Remove deps_info system and and the running of llvm-nm on input file. NFC

This uses a new "stub object" construct to tell the linker (wasm-ld)
not only about the existence of the JS library symbols but the native
symbols on which they depend (a.k.a reverse dependencies).

This allows us to completely remove deps_info.py in favor of just using
normal `__deps` entries in the library files.  It also means we no
longer need to run `llvm-nm` on the linker inputs to discover the
symbols they use.

Depends on: https://reviews.llvm.org/D145308

Fixes: #18875

Author: sbc100

emcc.py

@@ -50,7 +50,6 @@
 from tools.minimal_runtime_shell import generate_minimal_runtime_html
 import tools.line_endings
 from tools import feature_matrix
-from tools import deps_info
 from tools import js_manipulation
 from tools import wasm2c
 from tools import webassembly
@@ -1316,11 +1315,19 @@ def run(args):
     js_info = get_js_sym_info()
     if not settings.SIDE_MODULE:
       js_syms = js_info['deps']
-      deps_info.append_deps_info(js_syms)
+      if not settings.USES_DYNAMIC_ALLOC:
+        # When USES_DYNAMIC_ALLOC=0 is set we don't export malloc/free, even
+        # if the JS library symbols depend on them.  In this mode we instead
+        # fail at runtime if they are actaully called.
+        for value in js_syms.values():
+          if 'malloc' in value:
+            value.remove('malloc')
+          if 'free' in value:
+            value.remove('free')
     if settings.ASYNCIFY:
       settings.ASYNCIFY_IMPORTS += ['env.' + x for x in js_info['asyncFuncs']]
 
-  phase_calculate_system_libraries(state, linker_arguments, linker_inputs, newargs)
+  phase_calculate_system_libraries(state, linker_arguments, newargs)
 
   phase_link(linker_arguments, wasm_target, js_syms)
 
@@ -2082,11 +2089,6 @@ def phase_linker_setup(options, state, newargs):
       settings.INCLUDE_FULL_LIBRARY = 1
     settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['$loadDylibs']
 
-  # If we are including the entire JS library then we know for sure we will, by definition,
-  # require all the reverse dependencies.
-  if settings.INCLUDE_FULL_LIBRARY:
-    default_setting('REVERSE_DEPS', 'all')
-
   if settings.MAIN_MODULE == 1 or settings.SIDE_MODULE == 1:
     settings.LINKABLE = 1
 
@@ -3079,14 +3081,13 @@ def compile_source_file(i, input_file):
 
 
 @ToolchainProfiler.profile_block('calculate system libraries')
-def phase_calculate_system_libraries(state, linker_arguments, linker_inputs, newargs):
+def phase_calculate_system_libraries(state, linker_arguments, newargs):
   extra_files_to_link = []
   # Link in ports and system libraries, if necessary
   if not settings.SIDE_MODULE:
     # Ports are always linked into the main module, never the side module.
     extra_files_to_link += ports.get_libs(settings)
-  all_linker_inputs = [f for _, f in sorted(linker_inputs)] + extra_files_to_link
-  extra_files_to_link += system_libs.calculate(all_linker_inputs, newargs, forced=state.forced_stdlibs)
+  extra_files_to_link += system_libs.calculate(newargs, forced=state.forced_stdlibs)
   linker_arguments.extend(extra_files_to_link)
 
 

site/source/docs/porting/connecting_cpp_and_javascript/Interacting-with-code.rst

@@ -596,9 +596,6 @@ See the `library_*.js`_ files for other examples.
      This is useful when all the implemented methods use a JavaScript
      singleton containing helper methods. See ``library_webgl.js`` for
      an example.
-   - If a JavaScript library depends on a compiled C library (like most
-     of *libc*), you must edit `src/deps_info.json`_. Search for
-     "deps_info" in `tools/system_libs.py`_.
    - The keys passed into `mergeInto` generate functions that are prefixed
      by ``_``. In other words ``my_func: function() {},`` becomes
      ``function _my_func() {}``, as all C methods in emscripten have a ``_`` prefix. Keys starting with ``$`` have the ``$``
@@ -810,7 +807,6 @@ you can give it a try. See `Emnapi documentation`_ for more details.
 
