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fix inplace python opers

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git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk@5859 626c5289-ae23-0410-ae9c-e8d60b6d4f22
This commit is contained in:
Marcelo Matus 2004-04-09 21:58:47 +00:00
commit a9b4a82eae
2 changed files with 82 additions and 10 deletions
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26
SWIG/Source/Swig/cwrap.c
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@ -624,6 +624,32 @@ Swig_MethodToFunction(Node *n, String *classname, int flags) {
SwigType_add_pointer(type);
p = NewParm(type,"self");
Setattr(p,"hidden","1");
/*
Disable the 'this' ownership in 'self' to manage inplace
operations like:
A& A::operator+=(int i) { ...; return *this;}
Here the 'self' parameter ownership needs to be disabled since
there could be two objects sharing the same 'this' pointer: the
input and the result one. And worse, the pointer could be deleted
in one of the objects (input), leaving the other (output) with
just a seg. fault to happen.
To avoid the previous problem, use
%feature("self:disown") *::operator+=;
%feature("new") *::operator+=;
These two lines just transfer the ownership of the 'this' pointer
from the input to the output wrapping object.
This happens in python, but may also happens in other target
languages.
*/
if (Getattr(n,"feature:self:disown")) {
Setattr(p,"wrap:disown",Getattr(n,"feature:self:disown"));
}
set_nextSibling(p,parms);
Delete(type);