Revise how EMCC_STRICT and -s STRICT=1 are read so that they are alwa…

…ys visible.

emcc.py

@@ -253,7 +253,8 @@ def filter_emscripten_options(argv):
     if not use_js:
       cmd += shared.EMSDK_OPTS + ['-D__EMSCRIPTEN__']
       # The preprocessor define EMSCRIPTEN is deprecated. Don't pass it to code in strict mode. Code should use the define __EMSCRIPTEN__ instead.
-      if not shared.is_emscripten_strict(): cmd += ['-DEMSCRIPTEN']
+      if not shared.Settings.STRICT:
+        cmd += ['-DEMSCRIPTEN']
     if use_js: cmd += ['-s', 'ERROR_ON_UNDEFINED_SYMBOLS=1'] # configure tests should fail when an undefined symbol exists
 
     logging.debug('just configuring: ' + ' '.join(cmd))
@@ -921,6 +922,22 @@ def detect_fixed_language_mode(args):
       if separate_asm:
         shared.Settings.SEPARATE_ASM = os.path.basename(asm_target)
 
+      if 'EMCC_STRICT' in os.environ:
+        shared.Settings.STRICT = int(os.environ.get('EMCC_STRICT'))
+
+      STRICT = ([None] + filter(lambda x: x.startswith('STRICT='), settings_changes))[-1]
+      if STRICT:
+        shared.Settings.STRICT = int(STRICT[len('STRICT='):])
+
+      if shared.Settings.STRICT:
+        shared.Settings.ERROR_ON_UNDEFINED_SYMBOLS = 1
+        shared.Settings.ERROR_ON_MISSING_LIBRARIES = 1
+
+      # Libraries are searched before settings_changes are applied, so pull its value from the command line already here.
+      ERROR_ON_MISSING_LIBRARIES = ([None] + filter(lambda x: x.startswith('ERROR_ON_MISSING_LIBRARIES='), settings_changes))[-1]
+      if ERROR_ON_MISSING_LIBRARIES:
+        shared.Settings.ERROR_ON_MISSING_LIBRARIES = int(ERROR_ON_MISSING_LIBRARIES[len('ERROR_ON_MISSING_LIBRARIES='):])
+
       system_js_libraries = []
 
       # Find library files
@@ -1009,6 +1026,15 @@ def check(input_file):
       if shared.get_llvm_target() == shared.WASM_TARGET:
         shared.Settings.WASM_BACKEND = 1
 
+      if not shared.Settings.STRICT:
+        # The preprocessor define EMSCRIPTEN is deprecated. Don't pass it to code in strict mode. Code should use the define __EMSCRIPTEN__ instead.
+        shared.COMPILER_OPTS += ['-DEMSCRIPTEN']
+
+        # The system include path system/include/emscripten/ is deprecated, i.e. instead of #include <emscripten.h>, one should pass in #include <emscripten/emscripten.h>.
+        # This path is not available in Emscripten strict mode.
+        if shared.USE_EMSDK:
+          shared.C_INCLUDE_PATHS += [shared.path_from_root('system', 'include', 'emscripten')]
+
       # Use settings
 
       try:

tests/test_other.py

@@ -7040,3 +7040,24 @@ def test_check_engine(self):
     except SystemExit as e:
       caught_exit = e.code
     self.assertEqual(1, caught_exit, 'Did not catch SystemExit with bogus JS engine')
+
+  def test_error_on_missing_libraries(self):
+    env = os.environ.copy()
+    if 'EMCC_STRICT' in env: del env['EMCC_STRICT']
+
+    process = Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.cpp'), '-lsomenonexistingfile', '-s', 'STRICT=1'], stdout=PIPE, stderr=PIPE, env=env)
+    process.communicate()
+    assert process.returncode is not 0, '-llsomenonexistingfile is an error in strict mode'
+
+    process = Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.cpp'), '-lsomenonexistingfile', '-s', 'ERROR_ON_MISSING_LIBRARIES=0'], stdout=PIPE, stderr=PIPE, env=env)
+    process.communicate()
+    assert process.returncode is 0, '-llsomenonexistingfile is not an error if -s ERROR_ON_MISSING_LIBRARIES=0 is passed'
+
+    process = Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.cpp'), '-lsomenonexistingfile', '-s', 'STRICT=1', '-s', 'ERROR_ON_MISSING_LIBRARIES=0'], stdout=PIPE, stderr=PIPE, env=env)
+    process.communicate()
+    assert process.returncode is 0, '-s ERROR_ON_MISSING_LIBRARIES=0 should override -s STRICT=1'
+
+    process = Popen([PYTHON, EMCC, path_from_root('tests', 'hello_world.cpp'), '-lsomenonexistingfile', '-s', 'STRICT=0'], stdout=PIPE, stderr=PIPE, env=env)
+    process.communicate()
+    # TODO: TEMPORARY: When -s ERROR_ON_MISSING_LIBRARIES=1 becomes the default, change the following line to expect failure instead of 0.
+    assert process.returncode is 0, '-llsomenonexistingfile is not yet an error in non-strict mode'

tools/shared.py

@@ -472,15 +472,6 @@ def find_temp_directory():
 def get_emscripten_version(path):
   return open(path).read().strip().replace('"', '')
 
-# Returns true if Emscripten is running in 'strict' mode, in which deprecated compiler features are not supported.
-def is_emscripten_strict():
-  if os.environ.get('EMCC_STRICT') and int(os.environ.get('EMCC_STRICT')) != 0: return True
-  try:
-    return Settings.STRICT
-  except:
-    pass
-  return False
-
 # Check that basic stuff we need (a JS engine to compile, Node.js, and Clang and LLVM)
 # exists.
 # The test runner always does this check (through |force|). emcc does this less frequently,
@@ -941,9 +932,6 @@ def get_llvm_target():
                                    '-D__unix',
                                    '-D__unix__']
 
-  # The preprocessor define EMSCRIPTEN is deprecated. Don't pass it to code in strict mode. Code should use the define __EMSCRIPTEN__ instead.
-  if not is_emscripten_strict(): COMPILER_OPTS += ['-DEMSCRIPTEN']
-
 # Changes to default clang behavior
 
 # Implicit functions can cause horribly confusing function pointer type errors, see #2175
@@ -967,11 +955,6 @@ def get_llvm_target():
     path_from_root('system', 'local', 'include')
   ]
 
-  # The system include path system/include/emscripten/ is deprecated, i.e. instead of #include <emscripten.h>, one should pass in #include <emscripten/emscripten.h>.
-  # This path is not available in Emscripten strict mode.
-  if not is_emscripten_strict():
-    C_INCLUDE_PATHS += [path_from_root('system', 'include', 'emscripten')]
-
   CXX_INCLUDE_PATHS = [
     path_from_root('system', 'include', 'libcxx'),
     path_from_root('system', 'lib', 'libcxxabi', 'include')
@@ -1111,13 +1094,6 @@ def load(self, args=[]):
       settings = re.sub(r'var ([\w\d]+)', r'self.attrs["\1"]', settings)
       exec settings
 
-      # Apply default values for settings that are configured from environment variables.
-      if is_emscripten_strict():
-        # Specify default values for Emscripten strict mode.
-        self.attrs['STRICT'] = 1
-        self.attrs['ERROR_ON_UNDEFINED_SYMBOLS'] = 1
-        self.attrs['ERROR_ON_MISSING_LIBRARIES'] = 1
-
       # Apply additional settings. First -O, then -s
       for i in range(len(args)):
         if args[i].startswith('-O'):
@@ -2033,9 +2009,7 @@ def path_to_system_js_libraries(library_name):
     elif library_name.endswith('.js') and os.path.isfile(shared.path_from_root('src', 'library_' + library_name)):
       library_files += ['library_' + library_name]
     else:
-      emscripten_strict_mode = shared.is_emscripten_strict() or 'STRICT=1' in settings_changes
-      error_on_missing_libraries = (emscripten_strict_mode and not 'ERROR_ON_MISSING_LIBRARIES=0' in settings_changes) or 'ERROR_ON_MISSING_LIBRARIES=1' in settings_changes
-      if error_on_missing_libraries:
+      if Settings.ERROR_ON_MISSING_LIBRARIES:
         logging.fatal('emcc: cannot find library "%s"', library_name)
         exit(1)
       else: