Massively speed up U-Boot parsing

U-Boot has a ton of definition locations for some symbols, causing a lot
of redundant work when iterating over Kconfig.defined_syms in
_build_dep(). Iterate over set(Kconfig.defined_syms) instead, wherever
possible.

This speeds up the U-Boot parsing time from 4 seconds to 0.6 seconds on
my machine.

Also update the bundled tools to iterate over set(Kconfig.defined_syms).
The performance loss is negligible even for projects that don't use
multiple definition locations.

Update the documentation to clarify that symbols/choices defined in
multiple locations appear multiple times in Kconfig.defined_syms/choices
as well.

1 files changed, 3 insertions, 1 deletions

diff --git a/allmodconfig.py b/allmodconfig.py
index b8f792a..a7804b3 100755
--- a/allmodconfig.py
+++ b/allmodconfig.py
@@ -25,7 +25,9 @@ def main():
     BOOL = kconfiglib.BOOL
     TRISTATE = kconfiglib.TRISTATE
 
-    for sym in kconf.defined_syms:
+    # The set() speeds things up for projects that use multiple definition
+    # locations a lot
+    for sym in set(kconf.defined_syms):
         if sym.orig_type == BOOL:
             # 'bool' choice symbols get their default value, as determined by
             # e.g. 'default's on the choice