1 //===-- runtime/edit-output.cpp -------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "edit-output.h"
10 #include "utf.h"
11 #include "flang/Common/uint128.h"
12 #include <algorithm>
13 
14 namespace Fortran::runtime::io {
15 
16 // B/O/Z output of arbitrarily sized data emits a binary/octal/hexadecimal
17 // representation of what is interpreted to be a single unsigned integer value.
18 // When used with character data, endianness is exposed.
19 template <int LOG2_BASE>
20 static bool EditBOZOutput(IoStatementState &io, const DataEdit &edit,
21     const unsigned char *data0, std::size_t bytes) {
22   int digits{static_cast<int>((bytes * 8) / LOG2_BASE)};
23   int get{static_cast<int>(bytes * 8) - digits * LOG2_BASE};
24   if (get > 0) {
25     ++digits;
26   } else {
27     get = LOG2_BASE;
28   }
29   int shift{7};
30   int increment{isHostLittleEndian ? -1 : 1};
31   const unsigned char *data{data0 + (isHostLittleEndian ? bytes - 1 : 0)};
32   int skippedZeroes{0};
33   int digit{0};
34   // The same algorithm is used to generate digits for real (below)
35   // as well as for generating them only to skip leading zeroes (here).
36   // Bits are copied one at a time from the source data.
37   // TODO: Multiple bit copies for hexadecimal, where misalignment
38   // is not possible; or for octal when all 3 bits come from the
39   // same byte.
40   while (bytes > 0) {
41     if (get == 0) {
42       if (digit != 0) {
43         break; // first nonzero leading digit
44       }
45       ++skippedZeroes;
46       get = LOG2_BASE;
47     } else if (shift < 0) {
48       data += increment;
49       --bytes;
50       shift = 7;
51     } else {
52       digit = 2 * digit + ((*data >> shift--) & 1);
53       --get;
54     }
55   }
56   // Emit leading spaces and zeroes; detect field overflow
57   int leadingZeroes{0};
58   int editWidth{edit.width.value_or(0)};
59   int significant{digits - skippedZeroes};
60   if (edit.digits && significant <= *edit.digits) { // Bw.m, Ow.m, Zw.m
61     if (*edit.digits == 0 && bytes == 0) {
62       editWidth = std::max(1, editWidth);
63     } else {
64       leadingZeroes = *edit.digits - significant;
65     }
66   } else if (bytes == 0) {
67     leadingZeroes = 1;
68   }
69   int subTotal{leadingZeroes + significant};
70   int leadingSpaces{std::max(0, editWidth - subTotal)};
71   if (editWidth > 0 && leadingSpaces + subTotal > editWidth) {
72     return io.EmitRepeated('*', editWidth);
73   }
74   if (!(io.EmitRepeated(' ', leadingSpaces) &&
75           io.EmitRepeated('0', leadingZeroes))) {
76     return false;
77   }
78   // Emit remaining digits
79   while (bytes > 0) {
80     if (get == 0) {
81       char ch{static_cast<char>(digit >= 10 ? 'A' + digit - 10 : '0' + digit)};
82       if (!io.Emit(&ch, 1)) {
83         return false;
84       }
85       get = LOG2_BASE;
86       digit = 0;
87     } else if (shift < 0) {
88       data += increment;
89       --bytes;
90       shift = 7;
91     } else {
92       digit = 2 * digit + ((*data >> shift--) & 1);
93       --get;
94     }
95   }
96   return true;
97 }
98 
99 template <int KIND>
100 bool EditIntegerOutput(IoStatementState &io, const DataEdit &edit,
101     common::HostSignedIntType<8 * KIND> n) {
102   char buffer[130], *end{&buffer[sizeof buffer]}, *p{end};
103   bool isNegative{n < 0};
104   using Unsigned = common::HostUnsignedIntType<8 * KIND>;
105   Unsigned un{static_cast<Unsigned>(n)};
106   int signChars{0};
107   switch (edit.descriptor) {
108   case DataEdit::ListDirected:
109   case 'G':
110   case 'I':
111     if (isNegative) {
112       un = -un;
113     }
114     if (isNegative || (edit.modes.editingFlags & signPlus)) {
