Duplicate class template instantiations via %template changes

Named duplicate class template instantiations now issue a warning and are ignored.
Duplicate empty class template instantiations are quietly ignored.

The test cases are fixed for this new behaviour.

This commit is a pre-requisite for the near future so that the Python
builtin wrappers can correctly use the SwigType_namestr function without
generating duplicate symbol names.
This commit is contained in:
William S Fulton 2022-11-18 18:49:48 +00:00
commit 4729cf2b1f
16 changed files with 283 additions and 55 deletions

View file

@ -7,6 +7,50 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
Version 4.2.0 (in progress)
===========================
2022-11-18: wsfulton
Duplicate class template instantiations via %template now issue a warning and are ignored.
%template(Aint) A<int>;
%template(Aint2) A<int>; // Now ignored and issues a warning
example.i:7: Warning 404: Duplicate template instantiation of 'A< int >' with name 'Aint2' ignored,
example.i:6: Warning 404: previous instantiation of 'A< int >' with name 'Aint'.
A single empty template instantiation before a named instantiation is the one exception
for allowing duplicate template instantiations as the empty template instantation does not
create a wrapper for the template, it merely adds the instantiation into SWIG's internal
type system.
Duplicate empty template instantiations are quietly ignored.
%template() B<int>;
%template(Bint) B<int>; // OK
%template() C<int>;
%template() C<int>; // Quietly ignored now
%template(Cint) C<int>; // OK
Note that default template parameters are considered when looking for duplicates such as:
template <typename T, typename U = short> struct D {};
%template(Dint) D<int>;
%template(Dintshort) D<int, short>;
example.i:7: Warning 404: Duplicate template instantiation of 'D< int,short >' with name 'Dintshort' ignored,
example.i:6: Warning 404: previous instantiation of 'D< int >' with name 'Dint'.
Note that the following always was ignored, but that was because the chosen name was a
duplicate rather than the template being a duplicate:
%template(Eint) E<int>;
%template(Eint) E<int>; // Always has been ignored as a redefined identifier
The old warning was:
example.i:7: Warning 302: Identifier 'Eint' redefined (ignored) (Renamed from 'E< int >'),
example.i:6: Warning 302: previous definition of 'Eint' (Renamed from 'E< int >').
*** POTENTIAL INCOMPATIBILITY ***
2022-11-05: wsfulton
#2417 Fix -swiglib for Windows when building with CMake.