[Bug pch/14400] Cannot compile qt-x11-free-3.3.0

["geoffk at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

------- Additional Comments From geoffk at gcc dot gnu dot org  2004-03-30 01:42 -------
I believe I saw this on Darwin before implementing the scheme it uses now.  I don't believe there's any 
solution to the general problem that doesn't know more about the host's memory map; the current 
generic solution is just a heuristic and is not reliable.  For reliable operation, *especially* on x86-linux-
gnu, I recommend implementing a solution like Darwin's.  That would also fix 14206.

This is not a problem that you can solve with a 'quick fix'.  It's possible to have an arbitrary amount of 
memory allocated before the PCH file is loaded, even if you do something special for the main input 
file.  All you need to do is ensure that more memory is allocated before the PCH file is loaded than was 
allocated before it was saved.  I would suggest a test case where the PCH file is empty, and the main 
input file looks like

#define FOO_1 "1234567890"
#define FOO_2 "1234567891"
...
#define FOO_1000 "1234568889"
#include "empty.h"

maybe with more complicated macro definitions, to use as much memory as possible.
 

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14400