Re: followup to segfault/builtin_expect

[Andreas Jaeger]

>>>>> David Ford writes:

 > Andreas Jaeger wrote:
>> >>>>> David Ford writes:
>> 
>> > I checked an older compile, of 2.2, and the config.log.
>> > HAVE_BUILTIN_EXPECT is undefined in the previous compile and the
>> > config.log shows a failure for it, however the config.h had it defined.
>> 
>> > I undefined it and commented it out.  I'd recommed someone taking a peek
>> > at the configure script to figure out why the failure resulted in a
>> > success.
>> 
>> Please check it for yourself - it seem to work for everybody else.
>> The program is very simple:
>> 
>> int foo (int a)
>> {
>> a = __builtin_expect (a, 10);
>> return a == 10 ? 0 : 1;
>> }
>> 
>> Compile it with your comiler and check what happens.

[...]
 > # gcc -o t t.c
 > /lib/crt1.o: In function `_start':
 > /lib/crt1.o(.text+0x18): undefined reference to `main'
 > /var/tmp/ccEfOlLm.o: In function `foo':
 > /var/tmp/ccEfOlLm.o(.text+0x10): undefined reference to `__builtin_expect'


 > As expected.  It is undefined.  The problem is configure built a config.h 
 > with
 > HAVE_BUILTIN_EXPECT defined even though the configure script did not succeed
 > at this:

 > configure:3160: checking for __builtin_expect
 > configure:3173: gcc  -nostdlib -nostartfiles -o conftest conftest.c -lgcc >&5
 > /usr/local/bin/ld.orig: warning: cannot find entry symbol _start; defaulting
 > to
 > 08048080
 > /var/tmp/ccbv0Ssj.o: In function `foo':
 > /var/tmp/ccbv0Ssj.o(.text+0x10): undefined reference to `__builtin_expect'

I just tried it on my system (i686-linux) and everything works fine.
I get the same output in configure - but config.h is fine.

Since this doesn't work for you and I can't reproduce it, please check
exactly why configure fails.  It might be that your /bin/sh is broken.

Andreas
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 Andreas Jaeger
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