Make it possible to check that an implementation is supported at runtime (#1197)

* Make it possible to check that an implementation is supported at runtime.

* add CI fuzzing on arm 64 bit

This adds fuzzing on drone.io arm64

For some reason, leak detection had to be disabled. If it is enabled, the fuzzer falsely reports a crash at the end of fuzzing.

Closes: #1188

* Guarding the implementation accesses.

* Better doc.

* Updating cxxopts.

* Make it possible to check that an implementation is supported at runtime.

* Guarding the implementation accesses.

* Better doc.

* Updating cxxopts.

* We need to accomodate cxxopts

Co-authored-by: Paul Dreik <github@pauldreik.se>

benchmark/benchfeatures.cpp

@@ -96,8 +96,14 @@ struct option_struct {
       case 'v':
         verbose = true;
         break;
-      case 'a':
-        simdjson::active_implementation = simdjson::available_implementations[optarg];
+      case 'a': {
+          auto impl = simdjson::available_implementations[optarg];
+          if(impl && impl->supported_by_runtime_system()) {
+            simdjson::active_implementation = impl; 
+          } else { 
+            std::cerr << "implementation " << optarg << " not found or not supported " << std::endl;
+          }
+        } 
         break;
       case 's':
         if (!strcmp(optarg, "stage1")) {

benchmark/minifiercompetition.cpp

@@ -125,9 +125,11 @@ int main(int argc, char *argv[]) {
   size_t outlength;
   uint8_t *cbuffer = (uint8_t *)buffer;
   for (auto imple : simdjson::available_implementations) {
-    BEST_TIME((std::string("simdjson->minify+")+imple->name()).c_str(), (imple->minify(cbuffer, p.size(), cbuffer, outlength) == simdjson::SUCCESS ? outlength : -1),
+    if(imple->supported_by_runtime_system()) {
+      BEST_TIME((std::string("simdjson->minify+")+imple->name()).c_str(), (imple->minify(cbuffer, p.size(), cbuffer, outlength) == simdjson::SUCCESS ? outlength : -1),
             outlength, memcpy(buffer, p.data(), p.size()), repeat, volume,
             !just_data);
+    }
   }
 
   printf("minisize = %zu, original size = %zu  (minified down to %.2f percent "

benchmark/parse.cpp

@@ -67,7 +67,9 @@ void print_usage(ostream& out) {
   out << "-a IMPL      - Use the given parser implementation. By default, detects the most advanced" << endl;
   out << "               implementation supported on the host machine." << endl;
   for (auto impl : simdjson::available_implementations) {
-    out << "-a " << std::left << std::setw(9) << impl->name() << " - Use the " << impl->description() << " parser implementation." << endl;
+    if(impl->supported_by_runtime_system()) {
+      out << "-a " << std::left << std::setw(9) << impl->name() << " - Use the " << impl->description() << " parser implementation." << endl;
+    }
   }
 }
 
@@ -115,11 +117,13 @@ struct option_struct {
         break;
       case 'a': {
         const implementation *impl = simdjson::available_implementations[optarg];
-        if (!impl) {
+        if ((!impl) || (!impl->supported_by_runtime_system())) {
           std::string exit_message = string("Unsupported option value -a ") + optarg + ": expected -a  with one of ";
           for (auto imple : simdjson::available_implementations) {
-            exit_message += imple->name();
-            exit_message += " ";
+            if(imple->supported_by_runtime_system()) {
+              exit_message += imple->name();
+              exit_message += " ";
+            }
           }
           exit_usage(exit_message);
         }