ddr: check for common DLL errors (#355)

## Link to GitHub Issue, if one exists
#345 

## Description of change
Check if the path to codecs directory contains non-ASCII characters, and
display a giant warning. This is to help with troubleshooting, since
registration of xactengine silently fails (creates a bad registry entry)
if the path contains non-ASCII chars.

Log the size of codec DLLs, and log any failures from `regsvr32`.

Detect the case where user specified `-exec gamemdx.dll` for DDR which
seems to be a common pitfall. This doesn't work because gamemdx.dll does
not have a DLL entry, but for some reason people are really tempted to
do this.

## Testing
Validated the error cases.

src/spice2x/avs/game.cpp

@@ -80,7 +80,7 @@ namespace avs {
             if (130 <= dll_path_s.length()) {
                 log_warning(
                     "avs-game",
-                    "PATH TOO LONG WARNING\n\n\n"
+                    "PATH TOO LONG WARNING\n\n"
                     "-------------------------------------------------------------------\n"
                     "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n"
                     "WARNING - WARNING - WARNING - WARNING - WARNING - WARNING - WARNING\n"
@@ -95,10 +95,26 @@ namespace avs {
                     "-------------------------------------------------------------------\n\n",
                     dll_path_s, dll_path_s.length());
             }
+
+            // ddr gamemdx.dll user error
+            if (avs::game::is_model("MDX") && DLL_NAME == "gamemdx.dll") {
+                log_fatal(
+                    "ddr",
+                    "BAD GAME DLL ERROR\n\n"
+                    "!!!                                                            !!!\n"
+                    "!!! -exec gamemdx.dll was specified                            !!!\n"
+                    "!!! this is the wrong DLL; the game will not load              !!!\n"
+                    "!!! remove -exec argument and try again.                       !!!\n"
+                    "!!!                                                            !!!\n"
+                    );
+            }
+
+            // file not found on disk
             if (!fileutils::file_exists(dll_path)) {
                 log_warning("avs-game", "game DLL could not be found on disk: {}", dll_path.string().c_str());
                 log_warning("avs-game", "double check -exec and -modules parameters; unless you know what you're doing, leave them blank");
             }
+
             if (fileutils::verify_header_pe(dll_path)) {
                 DLL_INSTANCE = libutils::load_library(dll_path);
             }
@@ -106,7 +122,7 @@ namespace avs {
             // load entry points
             dll_entry_init = (ENTRY_INIT_T) libutils::get_proc(DLL_INSTANCE, ENTRY_INIT_NAME);
             dll_entry_main = (ENTRY_MAIN_T) libutils::get_proc(DLL_INSTANCE, ENTRY_MAIN_NAME);
-            log_info("avs-game", "loaded successfully ({})", fmt::ptr(DLL_INSTANCE));
+            log_info("avs-game", "loaded {} successfully ({})", DLL_NAME, fmt::ptr(DLL_INSTANCE));
         }
 
         bool entry_init(char *sid_code, void *app_param) {

src/spice2x/games/ddr/ddr.cpp

@@ -50,6 +50,15 @@ namespace games::ddr {
         return SendMessage_real(hWnd, Msg, wParam, lParam);
     }
 
+    bool contains_only_ascii(const std::string& str) {
+        for (auto c: str) {
+            if (static_cast<unsigned char>(c) > 127) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     DDRGame::DDRGame() : Game("Dance Dance Revolution") {
     }
 
@@ -82,7 +91,7 @@ namespace games::ddr {
                 continue;
             }
 
-            log_info("ddr", "found DLL: {}", filename.string());
+            log_info("ddr", "found DLL: {}, size: {} bytes", filename.string(), file.file_size());
             if (filename == "k-clvsd.dll" || filename.string().find("xactengine") == 0) {
                 const std::wstring wcmd = L"regsvr32.exe /s \"" + file.path().wstring() + L"\"";
                 const std::string cmd = "regsvr32.exe /s \"" + file.path().string() + "\"";
@@ -92,7 +101,23 @@ namespace games::ddr {
                     result = _wsystem(wcmd.c_str());
                 });
                 t.join();
-                log_info("ddr", "`{}` returned {}", cmd, result);
+
+                if (result == 0) {
+                    log_info("ddr", "`{}` returned {}", cmd, result);
+                } else {
+                    log_warning("ddr", "`{}` failed, returned {}", cmd, result);
+                }
+
+                if (!contains_only_ascii(file.path().string())) {
+                    log_warning(
+                        "ddr",
+                        "BAD PATH ERROR\n\n\n"
+                        "!!!                                                          !!!\n"
+                        "!!! filesystem path to codec contains non-ASCII characters!  !!!\n"
+                        "!!! this may cause the game to crash!                        !!!\n"
+                        "!!!                                                          !!!\n"
+                        );
+                }
             }
         }
     }
@@ -134,8 +159,15 @@ namespace games::ddr {
                 );
         }
 
-        if (!cfg::CONFIGURATOR_STANDALONE && !NO_CODEC_REGISTRATION) {
+        if (!cfg::CONFIGURATOR_STANDALONE) {
-            this->register_codecs();
+            if (!NO_CODEC_REGISTRATION) {
+                this->register_codecs();
+            } else {
+                log_warning(
+                    "ddr",
+                    "skipping codec registration (-ddrnocodec), "
+                    "game may crash if you didn't register codecs before launching the game");
+            }
         }
     }