Issue 5201 - [emscripten] Replace EM_ASM calls by a custom JavaScript library

compile

Index: compile
===================================================================
--- a/compile
+++ b/compile
@@ -17,16 +17,17 @@
 
 import argparse
 import os
 import subprocess
 import sys
 
 BASE_DIR = os.path.dirname(__file__)
 SOURCE_DIR = os.path.join(BASE_DIR, 'compiled')
+JS_LIBRARY = os.path.join(SOURCE_DIR, 'library.js')
 BINDINGS_GENERATOR = os.path.join(SOURCE_DIR, 'bindings.cpp.js')
 BINDINGS_OUTPUT = os.path.join(SOURCE_DIR, 'bindings.js')
 COMPILER_OUTPUT = os.path.join(BASE_DIR, 'lib', 'compiled.js')
 GENERATION_PARAMS = {
     'SHELL_FILE': "'{}'".format(os.path.abspath(os.path.join(SOURCE_DIR,
                                                              'shell.js'))),
     'ASM_JS': 2,  # "almost asm"
     'TOTAL_MEMORY': 16*1024*1024,
@@ -37,17 +38,17 @@ GENERATION_PARAMS = {
     'NO_FILESYSTEM': 1,
     'INVOKE_RUN': 0,
     'TEXTDECODER': 0,
     'EXPORTED_RUNTIME_METHODS': ['cwrap', 'ccall', 'stringToAscii'],
 }
 DEFINES = []
 ADDITIONAL_PARAMS = ['-O3', '-m32', '-std=gnu++14', '--memory-init-file', '0',
                      '--emit-symbol-map', '-Wall', '-Werror', '-fno-exceptions',
-                     '-fno-rtti']
+                     '-fno-rtti', '--js-library', JS_LIBRARY]
 
 
 def get_source_files(phase):
     for (path, dirs, files) in os.walk(SOURCE_DIR):
         for f in files:
             if os.path.splitext(f)[1] != '.cpp':
                 continue
             if (
@@ -69,17 +70,17 @@ def getenv(emscripten_config):
         'NODE_JS': scope.get('NODE_JS', 'node'),
     })
     return env
 
 
 def generate_bindings(env):
     params = [
         env['PYTHON'], os.path.join(env['EMSCRIPTEN'], 'emcc'),
-        '-o', BINDINGS_GENERATOR, '-std=gnu++14', '-DPRINT_BINDINGS',
+        '-o', BINDINGS_GENERATOR, '-std=gnu++14', '--js-library', JS_LIBRARY,
     ] + list(get_source_files('bindings'))
     subprocess.check_call(params, env=env)
 
     with open(BINDINGS_OUTPUT, 'w') as file:
         subprocess.check_call([env['NODE_JS'], BINDINGS_GENERATOR],
                               stdout=file)