applied patch #1912699 - "Pinned" / always loaded plugins support

this patch also adds plugin_api_version to exec_flags so your plug-in can now tell if features it needs are available
more plug-ins that need this will be converted once the patch to make both the stubs and the plug-ins use the same header file is in place

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@5809 212acab6-be3b-0410-9dea-997c60f758d6

Contrib/ExDLL/exdll.h

@@ -75,7 +75,7 @@ typedef struct {
   int exec_reboot;
   int reboot_called;
   int XXX_cur_insttype; // deprecated
-  int XXX_insttype_changed; // deprecated
+  int plugin_api_version; // used to be XXX_insttype_changed, but that was deprecated
   int silent;
   int instdir_error;
   int rtl;
@@ -84,10 +84,23 @@ typedef struct {
   int status_update;
 } exec_flags_type;
 
+// NSIS Plug-In Callback Messages
+enum NSPIM 
+{
+	NSPIM_UNLOAD,    // This is the last message a plugin gets, do final cleanup
+	NSPIM_GUIUNLOAD, // Called after .onGUIEnd
+};
+
+// Prototype for callbacks registered with extra_parameters->RegisterPluginCallback()
+// Return NULL for unknown messages
+// Should always be __cdecl for future expansion possibilities
+typedef UINT_PTR (*NSISPLUGINCALLBACK)(NSPIM);
+
 typedef struct {
   exec_flags_type *exec_flags;
   int (__stdcall *ExecuteCodeSegment)(int, HWND);
   void (__stdcall *validate_filename)(char *);
+  BOOL (__stdcall *RegisterPluginCallback)(HMODULE, NSISPLUGINCALLBACK);
 } extra_parameters;
 
 // utility functions (not required but often useful)

Contrib/System/Source/Plugin.c

@@ -166,6 +166,11 @@ HANDLE GlobalCopy(HANDLE Old)
     return copymem(GlobalAlloc(GPTR, size), Old, (int) size);
 }
 
+UINT_PTR NSISCallback(UINT msg)
+{
+  return (UINT_PTR) NULL;
+}
+
 #ifdef _DEBUG
 void main()
 {

Contrib/System/Source/Plugin.h

@@ -36,11 +36,23 @@ INST_LANG,      // $LANGUAGE
 __INST_LAST
 };
 
-#define PLUGINFUNCTION(name) void __declspec(dllexport) name(HWND hwndParent, int string_size, char *variables, stack_t **stacktop) { \
+typedef UINT_PTR (*NSISPLUGINCALLBACK)(UINT);
-/*  g_hwndParent=hwndParent; */\
+
+typedef struct {
+  void *exec_flags;
+  int (__stdcall *ExecuteCodeSegment)(int, HWND);
+  void (__stdcall *validate_filename)(char *);
+  BOOL (__stdcall *RegisterPluginCallback)(HMODULE, NSISPLUGINCALLBACK);
+} extra_parameters;
+
+#define PLUGINFUNCTION(name) \
+  void __declspec(dllexport) name( \
+    HWND hwndParent, int string_size, char *variables, stack_t **stacktop, extra_parameters *extra) { \
+  /*g_hwndParent=hwndParent;*/ \
   g_stringsize=string_size; \
   g_stacktop=stacktop; \
-  g_variables=variables; 
+  g_variables=variables; \
+  extra->RegisterPluginCallback(g_hInstance, NSISCallback);
 #define PLUGINFUNCTIONEND }
 
 #define PLUGINFUNCTIONSHORT(name) void __declspec(dllexport) name(HWND hwndParent, int string_size, char *variables, stack_t **stacktop) { \
@@ -61,9 +73,12 @@ extern void pushint(int value);
 extern HANDLE GlobalCopy(HANDLE Old);
 extern char *copymem(char *output, char *input, int size);
 
+extern UINT_PTR NSISCallback(UINT);
+
 extern HWND g_hwndParent;
 extern int g_stringsize;
 extern stack_t **g_stacktop;
 extern char *g_variables;
+extern HINSTANCE g_hInstance;
 
