__attribute__(constructor) actually works

wasm@deco:~/trydynlib$ make -B
emcc -s WASM=0 -s SIDE_MODULE=1 -DLIBF_COMPILE -o libf_so.js libf.c
emcc -s WASM=0 -s SIDE_MODULE=1 -s RUNTIME_LINKED_LIBS="['libf_so.js']" -DLIBK_COMPILE -o libk_so.js libk.c
warning: unexpected number of arguments 0 in call to 'ffunc1', should be 1
emcc -s WASM=0 -s MAIN_MODULE=1 -s RUNTIME_LINKED_LIBS="['libk_so.js']" -o prog.js prog.c
warning: unexpected number of arguments 0 in call to 'kfunc1', should be 1

wasm@deco:~/trydynlib$ node prog.js
prog!
libf.ffunc1
libk.kfunc1 -> 12

Makefile

@@ -17,7 +17,7 @@ all	: prog.js
 libf_so.$(SO)	: libf.c
 	$(CC) -s SIDE_MODULE=1 -DLIBF_COMPILE -o $@ $<
 
-libk_so.$(SO)	: libk.cpp libf.h libf_so.$(SO)
+libk_so.$(SO)	: libk.c libf.h libf_so.$(SO)
 	$(CC) -s SIDE_MODULE=1 -s RUNTIME_LINKED_LIBS="['libf_so.$(SO)']" -DLIBK_COMPILE -o $@ $<
 
 

libk.cpp → libk.c

@@ -5,26 +5,12 @@
 
 
 // XXX should be in make, but currently emscripten cannot do this
-#if 1
-__attribute__((constructor))	// FIXME does not work (in C) ?
+__attribute__((constructor))
 static void init_ctor() {
 	EM_ASM({
 	    loadDynamicLibrary('libf_so.js');
 	});
 }
-#endif
-
-#if 0
-class init {
-	init() {
-		EM_ASM({
-		    loadDynamicLibrary('libf_so.js');
-		});
-	}
-};
-
-static init _();
-#endif
 
 LIBKAPI
 int kfunc1() {

libk_so.js

@@ -45,7 +45,7 @@ gb = alignMemory(getMemory(48 + 1), 1 || 1);
 for (var i = gb; i < gb + 48; ++i) HEAP8[i] = 0;
 
 // STATICTOP = STATIC_BASE + 48;
-/* global initializers */  __ATINIT__.push({ func: function() { __ZL9init_ctorv() } });
+/* global initializers */  __ATINIT__.push({ func: function() { _init_ctor() } });
 
 
 /* memory initializer */ allocate([123,32,108,111,97,100,68,121,110,97,109,105,99,76,105,98,114,97,114,121,40,39,108,105,98,102,95,115,111,46,106,115,39,41,59,32,125,0], "i8", ALLOC_NONE, gb);
@@ -194,7 +194,7 @@ function setThrew(threw, value) {
   }
 }
 
-function __ZL9init_ctorv() {
+function _init_ctor() {
  var $0 = 0, label = 0, sp = 0;
  sp = STACKTOP;
  $0 = _emscripten_asm_const_i(0)|0;
@@ -216,15 +216,15 @@ function runPostSets() {
 // EMSCRIPTEN_END_FUNCS
 
 
-  return { __ZL9init_ctorv: __ZL9init_ctorv, _kfunc1: _kfunc1, establishStackSpace: establishStackSpace, runPostSets: runPostSets, setThrew: setThrew, stackAlloc: stackAlloc, stackRestore: stackRestore, stackSave: stackSave };
+  return { _init_ctor: _init_ctor, _kfunc1: _kfunc1, establishStackSpace: establishStackSpace, runPostSets: runPostSets, setThrew: setThrew, stackAlloc: stackAlloc, stackRestore: stackRestore, stackSave: stackSave };
 })
 // EMSCRIPTEN_END_ASM
 (Module.asmGlobalArg, Module.asmLibraryArg, buffer);
 
-var real___ZL9init_ctorv = asm["__ZL9init_ctorv"]; asm["__ZL9init_ctorv"] = function() {
+var real__init_ctor = asm["_init_ctor"]; asm["_init_ctor"] = function() {
   assert(runtimeInitialized, 'you need to wait for the runtime to be ready (e.g. wait for main() to be called)');
   assert(!runtimeExited, 'the runtime was exited (use NO_EXIT_RUNTIME to keep it alive after main() exits)');
-  return real___ZL9init_ctorv.apply(null, arguments);
+  return real__init_ctor.apply(null, arguments);
 };
 
 var real__kfunc1 = asm["_kfunc1"]; asm["_kfunc1"] = function() {
@@ -238,7 +238,7 @@ var real_setThrew = asm["setThrew"]; asm["setThrew"] = function() {
   assert(!runtimeExited, 'the runtime was exited (use NO_EXIT_RUNTIME to keep it alive after main() exits)');
   return real_setThrew.apply(null, arguments);
 };
-var __ZL9init_ctorv = Module["__ZL9init_ctorv"] = asm["__ZL9init_ctorv"];
+var _init_ctor = Module["_init_ctor"] = asm["_init_ctor"];
 var _kfunc1 = Module["_kfunc1"] = asm["_kfunc1"];
 var runPostSets = Module["runPostSets"] = asm["runPostSets"];
 var setThrew = Module["setThrew"] = asm["setThrew"];