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nickg / nvc / 6935971286

20 Nov 2023 09:23PM UTC coverage: 91.231% (-0.01%) from 91.244%
6935971286

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nickg
Fix wrong result bounds when TO_UNSIGNED is constant folded

Fixes #799

31 of 34 new or added lines in 1 file covered. (91.18%)

8 existing lines in 2 files now uncovered.

50705 of 55579 relevant lines covered (91.23%)

607472.84 hits per line

Source File
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87.44
/src/eval.c
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//
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//  Copyright (C) 2013-2023  Nick Gasson
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//
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//  This program is free software: you can redistribute it and/or modify
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//  it under the terms of the GNU General Public License as published by
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//  the Free Software Foundation, either version 3 of the License, or
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//  (at your option) any later version.
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//
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//  This program is distributed in the hope that it will be useful,
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//  but WITHOUT ANY WARRANTY; without even the implied warranty of
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//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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//  GNU General Public License for more details.
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//
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//  You should have received a copy of the GNU General Public License
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//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
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//
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18
#include "util.h"
19
#include "common.h"
20
#include "diag.h"
21
#include "eval.h"
22
#include "hash.h"
23
#include "ident.h"
24
#include "jit/jit.h"
25
#include "jit/jit-ffi.h"
26
#include "lib.h"
27
#include "lower.h"
28
#include "option.h"
29
#include "phase.h"
30
#include "tree.h"
31
#include "type.h"
32
#include "vcode.h"
33

34
#include <assert.h>
35
#include <stdint.h>
36
#include <stdlib.h>
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#include <stdarg.h>
38
#include <inttypes.h>
39
#include <string.h>
40

41
static const char *eval_expr_name(tree_t expr)
×
42
{
43
   const tree_kind_t kind = tree_kind(expr);
×
44
   if (kind == T_FCALL)
×
45
      return istr(tree_ident(expr));
×
46
   else
47
      return tree_kind_str(kind);
×
48
}
49

50
static tree_t eval_value_to_tree(jit_scalar_t value, type_t type,
8,989✔
51
                                 const loc_t *loc)
52
{
53
   tree_t tree = NULL;
8,989✔
54

55
   if (type_is_enum(type)) {
8,989✔
56
      type_t base = type_base_recur(type);
2,095✔
57
      if ((unsigned)value.integer >= type_enum_literals(base))
2,095✔
58
         fatal_at(loc, "enum position %"PRIi64" out of range for type %s",
×
59
                  value.integer, type_pp(base));
60

61
      tree_t lit = type_enum_literal(base, value.integer);
2,095✔
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63
      tree = tree_new(T_REF);
2,095✔
64
      tree_set_ref(tree, lit);
2,095✔
65
      tree_set_ident(tree, tree_ident(lit));
2,095✔
66
   }
67
   else if (type_is_integer(type)) {
6,894✔
68
      tree = tree_new(T_LITERAL);
1,002✔
69
      tree_set_subkind(tree, L_INT);
1,002✔
70
      tree_set_ival(tree, value.integer);
1,002✔
71
   }
72
   else if (type_is_real(type)) {
5,892✔
73
      tree = tree_new(T_LITERAL);
5,808✔
74
      tree_set_subkind(tree, L_REAL);
5,808✔
75
      tree_set_dval(tree, value.real);
5,808✔
76
   }
77
   else if (type_is_physical(type)) {
84✔
78
      tree = tree_new(T_LITERAL);
84✔
79
      tree_set_subkind(tree, L_PHYSICAL);
84✔
80
      tree_set_ival(tree, value.integer);
84✔
81
   }
82
   else
83
      fatal_trace("cannot convert 0x%"PRIx64" to %s", value.integer,
×
84
                  type_pp(type));
85

86
   tree_set_type(tree, type);
8,989✔
87
   tree_set_loc(tree, loc);
8,989✔
88
   return tree;
8,989✔
89
}
90

91
static void *thunk_result_cb(jit_scalar_t *args, void *user)
9,154✔
92
{
93
   tree_t expr = user;
9,154✔
94
   type_t type = tree_type(expr);
9,154✔
95
   const loc_t *loc = tree_loc(expr);
9,154✔
96

97
   if (type_is_array(type)) {
9,154✔
98
      assert(dimension_of(type) == 1);
177✔
99

100
      type_t elem = type_elem(type);
177✔
101
      assert(type_is_scalar(elem));
177✔
102

103
      type_t base = type_base_recur(elem);
177✔
104

105
      bool all_chars = true;
177✔
106
      tree_t *lits LOCAL = NULL;
354✔
107
      if (type_is_enum(elem)) {
177✔
108
         const int nlits = type_enum_literals(base);
172✔
109
         lits = xcalloc_array(nlits, sizeof(tree_t));
172✔
110
      }
111
      else
112
         all_chars = false;
113

114
      range_kind_t dir;
177✔
115
      int64_t length, ileft, iright;
177✔
116
      if (!type_const_bounds(type)) {
177✔
117
         length = ffi_array_length(args[2].integer);
176✔
118
         dir = ffi_array_dir(args[2].integer);
176✔
119
         ileft = args[1].integer;
176✔
120
         iright = ffi_array_right(args[1].integer, args[2].integer);
275✔
121
      }
122
      else {
123
         tree_t r = range_of(type, 0);
1✔
124
         if (!folded_length(r, &length))
1✔
NEW
125
            fatal_at(loc, "cannot determine static length of array");
×
126

127
         dir = tree_subkind(r);
1✔
128
         ileft = assume_int(tree_left(r));
1✔
129
         iright = assume_int(tree_right(r));
1✔
130
      }
131

132
      const int bytes = (type_bit_width(elem) + 7) / 8;
177✔
133
      tree_t *elts LOCAL = xmalloc_array(length, sizeof(tree_t));
354✔
134
      for (int i = 0; i < length; i++) {
1,651✔
135
#define UNPACK_VALUE(type) do {                                    \
136
            value.integer = ((type *)args[0].pointer)[i];          \
137
         } while (0);
138

139
         jit_scalar_t value = { .integer = 0 };
1,474✔
140
         FOR_ALL_SIZES(bytes, UNPACK_VALUE);
1,474✔
141

142
         if (lits != NULL) {
1,474✔
143
            assert(value.integer >= 0);
1,462✔
144

145
            if (lits[value.integer] == NULL) {
1,462✔
146
               tree_t li = type_enum_literal(base, value.integer);
302✔
147
               lits[value.integer] = make_ref(li);
302✔
148
               all_chars &= ident_char(tree_ident(li), 0) == '\'';
302✔
149
            }
150

151
            elts[i] = lits[value.integer];
1,462✔
152
         }
153
         else
154
            elts[i] = eval_value_to_tree(value, elem, loc);
12✔
155
      }
156

157
      type_t sub = type_new(T_SUBTYPE);
177✔
158
      type_set_base(sub, type);
177✔
159

160
      type_t index_type = index_type_of(type, 0);
177✔
161

162
      tree_t left = NULL, right = NULL;
177✔
163
      if (type_is_enum(index_type)) {
177✔
NEW
164
         left = get_enum_lit(expr, index_type, ileft);
×
NEW
165
         right = get_enum_lit(expr, index_type, iright);
×
166
      }
167
      else {
168
         left = get_int_lit(expr, index_type, ileft);
177✔
169
         right = get_int_lit(expr, index_type, iright);
177✔
170
      }
171

172
      tree_t r = tree_new(T_RANGE);
177✔
173
      tree_set_subkind(r, dir);
177✔
174
      tree_set_left(r, left);
177✔
175
      tree_set_right(r, right);
177✔
176
      tree_set_loc(r, loc);
177✔
177
      tree_set_type(r, index_type);
177✔
178

179
      tree_t c = tree_new(T_CONSTRAINT);
177✔
180
      tree_set_subkind(c, C_INDEX);
177✔
181
      tree_add_range(c, r);
177✔
182
      tree_set_loc(c, loc);
177✔
183

184
      type_add_constraint(sub, c);
177✔
185

186
      if (all_chars) {
177✔
187
         tree_t tree = tree_new(T_STRING);
171✔
188

189
         for (int i = 0; i < length; i++)
1,631✔
190
            tree_add_char(tree, elts[i]);
1,460✔
191

192
         tree_set_loc(tree, loc);
171✔
193
         tree_set_type(tree, sub);
171✔
194
         return tree;
171✔
195
      }
196
      else {
197
         tree_t tree = tree_new(T_AGGREGATE);
6✔
198
         tree_set_type(tree, sub);
6✔
199
         tree_set_loc(tree, loc);
6✔
200

201
         for (int i = 0; i < length; i++) {
20✔
202
            tree_t a = tree_new(T_ASSOC);
14✔
203
            tree_set_loc(a, loc);
14✔
204
            tree_set_subkind(a, A_POS);
14✔
205
            tree_set_pos(a, i);
14✔
206
            tree_set_value(a, elts[i]);
14✔
207

