Re: [PATCH v3 3/4] powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS

Steven Rostedt [off-list ref] writes:

On Mon, 14 May 2018 13:52:27 +1000
Nicholas Piggin [off-list ref] wrote:

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

...

quoted

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 191eb949d52c..3c67304a7425 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl

@@ -274,6 +274,13 @@ if ($arch eq "x86_64") {
     if ($bits == 64) {
 	$type = ".quad";
     }
+    if ($endian eq "big") {
+	    $cc .= " -mbig-endian ";
+	    $ld .= " -EB ";
+    } else {
+	    $cc .= " -mlittle-endian ";
+	    $ld .= " -EL ";
+    }

Have you tried building all current archs with function tracing enabled
to make sure this doesn't break any of them? I can do it if you want.

We shouldn't need to should we? This is only touching powerpc specific
code (if I understand perl that is).

eg:

$ git diff -U9 scripts/recordmcount.pl

diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl
index 191eb949d52c..3c67304a7425 100755
--- a/scripts/recordmcount.pl
+++ b/scripts/recordmcount.pl

@@ -268,18 +268,25 @@ if ($arch eq "x86_64") {
 } elsif ($arch eq "powerpc") {
     $local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
     # See comment in the sparc64 section for why we use '\w'.
     $function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?\\w*?)>:";
     $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";
 
     if ($bits == 64) {
        $type = ".quad";
     }
+    if ($endian eq "big") {
+           $cc .= " -mbig-endian ";
+           $ld .= " -EB ";
+    } else {
+           $cc .= " -mlittle-endian ";
+           $ld .= " -EL ";
+    }
 
 } elsif ($arch eq "arm") {
     $alignment = 2;
     $section_type = '%progbits';
     $mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_ARM_(CALL|PC24|THM_CALL)" .
                        "\\s+(__gnu_mcount_nc|mcount)\$";
 
 } elsif ($arch eq "arm64") {
     $alignment = 3;

cheers