Merge pull request #23255 from seberg/malloc0

MAINT: Remove malloc(0) calls in linalg and pocketfft

4 files changed, 74 insertions, 34 deletions

diff --git a/numpy/core/src/npysort/heapsort.cpp b/numpy/core/src/npysort/heapsort.cpp
index 3956de51f..77a4bda74 100644
--- a/numpy/core/src/npysort/heapsort.cpp
+++ b/numpy/core/src/npysort/heapsort.cpp
@@ -55,6 +55,9 @@ npy_heapsort(void *start, npy_intp num, void *varr)
     PyArrayObject *arr = (PyArrayObject *)varr;
     npy_intp elsize = PyArray_ITEMSIZE(arr);
     PyArray_CompareFunc *cmp = PyArray_DESCR(arr)->f->compare;
+    if (elsize == 0) {
+        return 0;  /* no need for sorting elements of no size */
+    }
     char *tmp = (char *)malloc(elsize);
     char *a = (char *)start - elsize;
     npy_intp i, j, l;
diff --git a/numpy/core/src/npysort/npysort_heapsort.h b/numpy/core/src/npysort/npysort_heapsort.h
index 442320094..16750b817 100644
--- a/numpy/core/src/npysort/npysort_heapsort.h
+++ b/numpy/core/src/npysort/npysort_heapsort.h
@@ -128,6 +128,10 @@ int string_heapsort_(type *start, npy_intp n, void *varr)
 {
     PyArrayObject *arr = (PyArrayObject *)varr;
     size_t len = PyArray_ITEMSIZE(arr) / sizeof(type);
+    if (len == 0) {
+        return 0;  /* no need for sorting if strings are empty */
+    }
+
     type *tmp = (type *)malloc(PyArray_ITEMSIZE(arr));
     type *a = (type *)start - len;
     npy_intp i, j, l;
diff --git a/numpy/fft/_pocketfft.c b/numpy/fft/_pocketfft.c
index 86de57bd3..37649386f 100644
--- a/numpy/fft/_pocketfft.c
+++ b/numpy/fft/_pocketfft.c
@@ -23,7 +23,7 @@
 #include <stdlib.h>
 
 #define RALLOC(type,num) \
-  ((type *)malloc((num)*sizeof(type)))
+  (assert(num != 0), ((type *)malloc((num)*sizeof(type))))
 #define DEALLOC(ptr) \
   do { free(ptr); (ptr)=NULL; } while(0)
 
@@ -1056,8 +1056,10 @@ static cfftp_plan make_cfftp_plan (size_t length)
   if (length==1) return plan;
   if (cfftp_factorize(plan)!=0) { DEALLOC(plan); return NULL; }
   size_t tws=cfftp_twsize(plan);
-  plan->mem=RALLOC(cmplx,tws);
-  if (!plan->mem) { DEALLOC(plan); return NULL; }
+  if (tws != 0) {
+    plan->mem=RALLOC(cmplx,tws);
+    if (!plan->mem) { DEALLOC(plan); return NULL; }
+  }
   if (cfftp_comp_twiddle(plan)!=0)
     { DEALLOC(plan->mem); DEALLOC(plan); return NULL; }
   return plan;
@@ -1820,7 +1822,6 @@ static size_t rfftp_twsize(rfftp_plan plan)
     l1*=ip;
     }
   return twsize;
-  return 0;
   }
 
 WARN_UNUSED_RESULT NOINLINE static int rfftp_comp_twiddle (rfftp_plan plan)
@@ -1876,8 +1877,10 @@ NOINLINE static rfftp_plan make_rfftp_plan (size_t length)
   if (length==1) return plan;
   if (rfftp_factorize(plan)!=0) { DEALLOC(plan); return NULL; }
   size_t tws=rfftp_twsize(plan);
-  plan->mem=RALLOC(double,tws);
-  if (!plan->mem) { DEALLOC(plan); return NULL; }
+  if (tws != 0) {
+    plan->mem=RALLOC(double,tws);
+    if (!plan->mem) { DEALLOC(plan); return NULL; }
+  }
   if (rfftp_comp_twiddle(plan)!=0)
     { DEALLOC(plan->mem); DEALLOC(plan); return NULL; }
   return plan;
@@ -2229,6 +2232,8 @@ execute_real_forward(PyObject *a1, double fct)
 {
     rfft_plan plan=NULL;
     int fail = 0;
+    npy_intp tdim[NPY_MAXDIMS];
+
     PyArrayObject *data = (PyArrayObject *)PyArray_FromAny(a1,
             PyArray_DescrFromType(NPY_DOUBLE), 1, 0,
             NPY_ARRAY_DEFAULT | NPY_ARRAY_ENSUREARRAY | NPY_ARRAY_FORCECAST,
@@ -2238,15 +2243,11 @@ execute_real_forward(PyObject *a1, double fct)
     int ndim = PyArray_NDIM(data);
     const npy_intp *odim = PyArray_DIMS(data);
     int npts = odim[ndim - 1];
-    npy_intp *tdim=(npy_intp *)malloc(ndim*sizeof(npy_intp));
-    if (!tdim)
-      { Py_XDECREF(data); return NULL; }
     for (int d=0; d<ndim-1; ++d)
       tdim[d] = odim[d];
     tdim[ndim-1] = npts/2 + 1;
     PyArrayObject *ret = (PyArrayObject *)PyArray_Empty(ndim,
             tdim, PyArray_DescrFromType(NPY_CDOUBLE), 0);
-    free(tdim);
     if (!ret) fail=1;
     if (!fail) {
       int rstep = PyArray_DIM(ret, PyArray_NDIM(ret) - 1)*2;
diff --git a/numpy/linalg/umath_linalg.cpp b/numpy/linalg/umath_linalg.cpp
index 639de6ee0..68db2b2f1 100644
--- a/numpy/linalg/umath_linalg.cpp
+++ b/numpy/linalg/umath_linalg.cpp
@@ -1149,7 +1149,7 @@ slogdet(char **args,
                void *NPY_UNUSED(func))
 {
     fortran_int m;
-    npy_uint8 *tmp_buff = NULL;
+    char *tmp_buff = NULL;
     size_t matrix_size;
     size_t pivot_size;
     size_t safe_m;
@@ -1163,10 +1163,11 @@ slogdet(char **args,
      */
     INIT_OUTER_LOOP_3
     m = (fortran_int) dimensions[0];
-    safe_m = m;
+    /* avoid empty malloc (buffers likely unused) and ensure m is `size_t` */
+    safe_m = m != 0 ? m : 1;
     matrix_size = safe_m * safe_m * sizeof(typ);
     pivot_size = safe_m * sizeof(fortran_int);
-    tmp_buff = (npy_uint8 *)malloc(matrix_size + pivot_size);
+    tmp_buff = (char *)malloc(matrix_size + pivot_size);
 
     if (tmp_buff) {
         LINEARIZE_DATA_t lin_data;
@@ -1183,6 +1184,13 @@ slogdet(char **args,
 
         free(tmp_buff);
     }
+    else {
+        /* TODO: Requires use of new ufunc API to indicate error return */
+        NPY_ALLOW_C_API_DEF
+        NPY_ALLOW_C_API;
+        PyErr_NoMemory();
+        NPY_DISABLE_C_API;
+    }
 }
 
 template<typename typ, typename basetyp>
@@ -1193,7 +1201,7 @@ det(char **args,
            void *NPY_UNUSED(func))
 {
     fortran_int m;
-    npy_uint8 *tmp_buff;
+    char *tmp_buff;
     size_t matrix_size;
     size_t pivot_size;
     size_t safe_m;
@@ -1207,10 +1215,11 @@ det(char **args,
      */
     INIT_OUTER_LOOP_2
     m = (fortran_int) dimensions[0];
-    safe_m = m;
+    /* avoid empty malloc (buffers likely unused) and ensure m is `size_t` */
+    safe_m = m != 0 ? m : 1;
     matrix_size = safe_m * safe_m * sizeof(typ);
     pivot_size = safe_m * sizeof(fortran_int);
-    tmp_buff = (npy_uint8 *)malloc(matrix_size + pivot_size);
+    tmp_buff = (char *)malloc(matrix_size + pivot_size);
 
     if (tmp_buff) {
         LINEARIZE_DATA_t lin_data;
@@ -1231,6 +1240,13 @@ det(char **args,
 
         free(tmp_buff);
     }
+    else {
+        /* TODO: Requires use of new ufunc API to indicate error return */
+        NPY_ALLOW_C_API_DEF
+        NPY_ALLOW_C_API;
+        PyErr_NoMemory();
+        NPY_DISABLE_C_API;
+    }
 }
 
 
@@ -3738,16 +3754,16 @@ scalar_trait)
     fortran_int lda = fortran_int_max(1, m);
     fortran_int ldb = fortran_int_max(1, fortran_int_max(m,n));
 
-    mem_buff = (npy_uint8 *)malloc(a_size + b_size + s_size);
-
-    if (!mem_buff)
-        goto error;
+    size_t msize = a_size + b_size + s_size;
+    mem_buff = (npy_uint8 *)malloc(msize != 0 ? msize : 1);
 
+    if (!mem_buff) {
+        goto no_memory;
+    }
     a = mem_buff;
     b = a + a_size;
     s = b + b_size;
 
-
     params->M = m;
     params->N = n;
     params->NRHS = nrhs;
@@ -3767,9 +3783,9 @@ scalar_trait)
         params->RWORK = NULL;
         params->LWORK = -1;
 
-        if (call_gelsd(params) != 0)
+        if (call_gelsd(params) != 0) {
             goto error;
-
+        }
         work_count = (fortran_int)work_size_query;
 
         work_size  = (size_t) work_size_query * sizeof(ftyp);
@@ -3777,9 +3793,9 @@ scalar_trait)
     }
 
     mem_buff2 = (npy_uint8 *)malloc(work_size + iwork_size);
-    if (!mem_buff2)
-        goto error;
-
+    if (!mem_buff2) {
+        goto no_memory;
+    }
     work = mem_buff2;
     iwork = work + work_size;
 
@@ -3789,12 +3805,18 @@ scalar_trait)
     params->LWORK = work_count;
 
     return 1;
+
+ no_memory:
+    NPY_ALLOW_C_API_DEF
+    NPY_ALLOW_C_API;
+    PyErr_NoMemory();
+    NPY_DISABLE_C_API;
+
  error:
     TRACE_TXT("%s failed init\n", __FUNCTION__);
     free(mem_buff);
     free(mem_buff2);
     memset(params, 0, sizeof(*params));
-
     return 0;
 }
 
@@ -3858,16 +3880,17 @@ using frealtyp = basetype_t<ftyp>;
     fortran_int lda = fortran_int_max(1, m);
     fortran_int ldb = fortran_int_max(1, fortran_int_max(m,n));
 
-    mem_buff = (npy_uint8 *)malloc(a_size + b_size + s_size);
+    size_t msize = a_size + b_size + s_size;
+    mem_buff = (npy_uint8 *)malloc(msize != 0 ? msize : 1);
 
-    if (!mem_buff)
-        goto error;
+    if (!mem_buff) {
+        goto no_memory;
+    }
 
     a = mem_buff;
     b = a + a_size;
     s = b + b_size;
 
-
     params->M = m;
     params->N = n;
     params->NRHS = nrhs;
@@ -3888,8 +3911,9 @@ using frealtyp = basetype_t<ftyp>;
         params->RWORK = &rwork_size_query;
         params->LWORK = -1;
 
-        if (call_gelsd(params) != 0)
+        if (call_gelsd(params) != 0) {
             goto error;
+        }
 
         work_count = (fortran_int)work_size_query.r;
 
@@ -3899,8 +3923,9 @@ using frealtyp = basetype_t<ftyp>;
     }
 
     mem_buff2 = (npy_uint8 *)malloc(work_size + rwork_size + iwork_size);
-    if (!mem_buff2)
-        goto error;
+    if (!mem_buff2) {
+        goto no_memory;
+    }
 
     work = mem_buff2;
     rwork = work + work_size;
@@ -3912,6 +3937,13 @@ using frealtyp = basetype_t<ftyp>;
     params->LWORK = work_count;
 
     return 1;
+
+ no_memory:
+    NPY_ALLOW_C_API_DEF
+    NPY_ALLOW_C_API;
+    PyErr_NoMemory();
+    NPY_DISABLE_C_API;
+
  error:
     TRACE_TXT("%s failed init\n", __FUNCTION__);
     free(mem_buff);