iranks1[i] = i
-        cdef tmp2 = newarray(n, &iranks2)
+        cdef unused2 = newarray(n, &iranks2)
         #
         group1 = self.ob_mpi
         if group is not None:
@@ -175,7 +175,7 @@ cdef class Group:
         cdef int *p = NULL, (*ranges)[3]# = NULL ## XXX cython fails
         ranges = NULL
         cdef int n = <int>len(ranks)
-        cdef tmp1 = allocate(n, sizeof(int[3]), &ranges)
+        cdef unused1 = allocate(n, sizeof(int[3]), &ranges)
         for i in range(n):
             p = <int*> ranges[i]
             p[0], p[1], p[2] = ranks[i]
@@ -190,7 +190,7 @@ cdef class Group:
         cdef int *p = NULL, (*ranges)[3]# = NULL ## XXX cython fails
         ranges = NULL
         cdef int n = <int>len(ranks)
-        cdef tmp1 = allocate(n, sizeof(int[3]), &ranges)
+        cdef unused1 = allocate(n, sizeof(int[3]), &ranges)
         for i in range(n):
             p = <int*> ranges[i]
             p[0], p[1], p[2] = ranks[i]

src/mpi4py/MPI/Info.pyx

@@ -100,7 +100,7 @@ cdef class Info:
         cdef int buflen = MPI_MAX_INFO_VAL
         cdef int flag = 0
         key = asmpistr(key, &ckey)
-        cdef tmp = allocate(buflen+1, sizeof(char), &cvalue)
+        cdef unused = allocate(buflen+1, sizeof(char), &cvalue)
         CHKERR( MPI_Info_get_string(self.ob_mpi, ckey, &buflen, cvalue, &flag) )
         if not flag: return None
         return mpistr(cvalue)

src/mpi4py/MPI/Session.pyx

@@ -68,7 +68,7 @@ cdef class Session:
         """
         cdef int nlen = MPI_MAX_PSET_NAME_LEN
         cdef char *pset_name = NULL
-        cdef tmp = allocate(nlen+1, sizeof(char), &pset_name)
+        cdef unused = allocate(nlen+1, sizeof(char), &pset_name)
         CHKERR( MPI_Session_get_nth_pset(
             self.ob_mpi, info.ob_mpi, n, &nlen, pset_name) )
         return mpistr(pset_name)

src/mpi4py/MPI/Status.pyx

@@ -185,7 +185,7 @@ cdef class Status:
         cdef Py_ssize_t n = <int>(sizeof(MPI_Status)//sizeof(int))
         cdef MPI_Status *c_status = &status.ob_mpi
         cdef MPI_Fint *f_status = NULL
-        cdef tmp = allocate(n+1, sizeof(MPI_Fint), &f_status)
+        cdef unused = allocate(n+1, sizeof(MPI_Fint), &f_status)
         CHKERR( MPI_Status_c2f(c_status, f_status) )
         return [f_status[i] for i in range(n)]
 
@@ -197,7 +197,7 @@ cdef class Status:
         cdef MPI_Status *c_status = &status
         cdef Py_ssize_t n = <int>(sizeof(MPI_Status)//sizeof(int))
         cdef MPI_Fint *f_status = NULL
-        cdef tmp = allocate(n+1, sizeof(MPI_Fint), &f_status)
+        cdef unused = allocate(n+1, sizeof(MPI_Fint), &f_status)
         for i in range(n): f_status[i] = arg[i]
         CHKERR( MPI_Status_f2c(f_status, c_status) )
         return PyMPIStatus_New(c_status)

src/mpi4py/MPI/bufaimpl.pxi

@@ -60,12 +60,16 @@ cdef inline int detach_buffer_set(
     PyMPI_attach_buffer_type obj,
     object buf,
 ) except -1:
+    cdef Py_uintptr_t handle
     if PyMPI_attach_buffer_type is Py_uintptr_t:
+        handle = <Py_uintptr_t>obj; <void>handle;  # unused
         _mpi_buffer_comm[None] = buf
     if PyMPI_attach_buffer_type is Comm:
-        _mpi_buffer_comm[<Py_uintptr_t>obj.ob_mpi] = buf  #~> MPI-4.1
+        handle = <Py_uintptr_t>obj.ob_mpi  #~> MPI-4.1
+        _mpi_buffer_comm[handle] = buf     #~> MPI-4.1
     if PyMPI_attach_buffer_type is Session:
-        _mpi_buffer_session[<Py_uintptr_t>obj.ob_mpi] = buf  #~> MPI-4.1
+        handle = <Py_uintptr_t>obj.ob_mpi  #~> MPI-4.1
+        _mpi_buffer_session[handle] = buf  #~> MPI-4.1
     return 0
 
 cdef inline object detach_buffer_get(
@@ -76,6 +80,7 @@ cdef inline object detach_buffer_get(
     cdef Py_uintptr_t handle
     cdef buffer buf = <buffer>None
     if PyMPI_attach_buffer_type is Py_uintptr_t:
+        handle = <Py_uintptr_t>obj; <void>handle;  # unused
         buf = <buffer>_mpi_buffer_comm.pop(None, None)
     if PyMPI_attach_buffer_type is Comm:
         handle = <Py_uintptr_t>obj.ob_mpi                 #~> MPI-4.1