Add unique syscall entry numbers (SENs)

* Makefile.am (BUILT_SOURCES, CLEANFILES): Add sen.h.
(syscallent_names, syscallent_patterns, syscallent_files): New variables.
(sen.h): New rule.
* defs.h (struct sysent): Add sen field.
* generate_sen.sh: New file.
* linux/syscall.h: Include "sen.h".
* syscall.c (SEN_NAME): New temporary macro.
(SEN): Use it to prepend syscall entry number.
diff --git a/Makefile.am b/Makefile.am
index 4790f32..451a7da 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -163,6 +163,7 @@
 	debian/strace64.manpages	\
 	debian/watch			\
 	errnoent.sh			\
+	generate_sen.sh			\
 	ioctlsort.c			\
 	linux/32/ioctls_inc.h		\
 	linux/32/ioctls_inc_align32.h	\
@@ -567,7 +568,7 @@
 srpm: dist-xz
 	rpmbuild --define '%_srcrpmdir .' -ts $(distdir).tar.xz
 
-BUILT_SOURCES = .version sys_func.h
+BUILT_SOURCES = .version sys_func.h sen.h
 
 $(srcdir)/.version:
 	$(AM_V_GEN)echo $(VERSION) > $@-t && mv $@-t $@
@@ -579,6 +580,15 @@
 		sed -n 's/^SYS_FUNC(.*/extern &;/p' $$f; \
 	done | sort -u > $@
 
+syscallent_names = subcall.h syscallent.h syscallent1.h \
+		   syscallent-n32.h syscallent-n64.h syscallent-o32.h
+syscallent_patterns = $(patsubst %,\%/%,$(syscallent_names))
+syscallent_files = $(filter $(syscallent_patterns),$(EXTRA_DIST))
+
+sen.h: $(patsubst %,$(srcdir)/%,$(syscallent_files))
+	for f in $^; do cat -- $$f; done | \
+		$(srcdir)/generate_sen.sh > $@
+
 dist-hook:
 	$(AM_V_GEN)echo $(VERSION) > $(distdir)/.tarball-version
 
@@ -605,7 +615,7 @@
 ioctls_inc_h = $(wildcard $(srcdir)/$(OS)/$(ARCH)/ioctls_inc*.h)
 ioctlent_h = $(patsubst $(srcdir)/$(OS)/$(ARCH)/ioctls_inc%,ioctlent%,$(ioctls_inc_h))
 BUILT_SOURCES += $(ioctlent_h)
-CLEANFILES = sys_func.h $(ioctlent_h)
+CLEANFILES = sys_func.h sen.h $(ioctlent_h)
 
 ioctlent%.h: ioctlsort%
 	./$< > $@
diff --git a/defs.h b/defs.h
index ede39b4..25e377a 100644
--- a/defs.h
+++ b/defs.h
@@ -249,6 +249,7 @@
 typedef struct sysent {
 	unsigned nargs;
 	int	sys_flags;
+	int	sen;
 	int	(*sys_func)();
 	const char *sys_name;
 } struct_sysent;
diff --git a/generate_sen.sh b/generate_sen.sh
new file mode 100755
index 0000000..6c177ab
--- /dev/null
+++ b/generate_sen.sh
@@ -0,0 +1,8 @@
+#!/bin/sh -e
+
+echo 'enum {'
+echo 'SEN_printargs = 0,'
+    sed -n '/printargs/! s/.*SEN(\([^)]*\)).*/\1/p' |
+    sort -u |
+    sed 's/.*/SEN_&,/'
+echo '};'
diff --git a/linux/syscall.h b/linux/syscall.h
index bd70601..1b7cbc5 100644
--- a/linux/syscall.h
+++ b/linux/syscall.h
@@ -28,6 +28,7 @@
 
 #include "dummy.h"
 #include "sys_func.h"
+#include "sen.h"
 
 #if NEED_UID16_PARSERS
 extern SYS_FUNC(chown16);
diff --git a/syscall.c b/syscall.c
index b8f9f82..6753f2d 100644
--- a/syscall.c
+++ b/syscall.c
@@ -81,7 +81,8 @@
 #define SI STACKTRACE_INVALIDATE_CACHE
 #define SE STACKTRACE_CAPTURE_ON_ENTER
 
-#define SEN(syscall_name) SYS_FUNC_NAME(syscall_name)
+#define SEN_NAME(syscall_name) SEN_ ## syscall_name
+#define SEN(syscall_name) SEN_NAME(syscall_name), SYS_FUNC_NAME(syscall_name)
 
 const struct_sysent sysent0[] = {
 #include "syscallent.h"
@@ -101,6 +102,7 @@
 
 /* Now undef them since short defines cause wicked namespace pollution. */
 #undef SEN
+#undef SEN_NAME
 #undef TD
 #undef TF
 #undef TI