Buggy %rename behavior with templates and builtins

[sethrj]

[This example uses Python but applies to other languages with built-in keywords.]

There are a couple (probably related) issues here.

• A warning is issued for only templated classes when a built-in type is used, even though it has an %ignore directive
• A warning is issued for only templated classes when a built-in type is used, even though it's renamed with a %rename directive
• If a built-in type is renamed, the %rename is ignored unless it's applied to a specific template-instantiated class.

Consider the following example with a templated and non-templated class, both with the same keywordy function names:

%module test

// Templated
%ignore Foo::def;
%rename(printme) Foo::print;
%rename(lambduh) Foo<double>::lambda;
%rename(do_whatever) Foo::do_something;

// Non-templated
%ignore Bar::def;
%rename(printme) Bar::print;
%rename(lambduh) Bar::lambda;
%rename(do_whatever) Bar::do_something;

%inline %{
template<class T>
class Foo
{
  public:
    void def();
    void print();
    void lambda();
    void do_something();
};

class Bar
{
  public:
    void def();
    void print();
    void lambda();
    void do_something();
};

%}

%template(FooDouble) Foo<double>;

This produces warnings only for the templated class:

$ swig -c++ -python foo.i
foo.i:22: Warning 314: 'lambda' is a python keyword, renaming to '_lambda'
foo.i:20: Warning 314: 'def' is a python keyword, renaming to '_def'
foo.i:21: Warning 314: 'print' is a python keyword, renaming to '_print'

and even weirder, it ignores the %rename directive only for the templated class with the non-instantiated %rename, producing the following wrapper code:

class Bar(_object):
    def printme(self): ...
    def lambduh(self): ...
    def do_whatever(self): ...
    def __init__(self): ...

class FooDouble(_object):
    def _print(self): ...
    def lambduh(self): ...
    def do_whatever(self): ...
    def __init__(self): ...

Expected behavior is to have no warnings, and to have the _print in FooDouble actually renamed to printme.

[wsfulton]

This is related to a fix I happen to put in a recently, see 7268f58. Now FooDouble does have a correctly renamed printme method. The only remaining warning is:

example.i:22: Warning 314: 'lambda' is a python keyword, renaming to '_lambda'

The fix was for %ignore, but does not seem to cover the %namewarn case. If you run with swig -E you can see the macros in pythonkw.swg boil down to using %namewarn:

 %namewarn("314"":""'" "lambda" "' is a python keyword, renaming to '_" "lambda" "'",rename="_%s")  "lambda";

and in parser.y, Swig_name_namewarn_add is called instead of Swig_name_rename_add, so there is a bit more to do in naming.c.