minimal gcc version for jdk/jdk and usage of -Wno-int-in-bool-context flag in HS build

[Baesken, Matthias]

Hi  Aleksey ,  I tried  with  gcc 6.2   not  6.3  maybe this makes a difference .

Unfortunately I cannot see  your  exact gcc/g++  compile calls from the logfile .
Do you have  "-Wall"  set  which seems to be necessary to enable  the additional flag ?

https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html

-Wint-in-bool-context  
Warn for suspicious use of integer values where boolean values are expected, such as conditional expressions (?:) using non-boolean integer constants in boolean context, like if (a <= b ? 2 : 3). 
Or left shifting of signed integers in boolean context, like for (a = 0; 1 << a; a++);. Likewise for all kinds of multiplications regardless of the data type. 
This warning is enabled by -Wall.


The   configure flag  --with-extra-cflags   is not used by us .

Best regards, Matthias



> -----Original Message-----
> From: Aleksey Shipilev <shade at redhat.com>
> Sent: Mittwoch, 31. Oktober 2018 16:49
> To: Baesken, Matthias <matthias.baesken at sap.com>; 'build-
> dev at openjdk.java.net' <build-dev at openjdk.java.net>
> Subject: Re: minimal gcc version for jdk/jdk and usage of -Wno-int-in-bool-
> context flag in HS build
> 
> On 10/31/2018 04:40 PM, Baesken, Matthias wrote:
> >
> https://hg.openjdk.java.net/jdk/jdk/file/896e80158d35/make/hotspot/lib/C
> ompileJvm.gmk
> >
> > DISABLED_WARNINGS_gcc := extra parentheses comment unknown-
> pragmas address \
> >     delete-non-virtual-dtor char-subscripts array-bounds int-in-bool-context
> \
> >     ignored-qualifiers  missing-field-initializers implicit-fallthrough \
> >     empty-body strict-overflow sequence-point maybe-uninitialized \
> >     misleading-indentation
> >
> >
> > However   int-in-bool-context   (  -Wnoint-in-bool-context  )   seems to be
> available only  in gcc 7 + .
> > Example call  with gcc  6  leads to a warning  :
> 
> Current jdk/jdk build works fine with 6.3.0 for me:
> 
> https://builds.shipilev.net/openjdk-jdk/openjdk-jdk-b441-20181029-jdk-
> 12+17-linux-x86_64-fastdebug.configure.log
> 
> https://builds.shipilev.net/openjdk-jdk/openjdk-jdk-b441-20181029-jdk-
> 12+17-linux-x86_64-fastdebug.build.log
> 
> Is this the indication that build system actually probes the warnings before
> trying warning options?
> 
> The troubles start when you supply additional options, apparently:
>   https://bugs.openjdk.java.net/browse/JDK-8211088
> 
> -Aleksey