De-runtime-ification (#5954)

This removes the Runtime object from the generated code. Much of it was not needed at all, the rest is moved into plain JS functions in a new support.js file (which is easier for DCE to remove). This is something @juj suggested we do, and it helps with the goal of shrinking JS - this reduces code from a few % in something like libc++ to 15% in small hello world type things.

The history here is that in the early days I thought we'd have a coherent Runtime object, and it would be used at both compile time and execution time, sharing code between them. But with asm.js and wasm, we've been doing less and less in JS anyhow, so Runtime has made less and less sense. Also it turns out there are just a handful of methods we need both at compile time and execution time, at this point.

Another old idea was that we need to generate the runtime support dynamically, since we supported weird things like QUANTUM=1 (ints and pointers take one memory address location). That's why we had RuntimeGenerator and all that. But again, with asm.js and wasm, we really just support one type of memory, the plain C style. So it's easier to just write out those methods in support.js instead of generating them from a flexible template. This simplification may also help us in the future with more modularization of our runtime code (ES6 modules, etc.).

Breakage-wise, this does affect anyone that used anything on Runtime in a manual way: Runtime.X needs to change to just X. The Runtime object is sort of an internal implementation detail, so hopefully few people ever used it, but still, there's a risk. There are helper messages in assertions mode with some of the more likely candidates, hopefully that will help. Overall, I think this is unavoidable refactoring, and hopefully any inconvenience will be minor.

Author: kripken

emscripten.py

@@ -143,6 +143,9 @@ def parse_backend_output(backend_output, DEBUG):
   metadata_raw = backend_output[metadata_split+len(metadata_split_marker):]
   mem_init = backend_output[end_funcs+len(end_funcs_marker):metadata_split]
 
+  # we no longer use the "Runtime" object. TODO: stop emiting it in the backend
+  mem_init = mem_init.replace('Runtime.', '')
+
   try:
     #if DEBUG: print >> sys.stderr, "METAraw", metadata_raw
     metadata = json.loads(metadata_raw, object_pairs_hook=OrderedDict)
@@ -378,8 +381,6 @@ def create_module(function_table_sigs, metadata, settings,
 
   asm_end = create_asm_end(exports, settings)
 
-  runtime_library_overrides = create_runtime_library_overrides(settings)
-
   module = [
     asm_start,
     temp_float,
@@ -389,11 +390,11 @@ def create_module(function_table_sigs, metadata, settings,
     start_funcs_marker
   ] + runtime_funcs + funcs_js + ['\n  ',
     pre_tables, final_function_tables, asm_end,
-    '\n', receiving, ';\n', runtime_library_overrides]
+    '\n', receiving, ';\n']
 
   if settings['SIDE_MODULE']:
     module.append('''
-Runtime.registerFunctions(%(sigs)s, Module);
+parentModule['registerFunctions'](%(sigs)s, Module);
 ''' % { 'sigs': str(list(map(str, function_table_sigs))) })
 
   return module
@@ -564,7 +565,7 @@ def memory_and_global_initializers(pre, metadata, mem_init, settings):
                      mem_init=mem_init))
 
   if settings['SIDE_MODULE']:
-    pre = pre.replace('Runtime.GLOBAL_BASE', 'gb')
+    pre = pre.replace('GLOBAL_BASE', 'gb')
   if settings['SIDE_MODULE'] or settings['BINARYEN']:
     pre = pre.replace('{{{ STATIC_BUMP }}}', str(staticbump))
 
@@ -651,8 +652,8 @@ def get_implemented_functions(metadata):
 
 def proxy_debug_print(call_type, settings):
   if shared.Settings.PTHREADS_DEBUG:
-    if call_type == 'sync_on_main_thread_': return 'Runtime.warnOnce("sync proxying function " + code);';
-    elif call_type == 'async_on_main_thread_': return 'Runtime.warnOnce("async proxying function " + code);';
+    if call_type == 'sync_on_main_thread_': return 'warnOnce("sync proxying function " + code);';
+    elif call_type == 'async_on_main_thread_': return 'warnOnce("async proxying function " + code);';
   return ''
 
