Move runtime_legacy.js to library_legacy.js (#17390)

Author: sbc100

ChangeLog.md

@@ -29,11 +29,15 @@ See docs/process.md for more on how version tagging works.
   `DEFAULT_LIBRARY_FUNCS_TO_INCLUDE`.  This change allows us to transition
   runtime functions to JS library functions without the need to folks to add
   `DEFAULT_LIBRARY_FUNCS_TO_INCLUDE`. (#17369)
-- The `addFunction`/`removeFunction` runtime functions were converted into JS
-  library functions.  This means that won't get included in the output unless
-  explictly required.  Exporting them via `EXPORTED_RUNTIME_METHODS` will
-  continue to work.  For internal usage (without exporting them) they can be
-  added to `DEFAULT_LIBRARY_FUNCS_TO_INCLUDE`. (#17370)
+- The following function, which were previously part of the default runtime, are
+  now JS library functions:
+   - addFunction
+   - removeFunction
+   - allocate
+  This means they won't get included in the output unless explictly required.
+  Exporting them via `EXPORTED_RUNTIME_METHODS` will continue to work.  For
+  internal usage (without exporting them) they can be added to
+  `DEFAULT_LIBRARY_FUNCS_TO_INCLUDE`. (#17370)
 - The `run` runtime function is no longer exported by default.  It can be added
   to `EXPORTED_RUNTIME_METHODS` if needed.
 - The getWasmTableEntry/setWasmTableEntry library function are no longer

src/library_legacy.js

@@ -0,0 +1,40 @@
+/**
+ * @license
+ * Copyright 2010 The Emscripten Authors
+ * SPDX-License-Identifier: MIT
+ */
+
+mergeInto(LibraryManager.library, {
+  $ALLOC_NORMAL: 0,  // Tries to use _malloc()
+  $ALLOC_STACK: 1,  // Lives for the duration of the current function call
+
+  /**
+   * allocate(): This function is no longer used by emscripten but is kept around to avoid
+   *             breaking external users.
+   *             You should normally not use allocate(), and instead allocate
+   *             memory using _malloc()/stackAlloc(), initialize it with
+   *             setValue(), and so forth.
+   * @param {(Uint8Array|Array<number>)} slab: An array of data.
+   * @param {number=} allocator : How to allocate memory, see ALLOC_*
+   */
+  $allocate__deps: ['$ALLOC_NORMAL', '$ALLOC_STACK'],
+  $allocate: function(slab, allocator) {
+    var ret;
+  #if ASSERTIONS
+    assert(typeof allocator == 'number', 'allocate no longer takes a type argument')
+    assert(typeof slab != 'number', 'allocate no longer takes a number as arg0')
+  #endif
+
+    if (allocator == ALLOC_STACK) {
+      ret = stackAlloc(slab.length);
+    } else {
+      ret = {{{ makeMalloc('allocate', 'slab.length') }}};
+    }
+
+    if (!slab.subarray && !slab.slice) {
+      slab = new Uint8Array(slab);
+    }
+    HEAPU8.set(slab, ret);
+    return ret;
+  },
+});

src/modules.js

@@ -152,6 +152,10 @@ global.LibraryManager = {
       libraries.push('library_html5_webgpu.js');
     }
 
+    if (!STRICT) {
+      libraries.push('library_legacy.js');
+    }
+
     if (BOOTSTRAPPING_STRUCT_INFO) {
       libraries = [
         'library_bootstrap.js',
@@ -407,11 +411,8 @@ function exportRuntime() {
 
   // All possible runtime elements that can be exported
   let runtimeElements = [
-    'ALLOC_NORMAL',
-    'ALLOC_STACK',
     'ccall',
     'cwrap',
-    'allocate',
     'UTF8ArrayToString',
     'UTF8ToString',
     'stringToUTF8Array',

src/preamble.js

@@ -233,9 +233,6 @@ function _free() {
 #endif // free
 #endif // ASSERTIONS
 
-#if !STRICT
-#include "runtime_legacy.js"
-#endif
 #include "runtime_strings.js"
 #include "runtime_strings_extra.js"
 

src/runtime_legacy.js

@@ -1 +1 @@
-92392
+91192

tests/other/test_unoptimized_code_size.js.size

@@ -1 +1 @@
-54045
+53126

tests/other/test_unoptimized_code_size_no_asserts.js.size

@@ -7041,6 +7041,7 @@ def test(output_prefix='', args=None, assert_returncode=0):
 
     # see that direct usage (not on module) works. we don't export, but the use
     # keeps it alive through JSDCE
+    self.set_setting('DEFAULT_LIBRARY_FUNCS_TO_INCLUDE', ['$ALLOC_STACK'])
     test(args=['-DDIRECT'])
     # see that with assertions, we get a nice error message
     self.set_setting('EXPORTED_RUNTIME_METHODS', [])

tests/test_core.py

@@ -12072,9 +12072,21 @@ def test_stdint_limits(self):
 
   def test_legacy_runtime(self):
     self.set_setting('EXPORTED_FUNCTIONS', ['_malloc', '_main'])
+    self.set_setting('EXPORTED_RUNTIME_METHODS', ['ALLOC_NORMAL'])
+
+    # By default `allocate` is not available (its a JS library function not included by default)
+    self.do_runf(test_file('other/test_legacy_runtime.c'),
+                 'Aborted(Call to `allocate` which is a library function and not included by default',
+                 assert_returncode=NON_ZERO)
+
+    # Adding it to EXPORTED_RUNTIME_METHODS makes it available.
+    self.set_setting('EXPORTED_RUNTIME_METHODS', ['allocate', 'ALLOC_NORMAL'])
     self.do_runf(test_file('other/test_legacy_runtime.c'), 'hello from js')
+
+    # In strict mode the library function is not even available, so we get a build time error
     self.set_setting('STRICT')
-    self.do_runf(test_file('other/test_legacy_runtime.c'), 'ReferenceError: allocate is not defined', assert_returncode=NON_ZERO)
+    err = self.expect_fail([EMCC, test_file('other/test_legacy_runtime.c')] + self.get_emcc_args())
+    self.assertContained('warning: invalid item in EXPORTED_RUNTIME_METHODS: allocate', err)
 
   def test_fetch_settings(self):
     create_file('pre.js', '''