Config vars expand

ChangeLog.md

@@ -20,6 +20,9 @@ See docs/process.md for more on how version tagging works.
 
 6.0.2 (in development)
 ----------------------
+- The `GROWABLE_ARRAYBUFFERS` setting now defaults to 1, which means it will be
+  used when available. Note that this only affects programs that are built with
+  `ALLOW_MEMORY_GROWTH`, which is not enabled by default. (#27212)
 - New `-sNODERAWSOCKETS` setting that backs the POSIX sockets API with real TCP
   (`node:net`) and UDP (`node:dgram`) sockets on Node.js, with no `ws`, proxy
   process, or pthreads required. Supports incoming and outgoing TCP, UDP, IPv6,

site/source/docs/tools_reference/settings_reference.rst

@@ -3404,13 +3404,13 @@ GROWABLE_ARRAYBUFFERS
 Enable support for growable views of Wasm memory. This is a recent Web
 platform feature that can make growing the Wasm memory more efficient,
 especially in multi-threaded builds.
-Setting this to 1 will auto-detect the presence of this API and use it
-when available.
+The default setting of 1 will auto-detect the presence of this API and use
+it when available.
 Setting this to 2 will unconditionally require it. This is the only way
 to completely remove the overhead of growable memory + pthreads.
 This settings does nothing unless ALLOW_MEMORY_GROWTH is set.
 
-Default value: 0
+Default value: 1
 
 .. _cross_origin:
 

src/settings.js

@@ -2250,13 +2250,13 @@ var JS_BASE64_API = false;
 // Enable support for growable views of Wasm memory. This is a recent Web
 // platform feature that can make growing the Wasm memory more efficient,
 // especially in multi-threaded builds.
-// Setting this to 1 will auto-detect the presence of this API and use it
-// when available.
+// The default setting of 1 will auto-detect the presence of this API and use
+// it when available.
 // Setting this to 2 will unconditionally require it. This is the only way
 // to completely remove the overhead of growable memory + pthreads.
 // This settings does nothing unless ALLOW_MEMORY_GROWTH is set.
 // [link]
-var GROWABLE_ARRAYBUFFERS = 0;
+var GROWABLE_ARRAYBUFFERS = 1;
 
 // If the emscripten-generated program is hosted on separate origin then
 // starting new pthread worker can violate CSP rules.  Enabling

test/codesize/test_codesize_mem_O3_grow.json

@@ -1,10 +1,10 @@
 {
-  "a.out.js": 4339,
-  "a.out.js.gz": 2132,
+  "a.out.js": 4386,
+  "a.out.js.gz": 2154,
   "a.out.nodebug.wasm": 5261,
   "a.out.nodebug.wasm.gz": 2419,
-  "total": 9600,
-  "total_gz": 4551,
+  "total": 9647,
+  "total_gz": 4573,
   "sent": [
     "a (emscripten_resize_heap)"
   ],

test/codesize/test_codesize_mem_O3_grow_standalone.json

@@ -1,10 +1,10 @@
 {
-  "a.out.js": 3805,
-  "a.out.js.gz": 1869,
+  "a.out.js": 3852,
+  "a.out.js.gz": 1896,
   "a.out.nodebug.wasm": 5641,
   "a.out.nodebug.wasm.gz": 2659,
-  "total": 9446,
-  "total_gz": 4528,
+  "total": 9493,
+  "total_gz": 4555,
   "sent": [
     "args_get",
     "args_sizes_get",

test/codesize/test_codesize_minimal_pthreads_memgrowth.json

@@ -1,10 +1,10 @@
 {
-  "a.out.js": 7381,
-  "a.out.js.gz": 3643,
+  "a.out.js": 7552,
+  "a.out.js.gz": 3708,
   "a.out.nodebug.wasm": 19064,
   "a.out.nodebug.wasm.gz": 8804,
-  "total": 26445,
-  "total_gz": 12447,
+  "total": 26616,
+  "total_gz": 12512,
   "sent": [
     "a (memory)",
     "b (exit)",

tools/config.py

@@ -101,40 +101,50 @@ def set_config_from_tool_location(config_key, tool_binary, f):
     exit_with_error('%s is set to empty value in %s', config_key, EM_CONFIG)
 
 
+def expandvars(value):
+  if type(value) == list:
+    return [expandvars(v) for v in value]
+  return os.path.expandvars(value)
+
+
 def parse_config_file():
   """Parse the emscripten config file using python's exec.
 
