FLANG

format-implementation.h
1 //===-- runtime/format-implementation.h -------------------------*- C++ -*-===//
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 // Implements out-of-line member functions of template class FormatControl
10
11 #ifndef FORTRAN_RUNTIME_FORMAT_IMPLEMENTATION_H_
12 #define FORTRAN_RUNTIME_FORMAT_IMPLEMENTATION_H_
13
14 #include "format.h"
15 #include "io-stmt.h"
16 #include "main.h"
17 #include "flang/Common/format.h"
18 #include "flang/Decimal/decimal.h"
19 #include <algorithm>
20 #include <limits>
21
22 namespace Fortran::runtime::io {
23
24 template <typename CONTEXT>
25 FormatControl<CONTEXT>::FormatControl(const Terminator &terminator,
26 const CharType *format, std::size_t formatLength, int maxHeight)
27 : maxHeight_{static_cast<std::uint8_t>(maxHeight)}, format_{format},
28 formatLength_{static_cast<int>(formatLength)} {
29 RUNTIME_CHECK(terminator, maxHeight == maxHeight_);
30 RUNTIME_CHECK(
31 terminator, formatLength == static_cast<std::size_t>(formatLength_));
32 stack_[0].start = offset_;
33 stack_[0].remaining = Iteration::unlimited; // 13.4(8)
34 }
35
36 template <typename CONTEXT>
37 int FormatControl<CONTEXT>::GetMaxParenthesisNesting(
38 IoErrorHandler &handler, const CharType *format, std::size_t formatLength) {
39 int maxNesting{0};
40 int nesting{0};
41 const CharType *end{format + formatLength};
42 std::optional<CharType> quote;
43 int repeat{0};
44 for (const CharType *p{format}; p < end; ++p) {
45 if (quote) {
46 if (*p == *quote) {
47 quote.reset();
48 }
49 } else if (*p >= '0' && *p <= '9') {
50 repeat = 10 * repeat + *p - '0';
51 } else if (*p != ' ') {
52 switch (*p) {
53 case '\'':
54 case '"':
55 quote = *p;
56 break;
57 case 'h':
58 case 'H': // 9HHOLLERITH
59 p += repeat;
60 if (p >= end) {
61 handler.SignalError(IostatErrorInFormat,
62 "Hollerith (%dH) too long in FORMAT", repeat);
63 return maxNesting;
64 }
65 break;
66 case ' ':
67 break;
68 case '(':
69 ++nesting;
70 maxNesting = std::max(nesting, maxNesting);
71 break;
72 case ')':
73 nesting = std::max(nesting - 1, 0);
74 break;
75 }
76 repeat = 0;
77 }
78 }
79 if (quote) {
80 handler.SignalError(
81 IostatErrorInFormat, "Unbalanced quotation marks in FORMAT string");
82 } else if (nesting) {
83 handler.SignalError(
84 IostatErrorInFormat, "Unbalanced parentheses in FORMAT string");
85 }
86 return maxNesting;
87 }
88
89 template <typename CONTEXT>
90 int FormatControl<CONTEXT>::GetIntField(
91 IoErrorHandler &handler, CharType firstCh) {
92 CharType ch{firstCh ? firstCh : PeekNext()};
93 if (ch != '-' && ch != '+' && (ch < '0' || ch > '9')) {
94 handler.SignalError(IostatErrorInFormat,
95 "Invalid FORMAT: integer expected at '%c'", static_cast<char>(ch));
96 return 0;
97 }
98 int result{0};
99 bool negate{ch == '-'};
100 if (negate) {
101 firstCh = '\0';
102 ch = PeekNext();
103 }
104 while (ch >= '0' && ch <= '9') {
105 if (result >
106 std::numeric_limits<int>::max() / 10 - (static_cast<int>(ch) - '0')) {
107 handler.SignalError(
108 IostatErrorInFormat, "FORMAT integer field out of range");
109 return result;
110 }
111 result = 10 * result + ch - '0';
112 if (firstCh) {
113 firstCh = '\0';
114 } else {
115 ++offset_;
116 }
117 ch = PeekNext();
118 }
119 if (negate && (result *= -1) > 0) {
120 handler.SignalError(
121 IostatErrorInFormat, "FORMAT integer field out of range");
122 }
123 return result;
124 }
125
126 template <typename CONTEXT>
127 static void HandleControl(CONTEXT &context, char ch, char next, int n) {
128 MutableModes &modes{context.mutableModes()};
129 switch (ch) {
130 case 'B':
131 if (next == 'Z') {
132 modes.editingFlags |= blankZero;
133 return;
134 }
135 if (next == 'N') {
136 modes.editingFlags &= ~blankZero;
137 return;
138 }
139 break;
140 case 'D':
141 if (next == 'C') {
142 modes.editingFlags |= decimalComma;
143 return;
144 }
145 if (next == 'P') {
146 modes.editingFlags &= ~decimalComma;
147 return;
148 }
149 break;
150 case 'P':
151 if (!next) {
152 modes.scale = n; // kP - decimal scaling by 10**k
153 return;
154 }
155 break;
156 case 'R':
157 switch (next) {
158 case 'N':
159 modes.round = decimal::RoundNearest;
160 return;
161 case 'Z':
162 modes.round = decimal::RoundToZero;
163 return;