 .. _library.js: https://github.com/emscripten-core/emscripten/blob/main/src/library.js
 .. _test_js_libraries: https://github.com/emscripten-core/emscripten/blob/1.29.12/tests/test_core.py#L5043
-.. _src/deps_info.json: https://github.com/emscripten-core/emscripten/blob/main/src/deps_info.json
 .. _tools/system_libs.py: https://github.com/emscripten-core/emscripten/blob/main/tools/system_libs.py
 .. _library_\*.js: https://github.com/emscripten-core/emscripten/tree/main/src
 .. _test_add_function in test/test_core.py: https://github.com/emscripten-core/emscripten/blob/1.29.12/tests/test_core.py#L6237

src/jsifier.js

@@ -66,6 +66,25 @@ function isDefined(symName) {
   return false;
 }
 
+function getTransitiveDeps(symbol) {
+  const transitiveDeps = new Set();
+  const seen = new Set();
+  const toVisit = [symbol];
+  while (toVisit.length) {
+    const sym = toVisit.pop();
+    if (!seen.has(sym)) {
+      let directDeps = LibraryManager.library[sym + '__deps'] || [];
+      directDeps = directDeps.filter((d) => typeof d === 'string');
+      if (directDeps.length) {
+        directDeps.forEach(transitiveDeps.add, transitiveDeps);
+        toVisit.push(...directDeps);
+      }
+      seen.add(sym);
+    }
+  }
+  return Array.from(transitiveDeps);
+}
+
 function runJSify() {
   const libraryItems = [];
   const symbolDeps = {};
@@ -260,8 +279,14 @@ function ${name}(${args}) {
 
       if (symbolsOnly) {
         if (!isJsOnlySymbol(symbol) && LibraryManager.library.hasOwnProperty(symbol)) {
-          externalDeps = deps.filter((d) => !isJsOnlySymbol(d) && !(d in LibraryManager.library) && typeof d === 'string');
-          symbolDeps[symbol] = externalDeps;
+          var value = LibraryManager.library[symbol];
+          var resolvedSymbol = symbol;
+          // Resolve aliases before looking up deps
+          if (typeof value == 'string' && value[0] != '=' && LibraryManager.library.hasOwnProperty(value)) {
+            resolvedSymbol = value;
+          }
+          var transtiveDeps = getTransitiveDeps(resolvedSymbol);
+          symbolDeps[symbol] = transtiveDeps.filter((d) => !isJsOnlySymbol(d) && !(d in LibraryManager.library));
         }
         return;
       }

src/library.js

@@ -569,7 +569,7 @@ mergeInto(LibraryManager.library, {
 
   // TODO: Initialize these to defaults on startup from system settings.
   // Note: glibc has one fewer underscore for all of these. Also used in other related functions (timegm)
-  _tzset_js__deps: ['$stringToNewUTF8'],
+  _tzset_js__deps: ['$stringToNewUTF8', 'malloc'],
   _tzset_js__internal: true,
   _tzset_js: function(timezone, daylight, tzname) {
     // TODO: Use (malleable) environment variables instead of system settings.
@@ -1212,6 +1212,7 @@ mergeInto(LibraryManager.library, {
   // ==========================================================================
 
 #if SUPPORT_LONGJMP == 'emscripten'
+  _emscripten_throw_longjmp__deps: ['setThrew'],
   _emscripten_throw_longjmp: function() {
 #if EXCEPTION_STACK_TRACES
     throw new EmscriptenSjLj;
@@ -1721,7 +1722,7 @@ mergeInto(LibraryManager.library, {
     return { family: family, addr: addr, port: port };
   },
   $writeSockaddr__docs: '/** @param {number=} addrlen */',
-  $writeSockaddr__deps: ['$Sockets', '$inetPton4', '$inetPton6', '$zeroMemory'],
+  $writeSockaddr__deps: ['$Sockets', '$inetPton4', '$inetPton6', '$zeroMemory', 'htons'],
   $writeSockaddr: function (sa, family, addr, port, addrlen) {
     switch (family) {
       case {{{ cDefs.AF_INET }}}:
@@ -1858,7 +1859,7 @@ mergeInto(LibraryManager.library, {
     return 0;
   },
 
