more on duplicate decls

[Mark Mitchell]

Kenneth Zadeck wrote:

> The kludge to handle them is documented in cp/name-lookup.c around line 
> 670

Ugh.

IMO, the right thing here is that there should be only one FUNCTION_DECL 
for a given function, ever, period.  Default arguments are not part of 
"the function" in C++; they are an aspect of particular declarations of 
the function.  The problem we're having is that we associate them with 
the FUNCTION_DECL, rather than with the bindings (mappings from names to 
FUNCTION_DECLs).

Unfortunately, fixing that properly is a rather large change.

> It seems like a better way is to build a table of merges that need to be 
> done and find some place after the c++ front end is finished but before 
> the cgraph gets built and do one scan of the code and replace all of the 
> offending decls.

After the C++ front end is done, it would be OK to canoanicalize all 
FUNCTION_DECLs with a single UID into one.  A stupid way of doing that 
would be to just walk the entire translation unit, and whenever you find 
a reference to a non-canonical copy of the FUNCTION_DECL, re-point it at 
the right one.

The C++ front end always operates in unit-at-a-time mode, so, yes, you 
could do this when the C++ front end is finished.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
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