SConstruct: rename and document AddM5Option

Got rid of gratuitous M5 reference in the function name.
In the process, wondered why we have this function at all and
spent time trying to get rid of it and eventually firgured out
why it's needed.  Put the answer in a comment so we don't have
to wonder again.

1 files changed, 25 insertions, 13 deletions

diff --git a/SConstruct b/SConstruct
index 98c3da568..f5a46286c 100755
--- a/SConstruct
+++ b/SConstruct
@@ -129,7 +129,19 @@ help_texts = {
 
 Export("help_texts")
 
-def AddM5Option(*args, **kwargs):
+
+# There's a bug in scons in that (1) by default, the help texts from
+# AddOption() are supposed to be displayed when you type 'scons -h'
+# and (2) you can override the help displayed by 'scons -h' using the
+# Help() function, but these two features are incompatible: once
+# you've overridden the help text using Help(), there's no way to get
+# at the help texts from AddOptions.  See:
+#     http://scons.tigris.org/issues/show_bug.cgi?id=2356
+#     http://scons.tigris.org/issues/show_bug.cgi?id=2611
+# This hack lets us extract the help text from AddOptions and
+# re-inject it via Help().  Ideally someday this bug will be fixed and
+# we can just use AddOption directly.
+def AddLocalOption(*args, **kwargs):
     col_width = 30
 
     help = "  " + ", ".join(args)
@@ -144,18 +156,18 @@ def AddM5Option(*args, **kwargs):
 
     AddOption(*args, **kwargs)
 
-AddM5Option('--colors', dest='use_colors', action='store_true',
-            help="Add color to abbreviated scons output")
-AddM5Option('--no-colors', dest='use_colors', action='store_false',
-            help="Don't add color to abbreviated scons output")
-AddM5Option('--default', dest='default', type='string', action='store',
-            help='Override which build_opts file to use for defaults')
-AddM5Option('--ignore-style', dest='ignore_style', action='store_true',
-            help='Disable style checking hooks')
-AddM5Option('--update-ref', dest='update_ref', action='store_true',
-            help='Update test reference outputs')
-AddM5Option('--verbose', dest='verbose', action='store_true',
-            help='Print full tool command lines')
+AddLocalOption('--colors', dest='use_colors', action='store_true',
+               help="Add color to abbreviated scons output")
+AddLocalOption('--no-colors', dest='use_colors', action='store_false',
+               help="Don't add color to abbreviated scons output")
+AddLocalOption('--default', dest='default', type='string', action='store',
+               help='Override which build_opts file to use for defaults')
+AddLocalOption('--ignore-style', dest='ignore_style', action='store_true',
+               help='Disable style checking hooks')
+AddLocalOption('--update-ref', dest='update_ref', action='store_true',
+               help='Update test reference outputs')
+AddLocalOption('--verbose', dest='verbose', action='store_true',
+               help='Print full tool command lines')
 
 use_colors = GetOption('use_colors')
 if use_colors: