Ensure MAXIMUM_MEMORY is set correctly (#19960)

This avoids issues where MAXIMUM_MEMORY is inconsistent and simplifies
check that wants to check for max memory address.  Without this change
the following check in preable.js was producing the wrong result when
INITIAL_MEMORY was set to >4gb but MAXIMUM_MEMORY was not set:

```
#if MEMORY64 && MAXIMUM_MEMORY > FOUR_GB
```

When the user specifies INITIAL_MEMORY that should set a lower bound
for MAXIMUM_MEMORY.

When memory growth is disallowed MAXIMUM_MEMORY should match
INITIAL_MEMORY.

Author: sbc100

emcc.py

@@ -1778,6 +1778,22 @@ def include_and_export(name):
       settings.EXPORTED_RUNTIME_METHODS += ['ExitStatus']
 
 
+def set_max_memory():
+  # When memory growth is disallowed set MAXIMUM_MEMORY equal to INITIAL_MEMORY
+  if not settings.ALLOW_MEMORY_GROWTH:
+    if 'MAXIMUM_MEMORY' in user_settings:
+      diagnostics.warning('unused-command-line-argument', 'MAXIMUM_MEMORY is only meaningful with ALLOW_MEMORY_GROWTH')
+    settings.MAXIMUM_MEMORY = settings.INITIAL_MEMORY
+
+  # INITIAL_MEMORY sets a lower bound for MAXIMUM_MEMORY
+  if 'MAXIMUM_MEMORY' not in user_settings:
+    if settings.INITIAL_MEMORY > settings.MAXIMUM_MEMORY:
+      settings.MAXIMUM_MEMORY = settings.INITIAL_MEMORY
+
+  if settings.MAXIMUM_MEMORY < settings.INITIAL_MEMORY:
+    exit_with_error('MAXIMUM_MEMORY cannot be less than INITIAL_MEMORY')
+
+
 @ToolchainProfiler.profile_block('linker_setup')
 def phase_linker_setup(options, state, newargs):
   autoconf = os.environ.get('EMMAKEN_JUST_CONFIGURE') or 'conftest.c' in state.orig_args or 'conftest.cpp' in state.orig_args
@@ -2522,12 +2538,6 @@ def check_memory_setting(setting):
   if settings.MEMORY_GROWTH_LINEAR_STEP != -1:
     check_memory_setting('MEMORY_GROWTH_LINEAR_STEP')
 
-  if settings.ALLOW_MEMORY_GROWTH and settings.MAXIMUM_MEMORY < settings.INITIAL_MEMORY:
-    exit_with_error('MAXIMUM_MEMORY must be larger then INITIAL_MEMORY')
-
-  if 'MAXIMUM_MEMORY' in user_settings and not settings.ALLOW_MEMORY_GROWTH:
-    diagnostics.warning('unused-command-line-argument', 'MAXIMUM_MEMORY is only meaningful with ALLOW_MEMORY_GROWTH')
-
   if settings.EXPORT_ES6:
     if not settings.MODULARIZE:
       # EXPORT_ES6 requires output to be a module
@@ -2774,6 +2784,12 @@ def check_memory_setting(setting):
   if sanitize and settings.GENERATE_SOURCE_MAP:
     settings.LOAD_SOURCE_MAP = 1
 
+  set_max_memory()
+
+  # check if we can address the 2GB mark and higher.
+  if not settings.MEMORY64 and settings.MAXIMUM_MEMORY > 2 * 1024 * 1024 * 1024:
+    settings.CAN_ADDRESS_2GB = 1
+
   if settings.MINIMAL_RUNTIME:
     if settings.EXIT_RUNTIME:
       settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['proc_exit', '$callRuntimeCallbacks']
@@ -2874,14 +2890,6 @@ def get_full_import_name(name):
                                   'emscripten_stack_get_base',
                                   'emscripten_stack_get_end']
 
-  # check if we can address the 2GB mark and higher: either if we start at
-  # 2GB, or if we allow growth to either any amount or to 2GB or more.
-  if not settings.MEMORY64 and (settings.INITIAL_MEMORY > 2 * 1024 * 1024 * 1024 or
-     (settings.ALLOW_MEMORY_GROWTH and
-      (settings.MAXIMUM_MEMORY < 0 or
-       settings.MAXIMUM_MEMORY > 2 * 1024 * 1024 * 1024))):
-    settings.CAN_ADDRESS_2GB = 1
-
   settings.EMSCRIPTEN_VERSION = shared.EMSCRIPTEN_VERSION
   settings.SOURCE_MAP_BASE = options.source_map_base or ''
 

test/test_core.py

@@ -9781,9 +9781,7 @@ def setUp(self):
 # Run the wasm64 tests with all memory offsets > 4gb.  Be careful running this test
 # suite with any kind of parallelism.
 wasm64_4gb = make_run('wasm64_4gb', emcc_args=['-Wno-experimental', '--profiling-funcs'],
-                      settings={'MEMORY64': 1, 'INITIAL_MEMORY': '4200mb',
-                                'MAXIMUM_MEMORY': '4200mb', # TODO(sbc): should not be needed
-                                'GLOBAL_BASE': '4gb'},
+                      settings={'MEMORY64': 1, 'INITIAL_MEMORY': '4200mb', 'GLOBAL_BASE': '4gb'},
                       require_wasm64=True)
 # MEMORY64=2, or "lowered"
 wasm64l = make_run('wasm64l', emcc_args=['-O1', '-Wno-experimental', '--profiling-funcs'],

tools/building.py

@@ -213,6 +213,7 @@ def lld_flags_for_executable(external_symbols):
     cmd += [
       '-z', 'stack-size=%s' % settings.STACK_SIZE,
       '--initial-memory=%d' % settings.INITIAL_MEMORY,
+      '--max-memory=%d' % settings.MAXIMUM_MEMORY,
     ]
 
     if settings.STANDALONE_WASM:
@@ -228,10 +229,6 @@ def lld_flags_for_executable(external_symbols):
         # `__main_argv_argc`, but we should address that by using a single `_start`
         # function like we do in STANDALONE_WASM mode.
         cmd += ['--no-entry']
-    if not settings.ALLOW_MEMORY_GROWTH:
-      cmd.append('--max-memory=%d' % settings.INITIAL_MEMORY)
-    elif settings.MAXIMUM_MEMORY != -1:
-      cmd.append('--max-memory=%d' % settings.MAXIMUM_MEMORY)
 
   if settings.STACK_FIRST:
     cmd.append('--stack-first')