 def include_asm_consts(pre, forwarded_json, metadata, settings):
@@ -1151,9 +1152,8 @@ def table_size(table):
     if not settings['EMULATED_FUNCTION_POINTERS']:
       asm_setup += "\nModule['wasmMaxTableSize'] = %d;\n" % table_total_size
   if settings['RELOCATABLE']:
-    asm_setup += 'var setTempRet0 = Runtime.setTempRet0, getTempRet0 = Runtime.getTempRet0;\n'
     if not settings['SIDE_MODULE']:
-      asm_setup += 'var gb = Runtime.GLOBAL_BASE, fb = 0;\n'
+      asm_setup += 'var gb = GLOBAL_BASE, fb = 0;\n'
     side = 'parent' if settings['SIDE_MODULE'] else ''
     def check(extern):
       if settings['ASSERTIONS']:
@@ -1601,25 +1601,6 @@ def create_asm_end(exports, settings):
        'Module' + access_quote('asmLibraryArg'))
 
 
-def create_runtime_library_overrides(settings):
-  overrides = []
-  if not settings.get('SIDE_MODULE'):
-    overrides += [
-      'stackAlloc',
-      'stackSave',
-      'stackRestore',
-      'establishStackSpace',
-    ]
-    if settings['SAFE_HEAP']:
-      overrides.append('setDynamicTop')
-
-  if not settings['RELOCATABLE']:
-    overrides += ['setTempRet0', 'getTempRet0']
-
-  lines = ["Runtime.{0} = Module['{0}'];".format(func) for func in overrides]
-  return '\n'.join(lines)
-
-
 def create_first_in_asm(settings):
   first_in_asm = ''
   if settings['SPLIT_MEMORY']:
@@ -1995,15 +1976,15 @@ def create_module_wasm(sending, receiving, invoke_funcs, settings):
 STACKTOP = STACK_BASE + TOTAL_STACK;
 STACK_MAX = STACK_BASE;
 HEAP32[%d >> 2] = STACKTOP;
-Runtime.stackAlloc = Module['_stackAlloc'];
-Runtime.stackSave = Module['_stackSave'];
-Runtime.stackRestore = Module['_stackRestore'];
-Runtime.establishStackSpace = Module['establishStackSpace'];
+stackAlloc = Module['_stackAlloc'];
+stackSave = Module['_stackSave'];
+stackRestore = Module['_stackRestore'];
+establishStackSpace = Module['establishStackSpace'];
 ''' % shared.Settings.GLOBAL_BASE)
 
   module.append('''
-Runtime.setTempRet0 = Module['setTempRet0'];
-Runtime.getTempRet0 = Module['getTempRet0'];
+setTempRet0 = Module['setTempRet0'];
+getTempRet0 = Module['getTempRet0'];
 ''')
 
   module.append(invoke_wrappers)

src/Fetch.js

@@ -485,7 +485,7 @@ function emscripten_start_fetch(fetch, successcb, errorcb, progresscb) {
 #if FETCH_DEBUG
     console.log('fetch: operation success. e: ' + e);
 #endif
-    if (onsuccess && Runtime.dynCall) Module['dynCall_vi'](onsuccess, fetch);
+    if (onsuccess && typeof dynCall === 'function') Module['dynCall_vi'](onsuccess, fetch);
     else if (successcb) successcb(fetch);
   };
 
@@ -497,29 +497,29 @@ function emscripten_start_fetch(fetch, successcb, errorcb, progresscb) {
 #if FETCH_DEBUG
       console.log('fetch: IndexedDB store succeeded.');
 #endif
-      if (onsuccess && Runtime.dynCall) Module['dynCall_vi'](onsuccess, fetch);
+      if (onsuccess && typeof dynCall === 'function') Module['dynCall_vi'](onsuccess, fetch);
       else if (successcb) successcb(fetch);
     };
     var storeError = function(fetch, xhr, e) {
 #if FETCH_DEBUG
       console.error('fetch: IndexedDB store failed.');
 #endif
-      if (onsuccess && Runtime.dynCall) Module['dynCall_vi'](onsuccess, fetch);
+      if (onsuccess && typeof dynCall === 'function') Module['dynCall_vi'](onsuccess, fetch);
       else if (successcb) successcb(fetch);
     };
     __emscripten_fetch_cache_data(Fetch.dbInstance, fetch, xhr.response, storeSuccess, storeError);
   };
 
