Merge branch 'gencode2' into gencode3

2 files changed, 10 insertions, 5 deletions

diff --git a/tools/make_c_api.lua b/tools/make_c_api.lua
index 62fd370..9e6d734 100644
--- a/tools/make_c_api.lua
+++ b/tools/make_c_api.lua
@@ -30,11 +30,6 @@ function strip_proto(filename)
   return string.gsub(filename, '%.proto$','')
 end
 
---[[
-  [upb.TYPE_ENUM]     = 5,
-  [upb.TYPE_MESSAGE]  = 8,
---]]
-
 local function join(...)
   return table.concat({...}, ".")
 end
@@ -154,6 +149,12 @@ local function field_layout_rank(field)
   --   4. string fields
   --   5. submessage fields
   --   6. repeated fields
+  --
+  -- This has the following nice properties:
+  --
+  --  1. padding alignment is (nearly) minimized.
+  --  2. fields that might have defaults (1-4) are segregated
+  --     from fields that are always zero-initialized (5-7).
   local rank
   if field:containing_oneof() then
     rank = 100  -- These go last (actually we skip them).
diff --git a/tools/upbc.lua b/tools/upbc.lua
index 9d9531c..a538b1c 100644
--- a/tools/upbc.lua
+++ b/tools/upbc.lua
@@ -23,6 +23,10 @@ for _, argument in ipairs(arg) do
       return 1
     end
   else
+    if src then
+      print("upbc can only handle one input file at a time.")
+      return 1
+    end
     src = argument
   end
 end