Making it so lua-interface can really load from anywhere. Almost.

1 files changed, 95 insertions, 2 deletions

diff --git a/src/lua-interface-main.c b/src/lua-interface-main.c
index 35579db..5c16ef5 100644
--- a/src/lua-interface-main.c
+++ b/src/lua-interface-main.c
@@ -1,5 +1,98 @@
-int dll_main(int argc, char ** argv);
+#define MAX_PATH 1024
+
+#include <stdio.h>
+#include <string.h>
+
+#if defined(_WIN32)
+#define SHARED_EXT "dll"
+#elif defined(__APPLE__)
+#define SHARED_EXT "dylib"
+#else
+#define SHARED_EXT "so"
+#endif
+
+typedef void(*dll_main_t)(int argc, char ** argv);
+
+#if defined(_WIN32)
+#include <windows.h>
+
+static void showError() {
+    DWORD dwErrCode = GetLastError();
+    LPVOID lpMsgBuf;
+    if (FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                      FORMAT_MESSAGE_FROM_SYSTEM |
+                      FORMAT_MESSAGE_IGNORE_INSERTS,
+                      NULL, GetLastError(),
+                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
+                      (LPTSTR) &lpMsgBuf, 0, NULL )) {
+        fprintf(stderr, "Error: %s\n", lpMsgBuf);
+        LocalFree(lpMsgBuf);
+    }
+}
+
+static HMODULE LoadLibraryExWrap(LPCTSTR lpFileName, HANDLE hFile, DWORD dwFlags) {
+    HMODULE r = LoadLibraryEx(lpFileName, hFile, dwFlags);
+    if (!r)
+        showError();
+    return r;
+}
+
+static dll_main_t LoadDllMain(const char * searchpath) {
+    HMODULE handle;
+    const char * fname = "lua-interface." SHARED_EXT;
+
+    if (!(handle = LoadLibraryExWrap(fname, NULL, LOAD_WITH_ALTERED_SEARCH_PATH)) &&
+        !(handle = LoadLibraryExWrap(fname, NULL, NULL))) {
+        LuaLoadPlugin(&Input(fname), L);
+        return NULL;
+    }
+    
+    dll_main_t dll_main = (dll_main) GetProcAddress(handle, "dll_main");
+
+    if (!dll_main)
+        FreeLibrary(handle);
+    
+    return dll_main;
+}
+
+#else
+#include <dlfcn.h>
+
+static dll_main_t LoadDllMain(const char * searchpath) {
+    const char * fname = "./lua-interface." SHARED_EXT;
+    void * handle = dlopen(fname, RTLD_NOW | RTLD_GLOBAL);
+    
+    if (!handle) {
+        char full_fname[MAX_PATH];
+        strcpy(full_fname, searchpath);
+        strcat(full_fname, "lua-interface." SHARED_EXT);
+        handle = dlopen(full_fname, RTLD_NOW | RTLD_GLOBAL);
+        if (!handle) {
+            return NULL;;
+        }
+    }
+    
+    dll_main_t dll_main = (dll_main_t) dlsym(handle, "dll_main");
+    
+    if (!dll_main)
+        dlclose(handle);
+
+    return dll_main;    
+}
+
+#endif
 
 int main(int argc, char ** argv) {
-    dll_main(argc, argv);
+    char searchpath[MAX_PATH];
+    char * slash;
+    strcpy(searchpath, argv[0]);
+    slash = strrchr(searchpath, '/');
+    if (slash) {
+        *slash = 0;
+    } else {
+        searchpath[0] = 0;
+    }
+    dll_main_t dll_main = LoadDllMain(searchpath);
+    if (dll_main)
+        dll_main(argc, argv);
 }