Add Circom language support (#6204)

* add circom

* add circom grammar

* add circom grammar

* Apply suggestions from code review

Co-authored-by: Colin Seymour <colin@github.com>

* fix CI

---------

Co-authored-by: Colin Seymour <colin@github.com>

.gitmodules

@@ -368,6 +368,9 @@
 [submodule "vendor/grammars/chapel-tmbundle"]
 	path = vendor/grammars/chapel-tmbundle
 	url = https://github.com/chapel-lang/chapel-tmbundle
+[submodule "vendor/grammars/circom-highlighting-vscode"]
+	path = vendor/grammars/circom-highlighting-vscode
+	url = https://github.com/iden3/circom-highlighting-vscode.git
 [submodule "vendor/grammars/clarity.tmbundle"]
 	path = vendor/grammars/clarity.tmbundle
 	url = https://github.com/hirosystems/clarity.tmbundle.git

grammars.yml

@@ -304,6 +304,8 @@ vendor/grammars/ceylon-sublimetext:
 - source.ceylon
 vendor/grammars/chapel-tmbundle:
 - source.chapel
+vendor/grammars/circom-highlighting-vscode:
+- source.circom
 vendor/grammars/clarity.tmbundle:
 - source.clar
 vendor/grammars/cmake.tmbundle:

lib/linguist/languages.yml

@@ -1016,6 +1016,14 @@ ChucK:
   codemirror_mode: clike
   codemirror_mime_type: text/x-java
   language_id: 57
+Circom:
+  type: programming
+  ace_mode: text
+  extensions:
+  - ".circom"
+  color: "#707575"
+  tm_scope: source.circom
+  language_id: 1042332086
 Cirru:
   type: programming
   color: "#ccccff"

samples/Circom/binsum.circom

@@ -0,0 +1,101 @@
+/*
+    Copyright 2018 0KIMS association.
+
+    This file is part of circom (Zero Knowledge Circuit Compiler).
+
+    circom is a free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    circom is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+    License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with circom. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/*
+
+Binary Sum
+==========
+
+This component creates a binary sum componet of ops operands and n bits each operand.
+
+e is Number of carries: Depends on the number of operands in the input.
+
+Main Constraint:
+   in[0][0]     * 2^0  +  in[0][1]     * 2^1  + ..... + in[0][n-1]    * 2^(n-1)  +
+ + in[1][0]     * 2^0  +  in[1][1]     * 2^1  + ..... + in[1][n-1]    * 2^(n-1)  +
+ + ..
+ + in[ops-1][0] * 2^0  +  in[ops-1][1] * 2^1  + ..... + in[ops-1][n-1] * 2^(n-1)  +
+ ===
+   out[0] * 2^0  + out[1] * 2^1 +   + out[n+e-1] *2(n+e-1)
+
+To waranty binary outputs:
+
+    out[0]     * (out[0] - 1) === 0
+    out[1]     * (out[0] - 1) === 0
+    .
+    .
+    .
+    out[n+e-1] * (out[n+e-1] - 1) == 0
+
+ */
+
+
+/*
+    This function calculates the number of extra bits in the output to do the full sum.
+ */
+ pragma circom 2.0.0;
+
+function nbits(a) {
+    var n = 1;
+    var r = 0;
+    while (n-1<a) {
+        r++;
+        n *= 2;
+    }
+    return r;
+}
+
+
+template BinSum(n, ops) {
+    var nout = nbits((2**n -1)*ops);
+    signal input in[ops][n];
+    signal output out[nout];
+
+    var lin = 0;
+    var lout = 0;
+
+    var k;
+    var j;
+
+    var e2;
+
+    e2 = 1;
+    for (k=0; k<n; k++) {
+        for (j=0; j<ops; j++) {
+            lin += in[j][k] * e2;
+        }
+        e2 = e2 + e2;
+    }
+
+    e2 = 1;
+    for (k=0; k<nout; k++) {
+        out[k] <-- (lin >> k) & 1;
+
+        // Ensure out is binary
+        out[k] * (out[k] - 1) === 0;
+
+        lout += out[k] * e2;
+
+        e2 = e2+e2;
+    }
+
+    // Ensure the sum;
+
+    lin === lout;
+}

samples/Circom/switcher.circom

@@ -0,0 +1,43 @@
+
+/*
+    Copyright 2018 0KIMS association.
+
+    This file is part of circom (Zero Knowledge Circuit Compiler).
+
+    circom is a free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    circom is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+    License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with circom. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/*
+    Assume sel is binary.
+
+    If sel == 0 then outL = L and outR=R
+    If sel == 1 then outL = R and outR=L
+
+ */
+
+pragma circom 2.0.0;
+
+template Switcher() {
+    signal input sel;
+    signal input L;
+    signal input R;
+    signal output outL;
+    signal output outR;
+
+    signal aux;
+
+    aux <== (R-L)*sel;    // We create aux in order to have only one multiplication
+    outL <==  aux + L;
+    outR <== -aux + R;
+}

samples/Circom/xor3.circom

@@ -0,0 +1,45 @@
+/*
+    Copyright 2018 0KIMS association.
+
+    This file is part of circom (Zero Knowledge Circuit Compiler).
+
+    circom is a free software: you can redistribute it and/or modify it
+    under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    circom is distributed in the hope that it will be useful, but WITHOUT
+    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
+    License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with circom. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+/* Xor3 function for sha256
+
+out = a ^ b ^ c  =>
+
+out = a+b+c - 2*a*b - 2*a*c - 2*b*c + 4*a*b*c   =>
+
+out = a*( 1 - 2*b - 2*c + 4*b*c ) + b + c - 2*b*c =>
+
+mid = b*c
+out = a*( 1 - 2*b -2*c + 4*mid ) + b + c - 2 * mid
+
+*/
+pragma circom 2.0.0;
+
+template Xor3(n) {
+    signal input a[n];
+    signal input b[n];
+    signal input c[n];
+    signal output out[n];
+    signal mid[n];
+
+    for (var k=0; k<n; k++) {
+        mid[k] <== b[k]*c[k];
+        out[k] <== a[k] * (1 -2*b[k]  -2*c[k] +4*mid[k]) + b[k] + c[k] -2*mid[k];
+    }
+}

vendor/README.md

@@ -92,6 +92,7 @@ This is a list of grammars that Linguist selects to provide syntax highlighting
 - **Chapel:** [chapel-lang/chapel-tmbundle](https://github.com/chapel-lang/chapel-tmbundle)
 - **Checksums:** [Alhadis/language-etc](https://github.com/Alhadis/language-etc)
 - **ChucK:** [textmate/java.tmbundle](https://github.com/textmate/java.tmbundle)
+- **Circom:** [iden3/circom-highlighting-vscode](https://github.com/iden3/circom-highlighting-vscode)
 - **Cirru:** [Cirru/sublime-cirru](https://github.com/Cirru/sublime-cirru)
 - **Clarion:** [fushnisoft/SublimeClarion](https://github.com/fushnisoft/SublimeClarion)
 - **Clarity:** [hirosystems/clarity.tmbundle](https://github.com/hirosystems/clarity.tmbundle)

vendor/licenses/git_submodule/circom-highlighting-vscode.dep.yml

@@ -0,0 +1,31 @@
+---
+name: circom-highlighting-vscode
+version: 1e292d5457d9ba3a3e9832b5e4378cdd65a6cfb7
+type: git_submodule
+homepage: https://github.com/iden3/circom-highlighting-vscode.git
+license: mit
+licenses:
+- sources: COPYING
+  text: |-
+    MIT License
+
+    Copyright (c) 2022 0Kims Association <https://0kims.org>
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+notices: []