vmtester: Replace CLI11 with own command line args parsing

test/vmtester/CMakeLists.txt

@@ -19,7 +19,7 @@ add_test(NAME vmtester-help
     COMMAND evmc-vmtester --help
 )
 set_tests_properties(vmtester-help PROPERTIES
-    PASS_REGULAR_EXPRESSION "Options:"
+    PASS_REGULAR_EXPRESSION "Usage:"
 )
 
 add_test(NAME vmtester-nonexistingvm

test/vmtester/vmtester.cpp

@@ -6,8 +6,6 @@
 
 #include <evmc/loader.h>
 
-#include <CLI/CLI.hpp>
-
 #include <iostream>
 #include <memory>
 
@@ -32,28 +30,89 @@ int main(int argc, char* argv[])
 {
     try
     {
-        std::string vm_path;
+        const auto app_name = "EVMC VM Tester " PROJECT_VERSION;
 
-        CLI::App app{"EVMC VM Tester"};
-        app.add_option("vm", vm_path, "Path to the VM shared library to be tested");
         testing::InitGoogleTest(&argc, argv);
-        CLI11_PARSE(app, argc, argv);
 
-        std::cout << "Testing " << vm_path << "\n";
+        auto help = false;
+        auto version = false;
+
+        std::string evmc_module;
+        int num_args = 0;
+        for (int i = 1; i < argc; ++i)
+        {
+            auto arg = std::string{argv[i]};
+
+            auto x = arg.find_first_not_of('-');
+            if (x == 0)  // Argument.
+            {
+                ++num_args;
+                if (num_args > 1)
+                {
+                    std::cerr << "Unexpected argument \"" << arg << "\"\n";
+                    return -1;
+                }
+                evmc_module = std::move(arg);
+                continue;
+            }
+            else if (x <= 2)
+            {
+                arg.erase(0, x);
+
+                if (arg == "version")
+                {
+                    version = true;
+                    continue;
+                }
+                if (arg == "help")
+                {
+                    help = true;
+                    continue;
+                }
+            }
+
+            std::cerr << "Unknown option \"" << argv[i] << "\"\n";
+            return -1;
+        }
+
+        if (help)
+        {
+            std::cout << "\n"
+                      << app_name << "\n"
+                      << "Usage: " << argv[0] << " MODULE\n";
+            return 0;
+        }
+
+        if (version)
+        {
+            std::cout << app_name << "\n";
+            return 0;
+        }
+
+        if (num_args < 1)
+        {
+            std::cerr << "The MODULE argument is required.\n"
+                      << "Run with --help for more information.\n";
+            return -1;
+        }
+
+        std::cout << app_name << "\n";
+
+        std::cout << "Testing " << evmc_module << "\n";
         evmc_loader_error_code ec;
-        create_fn = evmc_load(vm_path.c_str(), &ec);
+        create_fn = evmc_load(evmc_module.c_str(), &ec);
         switch (ec)
         {
         case EVMC_LOADER_SUCCESS:
             break;
         case EVMC_LOADER_CANNOT_OPEN:
-            std::cerr << "Cannot open " << vm_path << "\n";
+            std::cerr << "Cannot open " << evmc_module << "\n";
             return static_cast<int>(ec);
         case EVMC_LOADER_SYMBOL_NOT_FOUND:
-            std::cerr << "EVMC create function not found in " << vm_path << "\n";
+            std::cerr << "EVMC create function not found in " << evmc_module << "\n";
             return static_cast<int>(ec);
         case EVMC_LOADER_INVALID_ARGUMENT:
-            std::cerr << "Invalid argument: \"" << vm_path << "\"\n";
+            std::cerr << "Invalid argument: \"" << evmc_module << "\"\n";
             return static_cast<int>(ec);
         default:
             std::cerr << "Unexpected error in evmc_load(): " << ec << "\n";
@@ -66,6 +125,6 @@ int main(int argc, char* argv[])
     catch (const std::exception& ex)
     {
         std::cerr << ex.what() << "\n";
-        return 1;
+        return -2;
     }
 }