From: Peter Lemenkov <lemenkov@gmail.com>

Date: Sun, 2 Nov 2014 19:49:55 +0300

Subject: [PATCH] Expose NIF version

This patch allows checking for NIF API version in a way similar to

driver version. E.g. by calling erlang:system_info(nif_version).

Signed-off-by: Peter Lemenkov <lemenkov@gmail.com>

diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml

index 8416839..81f98cb 100644

--- a/erts/doc/src/erlang.xml

+++ b/erts/doc/src/erlang.xml

@@ -6133,6 +6133,11 @@ ok

               <seealso marker="#system_info_multi_scheduling">erlang:system_info(multi_scheduling)</seealso>, and

               <seealso marker="#system_info_schedulers">erlang:system_info(schedulers)</seealso>.

           </item>

+          <tag><c>nif_version</c></tag>

+          <item>

+            
Returns a string containing the erlang NIF version

+              used by the runtime system. It will be on the form "<major ver>.<minor ver>".

+          </item>

           <tag><marker id="system_info_otp_release"><c>otp_release</c></marker></tag>

           <item>

             
Returns a string containing the OTP release number of the

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c

index 6efe9d9..da38eea 100644

--- a/erts/emulator/beam/erl_bif_info.c

+++ b/erts/emulator/beam/erl_bif_info.c

@@ -27,6 +27,7 @@

 #include "erl_process.h"

 #include "error.h"

 #include "erl_driver.h"

+#include "erl_nif.h"

 #include "bif.h"

 #include "big.h"

 #include "erl_version.h"

@@ -2459,6 +2460,13 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)

 			      ERL_DRV_EXTENDED_MINOR_VERSION);

 	hp = HAlloc(BIF_P, 2*n);

 	BIF_RET(buf_to_intlist(&hp, buf, n, NIL));

+    } else if (ERTS_IS_ATOM_STR("nif_version", BIF_ARG_1)) {

+	char buf[42];

+	int n = erts_snprintf(buf, 42, "%d.%d",

+			      ERL_NIF_MAJOR_VERSION,

+			      ERL_NIF_MINOR_VERSION);

+	hp = HAlloc(BIF_P, 2*n);

+	BIF_RET(buf_to_intlist(&hp, buf, n, NIL));

     } else if (ERTS_IS_ATOM_STR("smp_support", BIF_ARG_1)) {

 #ifdef ERTS_SMP

 	BIF_RET(am_true);

diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl

index 336b618..081789f 100644

--- a/erts/emulator/test/driver_SUITE.erl

+++ b/erts/emulator/test/driver_SUITE.erl

@@ -1199,8 +1199,8 @@ check_si_res(["sched_thrs", Value]) ->

     ?line Value = integer_to_list(erlang:system_info(schedulers));

 %% Data added in 3rd version of driver_system_info() (driver version 1.5)

-check_si_res(["emu_nif_vsn", _Value]) ->

-    true;

+check_si_res(["emu_nif_vsn", Value]) ->

+    ?line Value = erlang:system_info(nif_version);

 %% Data added in 4th version of driver_system_info() (driver version 3.1)

 check_si_res(["dirty_sched", _Value]) ->

diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl

index 98d7a94..de6a773 100644

--- a/erts/preloaded/src/erlang.erl

+++ b/erts/preloaded/src/erlang.erl

@@ -2251,6 +2251,7 @@ tuple_to_list(_Tuple) ->

          (modified_timing_level) -> integer() | undefined;

          (multi_scheduling) -> disabled | blocked | enabled;

          (multi_scheduling_blockers) -> [PID :: pid()];

+         (nif_version) -> string();

          (otp_release) -> string();

          (port_count) -> non_neg_integer();

          (port_limit) -> pos_integer();

diff --git a/lib/runtime_tools/src/system_information.erl b/lib/runtime_tools/src/system_information.erl

index f541d6e..04cc33e 100644

--- a/lib/runtime_tools/src/system_information.erl

+++ b/lib/runtime_tools/src/system_information.erl

@@ -371,6 +371,7 @@ erlang_system_info() ->

 	    logical_processors_online,

 	    logical_processors_available,

 	    driver_version,

+	    nif_version,

 	    emu_args,

 	    ethread_info,

 	    beam_jump_table,

diff --git a/lib/runtime_tools/test/system_information_SUITE_data/information_test_report.dat b/lib/runtime_tools/test/system_information_SUITE_data/information_test_report.dat

index 1893837..bdc510e 100644

--- a/lib/runtime_tools/test/system_information_SUITE_data/information_test_report.dat

+++ b/lib/runtime_tools/test/system_information_SUITE_data/information_test_report.dat

@@ -9720,6 +9720,7 @@

                  {logical_processors_online,4},

                  {logical_processors_available,4},

                  {driver_version,"2.1"},

+                 {nif_version,"1.1"},

                  {taints,[]}]},

                {erts_compile_info,

                 [{ldflags,[]},