Remove windows-specific console coloring

ChangeLog.md

@@ -20,6 +20,8 @@ See docs/process.md for more on how version tagging works.
 
 4.0.16 (in development)
 -----------------------
+- For windows users, colored console output for error messages and logging now
+  requires Windows 10 or above. (#25502)
 - A warning was added about usage of embind without C++17 or above. (#25424)
 - The minimum supported versions of Node, Chrome and Firefox were bumped
   enabling the removal of the `globalThis` polyfill and universally enabling

test/test_other.py

@@ -11607,21 +11607,12 @@ def test_color_diagnostics_disable(self, flag):
   })
   def test_color_diagnostics_force(self, flag):
     create_file('src.c', 'int main() {')
-    # -fansi-escape-codes is needed here to make this test work on windows, which doesn't
-    # use ansi codes by default
-    output = self.expect_fail([EMCC, '-fansi-escape-codes', flag, 'src.c'])
+    # -fansi-escape-codes is needed on windows in order to get clang to emit ANSI colors
+    output = self.expect_fail([EMCC, flag, '-fansi-escape-codes', 'src.c'])
     self.assertIn("\x1b[1msrc.c:1:13: \x1b[0m\x1b[0;1;31merror: \x1b[0m\x1b[1mexpected '}'\x1b[0m", output)
-    # Verify that emcc errors show up as red and bold
+    # Verify that emcc errors show up as red and bold from emcc
     self.assertIn('emcc: \x1b[31m\x1b[1m', output)
 
-    if WINDOWS:
-      # Also test without -fansi-escape-codes on windows.
-      # In those mode the code will use kernel calls such as SetConsoleTextAttribute to
-      # change the output color.  We cannot detect this in the output, but we can at least
-      # get coverage of the code path in the diagnositics.py.
-      output = self.expect_fail([EMCC, flag, 'src.c'])
-      self.assertNotIn('\x1b', output)
-
   def test_sanitizer_color(self):
     create_file('src.c', '''
       #include <emscripten.h>

tools/cmdline.py

@@ -513,8 +513,6 @@ def consume_arg_file():
       diagnostics.color_enabled = True
     elif arg in ('-fno-color-diagnostics', '-fdiagnostics-color=never'):
       diagnostics.color_enabled = False
-    elif arg == '-fansi-escape-codes':
-      diagnostics.force_ansi = True
     elif arg == '-fno-exceptions':
       settings.DISABLE_EXCEPTION_CATCHING = 1
       settings.DISABLE_EXCEPTION_THROWING = 1

tools/colored_logger.py

@@ -11,88 +11,25 @@
 import logging
 
 
-def add_coloring_to_emit_windows(fn):
+def ansi_color_available():
+  if not sys.platform.startswith('win'):
+    return sys.stderr.isatty()
+
   # Constants from the Windows API
   STD_OUTPUT_HANDLE = -11
+  ENABLE_VIRTUAL_TERMINAL_PROCESSING = 0x0004
 
-  def _get_color():
-    SHORT = ctypes.c_short
-    WORD = ctypes.c_ushort
-
-    class COORD(ctypes.Structure):
-      _fields_ = [
-        ("X", SHORT),
-        ("Y", SHORT)]
-
-    class SMALL_RECT(ctypes.Structure):
-      _fields_ = [
-        ("Left", SHORT),
-        ("Top", SHORT),
-        ("Right", SHORT),
-        ("Bottom", SHORT)]
-
-    class CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):
-      _fields_ = [
-        ("dwSize", COORD),
-        ("dwCursorPosition", COORD),
-        ("wAttributes", WORD),
-        ("srWindow", SMALL_RECT),
-        ("dwMaximumWindowSize", COORD)]
+  kernel32 = ctypes.windll.kernel32
+  stdout_handle = kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
 
