From 725fc96b706c57ef8ceca5e7d82b175d9a72e845 Mon Sep 17 00:00:00 2001
From: Philipp Stephani <phst@google.com>
Date: Sun, 11 Apr 2021 16:50:29 +0200
Subject: [PATCH] Use pkg-config to check for libseccomp.

We need at list version 2.4.0 of libseccomp for seccomp-filter.c to
build cleanly.

* configure.ac: Use pkg-config to check for libseccomp.
* lib-src/Makefile.in (HAVE_LIBSECCOMP, LIBSECCOMP_LIBS)
(LIBSECCOMP_CFLAGS): New variables.
(SECCOMP_FILTER, seccomp-filter$(EXEEXT)): Use them.
---
 configure.ac        | 8 ++++----
 lib-src/Makefile.in | 9 ++++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index cb4a9ab2876..681c25b052c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4189,10 +4189,10 @@ AC_CHECK_HEADERS(
     #include <linux/seccomp.h>
     ]])])
 
-LIBSECCOMP=
-AC_CHECK_HEADER([seccomp.h],
-  [AC_CHECK_LIB([seccomp], [seccomp_init], [LIBSECCOMP=-lseccomp])])
-AC_SUBST([LIBSECCOMP])
+EMACS_CHECK_MODULES([LIBSECCOMP], [libseccomp >= 2.4.0])
+AC_SUBST([HAVE_LIBSECCOMP])
+AC_SUBST([LIBSECCOMP_LIBS])
+AC_SUBST([LIBSECCOMP_CFLAGS])
 
 OLD_LIBS=$LIBS
 LIBS="$LIB_PTHREAD $LIB_MATH $LIBS"
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index 5870286cd5c..b4143b33554 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -189,10 +189,12 @@ LIB_WSOCK32=@LIB_WSOCK32@
 ## Extra libraries for etags
 LIBS_ETAGS = $(LIB_CLOCK_GETTIME) $(LIB_GETRANDOM)
 
-LIBSECCOMP=@LIBSECCOMP@
+HAVE_LIBSECCOMP=@HAVE_LIBSECCOMP@
+LIBSECCOMP_LIBS=@LIBSECCOMP_LIBS@
+LIBSECCOMP_CFLAGS=@LIBSECCOMP_CFLAGS@
 
 # Currently, we can only generate seccomp filter files for x86-64.
-ifneq ($(LIBSECCOMP),)
+ifeq ($(HAVE_LIBSECCOMP),yes)
 ifeq ($(shell uname -m),x86_64)
 SECCOMP_FILTER=1
 endif
@@ -419,7 +421,8 @@ emacsclient.res: ../nt/emacsclient.rc $(NTINC)/../icons/emacs.ico
 
 ifeq ($(SECCOMP_FILTER),1)
 seccomp-filter$(EXEEXT): $(srcdir)/seccomp-filter.c $(config_h)
-	$(AM_V_CCLD)$(CC) $(ALL_CFLAGS) $< $(LIBSECCOMP) -o $@
+	$(AM_V_CCLD)$(CC) $(ALL_CFLAGS) $(LIBSECCOMP_CFLAGS) $< \
+	  $(LIBSECCOMP_LIBS) -o $@
 
 seccomp-filter.bpf seccomp-filter.pfc: seccomp-filter$(EXEEXT)
 	$(AM_V_GEN)./seccomp-filter$(EXEEXT) \