Use C preprocessor comments in assembly headers.
We generate .S files for assembly, which means they run through the C
preprocessor first. In gas targets where # is the comment marker, there
is a conflict with cpp directives.
The comments actually rely on #This and #source not being directives. If
I begin a line with "if", the build fails. Since the C preprocessor is
responsible for removing C preprocessor comments, we should be able to
safely use // everywhere with less ambiguity.
(In fact, we were already relying on this for 32-bit ARM. The 32-bit ARM
gas line comment marker is @. 64-bit ARM uses //, and x86/x86_64/ppc64
use #.)
This reportedly causes issues for goma. See
https://bugs.chromium.org/p/boringssl/issues/detail?id=448#c3
Bug: 448
Change-Id: Ib58f3152691c1dbcccfc045f21f486b56824283d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/49965
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/perlasm/ppc-xlate.pl b/crypto/perlasm/ppc-xlate.pl
index d62ae01..fff9c00 100644
--- a/crypto/perlasm/ppc-xlate.pl
+++ b/crypto/perlasm/ppc-xlate.pl
@@ -256,8 +256,8 @@
};
print <<___;
-# This file is generated from a similarly-named Perl script in the BoringSSL
-# source tree. Do not edit by hand.
+// This file is generated from a similarly-named Perl script in the BoringSSL
+// source tree. Do not edit by hand.
#if defined(__has_feature)
#if __has_feature(memory_sanitizer) && !defined(OPENSSL_NO_ASM)
diff --git a/crypto/perlasm/x86_64-xlate.pl b/crypto/perlasm/x86_64-xlate.pl
index 04abd0b..e3745f8 100755
--- a/crypto/perlasm/x86_64-xlate.pl
+++ b/crypto/perlasm/x86_64-xlate.pl
@@ -1136,7 +1136,7 @@
########################################################################
{
- my $comment = "#";
+ my $comment = "//";
$comment = ";" if ($masm || $nasm);
print <<___;
$comment This file is generated from a similarly-named Perl script in the BoringSSL
diff --git a/crypto/perlasm/x86asm.pl b/crypto/perlasm/x86asm.pl
index 51f3766..c22421f 100644
--- a/crypto/perlasm/x86asm.pl
+++ b/crypto/perlasm/x86asm.pl
@@ -275,7 +275,7 @@
sub ::asm_finish
{ &file_end();
- my $comment = "#";
+ my $comment = "//";
$comment = ";" if ($win32);
print <<___;
$comment This file is generated from a similarly-named Perl script in the BoringSSL