-    hdl = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
-    csbi = CONSOLE_SCREEN_BUFFER_INFO()
-    ctypes.windll.kernel32.GetConsoleScreenBufferInfo(hdl, ctypes.byref(csbi))
-    return csbi.wAttributes
+  # Get the current console mode
+  console_mode = ctypes.c_uint()
+  if not kernel32.GetConsoleMode(stdout_handle, ctypes.byref(console_mode)):
+    # Handle error if GetConsoleMode fails
+    return False
 
-  def _set_color(code):
-    hdl = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
-    ctypes.windll.kernel32.SetConsoleTextAttribute(hdl, code)
-
-  def new(*args):
-    # wincon.h
-    FOREGROUND_BLACK     = 0x0000 # noqa
-    FOREGROUND_BLUE      = 0x0001 # noqa
-    FOREGROUND_GREEN     = 0x0002 # noqa
-    FOREGROUND_CYAN      = 0x0003 # noqa
-    FOREGROUND_RED       = 0x0004 # noqa
-    FOREGROUND_MAGENTA   = 0x0005 # noqa
-    FOREGROUND_YELLOW    = 0x0006 # noqa
-    FOREGROUND_GREY      = 0x0007 # noqa
-    FOREGROUND_INTENSITY = 0x0008 # foreground color is intensified.
-
-    FOREGROUND_WHITE     = FOREGROUND_BLUE|FOREGROUND_GREEN |FOREGROUND_RED # noqa
-
-    BACKGROUND_BLACK     = 0x0000 # noqa
-    BACKGROUND_BLUE      = 0x0010 # noqa
-    BACKGROUND_GREEN     = 0x0020 # noqa
-    BACKGROUND_CYAN      = 0x0030 # noqa
-    BACKGROUND_RED       = 0x0040 # noqa
-    BACKGROUND_MAGENTA   = 0x0050 # noqa
-    BACKGROUND_YELLOW    = 0x0060 # noqa
-    BACKGROUND_GREY      = 0x0070 # noqa
-    BACKGROUND_INTENSITY = 0x0080 # background color is intensified.
-    levelno = args[1].levelno
-    if (levelno >= 50):
-        color = BACKGROUND_YELLOW | FOREGROUND_RED | FOREGROUND_INTENSITY | BACKGROUND_INTENSITY
-    elif (levelno >= 40):
-        color = FOREGROUND_RED | FOREGROUND_INTENSITY
-    elif (levelno >= 30):
-        color = FOREGROUND_YELLOW | FOREGROUND_INTENSITY
-    elif (levelno >= 20):
-        color = FOREGROUND_GREEN
-    elif (levelno >= 10):
-        color = FOREGROUND_MAGENTA
-    else:
-        color = FOREGROUND_WHITE
-
-    old_color = _get_color()
-    _set_color(color)
-    ret = fn(*args)
-    _set_color(old_color)
-    return ret
-
-  new.orig_func = fn
-  return new
+  # Check if the flag is set in the current console mode
+  return (console_mode.value & ENABLE_VIRTUAL_TERMINAL_PROCESSING) != 0
 
 
 def add_coloring_to_emit_ansi(fn):
@@ -117,11 +54,8 @@ def new(*args):
 
 
 def enable():
-  if sys.stderr.isatty():
-    if sys.platform.startswith('win'):
-      logging.StreamHandler.emit = add_coloring_to_emit_windows(logging.StreamHandler.emit)
-    else:
-      logging.StreamHandler.emit = add_coloring_to_emit_ansi(logging.StreamHandler.emit)
+  if ansi_color_available():
+    logging.StreamHandler.emit = add_coloring_to_emit_ansi(logging.StreamHandler.emit)
 
 
 def disable():

tools/diagnostics.py

@@ -6,24 +6,22 @@
 """Simple color-enabled diagnositics reporting functions.
 """
 
-import ctypes
 import logging
 import os
 import sys
 from typing import Dict
 
-WINDOWS = sys.platform.startswith('win')
+from . import colored_logger
 
+color_enabled = colored_logger.ansi_color_available()
 logger = logging.getLogger('diagnostics')
-color_enabled = sys.stderr.isatty()
 tool_name = os.path.splitext(os.path.basename(sys.argv[0]))[0]
-force_ansi = False
 