115       signChars = 1; // '-' or '+'
116     }
117     while (un > 0) {
118       auto quotient{un / 10u};
119       *--p = '0' + static_cast<int>(un - Unsigned{10} * quotient);
120       un = quotient;
121     }
122     break;
123   case 'B':
124     return EditBOZOutput<1>(
125         io, edit, reinterpret_cast<const unsigned char *>(&n), KIND);
126   case 'O':
127     return EditBOZOutput<3>(
128         io, edit, reinterpret_cast<const unsigned char *>(&n), KIND);
129   case 'Z':
130     return EditBOZOutput<4>(
131         io, edit, reinterpret_cast<const unsigned char *>(&n), KIND);
132   case 'A': // legacy extension
133     return EditCharacterOutput(
134         io, edit, reinterpret_cast<char *>(&n), sizeof n);
135   default:
136     io.GetIoErrorHandler().SignalError(IostatErrorInFormat,
137         "Data edit descriptor '%c' may not be used with an INTEGER data item",
138         edit.descriptor);
139     return false;
140   }
141 
142   int digits = end - p;
143   int leadingZeroes{0};
144   int editWidth{edit.width.value_or(0)};
145   if (edit.digits && digits <= *edit.digits) { // Iw.m
146     if (*edit.digits == 0 && n == 0) {
147       // Iw.0 with zero value: output field must be blank.  For I0.0
148       // and a zero value, emit one blank character.
149       signChars = 0; // in case of SP
150       editWidth = std::max(1, editWidth);
151     } else {
152       leadingZeroes = *edit.digits - digits;
153     }
154   } else if (n == 0) {
155     leadingZeroes = 1;
156   }
157   int subTotal{signChars + leadingZeroes + digits};
158   int leadingSpaces{std::max(0, editWidth - subTotal)};
159   if (editWidth > 0 && leadingSpaces + subTotal > editWidth) {
160     return io.EmitRepeated('*', editWidth);
161   }
162   if (edit.IsListDirected()) {
163     int total{std::max(leadingSpaces, 1) + subTotal};
164     if (io.GetConnectionState().NeedAdvance(static_cast<std::size_t>(total)) &&
165         !io.AdvanceRecord()) {
166       return false;
167     }
168     leadingSpaces = 1;
169   }
170   return io.EmitRepeated(' ', leadingSpaces) &&
171       io.Emit(n < 0 ? "-" : "+", signChars) &&
172       io.EmitRepeated('0', leadingZeroes) && io.Emit(p, digits);
173 }
174 
175 // Formats the exponent (see table 13.1 for all the cases)
176 const char *RealOutputEditingBase::FormatExponent(
177     int expo, const DataEdit &edit, int &length) {
178   char *eEnd{&exponent_[sizeof exponent_]};
179   char *exponent{eEnd};
180   for (unsigned e{static_cast<unsigned>(std::abs(expo))}; e > 0;) {
181     unsigned quotient{e / 10u};
182     *--exponent = '0' + e - 10 * quotient;
183     e = quotient;
184   }
185   if (edit.expoDigits) {
186     if (int ed{*edit.expoDigits}) { // Ew.dEe with e > 0
187       while (exponent > exponent_ + 2 /*E+*/ && exponent + ed > eEnd) {
188         *--exponent = '0';
189       }
190     } else if (exponent == eEnd) {
191       *--exponent = '0'; // Ew.dE0 with zero-valued exponent
192     }
193   } else { // ensure at least two exponent digits
194     while (exponent + 2 > eEnd) {
195       *--exponent = '0';
196     }
197   }
198   *--exponent = expo < 0 ? '-' : '+';
199   if (edit.expoDigits || edit.IsListDirected() || exponent + 3 == eEnd) {
200     *--exponent = edit.descriptor == 'D' ? 'D' : 'E'; // not 'G'
201   }
202   length = eEnd - exponent;
203   return exponent;
204 }
205 
206 bool RealOutputEditingBase::EmitPrefix(
207     const DataEdit &edit, std::size_t length, std::size_t width) {
208   if (edit.IsListDirected()) {
209     int prefixLength{edit.descriptor == DataEdit::ListDirectedRealPart ? 2
210             : edit.descriptor == DataEdit::ListDirectedImaginaryPart   ? 0