208
            tree_add_assoc(tree, a);
14✔
209
         }
210

211
         return tree;
212
      }
213
   }
214
   else
215
      return eval_value_to_tree(args[0], tree_type(expr), tree_loc(expr));
8,977✔
216
}
217

218
static tree_t eval_do_fold(jit_t *jit, tree_t expr, lower_unit_t *parent,
10,662✔
219
                           void *context)
220
{
221
   vcode_unit_t thunk = lower_thunk(parent, expr);
10,662✔
222
   if (thunk == NULL)
10,662✔
223
      return expr;
224

225
   const bool verbose = opt_get_verbose(OPT_EVAL_VERBOSE, NULL);
9,573✔
226

227
   tree_t result = jit_call_thunk(jit, thunk, context, thunk_result_cb, expr);
9,573✔
228

229
   vcode_unit_unref(thunk);
9,570✔
230
   thunk = NULL;
9,570✔
231

232
   if (result != NULL) {
9,570✔
233
      if (verbose) {
9,154✔
234
         LOCAL_TEXT_BUF tb = tb_new();
×
235
         capture_syntax(tb);
×
236
         dump(result);
×
237
         capture_syntax(NULL);
×
238
         tb_strip(tb);
×
239

240
         debugf("evaluating %s returned %s", eval_expr_name(expr), tb_get(tb));
×
241
      }
242

243
      return result;
9,154✔
244
   }
245
   else if (verbose) {
416✔
246
      diag_t *d = diag_new(DIAG_DEBUG, tree_loc(expr));
×
247
      diag_printf(d, "failed to evaluate %s", eval_expr_name(expr));
×
248
      diag_emit(d);
×
249
   }
250

251
   return expr;
252
}
253

254
tree_t eval_try_fold(jit_t *jit, tree_t expr, lower_unit_t *parent,
10,612✔
255
                     void *context)
256
{
257
   const bool verbose = opt_get_verbose(OPT_EVAL_VERBOSE, NULL);
10,612✔
258
   jit_set_silent(jit, !verbose);
10,612✔
259

260
   tree_t result = eval_do_fold(jit, expr, parent, context);
10,612✔
261

262
   jit_set_silent(jit, false);
10,609✔
263

264
   return result;
10,609✔
265
}
266

267
tree_t eval_must_fold(jit_t *jit, tree_t expr, lower_unit_t *parent,
50✔
268
                      void *context)
269
{
270
   return eval_do_fold(jit, expr, parent, context);
50✔
271
}
272

273
static bool eval_not_possible(tree_t t, const char *why)
8,958✔
274
{
275
   if (opt_get_verbose(OPT_EVAL_VERBOSE, NULL))
8,958✔
276
      warn_at(tree_loc(t), "%s prevents constant folding", why);
×
277

278
   return false;
8,958✔
279
}
280

281
bool eval_possible(tree_t t, unit_registry_t *ur)
82,031✔
282
{
283
   switch (tree_kind(t)) {
92,479✔
284
   case T_FCALL:
44,628✔
285
      {
286
         const tree_flags_t flags = tree_flags(t);
44,628✔
287
         if (!(flags & (TREE_F_LOCALLY_STATIC | TREE_F_GLOBALLY_STATIC)))
44,628✔
288
            return eval_not_possible(t, "non-static expression");
987✔
289

290
         tree_t decl = tree_ref(t);
43,641✔
291
         const subprogram_kind_t kind = tree_subkind(decl);
43,641✔
292
         if (is_foreign(kind))
43,641✔
293
            return eval_not_possible(t, "call to foreign function");
57✔
294
         else if (tree_flags(decl) & TREE_F_IMPURE)
43,584✔
295
            return eval_not_possible(t, "call to impure function");
×
296
         else if (kind != S_USER && !is_open_coded_builtin(kind)
43,584✔
297
                  && unit_registry_get(ur, tree_ident2(decl)) == NULL)
4,033✔
298
            return eval_not_possible(t, "not yet lowered predef");
153✔
299
         else if (kind == S_USER && !is_package(tree_container(decl)))
43,431✔
300
            return eval_not_possible(t, "subprogram not in package");
651✔
301

