Use standard named for native manipulation functions. NFC (#21555)

We continue to use the JS names when calling from JS code but use
prefixed, native symbol names for the native implementation.

I'm hoping we can eventually completely remove the `WASM_SYSTEM_EXPORTS`
special casing.

Author: sbc100

ChangeLog.md

@@ -22,12 +22,22 @@ See docs/process.md for more on how version tagging works.
 -----------------------
 - In `MODULARIZE` mode we no longer export the module ready promise as `ready`.
   This was previously exposed on the Module for historical reasons even though
-  in `MODULARIZE` mode the only way to get access to the module is to wait on the
-  promise returned from the factory function. (#21564)
+  in `MODULARIZE` mode the only way to get access to the module is to wait on
+  the promise returned from the factory function. (#21564)
 - JS library code is now executed in its own context/scope, which limits how
   much of the compiler internals are accessible. If there are build time JS
   symbols that you are depending on, but that were not added to this scope,
   please file a bug and we can add more to this scope. (#21542)
+- The JS functions for manipulating the native/shadow stack
+  (`stackSave`/`stackRestore`/`stackAlloc`) are now just regular JS library
+  function and as such are only included if you explicitly depend on them.  If
+  you use these functions in your JS code you will need to depend on them via
+  either:
+  - The `EM_JS_DEPS` macro for `EM_ASM`/`EM_JS` code.
+  - The `__deps` attribute for JS library functions
+  - The `-sDEFAULT_LIBRARY_FUNCS_TO_INCLUDE` flag for `--pre-js`/`--post-js`
+    code
+  (#21555)
 
 3.1.56 - 03/14/24
 -----------------

src/jsifier.mjs

@@ -31,6 +31,7 @@ import {
   printErr,
   read,
   warn,
+  warnOnce,
   warningOccured,
 } from './utility.mjs';
 import {LibraryManager, librarySymbols} from './modules.mjs';

src/library.js

@@ -21,6 +21,20 @@
 // new function with an '_', it will not be found.
 
 addToLibrary({
+  // JS aliases for native stack manipulation functions
+  $stackSave__deps: ['emscripten_stack_get_current'],
+  $stackSave: () => _emscripten_stack_get_current(),
+  $stackRestore__deps: ['_emscripten_stack_restore'],
+  $stackRestore: (val) => __emscripten_stack_restore(val),
+  $stackAlloc__deps: ['_emscripten_stack_alloc'],
+  $stackAlloc: (sz) => __emscripten_stack_alloc(sz),
+
+  // Aliases that allow legacy names (without leading $) for these
+  // stack functions to continue to work in `__deps` entries.
+  stackAlloc: '$stackAlloc',
+  stackSave: '$stackSave',
+  stackRestore: '$stackSave',
+
   $ptrToString: (ptr) => {
 #if ASSERTIONS
     assert(typeof ptr === 'number');
@@ -596,7 +610,7 @@ addToLibrary({
 #endif
 
   $withStackSave__internal: true,
-  $withStackSave__deps: ['stackSave', 'stackRestore'],
+  $withStackSave__deps: ['$stackSave', '$stackRestore'],
   $withStackSave: (f) => {
     var stack = stackSave();
     var ret = f();

src/library_async.js

@@ -541,7 +541,7 @@ addToLibrary({
     });
   },
 
-  $Fibers__deps: ['$Asyncify', 'emscripten_stack_set_limits', 'stackRestore'],
+  $Fibers__deps: ['$Asyncify', 'emscripten_stack_set_limits', '$stackRestore'],
   $Fibers: {
     nextFiber: 0,
     trampolineRunning: false,
@@ -601,7 +601,7 @@ addToLibrary({
     },
   },
 
