Request for review: 7102489: RFE: cleanup jlong typedef on __APPLE__ and _LP64 systems

[Mikael Vidstedt]

On 2013-01-12 15:05, David Holmes wrote:
> Sorry Harold I didn't see this before my other reply. Now I understand 
> your problem. We either have to:
>
> a) typedef long long jlong on all platforms; or
> b) special case the typedef for jlong on Apple; or
> c) special case the typedef for JLONG_FORMAT on Apple
>
> But even if we do (a) any platform that defines int64_t differently to 
> our jlong will mean we still need distinct format specifiers. Further 
> unless we know how int64_t is defined on a given platform we don't 
> know what format specifier to use (%ld or %lld).
>
> Do compilers that provide things like int64_t also define a format 
> specifier macro?

It's part of the C99 standard (not sure about c++) - the types have 
corresponding format specifier macros called PRI*, defined in 
inttypes.h. For example PRId64, PRIu64 or PRIx64 can be used to print 
the int64_t/uint64_t equivalents of %d, %u and %x respectively. Our own 
internal format macros (SIZE_FORMAT, INTPTR_FORMAT etc) are defined as 
derivatives of these.

In general "long" tends to be a mess... :(

/Mikael

>
> David
> -----
>
> On 12/01/2013 12:36 AM, harold seigel wrote:
>> Hi Vladimir,
>>
>> Thank you for your comments.  Mac OS defines int64_t as 'long long'.
>> So, int64_t needs a different format specifier than jlong, which this
>> fix now defines as 'long'.  This is because, as shown below, the Mac OS
>> C++ compiler is picky about format specifiers for values of types 'long
>> long' and 'long'.
>>
>>     $ gcc lld.cpp
>>     lld.cpp: In function int main(int, char**):
>>     lld.cpp:8: warning: format %lld expects type long long int, but
>>     argument 2 has type long int
>>     lld.cpp:9: warning: format %ld expects type long int, but argument 2
>>     has type int64_t
>>
>>     $ cat lld.cpp
>>     #include <stdio.h>
>>     #include <stdint.h>
>>
>>     int main(int argc, char * argv[]) {
>>        long long_val = 5;
>>        int64_t int64_val = 8;
>>        printf("long_val: %ld\n", long_val);
>>        printf("long_val: %lld\n", long_val); <---- Line 8
>>        printf("int64_val: %ld\n", int64_val); <--- Line 9
>>        printf("int64_val: %lld\n", int64_val);
>>        return 0;
>>     }
>>
>> That is why I added JLONG_FORMAT.
>>
>> Thanks, Harold
>>
>> On 1/10/2013 9:46 PM, Vladimir Kozlov wrote:
>>> Can we just define INT64_FORMAT as platform specific and use it
>>> instead of adding new JLONG_FORMAT?
>>>
>>> Thanks,
>>> Vladimir
>>>
>>> On 1/10/13 10:39 AM, harold seigel wrote:
>>>> Hi,
>>>>
>>>> Please review the following changes to fix bug 7102489.
>>>>
>>>> Summary:
>>>> The definition of type jlong differed on Mac OS from the other 64 bit
>>>> platforms.  This fix makes it consistent.  In order to do this, 
>>>> this fix
>>>> defines new macros, JLONG_FORMAT and JULONG_FORMAT, for printing and
>>>> scanning jlongs and julongs.
>>>>
>>>> This fix also does some cleanup.  Methods jlong_format_specifier() and
>>>> julong_format_specifer() were removed and some format specifiers were
>>>> replaced with appropriate macros.
>>>>
>>>> Open webrev at http://cr.openjdk.java.net/~hseigel/bug_7102489/
>>>> <http://cr.openjdk.java.net/%7Ehseigel/bug_7102489/>
>>>> Bug link at http://bugs.sun.com/view_bug.do?bug_id=7102489
>>>>
>>>> Thank you,
>>>> Harold