libsandbox: rework abi syscall header generation

Probe the availability of multilib headers at configure time so that we
can show the status more cleanly.  This allows the header generation to
be done in parallel and not output confusing warning messages to users.

URL: https://bugs.gentoo.org/536582
Reported-by: cmue81@gmx.de
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

3 files changed, 53 insertions, 16 deletions

diff --git a/configure.ac b/configure.ac
index dec9686..b57263e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -50,19 +50,45 @@ dnl multiple personality support (x86 & x86_64: multilib)
 AC_MSG_CHECKING([for multiple personalities])
 AC_ARG_ENABLE([schizo],
 	[AS_HELP_STRING([--enable-schizo],[Support multiple personalities])],
-	[],[enable_schizo="yes"])
-SB_SCHIZO_SETTINGS="no"
-if test "x$enable_schizo" = "xyes" ; then
-	case $host_alias in
-		x86_64*linux*) SB_SCHIZO_SETTINGS="x86_64:-m64 x86:-m32 x32:-mx32";;
+	[],[enable_schizo="auto"])
+AC_MSG_RESULT([$enable_schizo])
+SB_SCHIZO_SETTINGS=
+AC_DEFUN([SB_CHECK_SCHIZO],[dnl
+		AC_MSG_CHECKING([checking for $1/$2 compiler support])
+		ac_save_CFLAGS=$CFLAGS
+		CFLAGS="$CFLAGS $2"
+		AC_TRY_COMPILE([
+			#include <stdio.h>
+		], [
+			return 0
+		], [
+			enable_schizo=yes
+			AS_VAR_APPEND([SB_SCHIZO_SETTINGS], " $1:$2")
+			AS_VAR_APPEND([SB_SCHIZO_HEADERS], " trace_syscalls_$1.h")
+			AC_MSG_RESULT([yes])
+			AC_DEFINE_UNQUOTED([SB_SCHIZO_$1], 1, [Support for $1/$2 is available])
+		], [
+			AC_MSG_RESULT([no])
+		])
+		CFLAGS=$ac_save_CFLAGS
+])
+if test "x$enable_schizo" != "xno" ; then
+	enable_schizo=no
+	case $host in
+	i686*linux|x86_64*linux*)
+		SB_CHECK_SCHIZO([x86_64], [-m64])
+		SB_CHECK_SCHIZO([x86], [-m32])
+		SB_CHECK_SCHIZO([x32], [-mx32])
+		;;
 	esac
-fi
-if test "$SB_SCHIZO_SETTINGS" != "no" ; then
-	AC_DEFINE_UNQUOTED([SB_SCHIZO], ["$SB_SCHIZO_SETTINGS"], [Enable multiple personalities support])
+	SB_SCHIZO_SETTINGS=${SB_SCHIZO_SETTINGS# }
+	if test "x$enable_schizo" != "xno" ; then
+		AC_DEFINE_UNQUOTED([SB_SCHIZO], ["$SB_SCHIZO_SETTINGS"], [Enable multiple personalities support])
+	fi
 fi
 AC_SUBST(SB_SCHIZO_SETTINGS)
+AC_SUBST(SB_SCHIZO_HEADERS)
 AM_CONDITIONAL([SB_SCHIZO], test "$SB_SCHIZO_SETTINGS" != "no")
-AC_MSG_RESULT($SB_SCHIZO_SETTINGS)
 
 dnl this test fills up the stack and then triggers a segfault ...
 dnl but it's hard to wrap things without a stack, so let's ignore
diff --git a/libsandbox/Makefile.am b/libsandbox/Makefile.am
index 529d835..cbc73ba 100644
--- a/libsandbox/Makefile.am
+++ b/libsandbox/Makefile.am
@@ -70,18 +70,23 @@ TRACE_MAKE_HEADER = \
 	$(SB_AWK) $(GEN_TRACE_SCRIPT) -v MODE=gen | \
 		$(COMPILE) -E -P -include $(top_srcdir)/headers.h - $$f | \
 		$(SB_AWK) $(GEN_TRACE_SCRIPT) -v syscall_prefix=$$t > $$header
-trace_syscalls.h: $(GEN_TRACE_SCRIPT) Makefile
+trace_syscalls.h: $(GEN_TRACE_SCRIPT) $(SB_SCHIZO_HEADERS)
 if SB_SCHIZO
+	$(AM_V_GEN)touch $@
+else
+	$(AM_V_GEN)t= f= header=$@; $(TRACE_MAKE_HEADER)
+endif
+
+$(SB_SCHIZO_HEADERS): $(GEN_TRACE_SCRIPT)
 	$(AM_V_GEN)for pers in $(SB_SCHIZO_SETTINGS) ; do \
 		t=_$${pers%:*}; \
 		f=$${pers#*:}; \
-		header=trace_syscalls$${t}.h; \
-		$(TRACE_MAKE_HEADER) || exit $$?; \
+		header="trace_syscalls$${t}.h"; \
+		if [ "$$header" = "$@" ]; then \
+			$(TRACE_MAKE_HEADER) || exit $$?; \
+			break; \
+		fi; \
 	done
-	@touch $@
-else
-	$(AM_V_GEN)t= f= header=$@; $(TRACE_MAKE_HEADER)
-endif
 
 EXTRA_DIST = $(SYMBOLS_FILE) $(SYMBOLS_WRAPPERS) $(SB_NR_FILE) $(TRACE_FILES) headers.h
 
diff --git a/libsandbox/trace/linux/x86_64.c b/libsandbox/trace/linux/x86_64.c
index 5bd1361..82c492d 100644
--- a/libsandbox/trace/linux/x86_64.c
+++ b/libsandbox/trace/linux/x86_64.c
@@ -4,21 +4,27 @@
 #ifdef SB_SCHIZO
 
 static const struct syscall_entry syscall_table_32[] = {
+#ifdef SB_SCHIZO_x86
 #define S(s) { SB_SYS_x86_##s, SB_NR_##s, #s },
 #include "trace_syscalls_x86.h"
 #undef S
+#endif
 	{ SB_NR_UNDEF, SB_NR_UNDEF, NULL },
 };
 static const struct syscall_entry syscall_table_64[] = {
+#ifdef SB_SCHIZO_x86_64
 #define S(s) { SB_SYS_x86_64_##s, SB_NR_##s, #s },
 #include "trace_syscalls_x86_64.h"
 #undef S
+#endif
 	{ SB_NR_UNDEF, SB_NR_UNDEF, NULL },
 };
 static const struct syscall_entry syscall_table_x32[] = {
+#ifdef SB_SCHIZO_x32
 #define S(s) { SB_SYS_x32_##s, SB_NR_##s, #s },
 #include "trace_syscalls_x32.h"
 #undef S
+#endif
 	{ SB_NR_UNDEF, SB_NR_UNDEF, NULL },
 };