Allow -sFOO=1 as well as -s FOO=1 on the command line (#11550)

Fixes: #11463

ChangeLog.md

@@ -17,6 +17,9 @@ See docs/process.md for how version tagging works.
 
 Current Trunk
 -------------
+- Settings on the command line no longer require a space between the `-s` and
+  the name of the setting.   For example, `-sEXPORT_ALL` is now equivalent to
+  `-s EXPORT_ALL`.
 - Rename `EXCEPTION_CATCHING_WHITELIST` to `EXCEPTION_CATCHING_ALLOWED`. The
   functionality is unchanged, and the old name will be allowed as an alias
   for a few releases to give users time to migrate.

docs/emcc.txt

@@ -83,8 +83,8 @@ Options that are modified or new in *emcc* are listed below:
    Note: For more tips on optimizing your code, see Optimizing Code.
 
 "-s OPTION[=VALUE]"
-   JavaScript code generation option passed into the Emscripten
-   compiler. For the available options, see src/settings.js.
+   Emscripten build options. For the available options, see
+   src/settings.js.
 
    Note: You can prefix boolean options with "NO_" to reverse them.
      For example, "-s EXIT_RUNTIME=1" is the same as "-s
@@ -113,6 +113,9 @@ Options that are modified or new in *emcc* are listed below:
 
      * The specified file path must be absolute, not relative.
 
+   Note: Options can be specified as a single argument without a
+     space between the "-s" and option name.  e.g. "-sFOO=1".
+
 "-g"
    Preserve debug information.
 

emcc.py

@@ -838,17 +838,16 @@ def get_language_mode(args):
 
   language_mode = get_language_mode(args)
 
-  def is_minus_s_for_emcc(args, i):
-    # -s OPT=VALUE or -s OPT are interpreted as emscripten flags.
+  def is_dash_s_for_emcc(args, i):
+    # -s OPT=VALUE or -s OPT or -sOPT are all interpreted as emscripten flags.
     # -s by itself is a linker option (alias for --strip-all)
-    assert args[i] == '-s'
-    if len(args) > i + 1:
+    if args[i] == '-s':
+      if len(args) <= i + 1:
+        return False
       arg = args[i + 1]
-      if arg.split('=')[0].isupper():
-        return True
-
-    logger.debug('treating -s as linker option and not as -s OPT=VALUE for js compilation')
-    return False
+    else:
+      arg = args[i][2:]
+    return arg.split('=')[0].isupper()
 
   CONFIGURE_CONFIG = os.environ.get('EMMAKEN_JUST_CONFIGURE') or 'conftest.c' in args
   if CONFIGURE_CONFIG and not os.environ.get('EMMAKEN_JUST_CONFIGURE_RECURSE'):
@@ -1034,9 +1033,15 @@ def need_llvm_debug_info(options):
       start_time = time.time() # done after parsing arguments, which might affect debug state
 
     for i in range(len(newargs)):
-      if newargs[i] == '-s':
-        if is_minus_s_for_emcc(newargs, i):
-          key = newargs[i + 1]
+      if newargs[i].startswith('-s'):
+        if is_dash_s_for_emcc(newargs, i):
+          if newargs[i] == '-s':
+            key = newargs[i + 1]
+            newargs[i + 1] = ''
+          else:
+            key = newargs[i][2:]
+          newargs[i] = ''
+
           # If not = is specified default to 1
           if '=' not in key:
             key += '=1'
@@ -1051,7 +1056,7 @@ def need_llvm_debug_info(options):
             pass
 
           settings_changes.append(key)
-          newargs[i] = newargs[i + 1] = ''
+
     newargs = [arg for arg in newargs if arg]
 
     settings_key_changes = set()

site/source/docs/tools_reference/emcc.rst

@@ -82,7 +82,7 @@ Options that are modified or new in *emcc* are listed below:
 .. _emcc-s-option-value:
 
 ``-s OPTION[=VALUE]``
-  JavaScript code generation option passed into the Emscripten compiler. For the available options, see `src/settings.js <https://github.com/emscripten-core/emscripten/blob/master/src/settings.js>`_.
+  Emscripten build options. For the available options, see `src/settings.js <https://github.com/emscripten-core/emscripten/blob/master/src/settings.js>`_.
 
   .. note:: You can prefix boolean options with ``NO_`` to reverse them. For example, ``-s EXIT_RUNTIME=1`` is the same as ``-s NO_EXIT_RUNTIME=0``.
 
@@ -106,6 +106,9 @@ Options that are modified or new in *emcc* are listed below:
     - In this case the file might contain a JSON-formatted list of functions: ``["_func1", "func2"]``.
     - The specified file path must be absolute, not relative.
 
+  .. note:: Options can be specified as a single argument without a space
+            between the ``-s`` and option name.  e.g. ``-sFOO=1``.
+
 .. _emcc-g:
 
 ``-g``

tests/test_other.py

@@ -6843,6 +6843,11 @@ def test_dash_s_typo(self):
     self.assertContained("Attempt to set a non-existent setting: 'ZBINARYEN_ASYNC_COMPILATION'", stderr)
     self.assertNotContained(' BINARYEN_ASYNC_COMPILATION', stderr)
 
+  def test_dash_s_no_space(self):
+    run_process([EMCC, path_from_root('tests', 'hello_world.c'), '-sEXPORT_ALL=1'])
+    err = self.expect_fail([EMCC, path_from_root('tests', 'hello_world.cpp'), '-sEXPORTED_FUNCTIONS=["foo"]'])
+    self.assertContained('error: undefined exported function: "foo"', err)
+
   def test_python_2_3(self):
     # check emcc/em++ can be called by any python
     def trim_py_suffix(filename):