211                                                                        : 1};
212     int suffixLength{edit.descriptor == DataEdit::ListDirectedRealPart ||
213                 edit.descriptor == DataEdit::ListDirectedImaginaryPart
214             ? 1
215             : 0};
216     length += prefixLength + suffixLength;
217     ConnectionState &connection{io_.GetConnectionState()};
218     return (!connection.NeedAdvance(length) || io_.AdvanceRecord()) &&
219         io_.Emit(" (", prefixLength);
220   } else if (width > length) {
221     return io_.EmitRepeated(' ', width - length);
222   } else {
223     return true;
224   }
225 }
226 
227 bool RealOutputEditingBase::EmitSuffix(const DataEdit &edit) {
228   if (edit.descriptor == DataEdit::ListDirectedRealPart) {
229     return io_.Emit(edit.modes.editingFlags & decimalComma ? ";" : ",", 1);
230   } else if (edit.descriptor == DataEdit::ListDirectedImaginaryPart) {
231     return io_.Emit(")", 1);
232   } else {
233     return true;
234   }
235 }
236 
237 template <int binaryPrecision>
238 decimal::ConversionToDecimalResult RealOutputEditing<binaryPrecision>::Convert(
239     int significantDigits, enum decimal::FortranRounding rounding, int flags) {
240   auto converted{decimal::ConvertToDecimal<binaryPrecision>(buffer_,
241       sizeof buffer_, static_cast<enum decimal::DecimalConversionFlags>(flags),
242       significantDigits, rounding, x_)};
243   if (!converted.str) { // overflow
244     io_.GetIoErrorHandler().Crash(
245         "RealOutputEditing::Convert : buffer size %zd was insufficient",
246         sizeof buffer_);
247   }
248   return converted;
249 }
250 
251 // 13.7.2.3.3 in F'2018
252 template <int binaryPrecision>
253 bool RealOutputEditing<binaryPrecision>::EditEorDOutput(const DataEdit &edit) {
254   int editDigits{edit.digits.value_or(0)}; // 'd' field
255   int editWidth{edit.width.value_or(0)}; // 'w' field
256   int significantDigits{editDigits};
257   int flags{0};
258   if (edit.modes.editingFlags & signPlus) {
259     flags |= decimal::AlwaysSign;
260   }
261   if (editWidth == 0) { // "the processor selects the field width"
262     if (edit.digits.has_value()) { // E0.d
263       if (editDigits == 0) { // E0.0
264         editWidth = 7; // -.0E+ee
265       } else {
266         editWidth = editDigits + 6; // -.666E+ee
267       }
268     } else { // E0
269       flags |= decimal::Minimize;
270       significantDigits =
271           sizeof buffer_ - 5; // sign, NUL, + 3 extra for EN scaling
272     }
273   }
274   bool isEN{edit.variation == 'N'};
275   bool isES{edit.variation == 'S'};
276   int scale{edit.modes.scale}; // 'kP' value
277   int zeroesAfterPoint{0};
278   if (isEN) {
279     scale = IsZero() ? 1 : 3;
280     significantDigits += scale;
281   } else if (isES) {
282     scale = 1;
283     ++significantDigits;
284   } else if (scale < 0) {
285     if (scale <= -editDigits) {
286       io_.GetIoErrorHandler().SignalError(IostatBadScaleFactor,
287           "Scale factor (kP) %d cannot be less than -d (%d)", scale,
288           -editDigits);
289       return false;
290     }
291     zeroesAfterPoint = -scale;
292     significantDigits = std::max(0, significantDigits - zeroesAfterPoint);
293   } else if (scale > 0) {
294     if (scale >= editDigits + 2) {
295       io_.GetIoErrorHandler().SignalError(IostatBadScaleFactor,
296           "Scale factor (kP) %d cannot be greater than d+2 (%d)", scale,
297           editDigits + 2);
298       return false;
299     }
300     ++significantDigits;
301     scale = std::min(scale, significantDigits + 1);
302   }
303   // In EN editing, multiple attempts may be necessary, so this is a loop.
