Rename label to filename argument

Author: saleyn

erts/emulator/beam/erl_nif.c

@@ -68,7 +68,9 @@
 #endif
 #include "jit/beam_asm.h"
 #include "erl_global_literals.h"
+
 #include "erl_iolist.h"
+#include "erl_atom_table.h"
 
 #include <limits.h>
 #include <stddef.h> /* offsetof */
@@ -4884,38 +4886,41 @@ Eterm erts_load_nif(Process *c_p, ErtsCodePtr I, Eterm filename, Eterm args)
     /*
      * Accept either:
      *   Filename::string()|binary()              -- load from file (existing behaviour)
-     *   #{memory := NifSO}                       -- load from memory, auto-generated label
-     *   #{memory := NifSO, label := Filename}    -- load from memory with explicit label
+     *   #{filename := string()|binary()}         -- load from file (map form, no memory)
+     *   #{memory := NifSO}                       -- load from memory, auto-generated filename
+     *   #{memory := NifSO, filename := Filename} -- load from memory with explicit filename
+     *
+     * If the map contains only 'filename', it falls back to the string|binary filename implementation.
      */
     if (is_map(filename)) {
-        const Eterm *mem_val = erts_maps_get(am_memory, filename);
-        const Eterm *lbl_val = erts_maps_get(am_label, filename);
-        if (mem_val == NULL) {
+        const Eterm *fnm_val = erts_maps_get(am_filename, filename);
+        const Eterm *mem_val = erts_maps_get(am_memory,   filename);
+        if (fnm_val == NULL && mem_val == NULL) {
             return load_nif_error(c_p, "bad_lib",
-                "load_nif/2: map argument must contain a 'memory' key");
+                "load_nif/2: map argument must contain a 'memory' or 'filename'key");
         }
-        if (!is_bitstring(*mem_val) || TAIL_BITS(bitstring_size(*mem_val)) != 0) {
-            return load_nif_error(c_p, "bad_lib",
-                "load_nif/2: 'memory' value must be a binary");
+        if (mem_val) {
+            if (!is_bitstring(*mem_val) || TAIL_BITS(bitstring_size(*mem_val)) != 0) {
+                return load_nif_error(c_p, "bad_lib",
+                    "load_nif/2: 'memory' value must be a binary");
+            }
+            nif_binary    = *mem_val;
+            load_from_mem = 1;
         }
-        nif_binary    = *mem_val;
-        load_from_mem = 1;
-        if (lbl_val != NULL) {
-            filename = *lbl_val;   /* fall through to filename decoding for label */
+        if (fnm_val) {
+            filename = *fnm_val;   /* fall through to filename decoding from argument */
         } else {
             lib_name = NULL;   /* anonymous: erts_dlopen_mem will generate a name */
             goto after_lib_name;
         }
     }
-
     lib_name = erts_convert_filename_to_encoding(filename, NULL, 0,
                                                  ERTS_ALC_T_TMP, 1, 0, encoding,
                                                  NULL, 0);
-    if (!lib_name) {
+    if (!lib_name)
         return THE_NON_VALUE;
-    }
-after_lib_name:;
 
+after_lib_name:
     /* Find calling module */
     caller = erts_find_function_from_pc(I);
     ASSERT(caller != NULL);
@@ -4947,7 +4952,7 @@ after_lib_name:;
 	this_mi = module_p->on_load;
     }
 
-    /* If the caller passed #{memory => NifSO::binary(), label => Filename},
+    /* If the caller passed #{memory => NifSO::binary(), filename => Filename},
      * open the shared object from memory now so that `handle` is ready for
      * the common else-if chain below (which runs
      * erts_sys_ddll_load_nif_init / call_nif_init, version checks, and

erts/emulator/test/nif_SUITE.erl

@@ -383,7 +383,7 @@ run_load_nif_from_mem(Config) ->
     SoPath = filename:join(Data, "nif_mod.1.so"),
     {ok, SoBin} = file:read_file(SoPath),
 