164 case 'U':
165 modes.round = decimal::RoundUp;
166 return;
167 case 'D':
168 modes.round = decimal::RoundDown;
169 return;
170 case 'C':
171 modes.round = decimal::RoundCompatible;
172 return;
173 case 'P':
174 modes.round = executionEnvironment.defaultOutputRoundingMode;
175 return;
176 default:
177 break;
178 }
179 break;
180 case 'X':
181 if (!next) {
182 context.HandleRelativePosition(n);
183 return;
184 }
185 break;
186 case 'S':
187 if (next == 'P') {
188 modes.editingFlags |= signPlus;
189 return;
190 }
191 if (!next || next == 'S') {
192 modes.editingFlags &= ~signPlus;
193 return;
194 }
195 break;
196 case 'T': {
197 if (!next) { // Tn
198 context.HandleAbsolutePosition(n - 1); // convert 1-based to 0-based
199 return;
200 }
201 if (next == 'L' || next == 'R') { // TLn & TRn
202 context.HandleRelativePosition(next == 'L' ? -n : n);
203 return;
204 }
205 } break;
206 default:
207 break;
208 }
209 if (next) {
210 context.SignalError(IostatErrorInFormat,
211 "Unknown '%c%c' edit descriptor in FORMAT", ch, next);
212 } else {
213 context.SignalError(
214 IostatErrorInFormat, "Unknown '%c' edit descriptor in FORMAT", ch);
215 }
216 }
217
218 // Locates the next data edit descriptor in the format.
219 // Handles all repetition counts and control edit descriptors.
220 // Generally assumes that the format string has survived the common
221 // format validator gauntlet.
222 template <typename CONTEXT>
223 int FormatControl<CONTEXT>::CueUpNextDataEdit(Context &context, bool stop) {
224 int unlimitedLoopCheck{-1};
225 while (true) {
226 std::optional<int> repeat;
227 bool unlimited{false};
228 CharType ch{GetNextChar(context)};
229 while (ch == ',' || ch == ':') {
230 // Skip commas, and don't complain if they're missing; the format
231 // validator does that.
232 if (stop && ch == ':') {
233 return 0;
234 }
235 ch = GetNextChar(context);
236 }
237 if (ch == '-' || ch == '+' || (ch >= '0' && ch <= '9')) {
238 repeat = GetIntField(context, ch);
239 ch = GetNextChar(context);
240 } else if (ch == '*') {
241 unlimited = true;
242 ch = GetNextChar(context);
243 if (ch != '(') {
244 context.SignalError(IostatErrorInFormat,
245 "Invalid FORMAT: '*' may appear only before '('");
246 return 0;
247 }
248 }
249 ch = Capitalize(ch);
250 if (ch == '(') {
251 if (height_ >= maxHeight_) {
252 context.SignalError(IostatErrorInFormat,
253 "FORMAT stack overflow: too many nested parentheses");
254 return 0;
255 }
256 stack_[height_].start = offset_ - 1; // the '('
257 if (unlimited || height_ == 0) {
258 stack_[height_].remaining = Iteration::unlimited;
259 unlimitedLoopCheck = offset_ - 1;
260 } else if (repeat) {
261 if (*repeat <= 0) {
262 *repeat = 1; // error recovery
263 }
264 stack_[height_].remaining = *repeat - 1;
265 } else {
266 stack_[height_].remaining = 0;
267 }
268 ++height_;
269 } else if (height_ == 0) {
270 context.SignalError(IostatErrorInFormat, "FORMAT lacks initial '('");
271 return 0;
272 } else if (ch == ')') {
273 if (height_ == 1) {
274 if (stop) {
275 return 0; // end of FORMAT and no data items remain
276 }
277 context.AdvanceRecord(); // implied / before rightmost )
278 }
279 if (stack_[height_ - 1].remaining == Iteration::unlimited) {
280 offset_ = stack_[height_ - 1].start + 1;
281 if (offset_ == unlimitedLoopCheck) {
282 context.SignalError(IostatErrorInFormat,
283 "Unlimited repetition in FORMAT lacks data edit descriptors");
284 }
285 } else if (stack_[height_ - 1].remaining-- > 0) {
286 offset_ = stack_[height_ - 1].start + 1;
287 } else {
288 --height_;
289 }
290 } else if (ch == '\'' || ch == '"') {
291 // Quoted 'character literal'
292 CharType quote{ch};
293 auto start{offset_};
294 while (offset_ < formatLength_ && format_[offset_] != quote) {
295 ++offset_;
296 }
297 if (offset_ >= formatLength_) {
298 context.SignalError(IostatErrorInFormat,
299 "FORMAT missing closing quote on character literal");
300 return 0;
301 }
302 ++offset_;
303 std::size_t chars{
304 static_cast<std::size_t>(&format_[offset_] - &format_[start])};
305 if (PeekNext() == quote) {
306 // subtle: handle doubled quote character in a literal by including
307 // the first in the output, then treating the second as the start
308 // of another character literal.