304   while (true) {
305     decimal::ConversionToDecimalResult converted{
306         Convert(significantDigits, edit.modes.round, flags)};
307     if (IsInfOrNaN(converted)) {
308       return EmitPrefix(edit, converted.length, editWidth) &&
309           io_.Emit(converted.str, converted.length) && EmitSuffix(edit);
310     }
311     if (!IsZero()) {
312       converted.decimalExponent -= scale;
313     }
314     if (isEN) {
315       // EN mode: we need an effective exponent field that is
316       // a multiple of three.
317       if (int modulus{converted.decimalExponent % 3}; modulus != 0) {
318         if (significantDigits > 1) {
319           --significantDigits;
320           --scale;
321           continue;
322         }
323         // Rounded nines up to a 1.
324         scale += modulus;
325         converted.decimalExponent -= modulus;
326       }
327       if (scale > 3) {
328         int adjust{3 * (scale / 3)};
329         scale -= adjust;
330         converted.decimalExponent += adjust;
331       } else if (scale < 1) {
332         int adjust{3 - 3 * (scale / 3)};
333         scale += adjust;
334         converted.decimalExponent -= adjust;
335       }
336       significantDigits = editDigits + scale;
337     }
338     // Format the exponent (see table 13.1 for all the cases)
339     int expoLength{0};
340     const char *exponent{
341         FormatExponent(converted.decimalExponent, edit, expoLength)};
342     int signLength{*converted.str == '-' || *converted.str == '+' ? 1 : 0};
343     int convertedDigits{static_cast<int>(converted.length) - signLength};
344     int zeroesBeforePoint{std::max(0, scale - convertedDigits)};
345     int digitsBeforePoint{std::max(0, scale - zeroesBeforePoint)};
346     int digitsAfterPoint{convertedDigits - digitsBeforePoint};
347     int trailingZeroes{flags & decimal::Minimize
348             ? 0
349             : std::max(0,
350                   significantDigits - (convertedDigits + zeroesBeforePoint))};
351     int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
352         1 /*'.'*/ + zeroesAfterPoint + digitsAfterPoint + trailingZeroes +
353         expoLength};
354     int width{editWidth > 0 ? editWidth : totalLength};
355     if (totalLength > width) {
356       return io_.EmitRepeated('*', width);
357     }
358     if (totalLength < width && digitsBeforePoint == 0 &&
359         zeroesBeforePoint == 0) {
360       zeroesBeforePoint = 1;
361       ++totalLength;
362     }
363     return EmitPrefix(edit, totalLength, width) &&
364         io_.Emit(converted.str, signLength + digitsBeforePoint) &&
365         io_.EmitRepeated('0', zeroesBeforePoint) &&
366         io_.Emit(edit.modes.editingFlags & decimalComma ? "," : ".", 1) &&
367         io_.EmitRepeated('0', zeroesAfterPoint) &&
368         io_.Emit(
369             converted.str + signLength + digitsBeforePoint, digitsAfterPoint) &&
370         io_.EmitRepeated('0', trailingZeroes) &&
371         io_.Emit(exponent, expoLength) && EmitSuffix(edit);
372   }
373 }
374 
375 // 13.7.2.3.2 in F'2018
376 template <int binaryPrecision>
377 bool RealOutputEditing<binaryPrecision>::EditFOutput(const DataEdit &edit) {
378   int fracDigits{edit.digits.value_or(0)}; // 'd' field
379   const int editWidth{edit.width.value_or(0)}; // 'w' field
380   enum decimal::FortranRounding rounding{edit.modes.round};
381   int flags{0};
382   if (edit.modes.editingFlags & signPlus) {
383     flags |= decimal::AlwaysSign;
384   }
385   if (editWidth == 0) { // "the processor selects the field width"
386     if (!edit.digits.has_value()) { // F0
387       flags |= decimal::Minimize;
388       fracDigits = sizeof buffer_ - 2; // sign & NUL
389     }
390   }
391   // Multiple conversions may be needed to get the right number of
392   // effective rounded fractional digits.
