RFR : [XS] 8209942: [epsilon] range function for EpsilonTLABElasticity causes compiler warning

[Baesken, Matthias]

Hi Erik,   looks like gcc7  and  current clang   already  print  the macro  and show it  plus the position of  the error / warning   in it .

See   https://clang.llvm.org/diagnostics.html       Automatic Macro Expansion    for an example .

With Visual Studio I could not  find  anything similar ,   I asked our local Visual Studio experts for help,  maybe I overlooked something .
  
Best regards, Matthias


> ------------------------------
> 
> Message: 4
> Date: Wed, 5 Sep 2018 09:57:06 -0700
> From: Erik Joelsson <erik.joelsson at oracle.com>
> To: "Baesken, Matthias" <matthias.baesken at sap.com>,
> 	"'hotspot-dev at openjdk.java.net'" <hotspot-
> dev at openjdk.java.net>,
> 	"'build-dev at openjdk.java.net'" <build-dev at openjdk.java.net>
> Cc: "Simonis, Volker" <volker.simonis at sap.com>
> Subject: Re: RFR : [XS] 8209942: [epsilon] range function for
> 	EpsilonTLABElasticity causes compiler warning
> Message-ID: <c77b314f-7c7c-dbe0-38bb-9a07a726bc3b at oracle.com>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> 
> 
> On 2018-09-05 04:03, Baesken, Matthias wrote:
> > Hello,  when compiling    jdk/jdk   on Windows,  (with VS2017 update level
> 15.8 and not disabling warnings as errors )
> > I came across  this  warning   leading to build error :
> >
> > C:/jdk-just-
> clone/src/hotspot/share/runtime/flags/jvmFlagRangeList.cpp(341): error
> C2220: warning treated as error - no 'object' file generated
> > C:/jdk-just-
> clone/src/hotspot/share/runtime/flags/jvmFlagRangeList.cpp(341): warning
> C4305: 'argument': truncation from 'const intx' to 'double'
> >
> > Would have been helpful  to have a compiler flag set  that really   ***shows
> the code***  leading to the warning/error  (because it comes from heavy
> macro expansion).
> >
> Do you know of such a flag? If so we certain would like to add it.
> 
> /Erik
> 
>