circom/src/c_build.js
src/c_build.jsRaw
1/*
2 Copyright 2018 0KIMS association.
3
4 This file is part of circom (Zero Knowledge Circuit Compiler).
5
6 circom is a free software: you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
10
11 circom is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with circom. If not, see <https://www.gnu.org/licenses/>.
18*/
19
20const assert = require("assert");
21const bigInt = require("big-integer");
22const utils = require("./utils");
23const gen = require("./c_gen").gen;
24const createRefs = require("./c_gen").createRefs;
25const streamFromMultiArray = require("./stream_from_multiarray");
26
27module.exports = buildC;
28
29
30function buildC(ctx) {
31 ctx.definedFunctions = {};
32 ctx.functionCodes = [];
33 ctx.buildFunction = buildFunction;
34 ctx.code = "";
35 ctx.conditionalCodeHeader = "";
36 ctx.codes_sizes = [];
37 ctx.definedSizes = {};
38 ctx.addSizes = addSizes;
39 ctx.constants = [];
40 ctx.constantsMap = {};
41 ctx.addConstant = addConstant;
42 ctx.addConstant(bigInt.zero);
43 ctx.addConstant(bigInt.one);
44
45 const entryTables = buildEntryTables(ctx);
46 ctx.globalNames = ctx.uniqueNames;
47
48 const code = buildCode(ctx);
49 const functions = buildFuncFunctions(ctx);
50 const compnentsArray = buildComponentsArray(ctx);
51
52 const headder = buildHeader(ctx);
53 const sizes = buildSizes(ctx);
54 const constants = buildConstants(ctx);
55 const mapIsInput = buildMapIsInput(ctx);
56 const wit2Sig = buildWit2Sig(ctx);
57 const circuitVar = buildCircuitVar(ctx);
58
59 return streamFromMultiArray([
60 headder , "\n" ,
61 sizes , "\n" ,
62 constants , "\n" ,
63 entryTables , "\n" ,
64 functions , "\n" ,
65 code , "\n" ,
66 compnentsArray , "\n" ,
67 mapIsInput , "\n" ,
68 wit2Sig , "\n" ,
69 circuitVar
70 ]);
71}
72
73function buildEntryTables(ctx) {
74
75 const codes_hashMaps = [];
76 const codes_componentEntries = [];
77 const definedHashTables = {};
78 for (let i=0; i<ctx.components.length; i++) {
79 const {htName, htMap} = addHashTable(i);
80
81 let code = "";
82 const componentEntriesTableName = ctx.getUniqueName("_entryTable" + ctx.components[i].template);
83
84 code += `Circom_ComponentEntry ${componentEntriesTableName}[${htMap.length}] = {\n`;
85 for (let j=0; j<htMap.length; j++) {
86 const entry = ctx.components[i].names.o[htMap[j]];
87 code += j>0 ? " ," : " ";
88 const sizeName = ctx.addSizes(entry.sizes);
89
90 const ty = entry.type == "S" ? "_typeSignal" : "_typeComponent";
91 code += `{${entry.offset},${sizeName}, ${ty}}\n`;
92 }
93 code += "};\n";
94 codes_componentEntries.push(code);
95
96 ctx.components[i].htName = htName;
97 ctx.components[i].etName = componentEntriesTableName;
98 }
99
100
101 return [
102 "// HashMaps\n" ,
103 codes_hashMaps , "\n" ,
104 "\n" ,
105 "// Component Entries\n" ,
106 codes_componentEntries , "\n" ,
107 "\n"
108 ];
109
110 function addHashTable(cIdx) {
111 const keys = Object.keys(ctx.components[cIdx].names.o);
112 assert(keys.length<128);
113 keys.sort((a,b) => ((a>b) ? 1 : -1));
114 const h = utils.fnvHash(keys.join(","));
115 if (definedHashTables[h]) return definedHashTables[h];
116 definedHashTables[h] = {};
117 definedHashTables[h].htName = ctx.getUniqueName("_ht"+ctx.components[cIdx].template);
118 definedHashTables[h].htMap = [];
119 const t = [];
120 for (let i=0; i<keys.length; i++) {
121 definedHashTables[h].htMap[i] = keys[i];
122
123 const h2 = utils.fnvHash(keys[i]);
124 let pos = parseInt(h2.slice(-2), 16);
125 while (t[pos]) pos = (pos + 1) % 256;
126 t[pos] = [h2, i];
127 }
128 let code = `Circom_HashEntry ${definedHashTables[h].htName}[256] = {`;
129 for (let i=0; i<256; i++) {
130 code += i>0 ? "," : "";
131 if (t[i]) {
132 code += `{0x${t[i][0]}LL, ${t[i][1]}} /* ${keys[t[i][1]]} */`;
133 } else {
134 code += "{0,0}";
135 }
136 }
137 code += "};\n";
138
139 codes_hashMaps.push(code);
140
141 return definedHashTables[h];
142 }
143}
144
145function buildCode(ctx) {
146
147 const fDefined = {};
148
149 const fnComponents = [];
150 for (let i=0; i<ctx.components.length; i++) {
151 const {h, instanceDef} = hashComponentCall(ctx, i);
152 const fName = ctx.components[i].template+"_"+h;
153 if (!fDefined[fName]) {
154
155
156 ctx.scopes = [{}];
157 ctx.conditionalCode = false;
158 ctx.code = "";
159 ctx.codeHeader = "// Header\n";
160 ctx.codeFooter = "// Footer\n";
161 ctx.uniqueNames = Object.assign({},ctx.globalNames);
162 ctx.refs = [];
163 ctx.fileName = ctx.templates[ctx.components[i].template].fileName;
164 ctx.filePath = ctx.templates[ctx.components[i].template].filePath;
165
166 for (let p in ctx.components[i].params) {
167 if (ctx.scopes[0][p]) return ctx.throwError(`Repeated parameter at ${ctx.components[i].template}: ${p}`);
168 const refId = ctx.refs.length;
169 ctx.refs.push({
170 type: "BIGINT",
171 used: false,
172 value: utils.flatArray(ctx.components[i].params[p]),
173 sizes: utils.accSizes(utils.extractSizes(ctx.components[i].params[p])),
174 label: ctx.getUniqueName(p)
175 });
176 ctx.scopes[0][p] = refId;
177 }
178
179 createRefs(ctx, ctx.templates[ctx.components[i].template].block);
180 if (ctx.error) return;
181
182 gen(ctx, ctx.templates[ctx.components[i].template].block);
183 if (ctx.error) return;
184
185 const S =
186 "/*\n" +
187 instanceDef +
188 "\n*/\n" +
189 `void ${fName}(Circom_CalcWit *ctx, int __cIdx) {\n` +
190 utils.ident(
191 ctx.codeHeader + "\n" +
192 ctx.code + "\n" +
193 "ctx->finished(__cIdx);\n" +
194 ctx.codeFooter
195 ) +
196 "}\n";
197
198 fnComponents.push(S);
199 fDefined[fName] = true;
200 }
201 ctx.components[i].fnName = fName;
202 }
203
204 return fnComponents;
205}
206
207function buildFuncFunctions(ctx) {
208 if (ctx.functionCodes) {
209 return ["// Functions\n" ,
210 ctx.functionCodes
211 ];
212 } else {
213 return "";
214 }
215
216}
217
218function buildComponentsArray(ctx) {
219
220 const ccodes = [];
221 ccodes.push(`Circom_Component _components[${ctx.components.length}] = {\n`);
222 for (let i=0; i< ctx.components.length; i++) {
223 let newThread;
224 if (ctx.newThreadTemplates) {
225 if (ctx.newThreadTemplates.test(ctx.components[i].template)) {
226 newThread = "true";
227 } else {
228 newThread = "false";
229 }
230 } else {
231 newThread = "false";
232 }
233 ccodes.push(i>0 ? " ," : " ");
234 ccodes.push(`{${ctx.components[i].htName},${ctx.components[i].etName},${ctx.components[i].fnName}, ${ctx.components[i].nInSignals}, ${newThread}}\n`);
235 }
236 ccodes.push("};\n");
237
238 return [
239 "// Components\n" ,
240 ccodes , "\n"
241 ];
242}
243
244
245function buildHeader(ctx) {
246 return "#include \"circom.h\"\n" +
247 "#include \"calcwit.h\"\n" +
248 `#define NSignals ${ctx.signals.length}\n` +
249 `#define NComponents ${ctx.components.length}\n` +