393   int extraDigits{0};
394   bool canIncrease{true};
395   while (true) {
396     decimal::ConversionToDecimalResult converted{
397         Convert(extraDigits + fracDigits, rounding, flags)};
398     if (IsInfOrNaN(converted)) {
399       return EmitPrefix(edit, converted.length, editWidth) &&
400           io_.Emit(converted.str, converted.length) && EmitSuffix(edit);
401     }
402     int expo{converted.decimalExponent + edit.modes.scale /*kP*/};
403     int signLength{*converted.str == '-' || *converted.str == '+' ? 1 : 0};
404     int convertedDigits{static_cast<int>(converted.length) - signLength};
405     if (IsZero()) { // don't treat converted "0" as significant digit
406       expo = 0;
407       convertedDigits = 0;
408     }
409     int trailingOnes{0};
410     if (expo > extraDigits && extraDigits >= 0 && canIncrease) {
411       extraDigits = expo;
412       if (!edit.digits.has_value()) { // F0
413         fracDigits = sizeof buffer_ - extraDigits - 2; // sign & NUL
414       }
415       canIncrease = false; // only once
416       continue;
417     } else if (expo == -fracDigits && convertedDigits > 0) {
418       if (rounding != decimal::FortranRounding::RoundToZero) {
419         // Convert again without rounding so that we can round here
420         rounding = decimal::FortranRounding::RoundToZero;
421         continue;
422       } else if (converted.str[signLength] >= '5') {
423         // Value rounds up to a scaled 1 (e.g., 0.06 for F5.1 -> 0.1)
424         ++expo;
425         convertedDigits = 0;
426         trailingOnes = 1;
427       } else {
428         // Value rounds down to zero
429         expo = 0;
430         convertedDigits = 0;
431       }
432     } else if (expo < extraDigits && extraDigits > -fracDigits) {
433       extraDigits = std::max(expo, -fracDigits);
434       continue;
435     }
436     int digitsBeforePoint{std::max(0, std::min(expo, convertedDigits))};
437     int zeroesBeforePoint{std::max(0, expo - digitsBeforePoint)};
438     int zeroesAfterPoint{std::min(fracDigits, std::max(0, -expo))};
439     int digitsAfterPoint{convertedDigits - digitsBeforePoint};
440     int trailingZeroes{flags & decimal::Minimize
441             ? 0
442             : std::max(0,
443                   fracDigits -
444                       (zeroesAfterPoint + digitsAfterPoint + trailingOnes))};
445     if (digitsBeforePoint + zeroesBeforePoint + zeroesAfterPoint +
446             digitsAfterPoint + trailingOnes + trailingZeroes ==
447         0) {
448       zeroesBeforePoint = 1; // "." -> "0."
449     }
450     int totalLength{signLength + digitsBeforePoint + zeroesBeforePoint +
451         1 /*'.'*/ + zeroesAfterPoint + digitsAfterPoint + trailingOnes +
452         trailingZeroes};
453     int width{editWidth > 0 ? editWidth : totalLength};
454     if (totalLength > width) {
455       return io_.EmitRepeated('*', width);
456     }
457     if (totalLength < width && digitsBeforePoint + zeroesBeforePoint == 0) {
458       zeroesBeforePoint = 1;
459       ++totalLength;
460     }
461     return EmitPrefix(edit, totalLength, width) &&
462         io_.Emit(converted.str, signLength + digitsBeforePoint) &&
463         io_.EmitRepeated('0', zeroesBeforePoint) &&
464         io_.Emit(edit.modes.editingFlags & decimalComma ? "," : ".", 1) &&
465         io_.EmitRepeated('0', zeroesAfterPoint) &&
466         io_.Emit(
467             converted.str + signLength + digitsBeforePoint, digitsAfterPoint) &&
468         io_.EmitRepeated('1', trailingOnes) &&
469         io_.EmitRepeated('0', trailingZeroes) &&
470         io_.EmitRepeated(' ', trailingBlanks_) && EmitSuffix(edit);
471   }
472 }
473 
474 // 13.7.5.2.3 in F'2018
475 template <int binaryPrecision>
476 DataEdit RealOutputEditing<binaryPrecision>::EditForGOutput(DataEdit edit) {
477   edit.descriptor = 'E';
478   int significantDigits{
479       edit.digits.value_or(BinaryFloatingPoint::decimalPrecision)}; // 'd'
480   if (!edit.width.has_value() || (*edit.width > 0 && significantDigits == 0)) {
481     return edit; // Gw.0 -> Ew.0 for w > 0
482   }
483   int flags{0};
484   if (edit.modes.editingFlags & signPlus) {
485     flags |= decimal::AlwaysSign;
486   }
487   decimal::ConversionToDecimalResult converted{
488       Convert(significantDigits, edit.modes.round, flags)};
489   if (IsInfOrNaN(converted)) {
490     return edit;
491   }
492   int expo{IsZero() ? 1 : converted.decimalExponent}; // 's'
493   if (expo < 0 || expo > significantDigits) {
494     return edit; // Ew.d
495   }
496   edit.descriptor = 'F';
497   edit.modes.scale = 0; // kP is ignored for G when no exponent field
498   trailingBlanks_ = 0;
499   int editWidth{edit.width.value_or(0)};
500   if (editWidth > 0) {
501     int expoDigits{edit.expoDigits.value_or(0)};
502     trailingBlanks_ = expoDigits > 0 ? expoDigits + 2 : 4; // 'n'
503     *edit.width = std::max(0, editWidth - trailingBlanks_);
504   }
505   if (edit.digits.has_value()) {
506     *edit.digits = std::max(0, *edit.digits - expo);
507   }
508   return edit;
509 }
510 
511 // 13.10.4 in F'2018
512 template <int binaryPrecision>
513 bool RealOutputEditing<binaryPrecision>::EditListDirectedOutput(
514     const DataEdit &edit) {
515   decimal::ConversionToDecimalResult converted{Convert(1, edit.modes.round)};
516   if (IsInfOrNaN(converted)) {
517     return EditEorDOutput(edit);
518   }
519   int expo{converted.decimalExponent};
520   if (expo < 0 || expo > BinaryFloatingPoint::decimalPrecision) {
521     DataEdit copy{edit};
522     copy.modes.scale = 1; // 1P
523     return EditEorDOutput(copy);
524   }
525   return EditFOutput(edit);
526 }
527 
528 // 13.7.5.2.6 in F'2018
529 template <int binaryPrecision>
530 bool RealOutputEditing<binaryPrecision>::EditEXOutput(const DataEdit &) {
531   io_.GetIoErrorHandler().Crash(
532       "not yet implemented: EX output editing"); // TODO
533 }
534 
535 template <int KIND> bool RealOutputEditing<KIND>::Edit(const DataEdit &edit) {
536   switch (edit.descriptor) {
537   case 'D':
538     return EditEorDOutput(edit);
539   case 'E':
540     if (edit.variation == 'X') {
541       return EditEXOutput(edit);
542     } else {
543       return EditEorDOutput(edit);
544     }
545   case 'F':
