RFR: build pragma error with gcc 4.4.7

[Magnus Ihse Bursie]

On 2018-03-16 12:05, David Holmes wrote:
> Hi Michal,
>
> On 16/03/2018 8:48 PM, Michal Vala wrote:
>> Hi,
>>
>> I've been trying to build latest jdk with gcc 4.4.7 and I hit compile 
>> error due to pragma used in function:
I don't think gcc 4.4.7 is likely to work at all. Configure will 
complain (but continue) if you use a gcc prior to 4.7 (very recently 
raised to 4.8).

You can try getting past this error, but you are likely to hit more 
issues down the road.

Do you have any specific reasons for using such an old compiler?

/Magnus
>
> That's a very old gcc. Our "official" version is 4.9.2 but we're 
> working on getting gcc 7.x working as well. This code causes no 
> problem on 4.9.2+ so to make any change we'd have to know it will 
> continue to work on later versions.
>
> Also a google search indicates the "pragma diagnostic push" and pop 
> weren't added until gcc 4.6 ??
>
> David
> -----
>
>> /mnt/ramdisk/openjdk/src/hotspot/os/linux/os_linux.inline.hpp:103: 
>> error: #pragma GCC diagnostic not allowed inside functions
>>
>>
>> I'm sending little patch that fixes the issue by wrapping whole 
>> function. I've also created a macro for ignoring deprecated 
>> declaration inside compilerWarnings.hpp to line up with others.
>>
>> Can someone please review? If it's ok, I would also need a sponsor.
>>
>>
>> diff -r 422615764e12 src/hotspot/os/linux/os_linux.inline.hpp
>> --- a/src/hotspot/os/linux/os_linux.inline.hpp    Thu Mar 15 14:54:10 
>> 2018 -0700
>> +++ b/src/hotspot/os/linux/os_linux.inline.hpp    Fri Mar 16 10:50:24 
>> 2018 +0100
>> @@ -96,13 +96,12 @@
>>     return ::ftruncate64(fd, length);
>>   }
>>
>> -inline struct dirent* os::readdir(DIR* dirp, dirent *dbuf)
>> -{
>>   // readdir_r has been deprecated since glibc 2.24.
>>   // See https://sourceware.org/bugzilla/show_bug.cgi?id=19056 for 
>> more details.
>> -#pragma GCC diagnostic push
>> -#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
>> -
>> +PRAGMA_DIAG_PUSH
>> +PRAGMA_DEPRECATED_IGNORED
>> +inline struct dirent* os::readdir(DIR* dirp, dirent *dbuf)
>> +{
>>     dirent* p;
>>     int status;
>>     assert(dirp != NULL, "just checking");
>> @@ -114,11 +113,11 @@
>>     if((status = ::readdir_r(dirp, dbuf, &p)) != 0) {
>>       errno = status;
>>       return NULL;
>> -  } else
>> +  } else {
>>       return p;
>> -
>> -#pragma GCC diagnostic pop
>> +  }
>>   }
>> +PRAGMA_DIAG_POP
>>
>>   inline int os::closedir(DIR *dirp) {
>>     assert(dirp != NULL, "argument is NULL");
>> diff -r 422615764e12 src/hotspot/share/utilities/compilerWarnings.hpp
>> --- a/src/hotspot/share/utilities/compilerWarnings.hpp    Thu Mar 15 
>> 14:54:10 2018 -0700
>> +++ b/src/hotspot/share/utilities/compilerWarnings.hpp    Fri Mar 16 
>> 10:50:24 2018 +0100
>> @@ -48,6 +48,7 @@
>>   #define PRAGMA_FORMAT_NONLITERAL_IGNORED _Pragma("GCC diagnostic 
>> ignored \"-Wformat-nonliteral\"") \
>>                                            _Pragma("GCC diagnostic 
>> ignored \"-Wformat-security\"")
>>   #define PRAGMA_FORMAT_IGNORED _Pragma("GCC diagnostic ignored 
>> \"-Wformat\"")
>> +#define PRAGMA_DEPRECATED_IGNORED _Pragma("GCC diagnostic ignored 
>> \"-Wdeprecated-declarations\"")
>>
>>   #if defined(__clang_major__) && \
>>         (__clang_major__ >= 4 || \
>>
>>
>> Thanks!
>>