summaryrefslogtreecommitdiffstats
path: root/src/H5detect.c
blob: 54435fbb3894990d53b0cf59e9a50e6bbdcda1b8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * Copyright by the Board of Trustees of the University of Illinois.         *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*keep this declaration near the top of this file -RPM*/
static const char *FileHeader = "\n\
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\n\
 * Copyright by The HDF Group.                                               *\n\
 * Copyright by the Board of Trustees of the University of Illinois.         *\n\
 * All rights reserved.                                                      *\n\
 *                                                                           *\n\
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *\n\
 * terms governing use, modification, and redistribution, is contained in    *\n\
 * the COPYING file, which can be found at the root of the source code       *\n\
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *\n\
 * If you do not have access to either file, you may request a copy from     *\n\
 * help@hdfgroup.org.                                                        *\n\
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *";
/*
 * Purpose:    This code was borrowed heavily from the `detect.c'
 *        program in the AIO distribution from Lawrence
 *        Livermore National Laboratory.
 *
 *        Detects machine byte order and floating point
 *        format and generates a C source file (H5Tinit.c)
 *        to describe those parameters.
 *
 * Assumptions: We have an ANSI compiler.  We're on a Unix like
 *        system or configure has detected those Unix
 *        features which aren't available.  We're not
 *        running on a Vax or other machine with mixed
 *        endianness.
 *-------------------------------------------------------------------------
 */
#undef NDEBUG
#include "H5private.h"
/* Do NOT use HDfprintf in this file as it is not linked with the library,
 * which contains the H5system.c file in which the function is defined.
 */
#include "H5Tpublic.h"
#include "H5Rpublic.h"

#if defined(__has_attribute)
#if __has_attribute(no_sanitize_address)
#define HDF_NO_UBSAN __attribute__((no_sanitize_address))
#else
#define HDF_NO_UBSAN
#endif
#else
#define HDF_NO_UBSAN
#endif

#define MAXDETECT 64

/*
 * This structure holds information about a type that
 * was detected.
 */
typedef struct detected_t {
    const char *  varname;
    unsigned int  size;             /* total byte size                  */
    unsigned int  precision;        /* meaningful bits                  */
    unsigned int  offset;           /* bit offset to meaningful bits    */
    int           perm[32];         /* for detection of byte order      */
    hbool_t       is_vax;           /* for vax (float & double) only    */
    unsigned int  sign;             /* location of sign bit             */
    unsigned int  mpos, msize, imp; /* information about mantissa       */
    unsigned int  epos, esize;      /* information about exponent       */
    unsigned long bias;             /* exponent bias for floating pt    */
    unsigned int  align;            /* required byte alignment          */
    unsigned int  comp_align;       /* alignment for structure          */
} detected_t;

/* This structure holds structure alignment for pointers, vlen and reference
 * types. */
typedef struct malign_t {
    const char * name;
    unsigned int comp_align; /* alignment for structure          */
} malign_t;

FILE *rawoutstream = NULL;

/* global variables types detection code */
H5_GCC_DIAG_OFF("larger-than=")
static detected_t d_g[MAXDETECT];
H5_GCC_DIAG_ON("larger-than=")
static malign_t     m_g[MAXDETECT];
static volatile int nd_g = 0, na_g = 0;

static void         print_results(int nd, detected_t *d, int na, malign_t *m);
static void         iprint(detected_t *);
static int          byte_cmp(int, const void *, const void *, const unsigned char *);
static unsigned int bit_cmp(unsigned int, int *, void *, void *, const unsigned char *);
static void         fix_order(int, int, int *, const char **);
static unsigned int imp_bit(unsigned int, int *, void *, void *, const unsigned char *);
static unsigned int find_bias(unsigned int, unsigned int, int *, void *);
static void         precision(detected_t *);
static void         print_header(void);
static void         detect_C89_floats(void);
static void         detect_C99_floats(void);
static void         detect_alignments(void);

/*-------------------------------------------------------------------------
 * Function:    precision
 *
 * Purpose:     Determine the precision and offset.
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void
precision(detected_t *d)
{
    unsigned int n;

    if (0 == d->msize) {
        /*
         * An integer.    The permutation can have negative values at the
         * beginning or end which represent padding of bytes.  We must adjust
         * the precision and offset accordingly.
         */
        if (d->perm[0] < 0) {
            /*
             * Lower addresses are padded.
             */
            for (n = 0; n < d->size && d->perm[n] < 0; n++)
                /*void*/;
            d->precision = 8 * (d->size - n);
            d->offset    = 0;
        }
        else if (d->perm[d->size - 1] < 0) {
            /*
             * Higher addresses are padded.
             */
            for (n = 0; n < d->size && d->perm[d->size - (n + 1)]; n++)
                /*void*/;
            d->precision = 8 * (d->size - n);
            d->offset    = 8 * n;
        }
        else {
            /*
             * No padding.
             */
            d->precision = 8 * d->size;
            d->offset    = 0;
        }
    }
    else {
        /* A floating point */
        d->offset    = MIN3(d->mpos, d->epos, d->sign);
        d->precision = d->msize + d->esize + 1;
    }
}

/*-------------------------------------------------------------------------
 * Function:    DETECT_F
 *
 * Purpose:     This macro takes a floating point type like `double' and
 *              a base name like `natd' and detects byte order, mantissa
 *              location, exponent location, sign bit location, presence or
 *              absence of implicit mantissa bit, and exponent bias and
 *              initializes a detected_t structure with those properties.
 *-------------------------------------------------------------------------
 */
#define DETECT_F(TYPE, VAR, INFO)                                                                            \
    {                                                                                                        \
        TYPE          _v1, _v2, _v3;                                                                         \
        unsigned char _buf1[sizeof(TYPE)], _buf3[sizeof(TYPE)];                                              \
        unsigned char _pad_mask[sizeof(TYPE)];                                                               \
        unsigned char _byte_mask;                                                                            \
        int           _i, _j, _last = (-1);                                                                  \
        const char *  _mesg;                                                                                 \
                                                                                                             \
        HDmemset(&INFO, 0, sizeof(INFO));                                                                    \
        INFO.varname = #VAR;                                                                                 \
        INFO.size    = sizeof(TYPE);                                                                         \
                                                                                                             \
        /* Initialize padding mask */                                                                        \
        HDmemset(_pad_mask, 0, sizeof(_pad_mask));                                                           \
                                                                                                             \
        /* Padding bits.  Set a variable to 4.0, then flip each bit and see if                               \
         * the modified variable is equal ("==") to the original.  Build a                                   \
         * padding bitmask to indicate which bits in the type are padding (i.e.                              \
         * have no effect on the value and should be ignored by subsequent                                   \
         * steps).  This is necessary because padding bits can change arbitrarily                            \
         * and interfere with detection of the various properties below unless we                            \
         * know to ignore them. */                                                                           \
        _v1 = (TYPE)4.0L;                                                                                    \
        HDmemcpy(_buf1, (const void *)&_v1, sizeof(TYPE));                                                   \
        for (_i = 0; _i < (int)sizeof(TYPE); _i++)                                                           \
            for (_byte_mask = (unsigned char)1; _byte_mask; _byte_mask = (unsigned char)(_byte_mask << 1)) { \
                _buf1[_i] ^= _byte_mask;                                                                     \
                HDmemcpy((void *)&_v2, (const void *)_buf1, sizeof(TYPE));                                   \
                H5_GCC_CLANG_DIAG_OFF("float-equal")                                                         \
                if (_v1 != _v2)                                                                              \
                    _pad_mask[_i] |= _byte_mask;                                                             \
                H5_GCC_CLANG_DIAG_ON("float-equal")                                                          \
                _buf1[_i] ^= _byte_mask;                                                                     \
            } /* end for */                                                                                  \
                                                                                                             \
        /* Byte Order */                                                                                     \
        for (_i = 0, _v1 = (TYPE)0.0L, _v2 = (TYPE)1.0L; _i < (int)sizeof(TYPE); _i++) {                     \
            _v3 = _v1;                                                                                       \
            _v1 += _v2;                                                                                      \
            _v2 /= (TYPE)256.0L;                                                                             \
            HDmemcpy(_buf1, (const void *)&_v1, sizeof(TYPE));                                               \
            HDmemcpy(_buf3, (const void *)&_v3, sizeof(TYPE));                                               \
            _j = byte_cmp(sizeof(TYPE), _buf3, _buf1, _pad_mask);                                            \
            if (_j >= 0) {                                                                                   \
                INFO.perm[_i] = _j;                                                                          \
                _last         = _i;                                                                          \
            }                                                                                                \
        }                                                                                                    \
        fix_order(sizeof(TYPE), _last, INFO.perm, (const char **)&_mesg);                                    \
                                                                                                             \
        if (!HDstrcmp(_mesg, "VAX"))                                                                         \
            INFO.is_vax = TRUE;                                                                              \
                                                                                                             \
        /* Implicit mantissa bit */                                                                          \
        _v1      = (TYPE)0.5L;                                                                               \
        _v2      = (TYPE)1.0L;                                                                               \
        INFO.imp = imp_bit(sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask);                                  \
                                                                                                             \
        /* Sign bit */                                                                                       \
        _v1       = (TYPE)1.0L;                                                                              \
        _v2       = (TYPE)-1.0L;                                                                             \
        INFO.sign = bit_cmp(sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask);                                 \
                                                                                                             \
        /* Mantissa */                                                                                       \
        INFO.mpos = 0;                                                                                       \
                                                                                                             \
        _v1        = (TYPE)1.0L;                                                                             \
        _v2        = (TYPE)1.5L;                                                                             \
        INFO.msize = bit_cmp(sizeof(TYPE), INFO.perm, &_v1, &_v2, _pad_mask);                                \
        INFO.msize += 1 + (unsigned int)(INFO.imp ? 0 : 1) - INFO.mpos;                                      \
                                                                                                             \
        /* Exponent */                                                                                       \
        INFO.epos = INFO.mpos + INFO.msize;                                                                  \
                                                                                                             \
        INFO.esize = INFO.sign - INFO.epos;                                                                  \
                                                                                                             \
        _v1       = (TYPE)1.0L;                                                                              \
        INFO.bias = find_bias(INFO.epos, INFO.esize, INFO.perm, &_v1);                                       \
        precision(&(INFO));                                                                                  \
        if (!HDstrcmp(INFO.varname, "FLOAT") || !HDstrcmp(INFO.varname, "DOUBLE") ||                         \
            !HDstrcmp(INFO.varname, "LDOUBLE")) {                                                            \
            COMP_ALIGNMENT(TYPE, INFO.comp_align);                                                           \
        }                                                                                                    \
    }

/*-------------------------------------------------------------------------
 * Function:    DETECT_M
 *
 * Purpose:     This macro takes only miscellaneous structures or pointer.
 *              It constructs the names and decides the alignment in structure.
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
#define DETECT_M(TYPE, VAR, INFO)                                                                            \
    {                                                                                                        \
        INFO.name = #VAR;                                                                                    \
        COMP_ALIGNMENT(TYPE, INFO.comp_align);                                                               \
    }

/* Detect alignment for C structure */
#define COMP_ALIGNMENT(TYPE, COMP_ALIGN)                                                                     \
    {                                                                                                        \
        struct {                                                                                             \
            char c;                                                                                          \
            TYPE x;                                                                                          \
        } s;                                                                                                 \
                                                                                                             \
        COMP_ALIGN = (unsigned int)((char *)(&(s.x)) - (char *)(&s));                                        \
    }

/*-------------------------------------------------------------------------
 * Function:    print_results
 *
 * Purpose:     Prints information about the detected data types.
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void
print_results(int nd, detected_t *d, int na, malign_t *misc_align)
{
    int byte_order = 0; /*byte order of data types*/
    int i, j;

    /* Include files */
    fprintf(rawoutstream, "\
/****************/\n\
/* Module Setup */\n\
/****************/\n\
\n\
#include \"H5Tmodule.h\"          /* This source code file is part of the H5T module */\n\
\n\
\n\
/***********/\n\
/* Headers */\n\
/***********/\n\
#include \"H5private.h\"        /* Generic Functions            */\n\
#include \"H5Eprivate.h\"        /* Error handling              */\n\
#include \"H5FLprivate.h\"    /* Free Lists                */\n\
#include \"H5Iprivate.h\"        /* IDs                      */\n\
#include \"H5Tpkg.h\"        /* Datatypes                 */\n\
\n\
\n\
/****************/\n\
/* Local Macros */\n\
/****************/\n\
\n\
\n\
/******************/\n\
/* Local Typedefs */\n\
/******************/\n\
\n\
\n\
/********************/\n\
/* Package Typedefs */\n\
/********************/\n\
\n\
\n\
/********************/\n\
/* Local Prototypes */\n\
/********************/\n\
\n\
\n\
/********************/\n\
/* Public Variables */\n\
/********************/\n\
\n\
\n\
/*****************************/\n\
/* Library Private Variables */\n\
/*****************************/\n\
\n\
\n\
/*********************/\n\
/* Package Variables */\n\
/*********************/\n\
\n\
\n");
    fprintf(rawoutstream, "\n\
/*******************/\n\
/* Local Variables */\n\
/*******************/\n\
\n");

    /* The interface initialization function */
    fprintf(rawoutstream, "\n\
\n\
/*-------------------------------------------------------------------------\n\
 * Function:    H5T__init_native\n\
 *\n\
 * Purpose:    Initialize pre-defined native datatypes from code generated\n\
 *              during the library configuration by H5detect.\n\
 *\n\
 * Return:    Success:    non-negative\n\
 *        Failure:    negative\n\
 *\n\
 * Programmer:    Robb Matzke\n\
 *              Wednesday, December 16, 1998\n\
 *\n\
 *-------------------------------------------------------------------------\n\
 */\n\
herr_t\n\
H5T__init_native(void)\n\
{\n\
    H5T_t    *dt = NULL;\n\
    herr_t    ret_value = SUCCEED;\n\
\n\
    FUNC_ENTER_PACKAGE\n");

    for (i = 0; i < nd; i++) {
        /* The native endianness of this machine */
        /* The INFO.perm now contains `-1' for bytes that aren't used and
         * are always zero.  This happens on the Cray for `short' where
         * sizeof(short) is 8, but only the low-order 4 bytes are ever used.
         */
        if (d[i].is_vax) /* the type is a VAX floating number */
            byte_order = -1;
        else {
            for (j = 0; j < 32; j++) {
                /*Find the 1st containing valid data*/
                if (d[i].perm[j] > -1) {
                    byte_order = d[i].perm[j];
                    break;
                }
            }
        }

        /* Print a comment to describe this section of definitions. */
        fprintf(rawoutstream, "\n   /*\n");
        iprint(d + i);
        fprintf(rawoutstream, "    */\n");

        /* The part common to fixed and floating types */
        fprintf(rawoutstream, "\
    if(NULL == (dt = H5T__alloc()))\n\
        HGOTO_ERROR(H5E_DATATYPE, H5E_NOSPACE, FAIL, \"datatype allocation failed\")\n\
    dt->shared->state = H5T_STATE_IMMUTABLE;\n\
    dt->shared->type = H5T_%s;\n\
    dt->shared->size = %d;\n",
                d[i].msize ? "FLOAT" : "INTEGER", /*class            */
                d[i].size);                       /*size            */

        if (byte_order == -1)
            fprintf(rawoutstream, "\
    dt->shared->u.atomic.order = H5T_ORDER_VAX;\n");
        else if (byte_order == 0)
            fprintf(rawoutstream, "\
    dt->shared->u.atomic.order = H5T_ORDER_LE;\n");
        else
            fprintf(rawoutstream, "\
    dt->shared->u.atomic.order = H5T_ORDER_BE;\n");

        fprintf(rawoutstream, "\
    dt->shared->u.atomic.offset = %d;\n\
    dt->shared->u.atomic.prec = %d;\n\
    dt->shared->u.atomic.lsb_pad = H5T_PAD_ZERO;\n\
    dt->shared->u.atomic.msb_pad = H5T_PAD_ZERO;\n",
                d[i].offset,                            /*offset        */
                d[i].precision);                        /*precision        */
        /*HDassert((d[i].perm[0]>0)==(byte_order>0));*/ /* Double-check that byte-order doesn't change */

        if (0 == d[i].msize) {
            /* The part unique to fixed point types */
            fprintf(rawoutstream, "\
    dt->shared->u.atomic.u.i.sign = H5T_SGN_%s;\n",
                    d[i].sign ? "2" : "NONE");
        }
        else {
            /* The part unique to floating point types */
            fprintf(rawoutstream, "\
    dt->shared->u.atomic.u.f.sign = %d;\n\
    dt->shared->u.atomic.u.f.epos = %d;\n\
    dt->shared->u.atomic.u.f.esize = %d;\n\
    dt->shared->u.atomic.u.f.ebias = 0x%08lx;\n\
    dt->shared->u.atomic.u.f.mpos = %d;\n\
    dt->shared->u.atomic.u.f.msize = %d;\n\
    dt->shared->u.atomic.u.f.norm = H5T_NORM_%s;\n\
    dt->shared->u.atomic.u.f.pad = H5T_PAD_ZERO;\n",
                    d[i].sign,                      /*sign location */
                    d[i].epos,                      /*exponent loc    */
                    d[i].esize,                     /*exponent size */
                    (unsigned long)(d[i].bias),     /*exponent bias */
                    d[i].mpos,                      /*mantissa loc    */
                    d[i].msize,                     /*mantissa size */
                    d[i].imp ? "IMPLIED" : "NONE"); /*normalization */
        }

        /* Register the type */
        fprintf(rawoutstream, "\
    if((H5T_NATIVE_%s_g = H5I_register(H5I_DATATYPE, dt, FALSE)) < 0)\n\
        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, \"can't register ID for built-in datatype\")\n",
                d[i].varname);

        /* Variables for alignment of compound datatype */
        if (!HDstrcmp(d[i].varname, "SCHAR") || !HDstrcmp(d[i].varname, "SHORT") ||
            !HDstrcmp(d[i].varname, "INT") || !HDstrcmp(d[i].varname, "LONG") ||
            !HDstrcmp(d[i].varname, "LLONG") || !HDstrcmp(d[i].varname, "FLOAT") ||
            !HDstrcmp(d[i].varname, "DOUBLE") || !HDstrcmp(d[i].varname, "LDOUBLE")) {
            fprintf(rawoutstream, "    H5T_NATIVE_%s_ALIGN_g = %lu;\n", d[i].varname,
                    (unsigned long)(d[i].comp_align));
        }
    }

    /* Consider VAX a little-endian machine */
    if (byte_order == 0 || byte_order == -1) {
        fprintf(rawoutstream, "\n\
    /* Set the native order for this machine */\n\
    H5T_native_order_g = H5T_ORDER_%s;\n",
                "LE");
    }
    else {
        fprintf(rawoutstream, "\n\
    /* Set the native order for this machine */\n\
    H5T_native_order_g = H5T_ORDER_%s;\n",
                "BE");
    }

    /* Structure alignment for pointers, vlen and reference types */
    fprintf(rawoutstream, "\n    /* Structure alignment for pointers, vlen and reference types */\n");
    for (j = 0; j < na; j++)
        fprintf(rawoutstream, "    H5T_%s_ALIGN_g = %lu;\n", misc_align[j].name,
                (unsigned long)(misc_align[j].comp_align));

    fprintf(rawoutstream, "\
\n\
done:\n\
    if(ret_value < 0) {\n\
        if(dt != NULL) {\n\
            dt->shared = H5FL_FREE(H5T_shared_t, dt->shared);\n\
            dt = H5FL_FREE(H5T_t, dt);\n\
        } /* end if */\n\
    } /* end if */\n\
\n\
    FUNC_LEAVE_NOAPI(ret_value);\n} /* end H5T__init_native() */\n");

} /* end print_results() */

/*-------------------------------------------------------------------------
 * Function:    iprint
 *
 * Purpose:     Prints information about the fields of a floating point format.
 *
 * Return:      void

 *-------------------------------------------------------------------------
 */
static void
iprint(detected_t *d)
{
    unsigned int pass;

    for (pass = (d->size - 1) / 4;; --pass) {
        unsigned int i, k;
        /*
         * Print the byte ordering above the bit fields.
         */
        fprintf(rawoutstream, "    * ");
        for (i = MIN(pass * 4 + 3, d->size - 1); i >= pass * 4; --i) {
            fprintf(rawoutstream, "%4d", d->perm[i]);
            if (i > pass * 4)
                HDfputs("     ", stdout);
            if (!i)
                break;
        }

        /*
         * Print the bit fields
         */
        fprintf(rawoutstream, "\n    * ");
        for (i = MIN(pass * 4 + 3, d->size - 1), k = MIN(pass * 32 + 31, 8 * d->size - 1); i >= pass * 4;
             --i) {
            unsigned int j;

            for (j = 8; j > 0; --j) {
                if (k == d->sign && d->msize) {
                    HDfputc('S', rawoutstream);
                }
                else if (k >= d->epos && k < d->epos + d->esize) {
                    HDfputc('E', rawoutstream);
                }
                else if (k >= d->mpos && k < d->mpos + d->msize) {
                    HDfputc('M', rawoutstream);
                }
                else if (d->msize) {
                    HDfputc('?', rawoutstream); /*unknown floating point bit */
                }
                else if (d->sign) {
                    HDfputc('I', rawoutstream);
                }
                else {
                    HDfputc('U', rawoutstream);
                }
                --k;
            }
            if (i > pass * 4)
                HDfputc(' ', rawoutstream);
            if (!i)
                break;
        }
        HDfputc('\n', rawoutstream);
        if (!pass)
            break;
    }

    /*
     * Is there an implicit bit in the mantissa.
     */
    if (d->msize) {
        fprintf(rawoutstream, "    * Implicit bit? %s\n", d->imp ? "yes" : "no");
    }

    /*
     * Alignment
     */
    if (0 == d->align) {
        fprintf(rawoutstream, "    * Alignment: NOT CALCULATED\n");
    }
    else if (1 == d->align) {
        fprintf(rawoutstream, "    * Alignment: none\n");
    }
    else {
        fprintf(rawoutstream, "    * Alignment: %lu\n", (unsigned long)(d->align));
    }
}

/*-------------------------------------------------------------------------
 * Function:    byte_cmp
 *
 * Purpose:     Compares two chunks of memory A and B and returns the
 *              byte index into those arrays of the first byte that
 *              differs between A and B.  Ignores differences where the
 *              corresponding bit in pad_mask is set to 0.
 *
 * Return:      Success:    Index of differing byte.
 *              Failure:    -1 if all bytes are the same.
 *-------------------------------------------------------------------------
 */
static int
byte_cmp(int n, const void *_a, const void *_b, const unsigned char *pad_mask)
{
    int                  i;
    const unsigned char *a = (const unsigned char *)_a;
    const unsigned char *b = (const unsigned char *)_b;

    for (i = 0; i < n; i++)
        if ((a[i] & pad_mask[i]) != (b[i] & pad_mask[i]))
            return i;

    return -1;
}

/*-------------------------------------------------------------------------
 * Function:    bit_cmp
 *
 * Purpose:     Compares two bit vectors and returns the index for the
 *              first bit that differs between the two vectors.     The
 *              size of the vector is NBYTES.  PERM is a mapping from
 *              actual order to little endian.  Ignores differences where
 *              the corresponding bit in pad_mask is set to 0.
 *
 * Return:      Index of first differing bit.
 *
 *-------------------------------------------------------------------------
 */
static unsigned int
bit_cmp(unsigned int nbytes, int *perm, void *_a, void *_b, const unsigned char *pad_mask)
{
    unsigned int   i;
    unsigned char *a = (unsigned char *)_a;
    unsigned char *b = (unsigned char *)_b;
    unsigned char  aa, bb;

    for (i = 0; i < nbytes; i++) {
        HDassert(perm[i] < (int)nbytes);
        if ((aa = (unsigned char)(a[perm[i]] & pad_mask[perm[i]])) !=
            (bb = (unsigned char)(b[perm[i]] & pad_mask[perm[i]]))) {
            unsigned int j;

            for (j = 0; j < 8; j++, aa >>= 1, bb >>= 1) {
                if ((aa & 1) != (bb & 1))
                    return i * 8 + j;
            }
            fprintf(stderr, "INTERNAL ERROR");
            HDabort();
        }
    }
    fprintf(stderr, "INTERNAL ERROR");
    HDabort();
    return 0;
}

/*-------------------------------------------------------------------------
 * Function:    fix_order
 *
 * Purpose:      Given an array PERM with elements FIRST through LAST
 *              initialized with zero origin byte numbers, this function
 *              creates a permutation vector that maps the actual order
 *              of a floating point number to little-endian.
 *
 *              This function assumes that the mantissa byte ordering
 *              implies the total ordering.
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void
fix_order(int n, int last, int *perm, const char **mesg)
{
    int i;

    if (last > 1) {
        /*
         * We have at least three points to consider.
         */
        if (perm[last] < perm[last - 1] && perm[last - 1] < perm[last - 2]) {
            /*
             * Little endian.
             */
            if (mesg)
                *mesg = "Little-endian";
            for (i = 0; i < n; i++)
                perm[i] = i;
        }
        else if (perm[last] > perm[last - 1] && perm[last - 1] > perm[last - 2]) {
            /*
             * Big endian.
             */
            if (mesg)
                *mesg = "Big-endian";
            for (i = 0; i < n; i++)
                perm[i] = (n - 1) - i;
        }
        else {
            /*
             * Bi-endian machines like VAX.
             * (NOTE: This is not an actual determination of the VAX-endianness.
             *          It could have some other endianness and fall into this
             *          case - JKM & QAK)
             */
            HDassert(0 == n % 2);
            if (mesg)
                *mesg = "VAX";
            for (i = 0; i < n; i += 2) {
                perm[i]     = (n - 2) - i;
                perm[i + 1] = (n - 1) - i;
            }
        }
    }
    else {
        fprintf(stderr, "Failed to detect byte order of %d-byte floating point.\n", n);
        HDexit(1);
    }
}

/*-------------------------------------------------------------------------
 * Function:    imp_bit
 *
 * Purpose:     Looks for an implicit bit in the mantissa.  The value
 *              of _A should be 1.0 and the value of _B should be 0.5.
 *              Some floating-point formats discard the most significant
 *              bit of the mantissa after normalizing since it will always
 *              be a one (except for 0.0).  If this is true for the native
 *              floating point values stored in _A and _B then the function
 *              returns non-zero.
 *
 *              This function assumes that the exponent occupies higher
 *              order bits than the mantissa and that the most significant
 *              bit of the mantissa is next to the least significant bit
 *              of the exponent.
 *
 *
 * Return:      Success:    Non-zero if the most significant bit
 *                          of the mantissa is discarded (ie, the
 *                          mantissa has an implicit `one' as the
 *                          most significant bit).    Otherwise,
 *                          returns zero.
 *
 *              Failure:    1
 *
 *-------------------------------------------------------------------------
 */
static unsigned int
imp_bit(unsigned int n, int *perm, void *_a, void *_b, const unsigned char *pad_mask)
{
    unsigned char *a = (unsigned char *)_a;
    unsigned char *b = (unsigned char *)_b;
    unsigned int   changed, major, minor;
    unsigned int   msmb; /* most significant mantissa bit */

    /*
     * Look for the least significant bit that has changed between
     * A and B.  This is the least significant bit of the exponent.
     */
    changed = bit_cmp(n, perm, a, b, pad_mask);

    /*
     * The bit to the right (less significant) of the changed bit should
     * be the most significant bit of the mantissa.  If it is non-zero
     * then the format does not remove the leading `1' of the mantissa.
     */
    msmb  = changed - 1;
    major = msmb / 8;
    minor = msmb % 8;

    return (a[perm[major]] >> minor) & 0x01 ? 0 : 1;
}

/*-------------------------------------------------------------------------
 * Function:  find_bias
 *
 * Purpose:   Determines the bias of the exponent.  This function should
 *            be called with _A having a value of `1'.
 *
 * Return:    The exponent bias.
 *
 *-------------------------------------------------------------------------
 */
H5_ATTR_PURE static unsigned int
find_bias(unsigned int epos, unsigned int esize, int *perm, void *_a)
{
    unsigned char *a = (unsigned char *)_a;
    unsigned char  mask;
    unsigned int   b, shift = 0, nbits, bias = 0;

    while (esize > 0) {
        nbits = MIN(esize, (8 - epos % 8));
        mask  = (unsigned char)((1 << nbits) - 1);
        b     = (unsigned int)(a[perm[epos / 8]] >> (epos % 8)) & mask;
        bias |= b << shift;

        shift += nbits;
        esize -= nbits;
        epos += nbits;
    }
    return bias;
}

/*-------------------------------------------------------------------------
 * Function:    print_header
 *
 * Purpose:     Prints the C file header for the generated file.
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void
print_header(void)
{

    time_t      now = HDtime(NULL);
    struct tm * tm  = HDlocaltime(&now);
    char        real_name[30];
    char        host_name[256];
    int         i;
    const char *s;
#ifdef H5_HAVE_GETPWUID
    struct passwd *pwd = NULL;
#else
    int pwd      = 1;
#endif
    static const char *month_name[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
                                       "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
    static const char *purpose      = "\
This machine-generated source code contains\n\
information about the various integer and\n\
floating point numeric formats found on this\n\
architecture.  The parameters below should be\n\
checked carefully and errors reported to the\n\
HDF5 maintainer.\n\
\n\
Each of the numeric formats listed below are\n\
printed from most significant bit to least\n\
significant bit even though the actual bytes\n\
might be stored in a different order in\n\
memory.     The integers above each binary byte\n\
indicate the relative order of the bytes in\n\
memory; little-endian machines have\n\
decreasing numbers while big-endian machines\n\
have increasing numbers.\n\
\n\
The fields of the numbers are printed as\n\
letters with `S' for the mantissa sign bit,\n\
`M' for the mantissa magnitude, and `E' for\n\
the exponent.  The exponent has an associated\n\
bias which can be subtracted to find the\n\
true exponent.    The radix point is assumed\n\
to be before the first `M' bit.     Any bit\n\
of a floating-point value not falling into one\n\
of these categories is printed as a question\n\
mark.  Bits of integer types are printed as\n\
`I' for 2's complement and `U' for magnitude.\n\
\n\
If the most significant bit of the normalized\n\
mantissa (always a `1' except for `0.0') is\n\
not stored then an `implicit=yes' appears\n\
under the field description.  In this case,\n\
the radix point is still assumed to be\n\
before the first `M' but after the implicit\n\
bit.\n";

    /*
     * The real name is the first item from the passwd gecos field.
     */
#ifdef H5_HAVE_GETPWUID
    {
        size_t n;
        char * comma;
        if ((pwd = HDgetpwuid(HDgetuid()))) {
            if ((comma = HDstrchr(pwd->pw_gecos, ','))) {
                n = MIN(sizeof(real_name) - 1, (unsigned)(comma - pwd->pw_gecos));
                HDstrncpy(real_name, pwd->pw_gecos, n);
                real_name[n] = '\0';
            }
            else {
                HDstrncpy(real_name, pwd->pw_gecos, sizeof(real_name));
                real_name[sizeof(real_name) - 1] = '\0';
            }
        }
        else
            real_name[0] = '\0';
    }
#else
    real_name[0] = '\0';
#endif

    /*
     * The FQDM of this host or the empty string.
     */
#ifdef H5_HAVE_GETHOSTNAME
    if (HDgethostname(host_name, sizeof(host_name)) < 0) {
        host_name[0] = '\0';
    }
#else
    host_name[0] = '\0';
#endif

