SF patch #3394339 from Torsten Landschoff - new option -nomoduleglobal to disable installing the module table into the global namespace. Require call also returns the module table instead of a string

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12780 626c5289-ae23-0410-ae9c-e8d60b6d4f22

CHANGES.current

@@ -5,6 +5,11 @@ See the RELEASENOTES file for a summary of changes in each release.
 Version 2.0.5 (in progress)
 ===========================
 
+2011-08-22: wsfulton
+            [Lua] SF patch #3394339 from Torsten Landschoff - new option -nomoduleglobal to disable installing 
+            the module table into the global namespace. Require call also returns the module table instead 
+            of a string.
+
 2011-08-12: wsfulton
             SF bug # 3333549 - %shared_ptr fixes when the type is a template using template parameters
             that are typedef'd to another type. 

Doc/Manual/Lua.html

@@ -105,6 +105,29 @@ This creates a C/C++ source file <tt>example_wrap.c</tt> or <tt>example_wrap.cxx
 <p>
 The name of the wrapper file is derived from the name of the input file. For example, if the input file is <tt>example.i</tt>, the name of the wrapper file is <tt>example_wrap.c</tt>. To change this, you can use the -o option. The wrappered module will export one function <tt>"int luaopen_example(lua_State* L)"</tt> which must be called to register the module with the Lua interpreter. The name "luaopen_example" depends upon the name of the module.
 </p>
+
+<H3><a name="Lua_commandline"></a>25.2.1 Additional command line options</H3>
+
+<p>
+The following table list the additional commandline options available for the Lua module. They can also be seen by using: 
+</p>
+
+<div class="code"><pre>
+swig -lua -help 
+</pre></div>
+
+<table summary="Lua specific options">
+<tr>
+<th>Lua specific options</th>
+</tr>
+
+<tr>
+<td>-nomoduleglobal</td>
+<td>Do not register the module name as a global variable but return the module table from calls to require.</td>
+</tr>
+
+</table>
+
 <H3><a name="Lua_nn4"></a>25.2.1 Compiling and Linking and Interpreter</H3>
 
 

Examples/test-suite/lua/Makefile.in

@@ -11,12 +11,12 @@ top_builddir = @top_builddir@
 
 # sorry, currently very few test cases work/have been written
 
-#CPP_TEST_CASES += \
-#	cnum 
+CPP_TEST_CASES += \
+	lua_no_module_global \
 
-#C_TEST_CASES += \
-#	file_test \
-#	nondynamic
+
+C_TEST_CASES += \
+	lua_no_module_global \
 
 
 include $(srcdir)/../common.mk
@@ -25,7 +25,7 @@ include $(srcdir)/../common.mk
 LIBS       = -L.
 
 # Custom tests - tests with additional commandline options
-# none!
+lua_no_module_global.%: SWIGOPT += -nomoduleglobal
 
 # Rules for the different types of tests
 %.cpptest: 

Examples/test-suite/lua/lua_no_module_global_runme.lua

@@ -0,0 +1,24 @@
+-- require is only available in Lua 5.1
+
+if string.sub(_VERSION,1,7)=='Lua 5.1' then
+
+        -- Initially the package should not be loaded
+        assert(package.loaded["lua_no_module_global"] == nil)
+
+        -- Load the module
+        the_module = require "lua_no_module_global"
+
+        -- require should return the module table
+        assert(the_module.hi_mom ~= nil)
+        assert(the_module.hi_mom() == "hi mom!")
+
+        -- But it should not end up in the global table _G, subject to
+        -- the -nomoduleglobal swig option.
+        assert(_G["lua_no_module_global"] == nil)
+
+        -- According to the Lua 5.1 reference manual, require should also
+        -- store the module table into package.loaded["name"]
+        assert(package.loaded["lua_no_module_global"] == the_module)
+        assert(package.loaded["lua_no_module_global"].hi_mom() == "hi mom!")
+
+end

Examples/test-suite/lua_no_module_global.i

@@ -0,0 +1,5 @@
+%module lua_no_module_global
+%{
+    const char *hi_mom() { return "hi mom!"; }
+%}
+const char *hi_mom();

Lib/lua/luarun.swg

@@ -237,7 +237,7 @@ SWIGINTERN int SWIG_Lua_module_set(lua_State* L)
   return 0;
 }
 
-/* registering a module in lua */
+/* registering a module in lua. Pushes the module table on the stack. */
 SWIGINTERN void  SWIG_Lua_module_begin(lua_State* L,const char* name)
 {
   assert(lua_istable(L,-1));  /* just in case */
@@ -254,8 +254,16 @@ SWIGINTERN void  SWIG_Lua_module_begin(lua_State* L,const char* name)
   lua_newtable(L);    /* the .set table */
   lua_rawset(L,-3);  /* add .set into metatable */
   lua_setmetatable(L,-2);  /* sets meta table in module */
+#ifdef SWIG_LUA_MODULE_GLOBAL
+  /* If requested, install the module directly into the global namespace. */
   lua_rawset(L,-3);        /* add module into parent */
   SWIG_Lua_get_table(L,name);   /* get the table back out */
+#else
+  /* Do not install the module table as global name. The stack top has
+     the module table with the name below. We pop the top and replace
+     the name with it. */
+  lua_replace(L,-2);
+#endif
 }
 
 /* ending the register */

Lib/lua/luaruntime.swg

@@ -59,8 +59,9 @@ SWIGEXPORT int SWIG_init(lua_State* L)
   /* invoke user-specific initialization */
   SWIG_init_user(L);
   /* end module */
-  lua_pop(L,1);  /* tidy stack (remove module table)*/
-  lua_pop(L,1);  /* tidy stack (remove global table)*/
+  /* Note: We do not clean up the stack here (Lua will do this for us). At this
+     point, we have the globals table and out module table on the stack. Returning
+     one value makes the module table the result of the require command. */
   return 1;
 }
 

Source/Modules/lua.cxx

@@ -83,10 +83,11 @@ void display_mapping(DOH *d) {
 NEW LANGUAGE NOTE:END ************************************************/
 static const char *usage = (char *) "\
 Lua Options (available with -lua)\n\
-     [no additional options]\n\
+     -nomoduleglobal - Do not register the module name as a global variable \n\
+                       but return the module table from calls to require.\n\
 \n";
 
-
+static int nomoduleglobal = 0;
 
 /* NEW LANGUAGE NOTE:***********************************************
  To add a new language, you need to derive your class from
@@ -172,6 +173,9 @@ public:
       if (argv[i]) {
         if (strcmp(argv[i], "-help") == 0) {	// usage flags
           fputs(usage, stdout);
+        } else if (strcmp(argv[i], "-nomoduleglobal") == 0) {
+          nomoduleglobal = 1;
+          Swig_mark_arg(i);
         }
       }
     }
@@ -263,6 +267,12 @@ public:
     Printf(f_runtime, "\n");
     Printf(f_runtime, "#define SWIGLUA\n");
 
+    if (nomoduleglobal) {
+      Printf(f_runtime, "#define SWIG_LUA_NO_MODULE_GLOBAL\n");
+    } else {
+      Printf(f_runtime, "#define SWIG_LUA_MODULE_GLOBAL\n");
+    }
+
     //    if (NoInclude) {
     //      Printf(f_runtime, "#define SWIG_NOINCLUDE\n");
     //    }