   var reportProgress = function(fetch, xhr, e) {
-    if (onprogress && Runtime.dynCall) Module['dynCall_vi'](onprogress, fetch);
+    if (onprogress && typeof dynCall === 'function') Module['dynCall_vi'](onprogress, fetch);
     else if (progresscb) progresscb(fetch);
   };
 
   var reportError = function(fetch, xhr, e) {
 #if FETCH_DEBUG
     console.error('fetch: operation failed: ' + e);
 #endif
-    if (onerror && Runtime.dynCall) Module['dynCall_vi'](onerror, fetch);
+    if (onerror && typeof dynCall === 'function') Module['dynCall_vi'](onerror, fetch);
     else if (errorcb) errorcb(fetch);
   };
 

src/closure-externs.js

@@ -1025,6 +1025,9 @@ var VoidPtr;
 
 // Various Emscripten-specific global variables
 
+/**
+ * @suppress {duplicate}
+ */
 var tempRet0;
 var tempI64;
 var tempDouble;

src/jsifier.js

@@ -67,8 +67,13 @@ function JSify(data, functionsOnly) {
 
     var shellParts = read(shellFile).split('{{BODY}}');
     print(processMacros(preprocess(shellParts[0], shellFile)));
-    var preFile = BUILD_AS_SHARED_LIB || SIDE_MODULE ? 'preamble_sharedlib.js' : 'preamble.js';
-    var pre = processMacros(preprocess(read(preFile).replace('{{RUNTIME}}', getRuntime()), preFile));
+    var pre;
+    if (BUILD_AS_SHARED_LIB || SIDE_MODULE) {
+      pre = processMacros(preprocess(read('preamble_sharedlib.js'), 'preamble_sharedlib.js'));
+    } else {
+      pre = processMacros(preprocess(read('support.js'), 'support.js')) +
+            processMacros(preprocess(read('preamble.js'), 'preamble.js'));
+    }
     print(pre);
   }
 
@@ -114,8 +119,8 @@ function JSify(data, functionsOnly) {
     // name the function; overwrite if it's already named
     snippet = snippet.replace(/function(?:\s+([^(]+))?\s*\(/, 'function ' + finalName + '(');
     if (LIBRARY_DEBUG && !LibraryManager.library[ident + '__asm']) {
-      snippet = snippet.replace('{', '{ var ret = (function() { if (Runtime.debug) Module.printErr("[library call:' + finalName + ': " + Array.prototype.slice.call(arguments).map(Runtime.prettyPrint) + "]"); ');
-      snippet = snippet.substr(0, snippet.length-1) + '}).apply(this, arguments); if (Runtime.debug && typeof ret !== "undefined") Module.printErr("  [     return:" + Runtime.prettyPrint(ret)); return ret; \n}';
+      snippet = snippet.replace('{', '{ var ret = (function() { if (runtimeDebug) Module.printErr("[library call:' + finalName + ': " + Array.prototype.slice.call(arguments).map(prettyPrint) + "]"); ');
+      snippet = snippet.substr(0, snippet.length-1) + '}).apply(this, arguments); if (runtimeDebug && typeof ret !== "undefined") Module.printErr("  [     return:" + prettyPrint(ret)); return ret; \n}';
     }
     return snippet;
   }
@@ -130,7 +135,7 @@ function JSify(data, functionsOnly) {
     }
 
     var func = "function _emscripten_" + (sync ? '' : 'a') + 'sync_run_in_browser_thread_' + sig + '(func' + argsList(sig.length-1) + ') {\n';
-    if (sync) func += '  var waitAddress = Runtime.stackSave();\n';
+    if (sync) func += '  var waitAddress = stackSave();\n';
 