 #endif

Source/exehead/Main.c

@@ -25,6 +25,7 @@
 #include "lang.h"
 #include "state.h"
 #include "exec.h"
+#include "plugin.h"
 
 #if !defined(NSIS_CONFIG_VISIBLE_SUPPORT) && !defined(NSIS_CONFIG_SILENT_SUPPORT)
 #error One of NSIS_CONFIG_SILENT_SUPPORT or NSIS_CONFIG_VISIBLE_SUPPORT must be defined.
@@ -341,6 +342,8 @@ void NSISCALL CleanUp()
     dbd_hFile = INVALID_HANDLE_VALUE;
   }
 #endif
+  // Notify plugins that we are about to unload
+  Plugins_UnloadAll();
 #ifdef NSIS_CONFIG_PLUGIN_SUPPORT
   // Clean up after plug-ins
   myDelete(state_plugins_dir, DEL_DIR | DEL_RECURSE | DEL_REBOOT);

Source/exehead/SConscript

@@ -4,6 +4,7 @@ files = Split("""
 	exec.c
 	fileform.c
 	Main.c
+	plugin.c
 	Ui.c
 	util.c
 	#Source/crc32.c

Source/exehead/Ui.c

@@ -28,6 +28,7 @@
 #include "util.h"
 #include "ui.h"
 #include "exec.h"
+#include "plugin.h"
 #include "lang.h"
 #include "components.h"
 
@@ -268,6 +269,11 @@ FORCE_INLINE int NSISCALL ui_doinstall(void)
   // initialize auto close flag
   g_exec_flags.autoclose=g_flags&CH_FLAGS_AUTO_CLOSE;
 
+#ifdef NSIS_CONFIG_PLUGIN_SUPPORT
+  // initialize plugin api
+  g_exec_flags.plugin_api_version=NSISPIAPIVER_CURR;
+#endif
+
   // read install directory from registry
   if (!is_valid_instpath(state_install_directory))
   {
@@ -396,6 +402,9 @@ FORCE_INLINE int NSISCALL ui_doinstall(void)
       int ret=DialogBox(g_hInstance,MAKEINTRESOURCE(IDD_INST+dlg_offset),0,DialogProc);
 #if defined(NSIS_SUPPORT_CODECALLBACKS) && defined(NSIS_CONFIG_ENHANCEDUI_SUPPORT)
       ExecuteCallbackFunction(CB_ONGUIEND);
+#endif
+#ifdef NSIS_CONFIG_PLUGIN_SUPPORT
+      Plugins_SendMsgToAllPlugins(NSPIM_GUIUNLOAD);
 #endif
       return ret;
     }

Source/exehead/exec.c

@@ -23,6 +23,7 @@
 #include "ui.h"
 #include "components.h"
 #include "exec.h"
+#include "plugin.h"
 #include "lang.h"
 #include "resource.h"
 
@@ -48,10 +49,12 @@ struct {
   exec_flags *flags;
   void *ExecuteCodeSegment;
   void *validate_filename;
+  void *RegisterPluginCallback;
 } plugin_extra_parameters = {
   &g_exec_flags,
   &ExecuteCodeSegment,
-  &validate_filename
+  &validate_filename,
+  &RegisterPluginCallback
 };
 
 #if defined(NSIS_SUPPORT_ACTIVEXREG) || defined(NSIS_SUPPORT_CREATESHORTCUT)
@@ -996,7 +999,7 @@ static int NSISCALL ExecuteEntry(entry *entry_)
               update_status_text(LANG_CANNOTFINDSYMBOL,buf0);
               log_printf3("Error registering DLL: %s not found in %s",buf0,buf1);
             }
-            if (!parm3) FreeLibrary(h);
+            if (!parm3 && Plugins_CanUnload(h)) FreeLibrary(h);
           }
           else
           {

Source/exehead/fileform.h

@@ -498,7 +498,7 @@ typedef struct
   int __;
 #endif
   int XXX_cur_insttype; // depreacted
-  int XXX_insttype_changed; // deprecated
+  int plugin_api_version; // used to be XXX_insttype_changed, but that was deprecated
 #ifdef NSIS_CONFIG_SILENT_SUPPORT
   int silent;
 #else

Source/exehead/plugin.c

@@ -0,0 +1,81 @@
+#include "plugin.h"
+
+#ifdef NSIS_CONFIG_PLUGIN_SUPPORT
+
+typedef struct _loaded_plugin
+{
+	struct _loaded_plugin* next;
+	NSISPLUGINCALLBACK proc;
+	HMODULE dll;
+}
+loaded_plugin;
+
+static loaded_plugin* g_plugins = 0; // not thread safe!
+
+void NSISCALL Plugins_SendMsgToAllPlugins(int msg)
+{
+  loaded_plugin* p;
+
+	for (p = g_plugins; p; p = p->next)
+  {
+		p->proc(msg);
+  }
+}
+
+void NSISCALL Plugins_UnloadAll() 
+{
+	loaded_plugin* p = g_plugins;
+
+	Plugins_SendMsgToAllPlugins(NSPIM_UNLOAD);
+
+	while (p)
+	{
+		loaded_plugin* oldp = p;
+    p = oldp->next;
+		FreeLibrary(oldp->dll);
+		GlobalFree(oldp);
+	}
+
+	g_plugins = NULL;
+}
+
+BOOL NSISCALL Plugins_CanUnload(HANDLE pluginHandle)
+{
+  loaded_plugin* p;
+
+	for (p = g_plugins; p; p = p->next)
+  {
+    if (p->dll == pluginHandle)
+    {
+      return FALSE;
+    }
+  }
+	return TRUE;
+}
+
+BOOL NSISCALL RegisterPluginCallback(HMODULE pluginHandle, NSISPLUGINCALLBACK proc)
+{
+	loaded_plugin* p;
+
+	if (!Plugins_CanUnload(pluginHandle))
+  {
+    // already registered
+    return FALSE;
+  }
+	
+	p = (loaded_plugin*) GlobalAlloc(LPTR, sizeof(loaded_plugin));
+	if (p)
+	{
+		p->proc   = proc;
+		p->dll    = pluginHandle;
+		p->next   = g_plugins;
+
+		g_plugins = p;
+
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+#endif /* #ifdef NSIS_CONFIG_PLUGIN_SUPPORT */

Source/exehead/plugin.h

@@ -0,0 +1,36 @@
+#ifndef _PLUGINCALLBACKS_H_
+#define _PLUGINCALLBACKS_H_
+
+#include "../Platform.h"
+#include "fileform.h"
+
+#ifdef NSIS_CONFIG_PLUGIN_SUPPORT
+
+// Starting with NSIS 2.42, you can check the version of the plugin API in exec_flags->plugin_api_version
+// The format is 0xXXXXYYYY where X is the major version and Y is the minor version (MAKELONG(y,x))
+// When doing version checks, always remember to use >=, ex: if (pX->exec_flags->plugin_api_version >= NSISPIAPIVER_1_0) {}
+
+#define NSISPIAPIVER_1_0 0x00010000
+#define NSISPIAPIVER_CURR NSISPIAPIVER_1_0
+
+// NSIS Plug-In Callback Messages
+enum NSPIM 
+{
+	NSPIM_UNLOAD,    // This is the last message a plugin gets, do final cleanup
+	NSPIM_GUIUNLOAD, // Called after .onGUIEnd
+};
+
+// Prototype for callbacks registered with extra_parameters->RegisterPluginCallback()
+// Return NULL for unknown messages
+// Should always be __cdecl for future expansion possibilities
+typedef UINT_PTR (*NSISPLUGINCALLBACK)(NSPIM);
+
+extern BOOL NSISCALL RegisterPluginCallback(HMODULE pluginHandle, NSISPLUGINCALLBACK proc);
+
+extern void NSISCALL Plugins_SendMsgToAllPlugins(int msg);
+extern void NSISCALL Plugins_UnloadAll();
+extern BOOL NSISCALL Plugins_CanUnload(HANDLE pluginHandle);
+
+#endif /* #ifdef NSIS_CONFIG_PLUGIN_SUPPORT */
+
+#endif /* _PLUGINCALLBACKS_H_ */