302
         const int nparams = tree_params(t);
42,780✔
303
         for (int i = 0; i < nparams; i++) {
59,237✔
304
            tree_t p = tree_value(tree_param(t, i));
48,370✔
305
            if (!eval_possible(p, ur))
48,370✔
306
               return false;
307
            else if (tree_kind(p) == T_FCALL && type_is_scalar(tree_type(p)))
17,132✔
308
               return false;  // Would have been folded already if possible
309
         }
310

311
         return true;
312
      }
313

314
   case T_LITERAL:
315
   case T_STRING:
316
      return true;
317

318
   case T_TYPE_CONV:
3,908✔
319
      return eval_possible(tree_value(t), ur);
3,908✔
320

321
   case T_QUALIFIED:
2,298✔
322
      return eval_possible(tree_value(t), ur);
2,298✔
323

324
   case T_REF:
17,701✔
325
      {
326
         tree_t decl = tree_ref(t);
17,701✔
327
         switch (tree_kind(decl)) {
17,701✔
328
         case T_UNIT_DECL:
329
         case T_ENUM_LIT:
330
            return true;
331

332
         case T_CONST_DECL:
2,499✔
333
            if (tree_has_value(decl))
2,499✔
334
               return eval_possible(tree_value(decl), ur);
2,480✔
335
            else
336
               return false;
337

338
         default:
6,959✔
339
            return eval_not_possible(t, "reference");
6,959✔
340
         }
341
      }
342

343
   case T_RECORD_REF:
400✔
344
      return eval_possible(tree_value(t), ur);
400✔
345

346
   case T_ARRAY_REF:
1,422✔
347
      {
348
         const int nparams = tree_params(t);
1,422✔
349
         for (int i = 0; i < nparams; i++) {
2,807✔
350
            if (!eval_possible(tree_value(tree_param(t, i)), ur))
1,445✔
351
               return false;
352
         }
353

354
         return eval_possible(tree_value(t), ur);
1,362✔
355
      }
356

357
   case T_AGGREGATE:
1,611✔
358
      {
359
         const int nassocs = tree_assocs(t);
1,611✔
360
         for (int i = 0; i < nassocs; i++) {
10,365✔
361
            if (!eval_possible(tree_value(tree_assoc(t, i)), ur))
8,778✔
362
               return false;
363
         }
364

365
         return true;
366
      }
367

368
   case T_ATTR_REF:
3,240✔
369
      {
370
         if (tree_subkind(t) == ATTR_USER)
3,240✔
371
            return eval_not_possible(t, "user defined attribute");
×
372

373
         if (!eval_possible(tree_name(t), ur))
3,240✔
374
            return false;
375

376
         const int nparams = tree_params(t);
×
377
         for (int i = 0; i < nparams; i++) {
×
378
            if (!eval_possible(tree_value(tree_param(t, i)), ur))
×
379
               return false;
380
         }
381

382
         return true;
383
      }
384

385
   default:
151✔
386
      return eval_not_possible(t, tree_kind_str(tree_kind(t)));
151✔
387
   }
388
}
389

390
static void *case_result_cb(jit_scalar_t *args, void *user)
9✔
391
{
392
   jit_scalar_t *result = user;
9✔
393
   result->integer = args[0].integer;
9✔
394
   return result;
9✔
395
}
396

397
tree_t eval_case(jit_t *jit, tree_t stmt, lower_unit_t *parent, void *context)
9✔
398
{
399
   assert(tree_kind(stmt) == T_CASE_GENERATE);
9✔
400

401
   vcode_unit_t thunk = lower_case_generate_thunk(parent, stmt);
9✔
402

403
   jit_scalar_t result = { .integer = -1 };
9✔
404
   if (jit_call_thunk(jit, thunk, context, case_result_cb, &result) == NULL)
9✔
405
      error_at(tree_loc(tree_value(stmt)), "generate expression is not static");
×
406

407
   vcode_unit_unref(thunk);
9✔
408

409
   if (result.integer == -1)
9✔
410
      return NULL;
411
   else
412
      return tree_stmt(stmt, result.integer);
9✔
413
}
414

415
void *eval_instance(jit_t *jit, ident_t name, void *context)
6,955✔
416
{
417
   jit_handle_t h = jit_lazy_compile(jit, name);
6,955✔
418
   if (h == JIT_HANDLE_INVALID)
6,955✔
419
      fatal_trace("failed to compile instance %s", istr(name));
×
420

421
   jit_scalar_t result;
6,955✔
422
   if (!jit_try_call(jit, h, &result, context, context))
6,955✔
423
      return NULL;
424

425
   return result.pointer;
6,944✔
426
}
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