-    %% --- happy path: map with label ---
+    %% --- happy path: map with filename ---
     ok = nif_mod:load_nif_lib_from_mem(Config, 1, SoBin),
     1 = nif_mod:lib_version(),
 
@@ -399,7 +399,6 @@ run_load_nif_from_mem(Config) ->
     true = erlang:purge_module(nif_mod),
     receive unloaded -> ok after 1000 -> ok end,
 
-    %% --- error: label longer than PATH_MAX-9 ---
     {module, nif_mod} = erlang:load_module(nif_mod, ModBin),
     LongPath = lists:duplicate(4096-9, $x),
     {error, {load_failed, _}} = nif_mod:load_nif_mem_path(LongPath, SoBin),
@@ -415,6 +414,30 @@ run_load_nif_from_mem(Config) ->
     true = erlang:purge_module(nif_mod),
     receive unloaded -> ok after 1000 -> ok end,
 
+    %% --- error: both keys present but filename is not string/binary ---
+    {module, nif_mod} = erlang:load_module(nif_mod, ModBin),
+    Map1 = #{memory => SoBin, filename => 123},
+    {error, {bad_lib, _}} = erlang:load_nif(Map1, []),
+    true = erlang:delete_module(nif_mod),
+    true = erlang:purge_module(nif_mod),
+    receive unloaded -> ok after 1000 -> ok end,
+
+    %% --- error: map with neither memory nor filename ---
+    {module, nif_mod} = erlang:load_module(nif_mod, ModBin),
+    Map2 = #{foo => bar},
+    {error, {bad_lib, _}} = erlang:load_nif(Map2, []),
+    true = erlang:delete_module(nif_mod),
+    true = erlang:purge_module(nif_mod),
+    receive unloaded -> ok after 1000 -> ok end,
+
+    %% --- error: map with only filename key and non-string/binary value ---
+    {module, nif_mod} = erlang:load_module(nif_mod, ModBin),
+    Map3 = #{filename => 123},
+    {error, {bad_lib, _}} = erlang:load_nif(Map3, []),
+    true = erlang:delete_module(nif_mod),
+    true = erlang:purge_module(nif_mod),
+    receive unloaded -> ok after 1000 -> ok end,
+
     ok.
 
 %% Test old reload feature now always fails

erts/preloaded/src/erlang.erl

@@ -7538,12 +7538,14 @@ forms:
   on disc when an upgrade of the NIF is done. If the name is the same, but the
   contents differ, the old library may be loaded instead.
 
+- **`#{filename := string()|binary()}`** - Same as above.
+
 - **`#{memory := NifSO}`** - Load the NIF library directly from the in-memory
   binary `NifSO` (raw bytes of the shared-object file) without a label. An
   anonymous name is auto-generated for the shared-memory region. Only supported
   on Unix platforms that provide `memfd_create(2)` or POSIX shared memory.
 
-- **`#{memory := NifSO, label := Filename}`** - Same as above, but `Filename`
+- **`#{memory := NifSO, filename := Filename}`** - Same as above, but `Filename`
   (a `string()` or `binary()`) is used as the label for the shared-memory
   region and in error messages. `Filename` must be shorter than `PATH_MAX - 9`
   characters (to allow for the `/dev/shm/` prefix used internally).
@@ -7635,9 +7637,10 @@ target OS/hardware platform.
 -spec load_nif(Path, LoadInfo) -> ok | Error when
       Path :: string() |
               binary() |
+              #{filename := Filename :: string() | binary()} |
               #{memory := NifSO :: binary()} |
               #{memory := NifSO :: binary(),
-                label  := Filename :: string() | binary()},
+                filename := Filename :: string() | binary()},
       LoadInfo :: term(),
       Error :: {error, {Reason, Text :: string()}},
       Reason :: load_failed | bad_lib | load | reload | upgrade | old_code.