[wasm64] Fix pointer size detection (emscripten-core#20201)

Fixes: emscripten-core#20175

Author: sbc100

cmake/Modules/Platform/Emscripten.cmake

@@ -217,10 +217,16 @@ set(EMSCRIPTEN_SYSROOT "${_emcache_output}/sysroot")
 list(APPEND CMAKE_FIND_ROOT_PATH "${EMSCRIPTEN_SYSROOT}")
 list(APPEND CMAKE_SYSTEM_PREFIX_PATH /)
 
-if ($ENV{CFLAGS} MATCHES "MEMORY64")
+if (${CMAKE_C_FLAGS} MATCHES "MEMORY64")
   set(CMAKE_LIBRARY_ARCHITECTURE "wasm64-emscripten")
+  set(CMAKE_SIZEOF_VOID_P 8)
+  set(CMAKE_C_SIZEOF_DATA_PTR 8)
+  set(CMAKE_CXX_SIZEOF_DATA_PTR 8)
 else()
   set(CMAKE_LIBRARY_ARCHITECTURE "wasm32-emscripten")
+  set(CMAKE_SIZEOF_VOID_P 4)
+  set(CMAKE_C_SIZEOF_DATA_PTR 4)
+  set(CMAKE_CXX_SIZEOF_DATA_PTR 4)
 endif()
 
 if(CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
@@ -290,11 +296,8 @@ set(CMAKE_SIZEOF_INT 4)
 set(CMAKE_SIZEOF_UNSIGNED_LONG 4)
 set(CMAKE_SIZEOF_UNSIGNED_INT 4)
 set(CMAKE_SIZEOF_LONG 4)
-set(CMAKE_SIZEOF_VOID_P 4)
 set(CMAKE_SIZEOF_FLOAT 4)
 set(CMAKE_SIZEOF_DOUBLE 8)
-set(CMAKE_C_SIZEOF_DATA_PTR 4)
-set(CMAKE_CXX_SIZEOF_DATA_PTR 4)
 set(CMAKE_HAVE_LIMITS_H 1)
 set(CMAKE_HAVE_UNISTD_H 1)
 set(CMAKE_HAVE_PTHREAD_H 1)

test/cmake/check_type_size/CMakeLists.txt

@@ -2,6 +2,17 @@ cmake_minimum_required(VERSION 3.0)
 
 project(test_cmake)
 
+if (CMAKE_LIBRARY_ARCHITECTURE MATCHES "wasm64")
+  set(PTR_SIZE 8)
+else()
+  set(PTR_SIZE 4)
+endif()
+
+if (NOT "${CMAKE_SIZEOF_VOID_P}" EQUAL "${PTR_SIZE}")
+  message(FATAL_ERROR "CMAKE_SIZEOF_VOID_P is not ${PTR_SIZE}! (${CMAKE_SIZEOF_VOID_P})")
+endif()
+message(STATUS "CMAKE_SIZEOF_VOID_P -> ${CMAKE_SIZEOF_VOID_P}")
+
 include(CheckTypeSize)
 
 check_type_size("int" int_size)
@@ -15,3 +26,9 @@ if (NOT "${big_size}" EQUAL "1028")
   message(FATAL_ERROR "CHECK_TYPE_SIZE with int[256+1] did not return 1028! (${big_size})")
 endif()
 message(STATUS "CHECK_TYPE_SIZE int -> ${big_size}")
+
+check_type_size("void*" ptr_size)
+if (NOT "${ptr_size}" EQUAL "${PTR_SIZE}")
+  message(FATAL_ERROR "CHECK_TYPE_SIZE with void* did not return ${PTR_SIZE}! (${ptr_size})")
+endif()
+message(STATUS "CHECK_TYPE_SIZE void* -> ${ptr_size}")

test/test_other.py

@@ -939,12 +939,21 @@ def test_pkg_config_packages(self):
         self.assertContained(version, out)
 
   @parameterized({
-    '': [[]],
-    'pthreads': [['-DCMAKE_CXX_FLAGS=-pthread', '-DCMAKE_C_FLAGS=-pthread']],
+    '': [None],
+    'wasm64': ['-sMEMORY64'],
+    'pthreads': ['-pthread'],
   })
-  def test_cmake_check_type_size(self, flags):
-    cmd = [EMCMAKE, 'cmake', test_file('cmake/check_type_size')] + flags
-    self.run_process(cmd)
+  def test_cmake_check_type_size(self, cflag):
+    if cflag == '-sMEMORY64':
+      self.require_wasm64()
+    cmd = [EMCMAKE, 'cmake', test_file('cmake/check_type_size')]
+    if cflag:
+      cmd += [f'-DCMAKE_CXX_FLAGS={cflag}', f'-DCMAKE_C_FLAGS={cflag}']
+    output = self.run_process(cmd, stdout=PIPE).stdout
+    if cflag == '-sMEMORY64':
+      self.assertContained('CMAKE_SIZEOF_VOID_P -> 8', output)
+    else:
+      self.assertContained('CMAKE_SIZEOF_VOID_P -> 4', output)
 
     # Verify that this test works without needing to run node.  We do this by breaking node
     # execution.