     function sizeofType(t) {
       switch(t) {
@@ -421,10 +426,10 @@ function JSify(data, functionsOnly) {
         Variables.generatedGlobalBase = true;
         // Globals are done, here is the rest of static memory
         if (!SIDE_MODULE) {
-          print('STATIC_BASE = Runtime.GLOBAL_BASE;\n');
+          print('STATIC_BASE = GLOBAL_BASE;\n');
           print('STATICTOP = STATIC_BASE + ' + Runtime.alignMemory(Variables.nextIndexedOffset) + ';\n');
         } else {
-          print('gb = Runtime.alignMemory(getMemory({{{ STATIC_BUMP }}}, ' + MAX_GLOBAL_ALIGN + ' || 1));\n');
+          print('gb = alignMemory(getMemory({{{ STATIC_BUMP }}}, ' + MAX_GLOBAL_ALIGN + ' || 1));\n');
           print('// STATICTOP = STATIC_BASE + ' + Runtime.alignMemory(Variables.nextIndexedOffset) + ';\n'); // comment as metadata only
         }
         if (BINARYEN) {
@@ -461,7 +466,7 @@ function JSify(data, functionsOnly) {
         if (USE_PTHREADS) {
           print('if (!ENVIRONMENT_IS_PTHREAD) {') // Pthreads should not initialize memory again, since it's shared with the main thread.
         }
-        print('/* memory initializer */ ' + makePointer(memoryInitialization, null, 'ALLOC_NONE', 'i8', 'Runtime.GLOBAL_BASE' + (SIDE_MODULE ? '+H_BASE' : ''), true));
+        print('/* memory initializer */ ' + makePointer(memoryInitialization, null, 'ALLOC_NONE', 'i8', 'GLOBAL_BASE' + (SIDE_MODULE ? '+H_BASE' : ''), true));
         if (USE_PTHREADS) {
           print('}')
         }
@@ -472,7 +477,7 @@ function JSify(data, functionsOnly) {
       if (!BUILD_AS_SHARED_LIB && !SIDE_MODULE) {
         if (USE_PTHREADS) {
           print('var tempDoublePtr;\n');
-          print('if (!ENVIRONMENT_IS_PTHREAD) tempDoublePtr = Runtime.alignMemory(allocate(12, "i8", ALLOC_STATIC), 8);\n');
+          print('if (!ENVIRONMENT_IS_PTHREAD) tempDoublePtr = alignMemory(allocate(12, "i8", ALLOC_STATIC), 8);\n');
         } else {
           print('var tempDoublePtr = ' + makeStaticAlloc(8) + '\n');
         }
@@ -519,11 +524,11 @@ function JSify(data, functionsOnly) {
         for(i in proxiedFunctionInvokers) print(proxiedFunctionInvokers[i]+'\n');
         print('if (!ENVIRONMENT_IS_PTHREAD) {\n // Only main thread initializes these, pthreads copy them over at thread worker init time (in pthread-main.js)');
       }
-      print('DYNAMICTOP_PTR = Runtime.staticAlloc(4);\n');
-      print('STACK_BASE = STACKTOP = Runtime.alignMemory(STATICTOP);\n');
-      if (STACK_START > 0) print('if (STACKTOP < ' + STACK_START + ') STACK_BASE = STACKTOP = Runtime.alignMemory(' + STACK_START + ');\n');
+      print('DYNAMICTOP_PTR = staticAlloc(4);\n');
+      print('STACK_BASE = STACKTOP = alignMemory(STATICTOP);\n');
+      if (STACK_START > 0) print('if (STACKTOP < ' + STACK_START + ') STACK_BASE = STACKTOP = alignMemory(' + STACK_START + ');\n');
       print('STACK_MAX = STACK_BASE + TOTAL_STACK;\n');
-      print('DYNAMIC_BASE = Runtime.alignMemory(STACK_MAX);\n');
+      print('DYNAMIC_BASE = alignMemory(STACK_MAX);\n');
       print('HEAP32[DYNAMICTOP_PTR>>2] = DYNAMIC_BASE;\n');
       print('staticSealed = true; // seal the static portion of memory\n');
       if (ASSERTIONS) print('assert(DYNAMIC_BASE < TOTAL_MEMORY, "TOTAL_MEMORY not big enough for stack");\n');

src/library.js

@@ -565,14 +565,14 @@ LibraryManager.library = {
      * not an issue.
      */
 #if ASSERTIONS == 2
-    Runtime.warnOnce('using stub malloc (reference it from C to have the real one included)');
+    warnOnce('using stub malloc (reference it from C to have the real one included)');
 #endif
-    var ptr = Runtime.dynamicAlloc(bytes + 8);
+    var ptr = dynamicAlloc(bytes + 8);
     return (ptr+8) & 0xFFFFFFF8;
   },
   free: function() {
 #if ASSERTIONS == 2
-    Runtime.warnOnce('using stub free (reference it from C to have the real one included)');
+    warnOnce('using stub free (reference it from C to have the real one included)');
 #endif
 },
 
