master 17d20bb 1/2: Generate Seccomp filters only if we have the necessary constants.

[Philipp Stephani]

branch: master
commit 17d20bb3cbb233ed0d94c3f1f9f3db768f526223
Author: Philipp Stephani <phst@google.com>
Commit: Philipp Stephani <phst@google.com>

    Generate Seccomp filters only if we have the necessary constants.
    
    If we're missing SECCOMP_SET_MODE_FILTER, the seccomp-filter build
    fails.  Reuse the existing HAVE_SECCOMP configuration variable, which
    checks for these macros.
    
    * configure.ac (HAVE_SECCOMP): Substitute in Makefile.in.
    * lib-src/Makefile.in (HAVE_SECCOMP): New variable.
    (SECCOMP_FILTER): Define only if HAVE_SECCOMP.
---
 configure.ac        | 1 +
 lib-src/Makefile.in | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index 169ffc5..d3647bd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4188,6 +4188,7 @@ AC_CHECK_HEADERS(
     [[
     #include <linux/seccomp.h>
     ]])])
+AC_SUBST([HAVE_SECCOMP])
 
 EMACS_CHECK_MODULES([LIBSECCOMP], [libseccomp >= 2.4.0])
 AC_SUBST([HAVE_LIBSECCOMP])
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index 091f4fb..923d0cf 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -189,11 +189,13 @@ LIB_WSOCK32=@LIB_WSOCK32@
 ## Extra libraries for etags
 LIBS_ETAGS = $(LIB_CLOCK_GETTIME) $(LIB_GETRANDOM)
 
+HAVE_SECCOMP=@HAVE_SECCOMP@
 HAVE_LIBSECCOMP=@HAVE_LIBSECCOMP@
 LIBSECCOMP_LIBS=@LIBSECCOMP_LIBS@
 LIBSECCOMP_CFLAGS=@LIBSECCOMP_CFLAGS@
 
 # Currently, we can only generate seccomp filter files for x86-64.
+ifeq ($(HAVE_SECCOMP),yes)
 ifeq ($(HAVE_LIBSECCOMP),yes)
 ifeq ($(shell uname -m),x86_64)
 # We require SECCOMP_RET_KILL_PROCESS, which is only available in
@@ -205,6 +207,7 @@ SECCOMP_FILTER=1
 endif
 endif
 endif
+endif
 
 ifeq ($(SECCOMP_FILTER),1)
 DONT_INSTALL += seccomp-filter$(EXEEXT)