1486905 - add a way to differentiate between host linker and target linker on Windows

Status: RESOLVED FIXED

(Firefox Build System :: General, enhancement)

Description

[Nathan Froyd [:froydnj]]

For host and target binaries, we used a single LINKER variable.  At the very least, we should have an explicit HOST_LINKER that defaults to whatever LINKER is, thereby offering the opportunity for somebody to override that value.

Comment 1

[(Away)]

I wonder if this would simplify the `WIN64_LINK` code?

Comment 2

[Nathan Froyd [:froydnj]]

Attachment: add a HOST_LINKER variable for cross windows builds

This setup seems to work well enough to enable me to link
HOST_SIMPLE_PROGRAMS with an AArch64-cross setup.  Necessary library
paths are passed to the linker via -LIBPATH and HOST_LDFLAGS rather than
letting MSVC fish them out of the environment.  The change to
HOST_SIMPLE_PROGRAMS to pass HOST_LDFLAGS was necessary for this to
work, in addition to the HOST_LINKER changes.

Untested on our actual Windows builds, though, pushing to try now...

Comment 3

[Nathan Froyd [:froydnj]]

Comment on attachment 9004701 [details] [diff] [review]
add a HOST_LINKER variable for cross windows builds

Never mind, apparently this breaks linting in interesting ways:

https://treeherder.mozilla.org/#/jobs?repo=try&revision=1d8cbc64703bd1c4ee55771d8122cf7d471b85ce

Maybe the correct path forward is not to use the target linker as the default?

Comment 4

[Nathan Froyd [:froydnj]]

Attachment: add a HOST_LINKER variable for cross windows builds

OK, so for some reason, trying to use the target linker as input for the host
didn't work out so well, so this patch just does redetection.

Comment 5

[(Away)]

Comment on attachment 9005211 [details] [diff] [review]
add a HOST_LINKER variable for cross windows builds

Review of attachment 9005211 [details] [diff] [review]:
-----------------------------------------------------------------

::: config/rules.mk
@@ +689,5 @@
>  $(HOST_SHARED_LIBRARY): $(HOST_OBJS) Makefile
>  	$(REPORT_BUILD)
>  	$(RM) $@
>  ifdef _MSC_VER
>  	# /!\ We assume host and target are using the same compiler

Is this comment still relevant after this patch?

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/345269b39c6c
add a HOST_LINKER variable for cross windows builds; r=dmajor

Comment 7

[Nathan Froyd [:froydnj]]

(In reply to David Major [:dmajor] from comment #5)
> ::: config/rules.mk
> @@ +689,5 @@
> >  $(HOST_SHARED_LIBRARY): $(HOST_OBJS) Makefile
> >  	$(REPORT_BUILD)
> >  	$(RM) $@
> >  ifdef _MSC_VER
> >  	# /!\ We assume host and target are using the same compiler
> 
> Is this comment still relevant after this patch?

No!  Removed it in the committed version, thanks for catching that.

Comment 8

[(not currently active) Ted Mielczarek]

(In reply to David Major [:dmajor] from comment #1)
> I wonder if this would simplify the `WIN64_LINK` code?

It could, if someone wanted to do the work to make our win32 builds actual cross-compiles. Right now they default to 32-bit for both:
13:30:40     INFO -  checking for host system type... i686-pc-mingw32
13:30:40     INFO -  checking for target system type... i686-pc-mingw32

Comment 9

[Raul Gurzau (:RaulG)]

https://hg.mozilla.org/mozilla-central/rev/345269b39c6c