   Also check EM_<KEY> environment variables to override specific config keys.
   """
   config = {'__file__': EM_CONFIG}
   config_text = utils.read_file(EM_CONFIG)
+  os.environ['EM_CONFIG_DIR'] = os.path.dirname(EM_CONFIG)
   try:
     exec(config_text, config)
   except Exception as e:
     exit_with_error('error in evaluating config file (%s): %s, text: %s', EM_CONFIG, e, config_text)
 
   CONFIG_KEYS = (
     'NODE_JS',
-    'NODE_JS_TEST',
     'BINARYEN_ROOT',
-    'SPIDERMONKEY_ENGINE',
-    'V8_ENGINE',
     'LLVM_ROOT',
     'LLVM_ADD_VERSION',
     'CLANG_ADD_VERSION',
     'CLOSURE_COMPILER',
-    'JS_ENGINES',
-    'WASMER',
-    'WASMTIME',
-    'WASM_ENGINES',
     'FROZEN_CACHE',
     'CACHE',
     'PORTS',
     'COMPILER_WRAPPER',
   )
 
+  TEST_KEYS = (
+    'NODE_JS_TEST',
+    'V8_ENGINE',
+    'SPIDERMONKEY_ENGINE',
+    'JS_ENGINES',
+    'WASMER',
+    'WASMTIME',
+    'WASM_ENGINES',
+  )
+
   # Only propagate certain settings from the config file.
-  for key in CONFIG_KEYS:
+  for key in CONFIG_KEYS + TEST_KEYS:
     env_var = 'EM_' + key
     env_value = os.environ.get(env_var)
     if env_value is not None:
@@ -148,7 +158,7 @@ def parse_config_file():
           exit_with_error(f'environment variable {env_var} must be an absolute path: {env_value}')
       globals()[key] = env_value
     elif key in config:
-      globals()[key] = config[key]
+      globals()[key] = expandvars(config[key])
 
 
 def read_config():

tools/config_template.py

@@ -1,8 +1,9 @@
 # This file will be edited (the {{{ }}} things), and written to `.emscripten`
 # when emscripten is first used and no config file is found.
 
-# Note: If you put paths relative to the home directory, do not forget
-# os.path.expanduser
+# Note: Use can use environment variables in your settings, e.g. use `$HOME`
+# for paths relative to the home directory.  You can also use `$EM_CONFIG_DIR`
+# for the directory where the config file lives.
 #
 # Any config setting <KEY> in this file can be overridden by setting the
 # EM_<KEY> environment variable. For example, settings EM_LLVM_ROOT override
@@ -34,9 +35,8 @@
 #
 # JS_ENGINES = [NODE_JS_TEST] # add V8_ENGINE or SPIDERMONKEY_ENGINE if you have them installed too.
 #
-# import os
-# WASMER = os.path.expanduser(os.path.join('~', '.wasmer', 'bin', 'wasmer'))
-# WASMTIME = os.path.expanduser(os.path.join('~', 'wasmtime'))
+# WASMER = '$HOME/.wasmer/bin/wasmer'
+# WASMTIME = '$HOME/wasmtime'
 #
 # Wasm engines to use in STANDALONE_WASM tests.
 #

tools/link.py

@@ -1752,6 +1752,8 @@ def get_full_import_name(name):
       exit_with_error('wasm2js does not support WASM_BIGINT')
     if settings.CAN_ADDRESS_2GB:
       exit_with_error('wasm2js does not support >2gb address space')
+    # WASM2JS does not support GROWABLE_ARRAYBUFFERS at all
+    default_setting('GROWABLE_ARRAYBUFFERS', 0)
 
   if settings.NODE_CODE_CACHING:
     if settings.WASM_ASYNC_COMPILATION: