Add a plugin_globals vector to aid in safety checks for plugins that require globals

This allows "using df::global::foo" to be replaced by "REQUIRE_GLOBAL(foo)",
and DFHack will refuse to load the plugin if df::global::foo is NULL

library/PluginManager.cpp

@@ -30,6 +30,7 @@ distribution.
 #include "RemoteServer.h"
 #include "Console.h"
 #include "Types.h"
+#include "VersionInfo.h"
 
 #include "DataDefs.h"
 #include "MiscUtils.h"
@@ -167,6 +168,7 @@ Plugin::Plugin(Core * core, const std::string & filepath, const std::string & _f
     }
     plugin_lib = 0;
     plugin_init = 0;
+    plugin_globals = 0;
     plugin_shutdown = 0;
     plugin_status = 0;
     plugin_onupdate = 0;
@@ -235,13 +237,32 @@ bool Plugin::load(color_ostream &con)
     *plug_self = this;
     RefAutolock lock(access);
     plugin_init = (command_result (*)(color_ostream &, std::vector <PluginCommand> &)) LookupPlugin(plug, "plugin_init");
-    if(!plugin_init)
+    std::vector<std::string>** plugin_globals_ptr = (std::vector<std::string>**) LookupPlugin(plug, "plugin_globals");
+    if(!plugin_init || !plugin_globals_ptr)
     {
-        con.printerr("Plugin %s has no init function.\n", filename.c_str());
+        con.printerr("Plugin %s has no init function or globals vector.\n", filename.c_str());
         ClosePlugin(plug);
         state = PS_BROKEN;
         return false;
     }
+    plugin_globals = *plugin_globals_ptr;
+    if (plugin_globals->size())
+    {
+        std::vector<std::string> missing_globals;
+        for (auto it = plugin_globals->begin(); it != plugin_globals->end(); ++it)
+        {
+            if (!Core::getInstance().vinfo->getAddress(it->c_str()))
+                missing_globals.push_back(*it);
+        }
+        if (missing_globals.size())
+        {
+            con.printerr("Plugin %s is missing required globals: %s\n",
+                filename.c_str(), join_strings(", ", missing_globals).c_str());
+            ClosePlugin(plug);
+            state = PS_BROKEN;
+            return false;
+        }
+    }
     plugin_status = (command_result (*)(color_ostream &, std::string &)) LookupPlugin(plug, "plugin_status");
     plugin_onupdate = (command_result (*)(color_ostream &)) LookupPlugin(plug, "plugin_onupdate");
     plugin_shutdown = (command_result (*)(color_ostream &)) LookupPlugin(plug, "plugin_shutdown");

library/include/PluginManager.h

@@ -205,6 +205,7 @@ namespace DFHack
         void reset_lua();
 
         bool *plugin_is_enabled;
+        std::vector<std::string>* plugin_globals;
         command_result (*plugin_init)(color_ostream &, std::vector <PluginCommand> &);
         command_result (*plugin_status)(color_ostream &, std::string &);
         command_result (*plugin_shutdown)(color_ostream &);
@@ -264,7 +265,9 @@ namespace DFHack
 #define DFHACK_PLUGIN(plugin_name) \
     DFhackDataExport const char * version = DFHACK_VERSION;\
     DFhackDataExport const char * name = plugin_name;\
-    DFhackDataExport Plugin *plugin_self = NULL;
+    DFhackDataExport Plugin *plugin_self = NULL;\
+    std::vector<std::string> _plugin_globals;\
+    DFhackDataExport std::vector<std::string>* plugin_globals = &_plugin_globals;
 
 #define DFHACK_PLUGIN_IS_ENABLED(varname) \
     DFhackDataExport bool plugin_is_enabled = false; \
@@ -281,3 +284,8 @@ namespace DFHack
 #define DFHACK_LUA_FUNCTION(name) { #name, df::wrap_function(name,true) }
 #define DFHACK_LUA_EVENT(name) { #name, &name##_event }
 #define DFHACK_LUA_END { NULL, NULL }
+
+#define REQUIRE_GLOBAL(global_name) \
+    using df::global::global_name; \
+    static int VARIABLE_IS_NOT_USED CONCAT_TOKENS(required_globals_, __LINE__) = \
+        (plugin_globals->push_back(#global_name), 0);

plugins/3dveins.cpp

@@ -41,13 +41,12 @@ using namespace DFHack;
 using namespace MapExtras;
 using namespace DFHack::Random;
 
-using df::global::world;
+DFHACK_PLUGIN("3dveins");
-using df::global::gametype;
+REQUIRE_GLOBAL(world);
+REQUIRE_GLOBAL(gametype);
 
 command_result cmd_3dveins(color_ostream &out, std::vector <std::string> & parameters);
 
-DFHACK_PLUGIN("3dveins");
-
 DFhackCExport command_result plugin_init ( color_ostream &out, std::vector <PluginCommand> &commands)
 {
     commands.push_back(PluginCommand(