    /*
     * The file header: warning, copyright notice, build information.
     */
    fprintf(rawoutstream, "/* Generated automatically by H5detect -- do not edit */\n\n\n");
    HDfputs(FileHeader, rawoutstream); /*the copyright notice--see top of this file */

    fprintf(rawoutstream, " *\n * Created:\t\t%s %2d, %4d\n", month_name[tm->tm_mon], tm->tm_mday,
            1900 + tm->tm_year);
    if (pwd || real_name[0] || host_name[0]) {
        fprintf(rawoutstream, " *\t\t\t");
        if (real_name[0])
            fprintf(rawoutstream, "%s <", real_name);
#ifdef H5_HAVE_GETPWUID
        if (pwd)
            HDfputs(pwd->pw_name, rawoutstream);
#endif
        if (host_name[0])
            fprintf(rawoutstream, "@%s", host_name);
        if (real_name[0])
            fprintf(rawoutstream, ">");
        HDfputc('\n', rawoutstream);
    }
    fprintf(rawoutstream, " *\n * Purpose:\t\t");
    for (s = purpose; *s; s++) {
        HDfputc(*s, rawoutstream);
        if ('\n' == *s && s[1])
            fprintf(rawoutstream, " *\t\t\t");
    }

    fprintf(rawoutstream, " *\n * Modifications:\n *\n");
    fprintf(rawoutstream, " *\tDO NOT MAKE MODIFICATIONS TO THIS FILE!\n");
    fprintf(rawoutstream, " *\tIt was generated by code in `H5detect.c'.\n");

    fprintf(rawoutstream, " *\n *");
    for (i = 0; i < 73; i++)
        HDfputc('-', rawoutstream);
    fprintf(rawoutstream, "\n */\n\n");
}

/*-------------------------------------------------------------------------
 * Function:    detect_C89_floats
 *
 * Purpose:     Detect C89 floating point types
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void HDF_NO_UBSAN
detect_C89_floats(void)
{
    DETECT_F(float, FLOAT, d_g[nd_g]);
    nd_g++;
    DETECT_F(double, DOUBLE, d_g[nd_g]);
    nd_g++;
}

/*-------------------------------------------------------------------------
 * Function:    detect_C99_floats
 *
 * Purpose:     Detect C99 floating point types
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void HDF_NO_UBSAN
detect_C99_floats(void)
{
#if H5_SIZEOF_DOUBLE == H5_SIZEOF_LONG_DOUBLE
    /*
     * If sizeof(double)==sizeof(long double) then assume that `long double'
     * isn't supported and use `double' instead.  This suppresses warnings on
     * some systems and `long double' is probably the same as `double' here
     * anyway.
     */
    DETECT_F(double, LDOUBLE, d_g[nd_g]);
    nd_g++;
#else
    DETECT_F(long double, LDOUBLE, d_g[nd_g]);
    nd_g++;
#endif
}

/*-------------------------------------------------------------------------
 * Function:    detect_alignments
 *
 * Purpose:     Detect structure alignments
 *
 * Return:      void
 *-------------------------------------------------------------------------
 */
static void HDF_NO_UBSAN
detect_alignments(void)
{
    /* Detect structure alignment for pointers, vlen and reference types */
    DETECT_M(void *, POINTER, m_g[na_g]);
    na_g++;
    DETECT_M(hvl_t, HVL, m_g[na_g]);
    na_g++;
    DETECT_M(hobj_ref_t, HOBJREF, m_g[na_g]);
    na_g++;
    DETECT_M(hdset_reg_ref_t, HDSETREGREF, m_g[na_g]);
    na_g++;
    DETECT_M(H5R_ref_t, REF, m_g[na_g]);
    na_g++;
}

/*-------------------------------------------------------------------------
 * Function:    main
 *
 * Purpose:     Main entry point.
 *
 * Return:      Success:    EXIT_SUCCESS
 *
 *-------------------------------------------------------------------------
 */
int HDF_NO_UBSAN
main(int argc, char *argv[])
{
    char *fname = NULL;
    FILE *f; /* temporary holding place for the stream pointer
              * so that rawoutstream is changed only when succeeded */

    if (argc > 1)
        fname = argv[1];

    /* First check if filename is string "NULL" */
    if (fname != NULL) {
        /* binary output */
        if ((f = HDfopen(fname, "w")) != NULL)
            rawoutstream = f;
    }
    if (!rawoutstream)
        rawoutstream = stdout;

    print_header();

    /* C89 floating point types */
    detect_C89_floats();

    /* C99 floating point types */
    detect_C99_floats();

    /* Detect structure alignment */
    detect_alignments();

    print_results(nd_g, d_g, na_g, m_g);

    if (rawoutstream && rawoutstream != stdout) {
        if (HDfclose(rawoutstream))
            fprintf(stderr, "closing rawoutstream");
        else
            rawoutstream = NULL;
    }

    return EXIT_SUCCESS;
}

H5_GCC_CLANG_DIAG_ON("cast-align")