546     return EditFOutput(edit);
547   case 'B':
548     return EditBOZOutput<1>(io_, edit,
549         reinterpret_cast<const unsigned char *>(&x_),
550         common::BitsForBinaryPrecision(common::PrecisionOfRealKind(KIND)) >> 3);
551   case 'O':
552     return EditBOZOutput<3>(io_, edit,
553         reinterpret_cast<const unsigned char *>(&x_),
554         common::BitsForBinaryPrecision(common::PrecisionOfRealKind(KIND)) >> 3);
555   case 'Z':
556     return EditBOZOutput<4>(io_, edit,
557         reinterpret_cast<const unsigned char *>(&x_),
558         common::BitsForBinaryPrecision(common::PrecisionOfRealKind(KIND)) >> 3);
559   case 'G':
560     return Edit(EditForGOutput(edit));
561   case 'A': // legacy extension
562     return EditCharacterOutput(
563         io_, edit, reinterpret_cast<char *>(&x_), sizeof x_);
564   default:
565     if (edit.IsListDirected()) {
566       return EditListDirectedOutput(edit);
567     }
568     io_.GetIoErrorHandler().SignalError(IostatErrorInFormat,
569         "Data edit descriptor '%c' may not be used with a REAL data item",
570         edit.descriptor);
571     return false;
572   }
573   return false;
574 }
575 
576 bool ListDirectedLogicalOutput(IoStatementState &io,
577     ListDirectedStatementState<Direction::Output> &list, bool truth) {
578   return list.EmitLeadingSpaceOrAdvance(io) && io.Emit(truth ? "T" : "F", 1);
579 }
580 
581 bool EditLogicalOutput(IoStatementState &io, const DataEdit &edit, bool truth) {
582   switch (edit.descriptor) {
583   case 'L':
584   case 'G':
585     return io.EmitRepeated(' ', std::max(0, edit.width.value_or(1) - 1)) &&
586         io.Emit(truth ? "T" : "F", 1);
587   case 'B':
588     return EditBOZOutput<1>(io, edit,
589         reinterpret_cast<const unsigned char *>(&truth), sizeof truth);
590   case 'O':
591     return EditBOZOutput<3>(io, edit,
592         reinterpret_cast<const unsigned char *>(&truth), sizeof truth);
593   case 'Z':
594     return EditBOZOutput<4>(io, edit,
595         reinterpret_cast<const unsigned char *>(&truth), sizeof truth);
596   default:
597     io.GetIoErrorHandler().SignalError(IostatErrorInFormat,
598         "Data edit descriptor '%c' may not be used with a LOGICAL data item",
599         edit.descriptor);
600     return false;
601   }
602 }
603 
604 template <typename CHAR>
605 bool ListDirectedCharacterOutput(IoStatementState &io,
606     ListDirectedStatementState<Direction::Output> &list, const CHAR *x,
607     std::size_t length) {
608   bool ok{true};
609   MutableModes &modes{io.mutableModes()};
610   ConnectionState &connection{io.GetConnectionState()};
611   if (modes.delim) {
612     ok = ok && list.EmitLeadingSpaceOrAdvance(io);
613     // Value is delimited with ' or " marks, and interior
614     // instances of that character are doubled.
615     auto EmitOne{[&](CHAR ch) {
616       if (connection.NeedAdvance(1)) {
617         ok = ok && io.AdvanceRecord();
618       }
619       ok = ok && io.EmitEncoded(&ch, 1);
620     }};
621     EmitOne(modes.delim);
622     for (std::size_t j{0}; j < length; ++j) {
623       // Doubled delimiters must be put on the same record
624       // in order to be acceptable as list-directed or NAMELIST
625       // input; however, this requirement is not always possible
626       // when the records have a fixed length, as is the case with
627       // internal output.  The standard is silent on what should
628       // happen, and no two extant Fortran implementations do
629       // the same thing when tested with this case.
630       // This runtime splits the doubled delimiters across
631       // two records for lack of a better alternative.
