RFR: 8186780: clang-4.0 fastdebug assertion failure in os_linux_x86:os::verify_stack_alignment()

[Erik Joelsson]

Looks good to me.

/Erik


On 2018-06-20 16:49, Martin Buchholz wrote:
> Thanks Erik.
>
> On Wed, Jun 20, 2018 at 4:19 PM, Erik Joelsson 
> <erik.joelsson at oracle.com <mailto:erik.joelsson at oracle.com>> wrote:
>
>     Hello,
>
>     It's very probable that we have made several such mistakes with
>     our flags, since for the most part, we have a 1-1 mapping of
>     compiler and OS. We certainly appreciate correcting this whenever
>     possible. I don't have the expertise to verify your claim here,
>     but I will take your word for it.
>
>     The change looks ok, but there is already a big block of clang
>     specific stuff close by. Perhaps move this assignment there?
>
>
> Yes, that does look like a better place:
>
>  --- a/make/autoconf/flags-cflags.m4
> +++ b/make/autoconf/flags-cflags.m4
> @@ -470,14 +470,6 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
>      # COMMON to gcc and clang
>      TOOLCHAIN_CFLAGS_JVM="-pipe -fno-rtti -fno-exceptions \
>          -fvisibility=hidden -fno-strict-aliasing -fno-omit-frame-pointer"
> -
> -    if test "x$TOOLCHAIN_TYPE" = xclang; then
> -      # In principle the stack alignment below is cpu- and 
> ABI-dependent and
> -      # should agree with values of StackAlignmentInBytes in various
> -      # src/hotspot/cpu/*/globalDefinitions_*.hpp files, but this value
> -      # currently works for all platforms.
> -      TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM 
> -mno-omit-leaf-frame-pointer -mstack-alignment=16"
> -    fi
>    fi
>    if test "x$TOOLCHAIN_TYPE" = xgcc; then
> @@ -499,6 +491,12 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
>      # (see http://llvm.org/bugs/show_bug.cgi?id=7554)
>      TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM -flimit-debug-info"
> +    # In principle the stack alignment below is cpu- and 
> ABI-dependent and
> +    # should agree with values of StackAlignmentInBytes in various
> +    # src/hotspot/cpu/*/globalDefinitions_*.hpp files, but this value
> +    # currently works for all platforms.
> +    TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM 
> -mno-omit-leaf-frame-pointer -mstack-alignment=16"
> +
>      if test "x$OPENJDK_TARGET_OS" = xlinux; then
>        TOOLCHAIN_CFLAGS_JDK="-pipe"
>  TOOLCHAIN_CFLAGS_JDK_CONLY="-fno-strict-aliasing" # technically NOT 
> for CXX
>