250 `#define NInputs ${ctx.components[ ctx.getComponentIdx("main") ].nInSignals}\n`+
251 `#define NOutputs ${ctx.totals[ ctx.stOUTPUT ]}\n`+
252 `#define NVars ${ctx.totals[ctx.stONE] + ctx.totals[ctx.stOUTPUT] + ctx.totals[ctx.stPUBINPUT] + ctx.totals[ctx.stPRVINPUT] + ctx.totals[ctx.stINTERNAL]}\n` +
253 `#define __P__ "${ctx.field.p.toString()}"\n` +
254 "\n";
255}
256
257function buildSizes(ctx) {
258 return [
259 "// Sizes\n" ,
260 ctx.codes_sizes
261 ];
262}
263
264function buildConstants(ctx) {
265 const n64 = Math.floor((ctx.field.p.bitLength() - 1) / 64)+1;
266 const R = bigInt.one.shiftLeft(n64*64);
267
268 const lines = [];
269 lines.push("// Constants\n");
270 lines.push(`FrElement _constants[${ctx.constants.length}] = {\n`);
271 for (let i=0; i<ctx.constants.length; i++) {
272 lines.push((i>0 ? "," : " ") + "{" + number2Code(ctx.constants[i]) + "}\n");
273 }
274 lines.push("};\n");
275
276 return lines;
277
278 function number2Code(n) {
279 if (n.lt(bigInt("80000000", 16)) ) {
280 return addShortMontgomeryPositive(n);
281 }
282 if (n.geq(ctx.field.p.minus(bigInt("80000000", 16))) ) {
283 return addShortMontgomeryNegative(n);
284 }
285 return addLongMontgomery(n);
286
287
288 function addShortMontgomeryPositive(a) {
289 return `${a.toString()}, 0x40000000, { ${getLongString(toMontgomery(a))} }`;
290 }
291
292
293 function addShortMontgomeryNegative(a) {
294 const b = a.minus(ctx.field.p);
295 return `${b.toString()}, 0x40000000, { ${getLongString(toMontgomery(a))} }`;
296 }
297
298 function addLongMontgomery(a) {
299 return `0, 0xC0000000, { ${getLongString(toMontgomery(a))} }`;
300 }
301
302 function getLongString(a) {
303 let r = bigInt(a);
304 let S = "";
305 let i = 0;
306 while (!r.isZero()) {
307 if (S!= "") S = S+",";
308 S += "0x" + r.and(bigInt("FFFFFFFFFFFFFFFF", 16)).toString(16) + "LL";
309 i++;
310 r = r.shiftRight(64);
311 }
312 while (i<n64) {
313 if (S!= "") S = S+",";
314 S += "0LL";
315 i++;
316 }
317 return S;
318 }
319
320 function toMontgomery(a) {
321 return a.times(R).mod(ctx.field.p);
322 }
323
324 }
325}
326
327
328function buildMapIsInput(ctx) {
329 const arr = [];
330 let line = "";
331 let acc = 0;
332 let i;
333 for (i=0; i<ctx.signals.length; i++) {
334 if (ctx.signals[i].o & ctx.IN) {
335 acc = acc | (1 << (i%32) );
336 }
337 if ((i+1)%32==0) {
338 line += (i>31) ? "," : " ";
339 line += toHex(acc);
340 acc = 0;
341 if ( (i+1) % (32*64) == 0) {
342 arr.push(line);
343 line = "";
344 }
345 }
346 }
347
348 if ((i%32) != 0) {
349 line += (i>31) ? "," : " ";
350 line += toHex(acc);
351 }
352 if (line != "") {
353 arr.push(line);
354 }
355
356 return ["// mapIsArray\n" ,
357 `u32 _mapIsInput[${Math.floor((ctx.signals.length-1) / 32)+1}] = {\n`,
358 arr, "\n" ,
359 "};\n"
360 ];
361
362 function toHex(number) {
363 if (number < 0) number = 0xFFFFFFFF + number + 1;
364 let S=number.toString(16).toUpperCase();
365 while (S.length<8) S = "0" + S;
366 return "0x"+S;
367 }
368}
369
370
371function buildWit2Sig(ctx) {
372 const codes = [];
373 const NVars =
374 ctx.totals[ctx.stONE] +
375 ctx.totals[ctx.stOUTPUT] +
376 ctx.totals[ctx.stPUBINPUT] +
377 ctx.totals[ctx.stPRVINPUT] +
378 ctx.totals[ctx.stINTERNAL];
379 const arr = Array(NVars);
380 for (let i=0; i<ctx.signals.length; i++) {
381 const outIdx = ctx.signals[i].id;
382 if (ctx.signals[i].e>=0) continue; // If has an alias, continue..
