Tweak CLI interface

Add version option, return exit code 0 if `help` or `version`, clarify options

Champollion/main.cpp

@@ -36,7 +36,13 @@ struct Params
     std::vector<fs::path> inputs;
 };
 
-bool getProgramOptions(int argc, char* argv[], Params& params)
+enum OptionsResult{
+    Invalid = -1,
+    HelpOrVersion,
+    Good
+};
+
+OptionsResult getProgramOptions(int argc, char* argv[], Params& params)
 {
     params.outputAssembly = false;
     params.outputComment = false;
@@ -48,17 +54,19 @@ bool getProgramOptions(int argc, char* argv[], Params& params)
     params.assemblyDir = fs::current_path();
     params.papyrusDir = fs::current_path();
 
-    options::options_description desc("Champollion PEX decompiler V1.1.0");
+    std::string version_string = "Champollion PEX decompiler v1.1.0";
+    options::options_description desc(version_string);
     desc.add_options()
             ("help,h", "Display the help message")
-            ("asm,a", options::value<std::string>()->implicit_value(""), "Output assembly file(s) to this directory")
+            ("asm,a", options::value<std::string>()->implicit_value(""), "If defined, output assembly file(s) to this directory")
             ("psc,p", options::value<std::string>(), "Name of the output dir for psc decompilation")
             ("recreate-subdirs,s", "Recreates directory structure for script in root of output directory (Fallout 4 only, default false)")
             ("comment,c", "Output assembly in comments of the decompiled psc file")
             ("header,e", "Write header to decompiled psc file")
             ("threaded,t", "Run decompilation in parallel mode")
             ("trace,g", "Trace the decompilation and output results to rebuild log")
             ("no-dump-tree", "Do not dump tree for each node during decompilation tracing (requires --trace)")
+            ("version", "Output version number")
     ;
     options::options_description files;
     files.add_options()
@@ -80,13 +88,18 @@ bool getProgramOptions(int argc, char* argv[], Params& params)
     {
         std::cout << ex.what() << std::endl;
         std::cout << desc << std::endl;
-        return false;
+        return Invalid;
     }
 
     if (args.count("help"))
     {
         std::cout << desc;
-        return false;
+        return HelpOrVersion;
+    }
+    if (args.count("version"))
+    {
+        std::cout << version_string << std::endl;
+        return HelpOrVersion;
     }
 
     params.outputComment = (args.count("comment") != 0);
@@ -112,7 +125,7 @@ bool getProgramOptions(int argc, char* argv[], Params& params)
                 else if (!fs::is_directory(params.assemblyDir))
                 {
                     std::cout << params.assemblyDir << " is not a directory" << std::endl;
-                    return false;
+                    return Invalid;
                 }
             }
         }
@@ -128,14 +141,14 @@ bool getProgramOptions(int argc, char* argv[], Params& params)
             else if (!fs::is_directory(params.papyrusDir))
             {
                 std::cout << params.papyrusDir << " is not a directory" << std::endl;
-                return false;
+                return Invalid;
             }
         }
     }
     catch(const std::exception& ex)
     {
         std::cout << ex.what();
-        return false;
+        return Invalid;
     }
 
     if(args.count("input"))
@@ -158,9 +171,9 @@ bool getProgramOptions(int argc, char* argv[], Params& params)
     if (params.inputs.empty())
     {
         std::cout << "No input file given" << std::endl;
-        return false;
+        return Invalid;
     }
-    return true;
+    return Good;
 }
 
 typedef std::vector<std::string> ProcessResults;
@@ -238,7 +251,8 @@ int main(int argc, char* argv[])
 
     Params args;
     size_t countFiles = 0;
-    if (getProgramOptions(argc, argv, args))
+    auto result = getProgramOptions(argc, argv, args);
+    if (result == Good)
     {
         auto start = std::chrono::steady_clock::now();
         if(!args.parallel)
@@ -313,6 +327,9 @@ int main(int argc, char* argv[])
         std::cout << countFiles << " files processed in " << std::chrono::duration <double> (diff).count() << " s" << std::endl;
         return 0;
     }
+    if (result == HelpOrVersion){
+        return 0;
+    }
     return 1;
 }