309 } else {
310 --chars;
311 }
312 context.Emit(format_ + start, chars);
313 } else if (ch == 'H') {
314 // 9HHOLLERITH
315 if (!repeat || *repeat < 1 || offset_ + *repeat > formatLength_) {
316 context.SignalError(
317 IostatErrorInFormat, "Invalid width on Hollerith in FORMAT");
318 return 0;
319 }
320 context.Emit(format_ + offset_, static_cast<std::size_t>(*repeat));
321 offset_ += *repeat;
322 } else if (ch >= 'A' && ch <= 'Z') {
323 int start{offset_ - 1};
324 CharType next{Capitalize(PeekNext())};
325 if (next >= 'A' && next <= 'Z') {
326 ++offset_;
327 } else {
328 next = '\0';
329 }
330 if (ch == 'E' ||
331 (!next &&
332 (ch == 'A' || ch == 'I' || ch == 'B' || ch == 'O' || ch == 'Z' ||
333 ch == 'F' || ch == 'D' || ch == 'G' || ch == 'L'))) {
334 // Data edit descriptor found
335 offset_ = start;
336 return repeat && *repeat > 0 ? *repeat : 1;
337 } else {
338 // Control edit descriptor
339 if (ch == 'T') { // Tn, TLn, TRn
340 repeat = GetIntField(context);
341 }
342 HandleControl(context, static_cast<char>(ch), static_cast<char>(next),
343 repeat ? *repeat : 1);
344 }
345 } else if (ch == '/') {
346 context.AdvanceRecord(repeat && *repeat > 0 ? *repeat : 1);
347 } else {
348 context.SignalError(IostatErrorInFormat,
349 "Invalid character '%c' in FORMAT", static_cast<char>(ch));
350 return 0;
351 }
352 }
353 }
354
355 template <typename CONTEXT>
356 DataEdit FormatControl<CONTEXT>::GetNextDataEdit(
357 Context &context, int maxRepeat) {
358
359 // TODO: DT editing
360
361 // Return the next data edit descriptor
362 int repeat{CueUpNextDataEdit(context)};
363 auto start{offset_};
364 DataEdit edit;
365 edit.descriptor = static_cast<char>(Capitalize(GetNextChar(context)));
366 if (edit.descriptor == 'E') {
367 edit.variation = static_cast<char>(Capitalize(PeekNext()));
368 if (edit.variation >= 'A' && edit.variation <= 'Z') {
369 ++offset_;
370 }
371 }
372
373 if (edit.descriptor == 'A') { // width is optional for A[w]
374 auto ch{PeekNext()};
375 if (ch >= '0' && ch <= '9') {
376 edit.width = GetIntField(context);
377 }
378 } else {
379 edit.width = GetIntField(context);
380 }
381 edit.modes = context.mutableModes();
382 if (PeekNext() == '.') {
383 ++offset_;
384 edit.digits = GetIntField(context);
385 CharType ch{PeekNext()};
386 if (ch == 'e' || ch == 'E' || ch == 'd' || ch == 'D') {
387 ++offset_;
388 edit.expoDigits = GetIntField(context);
389 }
390 }
391
392 // Handle repeated nonparenthesized edit descriptors
393 if (repeat > 1) {
394 stack_[height_].start = start; // after repeat count
395 stack_[height_].remaining = repeat; // full count
396 ++height_;
397 }
398 edit.repeat = 1;
399 if (height_ > 1) {
400 int start{stack_[height_ - 1].start};
401 if (format_[start] != '(') {
402 if (stack_[height_ - 1].remaining > maxRepeat) {
403 edit.repeat = maxRepeat;
404 stack_[height_ - 1].remaining -= maxRepeat;
405 offset_ = start; // repeat same edit descriptor next time
406 } else {
407 edit.repeat = stack_[height_ - 1].remaining;
408 --height_;
409 }
410 }
411 }
412 return edit;
413 }
414
415 template <typename CONTEXT>
416 void FormatControl<CONTEXT>::Finish(Context &context) {
417 CueUpNextDataEdit(context, true /* stop at colon or end of FORMAT */);
418 }
419 } // namespace Fortran::runtime::io
420 #endif // FORTRAN_RUNTIME_FORMAT_IMPLEMENTATION_H_