[8u] RFR: 8219772: EXTRA_CFLAGS not being picked up for assembler files

[Andrew John Hughes]

On 11/03/2019 10:45, Severin Gehwolf wrote:
> Hi,
> 
> Could somebody please review this one-liner change for the 8u (OpenJDK)
> build system? The issue at hand is that for assembler source files
> extra C flags are not being passed to the compiler (GCC in the Linux
> case). This is a problem for instrumented builds to facilitate checks
> on produced binaries in terms of optimization flags and other build-
> time invariants[1]. The patch doesn't affect builds without extra C-
> flags. Thus, risk should be minimal.
> 
> This is an 8u-only change. The new build system in JDK 11 and up seems
> to handle these cases correctly.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8219772
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8219772/01/webrev/
> 
> Testing: Compiling with extra cflags, inspecting build logs for
> assembler source files on Linux x86_64
> 
> Thoughts?
> 
> Thanks,
> Severin
> 
> [1] https://developers.redhat.com/blog/2019/02/04/annocheck-examining-the-contents-of-binary-files/
> 

Surely the correct way to do this is to add an --with-extra-asflags
option rather than abuse flags for the C compiler?

The 11 version in make/autoconf/flags-other.m4 states:

  # Misuse EXTRA_CFLAGS to mimic old behavior

  $2JVM_ASFLAGS="$JVM_BASIC_ASFLAGS ${$2EXTRA_CFLAGS}"

which suggests this might not be the best way to do this. I'm not sure
what old behaviour it is trying to emulate if 8u doesn't support this.

Either way, I think this is a change that should wait until 8u222 at
this point.

Thanks,
-- 
Andrew :)

Senior Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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