[PATCH FOR REVIEW]: Fix warning in src/share/vm/adlc/archDesc.cpp

[Andrew John Hughes]

2009/9/6 Andrew John Hughes <gnu_andrew at member.fsf.org>:
> 2009/9/5 David Holmes - Sun Microsystems <David.Holmes at sun.com>:
>> Christian Thalinger said the following on 09/05/09 18:59:
>>>
>>> Well, looking more closely it's actually a system header attribute that
>>> brings up that warning:
>>>
>>>
>>> /mnt/builder/icedtea7/openjdk-ecj/hotspot/src/share/vm/adlc/archDesc.cpp:1034:
>>> error: ignoring return value of 'size_t fwrite(const void*, size_t,
>>> size_t, FILE*)', declared with attribute warn_unused_result
>>>
>>> And it seems there is no GCC switch to turn that warning off (except
>>> -O0).  Maybe we should check for the written bytes to be the same as
>>> requested:
>>>
>>>  assert(count == size, "copyright info truncated");
>>
>> I recall this coming up in the past. gcc manual lists:
>>
>> -Wno-unused-result
>>
>> but that might be version specific.
>>
>> David
>>
>
> It's a very recent addition:
>
> http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00474.html
>
> which means there is a period (which includes GCC 4.4) where the
> warning is produced but can't be disabled :(
>
> BTW, my current approach was influenced by
> http://hg.openjdk.java.net/jdk7/jdk7/hotspot/rev/2328d1d3f8cf where
> the same fix is applied to remove this warning.
> I have to say I personally prefer twisti's assert fix and can apply
> this if others are in agreement.
> --
> Andrew :-)
>
> Free Java Software Engineer
> Red Hat, Inc. (http://www.redhat.com)
>
> Support Free Java!
> Contribute to GNU Classpath and the OpenJDK
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>

This is interesting; that assertion fails:

g++ -m64 -Xlinker -O1  -m64 -export-dynamic -o
../generated/adfiles/adlc ../generated/adfiles/adlparse.o
../generated/adfiles/archDesc.o ../generated/adfiles/arena.o
../generated/adfiles/dfa.o ../generated/adfiles/dict2.o
../generated/adfiles/filebuff.o ../generated/adfiles/forms.o
../generated/adfiles/formsopt.o ../generated/adfiles/formssel.o
../generated/adfiles/main.o ../generated/adfiles/adlc-opcodes.o
../generated/adfiles/output_c.o ../generated/adfiles/output_h.o
../generated/adfiles/adlc -DLINUX -D_GNU_SOURCE -DAMD64 -q -T -D_LP64
../generated/adfiles/linux_x86_64.ad  \
 -c../generated/adfiles/mktmp11816/ad_x86_64.cpp
-h../generated/adfiles/mktmp11816/ad_x86_64.hpp
-a../generated/adfiles/mktmp11816/dfa_x86_64.cpp
-v../generated/adfiles/mktmp11816/adGlobals_x86_64.hpp \
	    || { rm -rf ../generated/adfiles/mktmp11816; exit 1; }
assert fails /mnt/builder/icedtea7/openjdk-ecj/hotspot/src/share/vm/adlc/archDesc.cpp
1035: copyright info truncated
/bin/sh: line 2: 12016 Aborted
../generated/adfiles/adlc -DLINUX -D_GNU_SOURCE -DAMD64 -q -T -D_LP64
../generated/adfiles/linux_x86_64.ad
-c../generated/adfiles/mktmp11816/ad_x86_64.cpp
-h../generated/adfiles/mktmp11816/ad_x86_64.hpp
-a../generated/adfiles/mktmp11816/dfa_x86_64.cpp
-v../generated/adfiles/mktmp11816/adGlobals_x86_64.hpp
make[7]: *** [refresh_adfiles] Error 1

-- 
Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

Support Free Java!
Contribute to GNU Classpath and the OpenJDK
http://www.gnu.org/software/classpath
http://openjdk.java.net

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Fingerprint: F8EF F1EA 401E 2E60 15FA  7927 142C 2591 94EF D9D8