bug#13818: 24.3.50; Bootstrap failed on Cygwin due to revno: 111870

[Paul Eggert]

On 02/26/13 04:42, Ken Brown wrote:
> On 2/26/2013 2:23 AM, Katsumi Yamaoka wrote:
>> In GNU Emacs 24.3.50.1 (i686-pc-cygwin, X toolkit, Xaw3d scroll bars)
>>   of 2013-02-26 on localhost
>> Bzr revision: 111880 monnier@iro.umontreal.ca-20130225232750-8wmx78e4uz1u7tfk
>> Windowing system distributor `The Cygwin/X Project', version 11.0.11302000
>> Configured using:
>>   `configure --verbose --with-x-toolkit=lucid --without-imagemagick
>>   --without-dbus --without-gconf --without-gsettings'
>>
>> When dumping temacs it stops by the following error:
>>
>> vm-limit.o: In function `memory_warnings':
>> src/vm-limit.c:239: undefined reference to `_data_start'

Can you please give the full shell command that
generated that line?  I assume it's something like
"gcc ... -o temacs ..." but would like the details.

> data_start used to be defined in pre-crt0.c on Cygwin,
> but this file was removed.

data_start is now supposed to be defined in vm-limit.c,
on hosts where the linker does not define it for you.

Is there some significance to the leading underscore
in that diagnostic?  (Is "_" automatically prepended
to external symbols on Cygwin?)

What does config.log say, after it says
"checking for data_start"?

What is the value of HAVE_DATA_START in src/config.h?

Also, please examine the output of "gcc -E ... vm-limit.c",
where "..." contains the same flags as used for compiling
vm-limit.c, to see how data_start was declared and defined
in the preprocessor output.