[cfe-dev] Aarch64 ASM quirk

[Joel Winarske via cfe-dev]

I added a Sed step.  I double up the semicolon, and only convert for  Clang
aarch64-unkown-windows.  Not ideal, but it works.

I'm onto lld-link problems now.


Thanks for all the input.

On Mon, Nov 11, 2019, 9:41 AM Peter Smith <peter.smith at linaro.org> wrote:

> I don't think that there is an alternative separator for the Windows
> target as both the CommentString and SeparatorString are ";". I don't
> have a strong opinion over changing the comment character for AArch64
> Windows target. Probably best addressed by the people that use/develop
> on it. It is true that armasm(64) uses ";" as its comment character,
> but as Martin says many of the directives and other bits of syntax are
> different so at least some form of scripted conversion is likely to be
> needed anyway.
>
> Peter
>
> On Fri, 8 Nov 2019 at 20:31, Joel Winarske <joel.winarske at gmail.com>
> wrote:
> >
> > Ah yes, a comment...
> >
> > Is there a seperator character that works?
> >
> > On Fri, Nov 8, 2019, 5:43 AM Martin Storsjö <martin at martin.st> wrote:
> >>
> >> On Fri, 8 Nov 2019, Peter Smith via cfe-dev wrote:
> >>
> >> > Hello Joel,
> >> >
> >> > The root cause is that the AArch64 target is using ';' as a comment
> >> > character, whereas in GNU as (and many other llvm MC backends),  the
> >> > ';' is used as a statement separator. In your example only the text up
> >> > to ';' is being parsed.
> >> >
> >> > Looking at AArch64MCAsmInfo.cpp
> >> >  SeparatorString = "%%";
> >> >  CommentString = ";";
> >> >
> >> > I think that this is likely to have been derived from Darwin as I
> >> > can't get the "%%" to work as a statement separator for
> >> > aarch64-linux-gnu targets.
> >>
> >> I don't know about the separator string, but if you look in
> >> AArch64MCAsmInfoELF (and AArch64MCAsmInfoGNUCOFF), the comment string is
> >> set to "//" instead.
> >>
> >> I suggested changing this for the GNUCOFF (aka MinGW) target, as
> mingw-w64
> >> contains a number of assembler files that uses this pattern of piling
> up a
> >> few directives on one line.
> >>
> >> As there's very little predecent for GNU style .s assembler for
> >> aarch64-windows-msvc targets (as the official tool from microsoft,
> >> armasm64, uses a totally different syntax), I'm guess it would be fine
> to
> >> change the comment string to "//" there as well, as there apparently is
> a
> >> demand for it?
> >>
> >> With a target that doesn't treat ";" as a comment char, your assembler
> >> example errors out due to issues with the section and type directives
> >> though, now that they actually are interpreted and not stripped out as
> >> comments.
> >>
> >> // Martin
> >>
>
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