@@ -598,7 +598,7 @@ LibraryManager.library = {
   atexit: function(func, arg) {
 #if ASSERTIONS
 #if NO_EXIT_RUNTIME == 1
-    Runtime.warnOnce('atexit() called, but NO_EXIT_RUNTIME is set, so atexits() will not be called. set NO_EXIT_RUNTIME to 0 (see the FAQ)');
+    warnOnce('atexit() called, but NO_EXIT_RUNTIME is set, so atexits() will not be called. set NO_EXIT_RUNTIME to 0 (see the FAQ)');
 #endif
 #endif
     __ATEXIT__.unshift({ func: func, arg: arg });
@@ -641,7 +641,7 @@ LibraryManager.library = {
       ENV['_'] = Module['thisProgram'];
       // Allocate memory.
       poolPtr = allocate(TOTAL_ENV_SIZE, 'i8', ALLOC_STATIC);
-      envPtr = allocate(MAX_ENV_VALUES * {{{ Runtime.QUANTUM_SIZE }}},
+      envPtr = allocate(MAX_ENV_VALUES * {{{ Runtime.POINTER_SIZE }}},
                         'i8*', ALLOC_STATIC);
       {{{ makeSetValue('envPtr', '0', 'poolPtr', 'i8*') }}};
       {{{ makeSetValue(makeGlobalUse('_environ'), 0, 'envPtr', 'i8*') }}};
@@ -1432,14 +1432,14 @@ LibraryManager.library = {
     if (!self.LLVM_SAVEDSTACKS) {
       self.LLVM_SAVEDSTACKS = [];
     }
-    self.LLVM_SAVEDSTACKS.push(Runtime.stackSave());
+    self.LLVM_SAVEDSTACKS.push(stackSave());
     return self.LLVM_SAVEDSTACKS.length-1;
   },
   llvm_stackrestore: function(p) {
     var self = _llvm_stacksave;
     var ret = self.LLVM_SAVEDSTACKS[p];
     self.LLVM_SAVEDSTACKS.splice(p, 1);
-    Runtime.stackRestore(ret);
+    stackRestore(ret);
   },
 
   __cxa_pure_virtual: function() {
@@ -1707,12 +1707,12 @@ LibraryManager.library = {
         var lib_data = FS.readFile(filename, { encoding: 'binary' });
         if (!(lib_data instanceof Uint8Array)) lib_data = new Uint8Array(lib_data);
         //Module.printErr('libfile ' + filename + ' size: ' + lib_data.length);
-        lib_module = Runtime.loadWebAssemblyModule(lib_data);
+        lib_module = loadWebAssemblyModule(lib_data);
 #else
         // the shared library is a JS file, which we eval
         var lib_data = FS.readFile(filename, { encoding: 'utf8' });
         lib_module = eval(lib_data)(
-          Runtime.alignFunctionTables(),
+          alignFunctionTables(),
           Module
         );
 #endif
@@ -1813,7 +1813,7 @@ LibraryManager.library = {
       } else {
         var result = lib.module[symbol];
         if (typeof result == 'function') {
-          result = Runtime.addFunction(result);
+          result = addFunction(result);
           //Module.printErr('adding function dlsym result for ' + symbol + ' => ' + result);
           lib.cached_functions = result;
         }
@@ -2005,7 +2005,7 @@ LibraryManager.library = {
     var dst = (summerOffset != winterOffset && date.getTimezoneOffset() == Math.min(winterOffset, summerOffset))|0;
     {{{ makeSetValue('tmPtr', C_STRUCTS.tm.tm_isdst, 'dst', 'i32') }}};
 