383 assert(typeof outIdx != "undefined", `Signal ${i} does not have index`);
384 if (outIdx>=NVars) continue; // Is a constant or a discarded variable
385 if (typeof arr[ctx.signals[i].id] == "undefined") {
386 arr[outIdx] = i;
387 }
388 }
389 codes.push("// Signal Table\n");
390 codes.push(`int _wit2sig[${NVars}] = {\n`);
391 let code = "";
392 for (let i=0; i<NVars; i++) {
393 code += (i>0) ? ",": " ";
394 code += arr[i];
395 if ((i>0)&&(i%64 == 0)) {
396 if (code != "") {
397 codes.push(code + "\n");
398 } else {
399 codes.push(code);
400 }
401 code ="";
402 }
403 }
404 if (code != "") codes.push(code + "\n");
405 codes.push("};\n");
406
407 return codes;
408
409}
410
411
412function buildCircuitVar() {
413 return "Circom_Circuit _circuit = {\n" +
414 " NSignals,\n"+
415 " NComponents,\n"+
416 " NInputs,\n"+
417 " NOutputs,\n"+
418 " NVars,\n"+
419 " _wit2sig,\n"+
420 " _components,\n"+
421 " _mapIsInput,\n"+
422 " _constants,\n" +
423 " __P__\n" +
424 "};\n";
425}
426
427
428
429
430function addSizes(_sizes) {
431 const sizes = _sizes || [];
432 let name = "sizes";
433 for (let i=0; i<sizes.length;i++) {
434 name+="_"+sizes[i];
435 }
436 if (name=="sizes") name="sizes_0";
437
438 if (this.definedSizes[name]) return this.definedSizes[name];
439 const labelName = this.getUniqueName(name);
440 this.definedSizes[name] = labelName;
441
442 const accSizes = utils.accSizes(sizes);
443
444 let code = `Circom_Size ${labelName}[${accSizes.length}] = {`;
445 for (let i=0; i<accSizes.length; i++) {
446 if (i>0) code += ",";
447 code += accSizes[i];
448 }
449 code += "};\n";
450 this.codes_sizes.push(code);
451
452 return labelName;
453}
454
455function addConstant(c) {
456 c = bigInt(c);
457 const s = c.toString();
458 if (typeof (this.constantsMap[s]) !== "undefined") return this.constantsMap[s];
459 const newId = this.constants.length;
460 this.constants.push(c);
461 this.constantsMap[s] = newId;
462 return newId;
463}
464
465function buildFunction(name, paramValues) {
466 const ctx = this;
467 const {h, instanceDef} = hashFunctionCall(ctx, name, paramValues);
468
469 if (ctx.definedFunctions[h]) return ctx.definedFunctions[h];
470
471 const res = {
472 fnName: `${name}_${h}`
473 };
474
475 const oldRefs = ctx.refs;
476 const oldConditionalCode = ctx.conditionalCode;
477 const oldCode = ctx.code;
478 const oldCodeHeader = ctx.codeHeader;
479 const oldCodeFooter = ctx.codeFooter;
480 const oldUniqueNames = ctx.uniqueNames;
481 const oldFileName = ctx.fileName;
482 const oldFilePath = ctx.oldFilePath;
483 const oldReturnSizes = ctx.returnSizes;
484 const oldReturnValue = ctx.returnValue;
485
486
487 ctx.scopes = [{}];
488 ctx.refs = [];
489 ctx.conditionalCode = false;
490 ctx.code = "";
491 ctx.codeHeader = "// Header\n";
492 ctx.codeFooter = "// Footer\n";
493 ctx.uniqueNames = Object.assign({},ctx.globalNames);
494 ctx.returnValue = null;
495 ctx.returnSizes = null;
496 ctx.fileName = ctx.functions[name].fileName;
497 ctx.filePath = ctx.functions[name].filePath;
498
499 let paramsStr = "";
500
501 for (let i=0; i<ctx.functions[name].params.length; i++) {
502
503 if (paramValues[i].used) {
504 paramsStr += `,PFrElement ${ctx.functions[name].params[i]}`;
505 const idRef = ctx.refs.length;
506 ctx.refs.push({
507 type: "BIGINT",
508 used: true,
509 sizes: paramValues[i].sizes,
510 label: ctx.functions[name].params[i],
511 });
512 ctx.scopes[0][ctx.functions[name].params[i]] = idRef;
513 } else {
514 const idRef = ctx.refs.length;
515 ctx.refs.push({
516 type: "BIGINT",
517 used: false,
518 sizes: paramValues[i].sizes,
519 label: ctx.functions[name].params[i],
520 value: paramValues[i].value
521 });
522 ctx.scopes[0][ctx.functions[name].params[i]] = idRef;
523 }
524 }
525
526 createRefs(ctx, ctx.functions[name].block);
527 if (ctx.error) return;
528
529 gen(ctx, ctx.functions[name].block);
530 if (ctx.error) return;
531
532 if (ctx.returnValue == null) {
533 if (ctx.returnSizes == null) assert(false, `Funciont ${name} does not return any value`);
534 res.type = "VARVAL_CONSTSIZE";
535 let code =
536 "/*\n" +
537 instanceDef +
538 "\n*/\n" +
539 `void ${name}_${h}(Circom_CalcWit *ctx, PFrElement __retValue ${paramsStr}) {`;
540 code += utils.ident(ctx.codeHeader);
541 code += utils.ident(ctx.code);
542 code += utils.ident("returnFunc:\n");
543 code += utils.ident(ctx.codeFooter);
544 code += utils.ident(";\n");
545 code += "}\n";
546 res.returnSizes = ctx.returnSizes;
547 ctx.functionCodes.push(code);
548 } else {
549 res.type = "CONSTVAL";
550 res.returnValue = ctx.returnValue;
551 res.returnSizes = ctx.returnSizes;
552 }
553
554 ctx.refs = oldRefs;
555 ctx.conditionalCode = oldConditionalCode;
556 ctx.code = oldCode;
557 ctx.codeHeader = oldCodeHeader;
558 ctx.codeFooter = oldCodeFooter;
559 ctx.uniqueNames = oldUniqueNames;
560 ctx.fileName = oldFileName;
561 ctx.filePath = oldFilePath;
562 ctx.returnSizes = oldReturnSizes;
563 ctx.returnValue = oldReturnValue;
564
565 ctx.definedFunctions[h] = res;
566
567 return res;
568}
569
570
571
572function hashComponentCall(ctx, cIdx) {
573 // TODO: At the moment generate a diferent function for each instance of the component
574 const constParams = [];
575 for (let p in ctx.components[cIdx].params) {
576 constParams.push(p + "=" + value2str(ctx.components[cIdx].params[p]));
577 }
578
579 for (let n in ctx.components[cIdx].names.o) {
580 const entry = ctx.components[cIdx].names.o[n];
581 if ((entry.type == "S")&&(ctx.signals[entry.offset].o & ctx.IN)) {
582 travelSizes(n, entry.offset, entry.sizes, (prefix, offset) => {
583 if (utils.isDefined(ctx.signals[offset].v)) {
584 constParams.push(prefix + "=" + bigInt(ctx.signals[offset].value));
585 }
586 });
587 }
588 }
589
590 let instanceDef = ctx.components[cIdx].template;
591 if (constParams.length>0) {
592 instanceDef += "\n";
593 constParams.sort();
594 instanceDef += constParams.join("\n");
595 }
596 const h = utils.fnvHash(instanceDef);
597 return {h, instanceDef};
598
599 function travelSizes(prefix, offset, sizes, fn) {
600 if (sizes.length == 0) {
601 fn(prefix, offset);
602 return 1;
603 } else {
604 let o = offset;
605 for (let i=0; i<sizes[0]; i++) {
606 o += travelSizes(prefix + "[" + i + "]", o, sizes.slice(1), fn);
607 }
608 return o-offset;
609 }
610 }
611}
612
613function hashFunctionCall(ctx, name, paramValues) {
614 // TODO
615 const constParams = [];
616 for (let i=0; i<ctx.functions[name].params.length; i++) {
617 if (!paramValues[i].used) {
618 constParams.push(ctx.functions[name].params[i] + utils.accSizes2Str(paramValues[i].sizes) + "=" + value2str(paramValues[i].value));
619 }
620 }
621 let instanceDef = name;
622 if (constParams.length>0) {
623 instanceDef += "\n";
624 constParams.sort();
625 instanceDef += constParams.join("\n");
626 }
627
628 const h = utils.fnvHash(instanceDef);
629 return {h, instanceDef};
630}
631
632function value2str(v) {
633 if (Array.isArray(v)) {
634 let S="[";
635 for (let i=0; i<v.length; i++) {
636 if (i>0) S+=",";
637 S+=value2str(v[i]);
638 }
639 S+="]";
640 return S;
641 } else {
642 return bigInt(v).toString();
643 }
644}