cleaned up error codes and their doc

docs/error.rst

@@ -5,12 +5,12 @@ Error (status) codes
 
 In all FINUFFT interfaces, the returned value ``ier`` is a status indicator.
 It is ``0`` if successful, otherwise the error code
-has the following meanings (see ``include/finufft_errors.h``):
+has the following meanings (see codes in ``include/finufft_errors.h``):
 
 ::
 
   1  requested tolerance epsilon too small to achieve (warning only)
-  2  attemped to allocate internal array larger than MAX_NF (defined in defs.h)
+  2  stopped due to needing internal array size >MAX_NF (defined in defs.h)
   3  spreader: fine grid too small compared to spread (kernel) width
   4  spreader: if chkbnds=1, a nonuniform point coordinate is out of input range [-3pi,3pi]^d
   5  spreader: array allocation error
@@ -19,11 +19,11 @@ has the following meanings (see ``include/finufft_errors.h``):
   8  upsampfac not a value with known Horner poly eval rule (currently 2.0 or 1.25 only)
   9  ntrans not valid in "many" (vectorized) or guru interface (should be >= 1)
   10 transform type invalid
-  11 general allocation failure
+  11 general internal allocation failure
   12 dimension invalid
   13 spread_thread option invalid
   14 invalid mode array (more than ~2^31 modes, dimension with 0 modes, etc)
-  15 cuda failure (failure to call any cuda function/kernel)
+  15 CUDA failure (failure to call any cuda function/kernel, malloc/memset, etc))
   16 attempt to destroy an uninitialized plan
   17 invalid spread/interp method for dim (attempt to blockgather in 1D, e.g.)
   18 size of bins for subprob/blockgather invalid

include/finufft_errors.h

@@ -2,9 +2,8 @@
 #define FINUFFT_ERRORS_H
 
 // ---------- Global error/warning output codes for the library ---------------
-// NB: if change these numbers, also must regen test/results/dumbinputs.refout
+// All documentation is at ../docs/errors.rst (not here):
 #define FINUFFT_WARN_EPS_TOO_SMALL         1
-// this means that a fine grid array dim exceeded MAX_NF; no malloc tried...
 #define FINUFFT_ERR_MAXNALLOC              2
 #define FINUFFT_ERR_SPREAD_BOX_SMALL       3
 #define FINUFFT_ERR_SPREAD_PTS_OUT_RANGE   4
@@ -14,17 +13,14 @@
 #define FINUFFT_ERR_HORNER_WRONG_BETA      8
 #define FINUFFT_ERR_NTRANS_NOTVALID        9
 #define FINUFFT_ERR_TYPE_NOTVALID          10
-// some generic internal allocation failure...
 #define FINUFFT_ERR_ALLOC                  11
 #define FINUFFT_ERR_DIM_NOTVALID           12
 #define FINUFFT_ERR_SPREAD_THREAD_NOTVALID 13
 #define FINUFFT_ERR_NDATA_NOTVALID         14
-// cuda malloc/memset/kernel failure/etc
 #define FINUFFT_ERR_CUDA_FAILURE           15
 #define FINUFFT_ERR_PLAN_NOTVALID          16
 #define FINUFFT_ERR_METHOD_NOTVALID        17
 #define FINUFFT_ERR_BINSIZE_NOTVALID       18
 #define FINUFFT_ERR_INSUFFICIENT_SHMEM     19
-// back to CPU errors
 #define FINUFFT_ERR_NUM_NU_PTS_INVALID     20
 #endif