Allow global operators to be SWIG-wrapped functions (by Karl Wette)

The Octave run-time allows global operators to be implemented,
e.g. op_scalar_add_X for adding a scalar and a wrapped struct X.
However it doesn't currently seem possible for these operators to
map to SWIG-wrapped functions. This is because dispatch_global_op()
looks for the operators to be installed as global variables, whereas
install_global() installs SWIG-wrapped functions as builtin functions;
the two appear to be separate symbol tables in Octave.

This patch modifies install_global() to install global operator functions
as both builtin functions and as global variables, where the value of the
global variable is a function handle to the operator function. It decides
if a function is a global operator if it begins with the prefix "op_"; this
prefix can be modified through a new command-line variable. It also always
installs the operators globally, regardless of whether the rest of the module
is being loaded globally. To accomplish this, install_global() is now always
called, but takes a bool argument specifying whether it should load symbols
globally. If a function is not a global operator, install_global() should
behave as before.

Tested that this compiles and works on Octave 3.2.4 and 3.4.0.



git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@12675 626c5289-ae23-0410-ae9c-e8d60b6d4f22

3 files changed, 30 insertions, 13 deletions

diff --git a/Lib/octave/octrun.swg b/Lib/octave/octrun.swg
index c4c01ed82..49b032fc9 100644
--- a/Lib/octave/octrun.swg
+++ b/Lib/octave/octrun.swg
@@ -457,22 +457,26 @@ namespace Swig {
       rhs.members.clear();
     }
 
-    void install_global() {
+    void install_global(bool global_load) {
       for (member_map::const_iterator it = members.begin(); it != members.end(); ++it) {
-	if (it->second.first && it->second.first->method)
+        bool is_global_op = (it->first.substr(0, strlen(SWIG_op_prefix)) == SWIG_op_prefix);
+        bool is_func_defined = (it->second.first && it->second.first->method);
+	if (is_func_defined && (is_global_op || global_load)) {
 	  install_builtin_function(it->second.first->method, it->first,
-				   it->second.first->doc?it->second.first->doc:std::string());
-	else if (it->second.second.is_defined()) {
+				   it->second.first->doc ? it->second.first->doc : std::string());
+        }
+        octave_value global_val = is_global_op ? make_fcn_handle(it->first) : it->second.second;
+	if (global_val.is_defined() && (is_global_op || global_load)) {
 #if OCTAVE_API_VERSION_NUMBER<37
 	  link_to_global_variable(curr_sym_tab->lookup(it->first, true));
 #else 
 	  symbol_table::varref(it->first);
 	  symbol_table::mark_global(it->first);
 #endif
-	  set_global_value(it->first, it->second.second);
+	  set_global_value(it->first, global_val);
 	  
 #if OCTAVE_API_VERSION_NUMBER<37
-	  octave_swig_type *ost = Swig::swig_value_deref(it->second.second);
+	  octave_swig_type *ost = Swig::swig_value_deref(global_val);
 	  if (ost) {
 	    const char* h = ost->help_text();
 	    if (h) {
@@ -775,7 +779,7 @@ namespace Swig {
     }
 
     static bool dispatch_global_op(const std::string &symbol, const octave_value_list &args, octave_value &ret) {
-      // we assume that "op_"-prefixed functions are installed in global namespace
+      // we assume that SWIG_op_prefix-prefixed functions are installed in global namespace
       // (rather than any module namespace).
 
       octave_value fcn = get_global_value(symbol, true);
@@ -792,7 +796,7 @@ namespace Swig {
       octave_value ret;
       if (ost->dispatch_unary_op(std::string("__") + op_name + std::string("__"), ret))
 	return ret;
-      std::string symbol = "op_" + ost->swig_type_name() + "_" + op_name;
+      std::string symbol = SWIG_op_prefix + ost->swig_type_name() + "_" + op_name;
       octave_value_list args;
       args.append(make_value_hack(x));
       if (dispatch_global_op(symbol, args, ret))
@@ -825,7 +829,7 @@ namespace Swig {
       args.append(make_value_hack(lhs));
       args.append(make_value_hack(rhs));
 
-      symbol = "op_";
+      symbol = SWIG_op_prefix;
       symbol += lhs_ost ? lhs_ost->swig_type_name() : lhs.type_name();
       symbol += "_";
       symbol += op_name;
@@ -834,7 +838,7 @@ namespace Swig {
       if (dispatch_global_op(symbol, args, ret))
 	return ret;
 
-      symbol = "op_";
+      symbol = SWIG_op_prefix;
       symbol += lhs_ost ? lhs_ost->swig_type_name() : lhs.type_name();
       symbol += "_";
       symbol += op_name;
@@ -843,7 +847,7 @@ namespace Swig {
       if (dispatch_global_op(symbol, args, ret))
 	return ret;
 
-      symbol = "op_";
+      symbol = SWIG_op_prefix;
       symbol += "any";
       symbol += "_";
       symbol += op_name;
diff --git a/Lib/octave/octruntime.swg b/Lib/octave/octruntime.swg
index 48da0cf48..da5b9c512 100644
--- a/Lib/octave/octruntime.swg
+++ b/Lib/octave/octruntime.swg
@@ -101,8 +101,7 @@ DEFUN_DLD (SWIG_name,args,nargout,SWIG_name_d) {
   // the incref is necessary so install_global doesn't destroy module_ns,
   // as it would if it installed something with the same name as the module.
   module_ns->incref();
-  if (global_load)
-    module_ns->install_global();
+  module_ns->install_global(global_load);
   module_ns->decref();
 
 #if OCTAVE_API_VERSION_NUMBER<37
diff --git a/Source/Modules/octave.cxx b/Source/Modules/octave.cxx
index dcd690844..b46214463 100644
--- a/Source/Modules/octave.cxx
+++ b/Source/Modules/octave.cxx
@@ -17,12 +17,14 @@ char cvsroot_octave_cxx[] = "$Id$";
 
 static bool    global_load = true;
 static String *global_name = 0;
+static String *op_prefix   = 0;
 
 static const char *usage = (char *) "\
 Octave Options (available with -octave)\n\
      -global         - Load all symbols into the global namespace [default]\n\
      -globals <name> - Set <name> used to access C global variables [default: 'cvar']\n\
      -noglobal       - Do not load all symbols into the global namespace\n\
+     -opprefix <str> - Prefix <str> for global operator functions [default: 'op_']\n\
 \n";
 
 
@@ -85,12 +87,23 @@ public:
 	  } else {
 	    Swig_arg_error();
 	  }
+	} else if (strcmp(argv[i], "-opprefix") == 0) {
+	  if (argv[i + 1]) {
+	    op_prefix = NewString(argv[i + 1]);
+	    Swig_mark_arg(i);
+	    Swig_mark_arg(i + 1);
+	    i++;
+	  } else {
+	    Swig_arg_error();
+	  }
         }            
       }
     }
 
     if (!global_name)
       global_name = NewString("cvar");
+    if (!op_prefix)
+      op_prefix = NewString("op_");
 
     SWIG_library_directory("octave");
     Preprocessor_define("SWIGOCTAVE 1", 0);
@@ -157,6 +170,7 @@ public:
     Printf(f_runtime, "\n");
     Printf(f_runtime, "#define SWIG_global_load      %s\n", global_load ? "true" : "false");
     Printf(f_runtime, "#define SWIG_global_name      \"%s\"\n", global_name);
+    Printf(f_runtime, "#define SWIG_op_prefix        \"%s\"\n", op_prefix);
 
     if (directorsEnabled()) {
       Printf(f_runtime, "#define SWIG_DIRECTORS\n");