 # diagnostic levels
 WARN = 1
 ERROR = 2
 
-# available colors
+# available (ANSI) colors
 RED = 1
 GREEN = 2
 YELLOW = 3
@@ -43,94 +41,19 @@
     ERROR: 'error: ',
 }
 
-# Constants from the Windows API
-STD_OUTPUT_HANDLE = -11
-
-
-def output_color_windows(color):
-  assert not force_ansi
-  # TODO(sbc): This code is duplicated in colored_logger.py.  Refactor.
-  # wincon.h
-  FOREGROUND_BLACK     = 0x0000 # noqa
-  FOREGROUND_BLUE      = 0x0001 # noqa
-  FOREGROUND_GREEN     = 0x0002 # noqa
-  FOREGROUND_CYAN      = 0x0003 # noqa
-  FOREGROUND_RED       = 0x0004 # noqa
-  FOREGROUND_MAGENTA   = 0x0005 # noqa
-  FOREGROUND_YELLOW    = 0x0006 # noqa
-  FOREGROUND_GREY      = 0x0007 # noqa
-
-  color_map = {
-    RED: FOREGROUND_RED,
-    GREEN: FOREGROUND_GREEN,
-    YELLOW: FOREGROUND_YELLOW,
-    BLUE: FOREGROUND_BLUE,
-    MAGENTA: FOREGROUND_MAGENTA,
-    CYAN: FOREGROUND_CYAN,
-    WHITE: FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED,
-  }
-
-  sys.stderr.flush()
-  hdl = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
-  ctypes.windll.kernel32.SetConsoleTextAttribute(hdl, color_map[color])
-
-
-def get_color_windows():
-  assert not force_ansi
-  SHORT = ctypes.c_short
-  WORD = ctypes.c_ushort
-
-  class COORD(ctypes.Structure):
-    _fields_ = [
-      ("X", SHORT),
-      ("Y", SHORT)]
-
-  class SMALL_RECT(ctypes.Structure):
-    _fields_ = [
-      ("Left", SHORT),
-      ("Top", SHORT),
-      ("Right", SHORT),
-      ("Bottom", SHORT)]
-
-  class CONSOLE_SCREEN_BUFFER_INFO(ctypes.Structure):
-    _fields_ = [
-      ("dwSize", COORD),
-      ("dwCursorPosition", COORD),
-      ("wAttributes", WORD),
-      ("srWindow", SMALL_RECT),
-      ("dwMaximumWindowSize", COORD)]
-
-  hdl = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
-  csbi = CONSOLE_SCREEN_BUFFER_INFO()
-  ctypes.windll.kernel32.GetConsoleScreenBufferInfo(hdl, ctypes.byref(csbi))
-  return csbi.wAttributes
-
-
-def reset_color_windows():
-  assert not force_ansi
-  sys.stderr.flush()
-  hdl = ctypes.windll.kernel32.GetStdHandle(STD_OUTPUT_HANDLE)
-  ctypes.windll.kernel32.SetConsoleTextAttribute(hdl, default_color)
-
 
 def output_color(color):
-  if WINDOWS and not force_ansi:
-    output_color_windows(color)
-    return ''
+  assert color_enabled
   return '\033[3%sm' % color
 
 
 def bold():
-  if WINDOWS and not force_ansi:
-    # AFAICT there is no way to enable bold output on windows
-    return ''
+  assert color_enabled
   return '\033[1m'
 
 
 def reset_color():
-  if WINDOWS and not force_ansi:
-    reset_color_windows()
-    return ''
+  assert color_enabled
   return '\033[0m'
 
 
@@ -260,7 +183,4 @@ def capture_warnings(argv):
   return manager.capture_warnings(argv)
 
 
-if WINDOWS:
-  default_color = get_color_windows()
-
 manager = WarningManager()