-  getaddrinfo__deps: ['$Sockets', '$DNS', '$inetPton4', '$inetNtop4', '$inetPton6', '$inetNtop6', '$writeSockaddr'],
+  getaddrinfo__deps: ['$Sockets', '$DNS', '$inetPton4', '$inetNtop4', '$inetPton6', '$inetNtop6', '$writeSockaddr', 'malloc', 'htonl'],
   getaddrinfo__proxy: 'sync',
   getaddrinfo: function(node, service, hint, out) {
     // Note getaddrinfo currently only returns a single addrinfo with ai_next defaulting to NULL. When NULL
@@ -2623,7 +2624,7 @@ mergeInto(LibraryManager.library, {
   // using builtin_malloc to avoid LSan reporting these as leaks.
   emscripten_get_compiler_setting__noleakcheck: true,
 #if RETAIN_COMPILER_SETTINGS
-  emscripten_get_compiler_setting__deps: ['$stringToNewUTF8'],
+  emscripten_get_compiler_setting__deps: ['$stringToNewUTF8', 'malloc'],
 #endif
   emscripten_get_compiler_setting: function(name) {
 #if RETAIN_COMPILER_SETTINGS
@@ -2805,7 +2806,7 @@ mergeInto(LibraryManager.library, {
 
   // Look up the function name from our stack frame cache with our PC representation.
 #if USE_OFFSET_CONVERTER
-  emscripten_pc_get_function__deps: ['$UNWIND_CACHE', 'free', '$stringToNewUTF8'],
+  emscripten_pc_get_function__deps: ['$UNWIND_CACHE', '$stringToNewUTF8', 'malloc', 'free'],
   // Don't treat allocation of _emscripten_pc_get_function.ret as a leak
   emscripten_pc_get_function__noleakcheck: true,
 #endif

src/library_async.js

@@ -489,7 +489,7 @@ mergeInto(LibraryManager.library, {
     });
   },
 
-  emscripten_wget_data__deps: ['$asyncLoad', 'malloc'],
+  emscripten_wget_data__deps: ['$asyncLoad', 'malloc', 'free'],
   emscripten_wget_data__async: true,
   emscripten_wget_data: function(url, pbuffer, pnum, perror) {
     return Asyncify.handleSleep((wakeUp) => {

src/library_browser.js

@@ -1212,6 +1212,7 @@ var LibraryBrowser = {
 
   // To avoid creating worker parent->child chains, always proxies to execute on the main thread.
   emscripten_create_worker__proxy: 'sync',
+  emscripten_create_worker__deps: ['$UTF8ToString', 'malloc', 'free'],
   emscripten_create_worker: function(url) {
     url = UTF8ToString(url);
     var id = Browser.workers.length;
@@ -1253,6 +1254,7 @@ var LibraryBrowser = {
     return id;
   },
 
+  emscripten_destroy_worker__deps: ['free'],
   emscripten_destroy_worker__proxy: 'sync',
   emscripten_destroy_worker: function(id) {
     var info = Browser.workers[id];

src/library_exceptions.js

@@ -224,7 +224,7 @@ var LibraryExceptions = {
     return type;
   },
 
-  __cxa_begin_catch__deps: ['$exceptionCaught', '$exception_addRef', '$uncaughtExceptionCount'],
+  __cxa_begin_catch__deps: ['$exceptionCaught', '$exception_addRef', '$uncaughtExceptionCount', '__cxa_can_catch', 'setTempRet0'],
   __cxa_begin_catch__sig: 'pp',
   __cxa_begin_catch: function(ptr) {
     var info = new ExceptionInfo(ptr);

src/library_glew.js

@@ -112,6 +112,7 @@ var LibraryGLEW = {
     },
   },
 
+  glewInit__deps: ['malloc'],
   glewInit: function() { return 0; },
 
   glewIsSupported: function(name) {

src/library_glfw.js

@@ -1121,7 +1121,7 @@ var LibraryGLFW = {
 /*******************************************************************************
  * GLFW FUNCTIONS
  ******************************************************************************/
-  glfwInit__deps: ['emscripten_get_device_pixel_ratio'],
+  glfwInit__deps: ['emscripten_get_device_pixel_ratio', 'malloc', 'free'],
   glfwInit__sig: 'i',
   glfwInit: function() {
     if (GLFW.windows) return 1; // GL_TRUE
@@ -1269,6 +1269,7 @@ var LibraryGLFW = {
   glfwPostEmptyEvent__sig: 'v',
   glfwPostEmptyEvent: function() {},
 
