From bfdcb3bcba3a0364301c4c3dc7820ef1f689e8ea Mon Sep 17 00:00:00 2001
From: Andriy Gapon <avg@FreeBSD.org>
Date: Sat, 2 Feb 2013 11:58:35 +0000
Subject: [PATCH] print compiler version in the kernel banner

And provide kernel compiler version as a sysctl as well.
This is useful while we have gcc and clang cohabitation.
This could be even more useful when we have support
for external toolchains.

In cooperation with:	mjg
MFC after:		13 days
---
 sys/conf/newvers.sh  | 2 ++
 sys/kern/init_main.c | 1 +
 sys/kern/kern_mib.c  | 3 +++
 sys/sys/systm.h      | 1 +
 4 files changed, 7 insertions(+)

diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index 3cb211bbba4..1e5e24bdc6f 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -86,6 +86,7 @@ fi
 touch version
 v=`cat version` u=${USER:-root} d=`pwd` h=${HOSTNAME:-`hostname`} t=`date`
 i=`${MAKE:-make} -V KERN_IDENT`
+compiler_v=$($(${MAKE:-make} -V CC) -v 2>&1 | grep 'version')
 
 for dir in /bin /usr/bin /usr/local/bin; do
 	if [ -x "${dir}/svnversion" ] && [ -z ${svnversion} ] ; then
@@ -159,6 +160,7 @@ $COPYRIGHT
 
 char sccs[sizeof(SCCSSTR) > 128 ? sizeof(SCCSSTR) : 128] = SCCSSTR;
 char version[sizeof(VERSTR) > 256 ? sizeof(VERSTR) : 256] = VERSTR;
+char compiler_version[] = "${compiler_v}";
 char ostype[] = "${TYPE}";
 char osrelease[sizeof(RELSTR) > 32 ? sizeof(RELSTR) : 32] = RELSTR;
 int osreldate = ${RELDATE};
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 00b1c3f90cd..a92b6dbab5b 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -325,6 +325,7 @@ print_version(void *data __unused)
 	while (len > 0 && version[len - 1] == '\n')
 		len--;
 	printf("%.*s %s\n", len, version, machine);
+	printf("%s\n", compiler_version);
 }
 
 SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t,
diff --git a/sys/kern/kern_mib.c b/sys/kern/kern_mib.c
index 29864a891b6..36cc4b088b5 100644
--- a/sys/kern/kern_mib.c
+++ b/sys/kern/kern_mib.c
@@ -99,6 +99,9 @@ SYSCTL_INT(_kern, KERN_OSREV, osrevision, CTLFLAG_RD|CTLFLAG_CAPRD,
 SYSCTL_STRING(_kern, KERN_VERSION, version, CTLFLAG_RD|CTLFLAG_MPSAFE,
     version, 0, "Kernel version");
 
+SYSCTL_STRING(_kern, KERN_VERSION, compiler_version, CTLFLAG_RD|CTLFLAG_MPSAFE,
+    compiler_version, 0, "Version of compiler used to compile kernel");
+
 SYSCTL_STRING(_kern, KERN_OSTYPE, ostype, CTLFLAG_RD|CTLFLAG_MPSAFE|
     CTLFLAG_CAPRD, ostype, 0, "Operating system type");
 
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 7c3f13e2af2..3b1e8def509 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -49,6 +49,7 @@ extern int cold;		/* nonzero if we are doing a cold boot */
 extern int rebooting;		/* kern_reboot() has been called. */
 extern const char *panicstr;	/* panic message */
 extern char version[];		/* system version */
+extern char compiler_version[];	/* system version */
 extern char copyright[];	/* system copyright */
 extern int kstack_pages;	/* number of kernel stack pages */