-  emscripten_fiber_swap__deps: ["$Asyncify", "$Fibers", 'stackSave'],
+  emscripten_fiber_swap__deps: ["$Asyncify", "$Fibers", '$stackSave'],
   emscripten_fiber_swap__async: true,
   emscripten_fiber_swap: (oldFiber, newFiber) => {
     if (ABORT) return;

src/library_ccall.js

@@ -15,7 +15,7 @@ addToLibrary({
   },
 
   // C calling interface.
-  $ccall__deps: ['$getCFunc', '$writeArrayToMemory', '$stringToUTF8OnStack', 'stackSave', 'stackRestore', 'stackAlloc'],
+  $ccall__deps: ['$getCFunc', '$writeArrayToMemory', '$stringToUTF8OnStack', '$stackSave', '$stackRestore', '$stackAlloc'],
   $ccall__docs: `
   /**
    * @param {string|null=} returnType

src/library_dylink.js

@@ -72,7 +72,7 @@ var LibraryDylink = {
   // generation time.
 #if !DISABLE_EXCEPTION_CATCHING || SUPPORT_LONGJMP == 'emscripten'
   $createInvokeFunction__internal: true,
-  $createInvokeFunction__deps: ['$dynCall', 'setThrew', 'stackSave', 'stackRestore'],
+  $createInvokeFunction__deps: ['$dynCall', 'setThrew', '$stackSave', '$stackRestore'],
   $createInvokeFunction: (sig) => {
     return function() {
       var sp = stackSave();

src/library_exceptions.js

@@ -287,7 +287,7 @@ var LibraryExceptions = {
 
 #endif
 #if WASM_EXCEPTIONS || !DISABLE_EXCEPTION_CATCHING
-  $getExceptionMessageCommon__deps: ['__get_exception_message', 'free', '$withStackSave', 'stackAlloc'],
+  $getExceptionMessageCommon__deps: ['__get_exception_message', 'free', '$withStackSave', '$stackAlloc'],
   $getExceptionMessageCommon: (ptr) => withStackSave(() => {
     var type_addr_addr = stackAlloc({{{ POINTER_SIZE }}});
     var message_addr_addr = stackAlloc({{{ POINTER_SIZE }}});

src/library_legacy.js

@@ -17,7 +17,7 @@ legacyFuncs = {
    * @param {(Uint8Array|Array<number>)} slab: An array of data.
    * @param {number=} allocator : How to allocate memory, see ALLOC_*
    */
-  $allocate__deps: ['$ALLOC_NORMAL', '$ALLOC_STACK', 'malloc', 'stackAlloc'],
+  $allocate__deps: ['$ALLOC_NORMAL', '$ALLOC_STACK', 'malloc', '$stackAlloc'],
   $allocate: (slab, allocator) => {
     var ret;
   #if ASSERTIONS

src/library_promise.js

@@ -77,9 +77,9 @@ addToLibrary({
   $makePromiseCallback__deps: ['$getPromise',
                                '$POINTER_SIZE',
                                'emscripten_promise_destroy',
-                               'stackAlloc',
-                               'stackRestore',
-                               'stackSave'],
+                               '$stackAlloc',
+                               '$stackRestore',
+                               '$stackSave'],
   $makePromiseCallback: (callback, userData) => {
     return (value) => {
 #if RUNTIME_DEBUG

src/library_pthread.js

@@ -960,7 +960,7 @@ var LibraryPThread = {
   $proxyToMainThreadPtr: (...args) => BigInt(proxyToMainThread(...args)),
 #endif
 
-  $proxyToMainThread__deps: ['$withStackSave', '_emscripten_run_on_main_thread_js'].concat(i53ConversionDeps),
+  $proxyToMainThread__deps: ['$withStackSave', '$stackAlloc', '_emscripten_run_on_main_thread_js'].concat(i53ConversionDeps),
   $proxyToMainThread__docs: '/** @type{function(number, (number|boolean), ...number)} */',
   $proxyToMainThread: (funcIndex, emAsmAddr, sync, ...callArgs) => {
     // EM_ASM proxying is done by passing a pointer to the address of the EM_ASM
@@ -1065,7 +1065,7 @@ var LibraryPThread = {
   },
 
   $establishStackSpace__internal: true,
-  $establishStackSpace__deps: ['stackRestore'],
+  $establishStackSpace__deps: ['$stackRestore'],
   $establishStackSpace: () => {
     var pthread_ptr = _pthread_self();
     var stackHigh = {{{ makeGetValue('pthread_ptr', C_STRUCTS.pthread.stack, '*') }}};

src/library_sdl.js

@@ -2157,7 +2157,7 @@ var LibrarySDL = {
   // We support JPG, PNG, TIF because browsers do
   IMG_Init: (flags) => flags,
 
-  IMG_Load_RW__deps: ['SDL_LockSurface', 'SDL_FreeRW', '$PATH_FS', '$withStackSave', '$stringToUTF8OnStack', 'stackAlloc'],
+  IMG_Load_RW__deps: ['SDL_LockSurface', 'SDL_FreeRW', '$PATH_FS', '$withStackSave', '$stringToUTF8OnStack', '$stackAlloc'],
   IMG_Load_RW__proxy: 'sync',
   IMG_Load_RW: (rwopsID, freeSrc) => {
     try {

src/library_strings.js

@@ -484,7 +484,7 @@ addToLibrary({
   },
 
   // Allocate stack space for a JS string, and write it there.
-  $stringToUTF8OnStack__deps: ['$lengthBytesUTF8', '$stringToUTF8'],
+  $stringToUTF8OnStack__deps: ['$lengthBytesUTF8', '$stringToUTF8', '$stackAlloc'],
   $stringToUTF8OnStack: (str) => {
     var size = lengthBytesUTF8(str) + 1;
     var ret = stackAlloc(size);

src/library_webgl.js

@@ -3942,6 +3942,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
 #if MEMORY64
   // Convert an array of i64 offsets to an array of i32 offsets returning a
   // pointer to the new (stack allocated) array.
+  $convertOffsets__deps: ['$stackAlloc'],
   $convertOffsets__internal: true,
   $convertOffsets: (offsets, count) => {
     var offsets32 = stackAlloc(count * 4);
@@ -3960,7 +3961,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
   glMultiDrawElements: 'glMultiDrawElementsWEBGL',
   glMultiDrawElementsANGLE: 'glMultiDrawElementsWEBGL',
 #if MEMORY64
-  glMultiDrawElementsWEBGL__deps: ['$convertOffsets', 'stackSave', 'stackRestore'],
+  glMultiDrawElementsWEBGL__deps: ['$convertOffsets', '$stackSave', '$stackRestore'],
 #endif
   glMultiDrawElementsWEBGL: (mode, counts, type, offsets, drawcount) => {
 #if MEMORY64
@@ -3983,7 +3984,7 @@ for (/**@suppress{duplicate}*/var i = 0; i < {{{ GL_POOL_TEMP_BUFFERS_SIZE }}};
   glMultiDrawElementsInstancedWEBGL__sig: 'vipippi',
   glMultiDrawElementsInstancedANGLE: 'glMultiDrawElementsInstancedWEBGL',
 #if MEMORY64
-  glMultiDrawElementsInstancedWEBGL__deps: ['$convertOffsets', 'stackSave', 'stackRestore'],
+  glMultiDrawElementsInstancedWEBGL__deps: ['$convertOffsets', '$stackSave', '$stackRestore'],
 #endif
   glMultiDrawElementsInstancedWEBGL: (mode, counts, type, offsets, instanceCounts, drawcount) => {
 #if MEMORY64

src/settings_internal.js

@@ -173,7 +173,7 @@ var SUPPORTS_PROMISE_ANY = false;
 // Wasm backend symbols that are considered system symbols and don't
 // have the normal C symbol name mangled applied (== prefix with an underscore)
 // (Also implicily on this list is any function that starts with string "dynCall_")
-var WASM_SYSTEM_EXPORTS = ['stackAlloc', 'stackSave', 'stackRestore', 'getTempRet0', 'setTempRet0'];
+var WASM_SYSTEM_EXPORTS = ['getTempRet0', 'setTempRet0'];
 
 // Internal: value of -flto argument (either full or thin)
 var LTO = 0;

system/lib/compiler-rt/stack_ops.S

@@ -1,6 +1,5 @@
-.globl stackSave
-.globl stackRestore
-.globl stackAlloc
+.globl _emscripten_stack_restore
+.globl _emscripten_stack_alloc
 .globl emscripten_stack_get_current
 
 #ifdef __wasm64__
@@ -13,19 +12,14 @@
 
 .globaltype __stack_pointer, PTR
 
-stackSave:
-  .functype stackSave() -> (PTR)
-  global.get __stack_pointer
-  end_function
-
-stackRestore:
-  .functype stackRestore(PTR) -> ()
+_emscripten_stack_restore:
+  .functype _emscripten_stack_restore(PTR) -> ()
   local.get 0
   global.set __stack_pointer
   end_function
 
