Review request (s): 7116081: USE_PRECOMPILED_HEADER=0 triggers a single threaded build of the JVM

[David Holmes]

On 29/11/2011 6:47 PM, Stefan Karlsson wrote:
> Updated webrev: http://cr.openjdk.java.net/~stefank/7116081/webrev.2/
>
> The rationale for this change is inlined:
<snip>
> While doing that I found another issue. In gcc.make we try to redefine
> USE_PRECOMPILED_HEADER:
>
> 88 ifneq ($(USE_PRECOMPILED_HEADER),0)
> 89 USE_PRECOMPILED_HEADER=1
>
>
> That doesn't work,

Why doesn't it work? We use similar logic elsewhere in the makefiles to 
ensure that if a variable is defined then it has an explicit value (0, 
1, true or false etc).

> so setting USE_PRECOMPILED_HEADER=<arbitrary string
> (not 0)> on the command line will leave the precompiled headers on, but
> later logic:
>
> 219 ifneq ($(USE_PRECOMPILED_HEADER),1)
> 220 CFLAGS += -DDONT_USE_PRECOMPILED_HEADER
>
> will empty the precompiled.hpp file. From precompiled.hpp:
>
> // Precompiled headers are turned off for Sun Studion,
> // or if the user passes USE_PRECOMPILED_HEADER=0 to the makefiles.
> #ifndef DONT_USE_PRECOMPILED_HEADER
>
> In the new webrev I've changed all places where we read
> USE_PRECOMPILED_HEADER to always compare against 0.

That makes sense.

Looks good to me.

David
-----

> thanks,
> StefanK
>
>>
>>
>> The removal of:
>>
>> PrecompiledOption = -DUSE_PRECOMPILED_HEADER
>>
>> seems okay.
>>
>> Cheers,
>> David
>>
>>
>