-    var zonePtr = {{{ makeGetValue(makeGlobalUse('_tzname'), 'dst ? Runtime.QUANTUM_SIZE : 0', 'i32') }}};
+    var zonePtr = {{{ makeGetValue(makeGlobalUse('_tzname'), 'dst ? ' + Runtime.QUANTUM_SIZE + ' : 0', 'i32') }}};
     {{{ makeSetValue('tmPtr', C_STRUCTS.tm.tm_zone, 'zonePtr', 'i32') }}};
 
     return tmPtr;
@@ -2052,9 +2052,9 @@ LibraryManager.library = {
 
   ctime_r__deps: ['localtime_r', 'asctime_r'],
   ctime_r: function(time, buf) {
-    var stack = Runtime.stackSave();
-    var rv = _asctime_r(_localtime_r(time, Runtime.stackAlloc({{{ C_STRUCTS.tm.__size__ }}})), buf);
-    Runtime.stackRestore(stack);
+    var stack = stackSave();
+    var rv = _asctime_r(_localtime_r(time, stackAlloc({{{ C_STRUCTS.tm.__size__ }}})), buf);
+    stackRestore(stack);
     return rv;
   },
 
@@ -4048,7 +4048,7 @@ LibraryManager.library = {
 
     // If user requested to see the original source stack, but no source map information is available, just fall back to showing the JS stack.
     if (flags & 8/*EM_LOG_C_STACK*/ && typeof emscripten_source_map === 'undefined') {
-      Runtime.warnOnce('Source map information is not available, emscripten_log with EM_LOG_C_STACK will be ignored. Build with "--pre-js $EMSCRIPTEN/src/emscripten-source-map.min.js" linker flag to add source map loading to code.');
+      warnOnce('Source map information is not available, emscripten_log with EM_LOG_C_STACK will be ignored. Build with "--pre-js $EMSCRIPTEN/src/emscripten-source-map.min.js" linker flag to add source map loading to code.');
       flags ^= 8/*EM_LOG_C_STACK*/;
       flags |= 16/*EM_LOG_JS_STACK*/;
     }
@@ -4176,7 +4176,7 @@ LibraryManager.library = {
   emscripten_log: function(flags, varargs) {
     // Extract the (optionally-existing) printf format specifier field from varargs.
     var format = {{{ makeGetValue('varargs', '0', 'i32', undefined, undefined, true) }}};
-    varargs += Math.max(Runtime.getNativeFieldSize('i32'), Runtime.getAlignSize('i32', null, true));
+    varargs += {{{ Math.max(Runtime.getNativeFieldSize('i32'), Runtime.getAlignSize('i32', null, true)) }}};
     var str = '';
     if (format) {
       var result = __formatString(format, varargs);
@@ -4190,7 +4190,7 @@ LibraryManager.library = {
   emscripten_get_compiler_setting: function(name) {
     name = Pointer_stringify(name);
 
-    var ret = Runtime.getCompilerSetting(name);
+    var ret = getCompilerSetting(name);
     if (typeof ret === 'number') return ret;
 
     if (!_emscripten_get_compiler_setting.cache) _emscripten_get_compiler_setting.cache = {};

src/library_bootstrap_structInfo.js

@@ -22,16 +22,16 @@ LibraryManager.library = {
     if (!self.called) {
       HEAP32[DYNAMICTOP_PTR>>2] = alignUp(HEAP32[DYNAMICTOP_PTR>>2], 16777216); // make sure we start out aligned
       self.called = true;
-      assert(Runtime.dynamicAlloc);
-      self.alloc = Runtime.dynamicAlloc;
-      Runtime.dynamicAlloc = function() { abort('cannot dynamically allocate, sbrk now has control') };
+      assert(dynamicAlloc);
+      self.alloc = dynamicAlloc;
+      dynamicAlloc = function() { abort('cannot dynamically allocate, sbrk now has control') };
     }
     var ret = HEAP32[DYNAMICTOP_PTR>>2];
     if (bytes != 0) self.alloc(bytes);
     return ret;  // Previous break location.
   },
   malloc: function(x) {
-    return Runtime.dynamicAlloc(x);
+    return dynamicAlloc(x);
   },
 };