+  glfwGetMonitors__deps: ['malloc'],
   glfwGetMonitors__sig: 'ii',
   glfwGetMonitors: function(count) {
     {{{ makeSetValue('count', '0', '1', 'i32') }}};

src/library_html5.js

@@ -235,7 +235,7 @@ var LibraryHTML5 = {
     },
   },
 
-  $registerKeyEventCallback__deps: ['$JSEvents', '$findEventTarget', '$stringToUTF8'],
+  $registerKeyEventCallback__deps: ['$JSEvents', '$findEventTarget', 'malloc', '$stringToUTF8'],
   $registerKeyEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -503,7 +503,7 @@ var LibraryHTML5 = {
 #endif
   },
 
-  $registerMouseEventCallback__deps: ['$JSEvents', '$fillMouseEventData', '$findEventTarget'],
+  $registerMouseEventCallback__deps: ['$JSEvents', '$fillMouseEventData', '$findEventTarget', 'malloc'],
   $registerMouseEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -616,7 +616,7 @@ var LibraryHTML5 = {
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
 
-  $registerWheelEventCallback__deps: ['$JSEvents', '$fillMouseEventData', '$findEventTarget'],
+  $registerWheelEventCallback__deps: ['$JSEvents', '$fillMouseEventData', '$findEventTarget', 'malloc'],
   $registerWheelEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -692,7 +692,7 @@ var LibraryHTML5 = {
     }
   },
 
-  $registerUiEventCallback__deps: ['$JSEvents', '$findEventTarget'],
+  $registerUiEventCallback__deps: ['$JSEvents', '$findEventTarget', 'malloc'],
   $registerUiEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -768,7 +768,7 @@ var LibraryHTML5 = {
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
 
-  $registerFocusEventCallback__deps: ['$JSEvents', '$findEventTarget', '$stringToUTF8'],
+  $registerFocusEventCallback__deps: ['$JSEvents', '$findEventTarget', 'malloc', '$stringToUTF8'],
   $registerFocusEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -911,7 +911,7 @@ var LibraryHTML5 = {
     {{{ makeSetValue('eventStruct', C_STRUCTS.EmscriptenDeviceMotionEvent.rotationRateGamma, 'rr["gamma"]', 'double') }}};
   },
 
-  $registerDeviceMotionEventCallback__deps: ['$JSEvents', '$fillDeviceMotionEventData', '$findEventTarget'],
+  $registerDeviceMotionEventCallback__deps: ['$JSEvents', '$fillDeviceMotionEventData', '$findEventTarget', 'malloc'],
   $registerDeviceMotionEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -979,7 +979,7 @@ var LibraryHTML5 = {
     {{{ makeSetValue('eventStruct', C_STRUCTS.EmscriptenOrientationChangeEvent.orientationAngle, 'orientation', 'i32') }}};
   },
 
-  $registerOrientationChangeEventCallback__deps: ['$JSEvents', '$fillOrientationChangeEventData', '$findEventTarget'],
+  $registerOrientationChangeEventCallback__deps: ['$JSEvents', '$fillOrientationChangeEventData', '$findEventTarget', 'malloc'],
   $registerOrientationChangeEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -1099,7 +1099,7 @@ var LibraryHTML5 = {
     }
   },
 
-  $registerFullscreenChangeEventCallback__deps: ['$JSEvents', '$fillFullscreenChangeEventData', '$findEventTarget'],
+  $registerFullscreenChangeEventCallback__deps: ['$JSEvents', '$fillFullscreenChangeEventData', '$findEventTarget', 'malloc'],
   $registerFullscreenChangeEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -1677,7 +1677,7 @@ var LibraryHTML5 = {
     stringToUTF8(id, eventStruct + {{{ C_STRUCTS.EmscriptenPointerlockChangeEvent.id }}}, {{{ cDefs.EM_HTML5_LONG_STRING_LEN_BYTES }}});
   },
 
