Subject: Re: [kvm-unit-tests PATCH v1 01/18] Makefile: Define __ASSEMBLY__ for assembly files

From: Alexandru Elisei <[email-masked]>
Date: Thu, 15 Feb 2024 16:05:56 +0000

Hi Drew,

On Mon, Jan 15, 2024 at 01:44:17PM +0100, Andrew Jones wrote:
> On Thu, Nov 30, 2023 at 04:07:03AM -0500, Shaoqin Huang wrote:
> > From: Alexandru Elisei <[email-masked]>
> > 
> > There are 25 header files today (found with grep -r "#ifndef __ASSEMBLY__)
> > with functionality relies on the __ASSEMBLY__ prepocessor constant being
> > correctly defined to work correctly. So far, kvm-unit-tests has relied on
> > the assembly files to define the constant before including any header
> > files which depend on it.
> > 
> > Let's make sure that nobody gets this wrong and define it as a compiler
> > constant when compiling assembly files. __ASSEMBLY__ is now defined for all
> > .S files, even those that didn't set it explicitely before.
> > 
> > Reviewed-by: Nikos Nikoleris <[email-masked]>
> > Reviewed-by: Andrew Jones <[email-masked]>
> > Signed-off-by: Alexandru Elisei <[email-masked]>
> > Signed-off-by: Shaoqin Huang <[email-masked]>
> > ---
> >  Makefile           | 5 ++++-
> >  arm/cstart.S       | 1 -
> >  arm/cstart64.S     | 1 -
> >  powerpc/cstart64.S | 1 -
> >  4 files changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/Makefile b/Makefile
> > index 602910dd..27ed14e6 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -92,6 +92,9 @@ CFLAGS += -Woverride-init -Wmissing-prototypes -Wstrict-prototypes
> >  
> >  autodepend-flags = -MMD -MP -MF $(dir $*).$(notdir $*).d
> >  
> > +AFLAGS  = $(CFLAGS)
> > +AFLAGS += -D__ASSEMBLY__
> > +
> >  LDFLAGS += -nostdlib $(no_pie) -z noexecstack
> >  
> >  $(libcflat): $(cflatobjs)
> > @@ -113,7 +116,7 @@ directories:
> >  	@mkdir -p $(OBJDIRS)
> >  
> >  %.o: %.S
> > -	$(CC) $(CFLAGS) -c -nostdlib -o $@ $<
> > +	$(CC) $(AFLAGS) -c -nostdlib -o $@ $<
> 
> I think we can drop the two hunks above from this patch and just rely on
> the compiler to add __ASSEMBLY__ for us when compiling assembly files.

I think the precompiler adds __ASSEMBLER__, not __ASSEMBLY__ [1]. Am I
missing something?

[1] https://gcc.gnu.org/onlinedocs/cpp/macros/predefined-macros.html#c.__ASSEMBLER__

Thanks,
Alex

> 
> Thanks,
> drew
> 
> >  
> >  -include */.*.d */*/.*.d
> >  
> > diff --git a/arm/cstart.S b/arm/cstart.S
> > index 3dd71ed9..b24ecabc 100644
> > --- a/arm/cstart.S
> > +++ b/arm/cstart.S
> > @@ -5,7 +5,6 @@
> >   *
> >   * This work is licensed under the terms of the GNU LGPL, version 2.
> >   */
> > -#define __ASSEMBLY__
> >  #include <auxinfo.h>
> >  #include <asm/assembler.h>
> >  #include <asm/thread_info.h>
> > diff --git a/arm/cstart64.S b/arm/cstart64.S
> > index bc2be45a..a8ad6dc8 100644
> > --- a/arm/cstart64.S
> > +++ b/arm/cstart64.S
> > @@ -5,7 +5,6 @@
> >   *
> >   * This work is licensed under the terms of the GNU GPL, version 2.
> >   */
> > -#define __ASSEMBLY__
> >  #include <auxinfo.h>
> >  #include <asm/asm-offsets.h>
> >  #include <asm/assembler.h>
> > diff --git a/powerpc/cstart64.S b/powerpc/cstart64.S
> > index 34e39341..fa32ef24 100644
> > --- a/powerpc/cstart64.S
> > +++ b/powerpc/cstart64.S
> > @@ -5,7 +5,6 @@
> >   *
> >   * This work is licensed under the terms of the GNU LGPL, version 2.
> >   */
> > -#define __ASSEMBLY__
> >  #include <asm/hcall.h>
> >  #include <asm/ppc_asm.h>
> >  #include <asm/rtas.h>
> > -- 
> > 2.40.1
> >