Allow referencing of typemap keywords inside of "$typemap("

Author: sethrj

Doc/Manual/Typemaps.html

@@ -2455,6 +2455,14 @@ <H4><a name="Typemaps_special_macro_typemap">14.4.4.2 $typemap(method, typepatte
 </pre>
 </div>
 
+<p>
+The first argument, the typemap method, can look up the keyword argument of a
+typemap by appending a colon and the keyowrd. For example,
+<tt>$typemap(directorin:descriptor, $type)</tt>  would be replaced by <tt>"D"</tt> if <tt>type</tt> is a <tt>double</tt>.
+</p>
+<p>
+<em>New in SWIG 4.1.</em>
+</p>
 
 <H3><a name="Typemaps_special_variable_attributes">14.4.5 Special variables and typemap attributes</a></H3>
 

Examples/test-suite/python/special_variable_macros_runme.py

@@ -1,10 +1,15 @@
 import special_variable_macros
 
+cvar = special_variable_macros.cvar
 name = special_variable_macros.Name()
 if special_variable_macros.testFred(name) != "none":
     raise "test failed"
+if cvar.accessed_examplekw != 0:
+    raise "Precondition failed"
 if special_variable_macros.testJack(name) != "$specialname":
     raise "test failed"
+if cvar.accessed_examplekw != 1:
+    raise "Postcondition failed"
 if special_variable_macros.testJill(name) != "jilly":
     raise "test failed"
 if special_variable_macros.testMary(name) != "SWIGTYPE_p_NameWrap":

Examples/test-suite/special_variable_macros.i

@@ -39,10 +39,13 @@ struct NameWrap {
 private:
   Name name;
 };
+
+// Global variable for testing whether examplekw was touched
+int accessed_examplekw = 0;
 %}
 
 // check $1 and $input get expanded properly when used from $typemap()
-%typemap(in) Name *GENERIC ($*1_type temp)
+%typemap(in, examplekw="accessed_examplekw=1;") Name *GENERIC ($*1_type temp)
 %{
   /*%typemap(in) Name *GENERIC start */
   temp = Name("$specialname");
@@ -80,6 +83,7 @@ static const char *nameDescriptor = "$descriptor(Name)";
 %typemap(in) Name *jack {
 // %typemap(in) Name *jack start
 $typemap(in, Name *GENERIC)
+$typemap(in:examplekw, Name *GENERIC)
 // %typemap(in) Name *jack end
 }
 

Source/Swig/typemap.c

@@ -511,7 +511,12 @@ int Swig_typemap_apply(ParmList *src, ParmList *dest) {
   if (sm) {
     /* Got a typemap.  Need to only merge attributes for methods that match our signature */
     Iterator ki;
+    Hash *deferred_add;
     match = 1;
+
+    /* Since typemap_register can modify the `sm` hash, we *cannot* call typemap_register while iterating over sm. 
+     * Create a temporary hash of typemaps to add immediately after. */
+    deferred_add = NewHash();
     for (ki = First(sm); ki.key; ki = Next(ki)) {
       /* Check for a signature match with the source signature */
       if ((count_args(ki.key) == narg) && (Strstr(ki.key, ssig))) {
@@ -521,34 +526,36 @@ int Swig_typemap_apply(ParmList *src, ParmList *dest) {
 	Replace(nkey, ssig, dsig, DOH_REPLACE_ANY);
 
 	/* Make sure the typemap doesn't already exist in the target map */
-
 	oldm = Getattr(tm, nkey);
 	if (!oldm || (!Getattr(tm, "code"))) {
 	  String *code;
-	  ParmList *locals;
-	  ParmList *kwargs;
 	  Hash *sm1 = ki.item;
 
 	  code = Getattr(sm1, "code");
-	  locals = Getattr(sm1, "locals");
-	  kwargs = Getattr(sm1, "kwargs");
 	  if (code) {
+	    Replace(nkey, dsig, "", DOH_REPLACE_ANY);
+	    Replace(nkey, "tmap:", "", DOH_REPLACE_ANY);
+	    Setattr(deferred_add, nkey, sm1);
+	  }
+	  Delete(nkey);
+	}
+      }
+    }
+
+    /* After assembling the key/item pairs, add the resulting typemaps */
+    for (ki = First(deferred_add); ki.key; ki = Next(ki)) {
+	    Hash *sm1 = ki.item;
 	    String *src_str = ParmList_str_multibrackets(src);
 	    String *dest_str = ParmList_str_multibrackets(dest);
 	    String *source_directive = NewStringf("apply %s { %s }", src_str, dest_str);
 
-	    Replace(nkey, dsig, "", DOH_REPLACE_ANY);
-	    Replace(nkey, "tmap:", "", DOH_REPLACE_ANY);
-	    typemap_register(nkey, dest, code, locals, kwargs, source_directive);
+	    typemap_register(ki.key, dest, Getattr(sm1, "code"), Getattr(sm1, "locals"), Getattr(sm1, "kwargs"), source_directive);
 
 	    Delete(source_directive);
 	    Delete(dest_str);
 	    Delete(src_str);
 	  }
-	}
-	Delete(nkey);
-      }
-    }
+    Delete(deferred_add);
   }
   Delete(ssig);
   Delete(dsig);
@@ -2090,14 +2097,22 @@ static void replace_embedded_typemap(String *s, ParmList *parm_sublist, Wrapper
 	  Printf(stdout, "Swig_typemap_attach_parms:  embedded\n");
 #endif
 	  if (already_substituting < 10) {
+	    char* found_colon;
 	    already_substituting++;
 	    if ((in_typemap_search_multi == 0) && typemap_search_debug) {
 	      String *dtypemap = NewString(dollar_typemap);
 	      Replaceall(dtypemap, "$TYPEMAP", "$typemap");
 	      Printf(stdout, "  Containing: %s\n", dtypemap);
 	      Delete(dtypemap);
 	    }
-	    Swig_typemap_attach_parms(tmap_method, to_match_parms, f);
+	    found_colon = Strstr(tmap_method, ":");
+	    if (found_colon) {
+	      String *temp_tmap_method = NewStringWithSize(Char(tmap_method), found_colon - Char(tmap_method));
+	      Swig_typemap_attach_parms(temp_tmap_method, to_match_parms, f);
+	      Delete(temp_tmap_method);
+	    } else {
+	      Swig_typemap_attach_parms(tmap_method, to_match_parms, f);
+	    }
 	    already_substituting--;
 
 	    /* Look for the typemap code */