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>

tools/json2json.cpp

@@ -9,7 +9,11 @@ SIMDJSON_PUSH_DISABLE_ALL_WARNINGS
 #include "cxxopts.hpp"
 SIMDJSON_POP_DISABLE_WARNINGS
 
+#if CXXOPTS__VERSION_MAJOR < 3 
 int main(int argc, char *argv[]) {
+#else
+int main(int argc, const char *argv[]) {
+#endif
 #ifdef __cpp_exceptions
   try {
 #endif

tools/jsonstats.cpp

@@ -188,8 +188,11 @@ stat_t simdjson_compute_stats(const simdjson::padded_string &p) {
   recurse(doc, s, 0);
   return s;
 }
-
+#if CXXOPTS__VERSION_MAJOR < 3 
 int main(int argc, char *argv[]) {
+#else
+int main(int argc, const char *argv[]) {
+#endif
 #ifdef __cpp_exceptions
   try {
 #endif

tools/minify.cpp

@@ -20,7 +20,11 @@ void usage(std::string message) {
   std::cerr << options.help() << std::endl;
 }
 
+#if CXXOPTS__VERSION_MAJOR < 3 
 int main(int argc, char *argv[]) {
+#else
+int main(int argc, const char *argv[]) {
+#endif
 #ifdef __cpp_exceptions
   try {
 #endif
@@ -28,7 +32,9 @@ int main(int argc, char *argv[]) {
   ss << "Parser implementation (by default, detects the most advanced implementation supported on the host machine)."  << std::endl;
   ss << "Available parser implementations:" << std::endl;
   for (auto impl : simdjson::available_implementations) {
-    ss << "-a " << std::left << std::setw(9) << impl->name() << " - Use the " << impl->description() << " parser implementation." << std::endl;
+    if(impl->supported_by_runtime_system()) {
+      ss << "-a " << std::left << std::setw(9) << impl->name() << " - Use the " << impl->description() << " parser implementation." << std::endl;
+    }
   }
   options.add_options()
     ("a,arch", ss.str(), cxxopts::value<std::string>())
@@ -54,6 +60,10 @@ int main(int argc, char *argv[]) {
       usage("Unsupported implementation.");
       return EXIT_FAILURE;
     }
+    if(!impl->supported_by_runtime_system()) {
+      usage("The selected implementation does not match your current CPU.");
+      return EXIT_FAILURE;
+    }
     simdjson::active_implementation = impl;
   }