RFR(L): 8161259: Simplify including platform files.

[David Holmes]

On 15/07/2016 5:30 PM, Lindenmaier, Goetz wrote:
> HI Kim,
>
> thanks for this version of the macros, it's working on all the platforms
> I can build.
>
> Actually, I would prefer having the '_' in the macros and not on the
> command line. This way, parts of the name construction are in
> CompileJvm.gmk, other parts are in macros.hpp.  But constructing
> the search path is also in the makefile, and uses the very same string
> as the file suffixes. (Without '_', one could include that in the macro, too.)
>
> But overall, I consider this a detail and am as fine with your solution
> as with the SUB() macros.  What is better is that the linux=1 etc
> problems are avoided.
>
> Any more opinions whether the macros should be upper case?

Yeah they probably should be.

Thanks,
David

> Best regards,
>   Goetz.
>
>
>> -----Original Message-----
>> From: Kim Barrett [mailto:kim.barrett at oracle.com]
>> Sent: Donnerstag, 14. Juli 2016 23:20
>> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
>> Cc: Andrew Haley <aph at redhat.com>; hotspot-compiler-
>> dev at openjdk.java.net; hotspot-runtime-dev at openjdk.java.net
>> Subject: Re: RFR(L): 8161259: Simplify including platform files.
>>
>>> On Jul 14, 2016, at 3:18 PM, Lindenmaier, Goetz
>> <goetz.lindenmaier at sap.com> wrote:
>>>
>>> Hi everybody,
>>>
>>> please take into account that these macros are only used within 20 lines of
>>> the file macro.hpp.  The code everybody needs to understand is
>>>    #include cpu_header(bytes)
>>> which, in this example, is in file bytes.hpp and expands to
>> bytes_<cpu>.hpp.
>>> There are six of these, for cpu/os/os_cpu and .hpp/.inline.hpp.
>>>
>>> I really would appreciate if I don't have to spend days editing the
>>> 12 lines that use SUB().
>>>
>>> @Kim
>>> I'm working on the s390 port, and posted my current progress claiming
>>> that the biggest shared change I need to do is adding the #includes.
>>> http://mail.openjdk.java.net/pipermail/hotspot-dev/2016-
>> July/023782.html
>>> This arose the discussion about the includes.
>>> Later I posted a prototype of what Volker proposed in that discussion
>>> to that thread:
>>> http://mail.openjdk.java.net/pipermail/hotspot-dev/2016-
>> July/023934.html
>>> which I now turned into a RFR.
>>
>> Thanks.
>>
>> I think I see what happened to the email thread for me; it looks like one of
>> Andrew’s replies went to hotspot-compiler-dev but not hotspot-runtime-
>> dev,
>> and I was not subscribed to the compiler list this morning.
>>
>> I like the idea, just quibbling over details.  I've only reviewed
>> macros.hpp so far; the rest looks like it can wait until the details
>> are settled.
>>
>> ------------------------------------------------------------------------------
>> src/share/vm/utilities/macros.hpp
>>  470 // Helper macros to workaround existing #defines that spoil
>>  471 // the macro expansion. Detected so far: linux=1, sparc=1.
>>
>> This issue can be dodged by making the leading underscore part of the
>> expansion for INCLUDE_SUFFIX_*, e.g. in make/lib/CompileJvm.gmk, use
>> instead
>>
>>   66 JVM_CFLAGS_TARGET_DEFINES += \
>>   67     -DINCLUDE_SUFFIX_OS=_$(HOTSPOT_TARGET_OS) \
>>   68     -DINCLUDE_SUFFIX_CPU=_$(HOTSPOT_TARGET_CPU_ARCH) \
>>
>> Note the insertion of leading "_" for the values.
>>
>> Then the whole macro block can be written as
>>
>> #define cpu_header_stem(basename) PASTE_TOKENS(basename,
>> INCLUDE_SUFFIX_CPU)
>> #define os_header_stem(basename) PASTE_TOKENS(basename,
>> INCLUDE_SUFFIX_OS)
>> #define os_cpu_header_stem(basename) PASTE_TOKENS(basename,
>> PASTE_TOKENS(INCLUDE_SUFFIX_OS, INCLUDE_SUFFIX_CPU))
>>
>> #define cpu_header(basename) XSTR(cpu_header_stem(basename).hpp)
>> #define cpu_header_inline(basename)
>> XSTR(cpu_header_stem(basename).inline.hpp)
>> #define os_header(basename) XSTR(os_header_stem(basename).hpp)
>> #define os_header_inline(basename)
>> XSTR(os_header_stem(basename).inline.hpp)
>> #define os_cpu_header(basename)
>> XSTR(os_cpu_header_stem(basename).hpp)
>> #define os_cpu_header_inline(basename)
>> XSTR(os_cpu_header_stem(basename).inline.hpp)
>>
>> And SUB is no longer used...
>>
>> If some future build system wants brackets instead of strings, just
>> replace XSTR(...) with <...>.
>>
>> We lose if _linux or _sparc (for example) are defined, but that's true
>> for the webrev.01 code too.  But note that underscore followed by a
>> lowercase letter is not in the reserved word pattern for C/C++.
>>
>> BTW, my preference would be to use uppercase for the macro names.  I
>> don't know what others think about that.
>>
>> ------------------------------------------------------------------------------
>