632       if (x[j] == static_cast<CHAR>(modes.delim)) {
633         EmitOne(x[j]);
634       }
635       EmitOne(x[j]);
636     }
637     EmitOne(modes.delim);
638   } else {
639     // Undelimited list-directed output
640     ok = ok && list.EmitLeadingSpaceOrAdvance(io, length > 0 ? 1 : 0, true);
641     std::size_t put{0};
642     std::size_t oneIfUTF8{connection.useUTF8<CHAR>() ? 1 : length};
643     while (ok && put < length) {
644       if (std::size_t chunk{std::min<std::size_t>(
645               std::min<std::size_t>(length - put, oneIfUTF8),
646               connection.RemainingSpaceInRecord())}) {
647         ok = io.EmitEncoded(x + put, chunk);
648         put += chunk;
649       } else {
650         ok = io.AdvanceRecord() && io.Emit(" ", 1);
651       }
652     }
653     list.set_lastWasUndelimitedCharacter(true);
654   }
655   return ok;
656 }
657 
658 template <typename CHAR>
659 bool EditCharacterOutput(IoStatementState &io, const DataEdit &edit,
660     const CHAR *x, std::size_t length) {
661   int len{static_cast<int>(length)};
662   int width{edit.width.value_or(len)};
663   switch (edit.descriptor) {
664   case 'A':
665     break;
666   case 'G':
667     if (width == 0) {
668       width = len;
669     }
670     break;
671   case 'B':
672     return EditBOZOutput<1>(io, edit,
673         reinterpret_cast<const unsigned char *>(x), sizeof(CHAR) * length);
674   case 'O':
675     return EditBOZOutput<3>(io, edit,
676         reinterpret_cast<const unsigned char *>(x), sizeof(CHAR) * length);
677   case 'Z':
678     return EditBOZOutput<4>(io, edit,
679         reinterpret_cast<const unsigned char *>(x), sizeof(CHAR) * length);
680   default:
681     io.GetIoErrorHandler().SignalError(IostatErrorInFormat,
682         "Data edit descriptor '%c' may not be used with a CHARACTER data item",
683         edit.descriptor);
684     return false;
685   }
686   return io.EmitRepeated(' ', std::max(0, width - len)) &&
687       io.EmitEncoded(x, std::min(width, len));
688 }
689 
690 template bool EditIntegerOutput<1>(
691     IoStatementState &, const DataEdit &, std::int8_t);
692 template bool EditIntegerOutput<2>(
693     IoStatementState &, const DataEdit &, std::int16_t);
694 template bool EditIntegerOutput<4>(
695     IoStatementState &, const DataEdit &, std::int32_t);
696 template bool EditIntegerOutput<8>(
697     IoStatementState &, const DataEdit &, std::int64_t);
698 template bool EditIntegerOutput<16>(
699     IoStatementState &, const DataEdit &, common::int128_t);
700 
701 template class RealOutputEditing<2>;
702 template class RealOutputEditing<3>;
703 template class RealOutputEditing<4>;
704 template class RealOutputEditing<8>;
705 template class RealOutputEditing<10>;
706 // TODO: double/double
707 template class RealOutputEditing<16>;
708 
709 template bool ListDirectedCharacterOutput(IoStatementState &,
710     ListDirectedStatementState<Direction::Output> &, const char *,
711     std::size_t chars);
712 template bool ListDirectedCharacterOutput(IoStatementState &,
713     ListDirectedStatementState<Direction::Output> &, const char16_t *,
714     std::size_t chars);
715 template bool ListDirectedCharacterOutput(IoStatementState &,
716     ListDirectedStatementState<Direction::Output> &, const char32_t *,
717     std::size_t chars);
718 
719 template bool EditCharacterOutput(
720     IoStatementState &, const DataEdit &, const char *, std::size_t chars);
721 template bool EditCharacterOutput(
722     IoStatementState &, const DataEdit &, const char16_t *, std::size_t chars);
723 template bool EditCharacterOutput(
724     IoStatementState &, const DataEdit &, const char32_t *, std::size_t chars);
725 
726 } // namespace Fortran::runtime::io
727