-stackAlloc:
-  .functype stackAlloc(PTR) -> (PTR)
+_emscripten_stack_alloc:
+  .functype _emscripten_stack_alloc(PTR) -> (PTR)
   .local PTR, PTR
   global.get __stack_pointer
   # Get arg 0 -> number of bytes to allocate
@@ -44,4 +38,3 @@ emscripten_stack_get_current:
   .functype emscripten_stack_get_current () -> (PTR)
   global.get __stack_pointer
   end_function
-

test/core/stackAlloc.cpp renamed to test/core/test_stackAlloc.c

@@ -5,6 +5,8 @@
 
 #include <emscripten.h>
 
+EM_JS_DEPS(deps, "$stackSave,$stackAlloc");
+
 int main() {
   EM_ASM({
     var size = 128;

test/core/stackAlloc.out renamed to test/core/test_stackAlloc.out

@@ -1,13 +1,13 @@
 __cxa_is_pointer_type
 __indirect_function_table
 __wasm_call_ctors
+_emscripten_stack_alloc
+_emscripten_stack_restore
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiji
 dynCall_viijii
+emscripten_stack_get_current
 main
 memory
-stackAlloc
-stackRestore
-stackSave

test/other/metadce/test_metadce_cxx_ctors1.exports

@@ -1 +1 @@
-125815
+125860

test/other/metadce/test_metadce_cxx_ctors1.size

@@ -1,12 +1,12 @@
 __cxa_is_pointer_type
 __indirect_function_table
+_emscripten_stack_alloc
+_emscripten_stack_restore
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiji
 dynCall_viijii
+emscripten_stack_get_current
 main
 memory
-stackAlloc
-stackRestore
-stackSave

test/other/metadce/test_metadce_cxx_ctors2.exports

@@ -1 +1 @@
-125274
+125319

test/other/metadce/test_metadce_cxx_ctors2.size

@@ -5,16 +5,16 @@ __cxa_increment_exception_refcount
 __cxa_is_pointer_type
 __indirect_function_table
 __wasm_call_ctors
+_emscripten_stack_alloc
+_emscripten_stack_restore
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiiii
 dynCall_jiji
 dynCall_viijii
+emscripten_stack_get_current
 main
 memory
 setTempRet0
 setThrew
-stackAlloc
-stackRestore
-stackSave

test/other/metadce/test_metadce_cxx_except.exports

@@ -1 +1 @@
-10931
+10942

test/other/metadce/test_metadce_cxx_except.gzsize

@@ -1 +1 @@
-28115
+28148

test/other/metadce/test_metadce_cxx_except.jssize

@@ -1 +1 @@
-168051
+168096

test/other/metadce/test_metadce_cxx_except.size

@@ -1,11 +1,11 @@
 __indirect_function_table
 __trap
 __wasm_call_ctors
+_emscripten_stack_alloc
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiji
 dynCall_viijii
 main
 memory
-stackAlloc

test/other/metadce/test_metadce_cxx_except_wasm.exports

@@ -1 +1 @@
-139189
+139202

test/other/metadce/test_metadce_cxx_except_wasm.size

@@ -6,17 +6,17 @@ __cxa_increment_exception_refcount
 __cxa_is_pointer_type
 __indirect_function_table
 __wasm_call_ctors
+_emscripten_stack_alloc
+_emscripten_stack_restore
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiiii
 dynCall_jiji
 dynCall_viijii
+emscripten_stack_get_current
 free
 main
 memory
 setTempRet0
 setThrew
-stackAlloc
-stackRestore
-stackSave

test/other/metadce/test_metadce_cxx_mangle.exports

@@ -1 +1 @@
-10939
+10949

test/other/metadce/test_metadce_cxx_mangle.gzsize

@@ -1 +1 @@
-28116
+28149

test/other/metadce/test_metadce_cxx_mangle.jssize

@@ -1 +1 @@
-223535
+223580

test/other/metadce/test_metadce_cxx_mangle.size

@@ -1,13 +1,13 @@
 __cxa_is_pointer_type
 __indirect_function_table
 __wasm_call_ctors
+_emscripten_stack_alloc
+_emscripten_stack_restore
 dynCall_iiiiiijj
 dynCall_iiiiij
 dynCall_iiiiijj
 dynCall_jiji
 dynCall_viijii
+emscripten_stack_get_current
 main
 memory
-stackAlloc
-stackRestore
-stackSave

test/other/metadce/test_metadce_cxx_noexcept.exports

@@ -1 +1 @@
-128612
+128657