Raise meaningful Python errors in C code

theano/tensor/blas_c.py

@@ -77,7 +77,11 @@ def ger_c_code(A, a, x, y, Z, destructive, fail):
                 %(fail)s
             }
         }
-        assert (%(Z)s != %(A)s);
+        if (%(Z)s == %(A)s)
+        {
+            PyErr_SetString(PyExc_AssertionError, "%(Z)s != %(A)s");
+            %(fail)s
+        }
         if (%(Z)s->descr->type_num == PyArray_FLOAT)
         {
             float * zoutdata = (float*)%(Z)s->data;
@@ -163,7 +167,10 @@ def ger_c_code(A, a, x, y, Z, destructive, fail):
                     (double*)(%(y)s->data), &Sy,
                     (double*)(%(Z)s->data), &Sz1);
             }
-            else { assert(0); }
+            else {
+                PyErr_SetString(PyExc_NotImplementedError, "not float nor double");
+                %(fail)s
+            }
         }
         else if (%(Z)s->strides[1] == elemsize)
         {
@@ -186,9 +193,19 @@ def ger_c_code(A, a, x, y, Z, destructive, fail):
                     (double*)(%(x)s->data), &Sx,
                     (double*)(%(Z)s->data), &Sz0);
             }
-            else { assert(0); }
+            else
+            {
+                PyErr_SetString(PyExc_NotImplementedError, "not float nor double");
+                %(fail)s
+            }
+        }
+        else
+        {
+            PyErr_SetString(PyExc_AssertionError,
+                "A is a double-strided matrix, and should have been copied "
+                "into a memory-contiguous one.");
+            %(fail)s
         }
-        else { assert(0); }
         }
     }
 
@@ -204,7 +221,7 @@ class CGer(BaseBLAS, Ger):
         return code
 
     def c_code_cache_version(self):
-        return (4,)
+        return (6,)
 
 
 @local_optimizer([ger, ger_destructive])
@@ -282,7 +299,11 @@ def gemv_c_code(aa, xx, yy, zz, alpha, beta, destructive, fail):
                 %(fail)s
             }
         }
-        assert (%(zz)s != %(aa)s);
+        if (%(zz)s == %(aa)s)
+        {
+            PyErr_SetString(PyExc_AssertionError, "%(zz)s != %(aa)s");
+            %(fail)s
+        }
         if (dbeta != 0)
         {
             if (%(zz)s->descr->type_num == PyArray_FLOAT)
@@ -362,7 +383,8 @@ def gemv_c_code(aa, xx, yy, zz, alpha, beta, destructive, fail):
                 }
                 else
                 {
-                    assert(0);
+                    PyErr_SetString(PyExc_AssertionError, "neither float nor double dtype");
+                    %(fail)s
                 }
             }
             else if (%(xx)s->strides[1] == elemsize)
@@ -392,14 +414,16 @@ def gemv_c_code(aa, xx, yy, zz, alpha, beta, destructive, fail):
                 }
                 else
                 {
-                    assert(0);
+                    PyErr_SetString(PyExc_AssertionError, "neither float nor double dtype");
+                    %(fail)s
                 }
             }
             else
             {
                 // if xx is strided in both directions, then just do the gemv with a
                 // pair of for loops.
-                assert (0);
+                PyErr_SetString(PyExc_NotImplementedError, "double-strided matrix");
+                %(fail)s
             }
         }
         else if (dbeta != 1.0)
@@ -429,7 +453,7 @@ class CGemv(BaseBLAS, Gemv):
         return code
 
     def c_code_cache_version(self):
-        return (2,)
+        return (3,)
 
 
 @local_optimizer([gemv_inplace, gemv_no_inplace])