Re: strtod [was: M4 1.4.14 on AIX 7.1BETA]

[Eric Blake]

On 07/30/2010 12:21 AM, Rainer Tammer wrote:
> 
> configure:25948: checking whether strtod obeys C99
> configure:26060: cc -qlanglvl=extc89 -qlanglvl=extc99 -o conftest -g  
> conftest.c  >&5
> configure:26060: $? = 0
> configure:26060: ./conftest
> configure:26060: $? = 3
> configure: program exited with status 3

Confirms my suspicion - your underlying strtod() misparses "0x".

> 
>> Another thing that might be helpful is to find _all_ strtod bugs in your
>> system, to make sure our wrapper is being careful for all of them.
> OK,
> this is the result (all line numbers are +2 in respect to the source
> from m4-1.4.14.6-ffa0.tar.gz):
> 
> test-strtod.c:391: assertion failed <- this is also OS related
> test-strtod.c:413: assertion failed <- this is caught by the replacement
> test-strtod.c:424: assertion failed <- ...
> test-strtod.c:435: assertion failed <- ...
> test-strtod.c:446: assertion failed <- ...
> test-strtod.c:457: assertion failed <- ...
> test-strtod.c:468: assertion failed <- ...
> test-strtod.c:479: assertion failed <- ...

All related to "0x<garbage>" not stopping after exactly "0", a new bug
to AIX 7.1 when compared to AIX 5.1 (or rather, AIX 5.1 lacked hex
parsing altogether, and AIX 7.1 added it but did so incorrectly), and
now fixed in the replacement.

> test-strtod.c:670: assertion failed <- ...
> test-strtod.c:671: assertion failed <- ...
> test-strtod.c:691: assertion failed <- ...
> test-strtod.c:720: assertion failed <- ...
> test-strtod.c:721: assertion failed <- ...
> test-strtod.c:762: assertion failed <- ...
> test-strtod.c:772: assertion failed <- ...

All related to "nan()" parsing, where hopefully the replacement works as
promised, and where AIX 5.1 had the same bug.

Thanks.  I'm updating the comments in test-strtod.c accordingly, and
will have another m4 snapshot soon that should hopefully fix all these.

-- 
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

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