Re: [PATCH v2 4/5] powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS

On Thu, 10 May 2018 23:03:08 +1000
Michael Ellerman [off-list ref] wrote:

Nicholas Piggin [off-list ref] writes:

quoted

The powerpc toolchain can compile combinations of 32/64 bit and
big/little endian, so it's convenient to consider, e.g.,

  `CC -m64 -mbig-endian`

To be the C compiler for the purpose of invoking it to build target
artifacts. So overriding the the CC variable to include thse flags
works for this purpose.

Unfortunately that is not compatible with the way the proposed new
Kconfig macro language will work.

After previous patches in this series, these flags can be carefully
passed in using flags instead.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/Makefile   | 16 +++++++++-------
 scripts/recordmcount.pl |  8 ++++++++  

We should probably at least Cc Rostedt on the recordmcount.pl change.

Sure I'll send another iteration after some more time for reviews and
cc him on it.

quoted

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 191eb949d52c..919711dd9d6c 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl

@@ -274,6 +274,14 @@ if ($arch eq "x86_64") {  

Despite what the above says you're patching the powerpc entry AFAICS, so
I guess that's pretty harmless.

Yeah I didn't think it was worth a separate patch.

quoted

     if ($bits == 64) {
 	$type = ".quad";
     }
+    $ld .= " -EB ";
+    if ($endian eq "big") {
+	    $cc .= " -mbig-endian ";
+	    $ld .= " -EB ";  

Don't we end up with two "-EB"s for the big endian case?

Or do I understand perl even less than I thought I did?

No I was testing things and that's leaked into the commit. Good eye. I
think it worked for le because the next -EL will override the first -EB,
but I'll take that out.

Thanks,
Nick