scons: Separate debug flags from debug-format flags

Debug flags are flags that aid with debugging by printing
relevant information when enabled. Debug-formatting flags
define how the debug flags will print the information.

Although a viability, this patch does not support declaring
compound format flags.

As a side effect, now debug flags and debug-formatting flags
are printed in different lists, when using --debug-help.

Change-Id: Ieae68745276218cf4e9c1d37d7bf3bd1f19709ae
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/39076
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/python/m5/debug.py

@@ -35,8 +35,8 @@ def help():
     sorted_flags = sorted(flags.items(), key=lambda kv: kv[0])
 
     print("Base Flags:")
-    for name, flag in filter(lambda kv: not isinstance(kv[1], CompoundFlag),
-                             sorted_flags):
+    for name, flag in filter(lambda kv: isinstance(kv[1], SimpleFlag)
+                             and not kv[1].isFormat, sorted_flags):
         print("    %s: %s" % (name, flag.desc))
     print()
     print("Compound Flags:")
@@ -45,6 +45,11 @@ def help():
         print("    %s: %s" % (name, flag.desc))
         printList([ c.name for c in flag.kids() ], indent=8)
     print()
+    print("Formatting Flags:")
+    for name, flag in filter(lambda kv: isinstance(kv[1], SimpleFlag)
+                             and kv[1].isFormat, sorted_flags):
+        print("    %s: %s" % (name, flag.desc))
+    print()
 
 class AllFlags(Mapping):
     def __init__(self):