On the rebasing problem of Emacs on Cygwin

[Angelo Graziosi]

I want to report the following, hoping it can be useful for other users of
Emacs on Cygwin.

Usually, on Cygwin, one needs to rebase (the DLLs) if an application
aborts with a message like this example:

-------------
C:\cygwin\bin\python.exe: *** unable to remap C:\cygwin\bin\cygssl.dll to
same address as parent(0xDF0000) != 0xE00000
-------------


But, since Cygwin DLL 1.5.17 was released, after the rebasing, Emacs
hangs.

This happens for the current version 21.2-13 and the exp. ver. 21.3.50-2
on Cygwin.

And also for Emacs-CVS.


So I have found useful to build Emacs-CVS in this way
----------------------------------------------
LDFLAGS='-Wl,--enable-auto-import -Wl,--enable-auto-image-base' \
../configure --prefix=/usr/local/emacs-cvs

make LD='$(CC)' bootstrap

make LD='$(CC)' install
-----------------------------------------------

This makes Emacs independent of rebasing.

Note that it needs

  LD='$(CC)'

in the bootstrap so that the GCC command line is


  gcc ... -Wl,--enable-auto-import -Wl,--enable-auto-image-base ...


otherwise it would be


  gcc ... -Wl,--image-base,0x20000000 -Wl,--enable-auto-import
-Wl,--enable-auto-image-base...


and Emacs would be built with the base address 0x20000000 and rebasing
Cygwin DLLs would cause the hanging.



Regards,

   Angelo.