feat: Add info command to bb (#2010)

Resolves #1922 
Resolves #1923 

# Checklist:
Remove the checklist to signal you've completed it. Enable auto-merge if
the PR is ready to merge.
- [ ] If the pull request requires a cryptography review (e.g.
cryptographic algorithm implementations) I have added the 'crypto' tag.
- [ ] I have reviewed my diff in github, line by line and removed
unexpected formatting changes, testing logs, or commented-out code.
- [ ] Every change is related to the PR description.
- [ ] I have
[linked](https://docs.github.com/en/issues/tracking-your-work-with-issues/linking-a-pull-request-to-an-issue)
this pull request to relevant issues (if any exist).

---------

Co-authored-by: Tom French <[email protected]>

cpp/src/barretenberg/bb/main.cpp

@@ -269,6 +269,39 @@ void vkAsFields(const std::string& vk_path, const std::string& output_path)
     }
 }
 
+/**
+ * @brief Returns ACVM related backend information
+ *
+ * Communication:
+ * - stdout: The json string is written to stdout
+ * - Filesystem: The json string is written to the path specified
+ *
+ * @param output_path Path to write the information to
+ */
+void acvmInfo(const std::string& output_path)
+{
+
+    const char* jsonData = R"({
+    "language": {
+        "name" : "PLONK-CSAT",
+        "width" : 3
+    },
+    "opcodes_supported" : ["arithmetic", "directive", "brillig", "memory_init", "memory_op"],
+    "black_box_functions_supported" : ["and", "xor", "range", "sha256", "blake2s", "keccak256", "schnorr_verify", "pedersen", "hash_to_field_128_security", "ecdsa_secp256k1", "ecdsa_secp256r1", "fixed_base_scalar_mul", "recursive_aggregation"]
+    })";
+
+    size_t length = strlen(jsonData);
+    std::vector<uint8_t> data(jsonData, jsonData + length);
+
+    if (output_path == "-") {
+        writeRawBytesToStdout(data);
+        vinfo("info written to stdout");
+    } else {
+        write_file(output_path, data);
+        vinfo("info written to: ", output_path);
+    }
+}
+
 bool flagPresent(std::vector<std::string>& args, const std::string& flag)
 {
     return std::find(args.begin(), args.end(), flag) != args.end();
@@ -322,6 +355,9 @@ int main(int argc, char* argv[])
         } else if (command == "vk_as_fields") {
             std::string output_path = getOption(args, "-o", vk_path + "_fields.json");
             vkAsFields(vk_path, output_path);
+        } else if (command == "info") {
+            std::string output_path = getOption(args, "-o", "info.json");
+            acvmInfo(output_path);
         } else {
             std::cerr << "Unknown command: " << command << "\n";
             return 1;

ts/src/info.json

@@ -0,0 +1,22 @@
+{
+  "language": {
+    "name": "PLONK-CSAT",
+    "width": 3
+  },
+  "opcodes_supported": ["arithmetic", "directive", "brillig", "memory_init", "memory_op"],
+  "black_box_functions_supported": [
+    "and",
+    "xor",
+    "range",
+    "sha256",
+    "blake2s",
+    "keccak256",
+    "schnorr_verify",
+    "pedersen",
+    "hash_to_field_128_security",
+    "ecdsa_secp256k1",
+    "ecdsa_secp256r1",
+    "fixed_base_scalar_mul",
+    "recursive_aggregation"
+  ]
+}

ts/src/main.ts

@@ -4,7 +4,7 @@ import createDebug from 'debug';
 import { readFileSync, writeFileSync } from 'fs';
 import { gunzipSync } from 'zlib';
 import { Command } from 'commander';
-
+import acvmInfoJson from './info.json' assert { type: 'json' };
 createDebug.log = console.error.bind(console);
 const debug = createDebug('bb.js');
 
@@ -132,6 +132,17 @@ export async function gateCount(bytecodePath: string) {
   }
 }
 
+export function acvmInfo(outputPath: string) {
+  const stringifiedJson = JSON.stringify(acvmInfoJson, null, 2);
+  if (outputPath === '-') {
+    process.stdout.write(stringifiedJson);
+    debug(`info written to stdout`);
+  } else {
+    writeFileSync(outputPath, stringifiedJson);
+    debug(`info written to: ${outputPath}`);
+  }
+}
+
 export async function verify(proofPath: string, isRecursive: boolean, vkPath: string) {
   const { api, acirComposer } = await initLite();
   try {
@@ -333,4 +344,13 @@ program
     await vkAsFields(vkPath, outputPath);
   });
 
+program
+  .command('info')
+  .description('Return ACVM related metadata about the backend')
+  .requiredOption('-o, --output-path <path>', 'Specify the path to write the JSON information to')
+  .action(({ outputPath }) => {
+    handleGlobalOptions();
+    acvmInfo(outputPath);
+  });
+
 program.name('bb.js').parse(process.argv);

ts/tsconfig.json

@@ -17,5 +17,5 @@
     "rootDir": "src",
     "tsBuildInfoFile": ".tsbuildinfo"
   },
-  "include": ["src"]
+  "include": ["src", "src/info.json"]
 }