-  $registerPointerlockChangeEventCallback__deps: ['$JSEvents', '$fillPointerlockChangeEventData', '$findEventTarget'],
+  $registerPointerlockChangeEventCallback__deps: ['$JSEvents', '$fillPointerlockChangeEventData', '$findEventTarget', 'malloc'],
   $registerPointerlockChangeEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -1923,7 +1923,7 @@ var LibraryHTML5 = {
     {{{ makeSetValue('eventStruct', C_STRUCTS.EmscriptenVisibilityChangeEvent.visibilityState, 'visibilityState', 'i32') }}};
   },
 
-  $registerVisibilityChangeEventCallback__deps: ['$JSEvents', '$fillVisibilityChangeEventData', '$findEventTarget'],
+  $registerVisibilityChangeEventCallback__deps: ['$JSEvents', '$fillVisibilityChangeEventData', '$findEventTarget', 'malloc'],
   $registerVisibilityChangeEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -1978,7 +1978,7 @@ var LibraryHTML5 = {
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
 
-  $registerTouchEventCallback__deps: ['$JSEvents', '$findEventTarget', '$getBoundingClientRect'],
+  $registerTouchEventCallback__deps: ['$JSEvents', '$findEventTarget', '$getBoundingClientRect', 'malloc'],
   $registerTouchEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -2137,7 +2137,7 @@ var LibraryHTML5 = {
     stringToUTF8(e.mapping, eventStruct + {{{ C_STRUCTS.EmscriptenGamepadEvent.mapping }}}, {{{ cDefs.EM_HTML5_MEDIUM_STRING_LEN_BYTES }}});
   },
 
-  $registerGamepadEventCallback__deps: ['$JSEvents', '$fillGamepadEventData', '$findEventTarget'],
+  $registerGamepadEventCallback__deps: ['$JSEvents', '$fillGamepadEventData', '$findEventTarget', 'malloc'],
   $registerGamepadEventCallback: function(target, userData, useCapture, callbackfunc, eventTypeId, eventTypeString, targetThread) {
 #if PTHREADS
     targetThread = JSEvents.getTargetThreadForEventCallback(targetThread);
@@ -2305,15 +2305,15 @@ var LibraryHTML5 = {
   },
 
   emscripten_set_batterychargingchange_callback_on_thread__proxy: 'sync',
-  emscripten_set_batterychargingchange_callback_on_thread__deps: ['$registerBatteryEventCallback', '$battery', 'malloc'],
+  emscripten_set_batterychargingchange_callback_on_thread__deps: ['$registerBatteryEventCallback', '$battery'],
   emscripten_set_batterychargingchange_callback_on_thread: function(userData, callbackfunc, targetThread) {
     if (!battery()) return {{{ cDefs.EMSCRIPTEN_RESULT_NOT_SUPPORTED }}}; 
     registerBatteryEventCallback(battery(), userData, true, callbackfunc, {{{ cDefs.EMSCRIPTEN_EVENT_BATTERYCHARGINGCHANGE }}}, "chargingchange", targetThread);
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
 
   emscripten_set_batterylevelchange_callback_on_thread__proxy: 'sync',
-  emscripten_set_batterylevelchange_callback_on_thread__deps: ['$registerBatteryEventCallback', '$battery', 'malloc'],
+  emscripten_set_batterylevelchange_callback_on_thread__deps: ['$registerBatteryEventCallback', '$battery'],
   emscripten_set_batterylevelchange_callback_on_thread: function(userData, callbackfunc, targetThread) {
     if (!battery()) return {{{ cDefs.EMSCRIPTEN_RESULT_NOT_SUPPORTED }}}; 
     registerBatteryEventCallback(battery(), userData, true, callbackfunc, {{{ cDefs.EMSCRIPTEN_EVENT_BATTERYLEVELCHANGE }}}, "levelchange", targetThread);