[Mesa-dev] [PATCH 03/35] genxml: Fix python crash when no dwords are found.

[Rafael Antognolli]

If the 'dwords' dict is empty, max(dwords.keys()) throws an exception.
This case could happen when we have an instruction that is only an array
of other structs, with variable length.

v2:
   - Add another clause for empty dwords and make it work with python 3
   (Dylan)
   - Set the length to 0 if dwords is empty, and do not declare dw

Signed-off-by: Rafael Antognolli <rafael.antognolli at intel.com>
Reviewed-by: Dylan Baker <dylan at pnwbakers.com>
---
 src/intel/genxml/gen_pack_header.py | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/intel/genxml/gen_pack_header.py b/src/intel/genxml/gen_pack_header.py
index 29bec40..d0b1336 100644
--- a/src/intel/genxml/gen_pack_header.py
+++ b/src/intel/genxml/gen_pack_header.py
@@ -346,7 +346,7 @@ class Group(object):
                 dwords[index + 1] = dwords[index]
                 index = index + 1
 
-    def emit_pack_function(self):
+    def collect_dwords_and_length(self):
         dwords = {}
         self.collect_dwords(dwords, 0, "")
 
@@ -356,9 +356,14 @@ class Group(object):
         # index we've seen plus one.
         if self.size > 0:
             length = self.size // 32
-        else:
+        elif dwords:
             length = max(dwords.keys()) + 1
+        else:
+            length = 0
+
+        return (dwords, length)
 
+    def emit_pack_function(self, dwords, length):
         for index in range(length):
             # Handle MBZ dwords
             if not index in dwords:
@@ -575,10 +580,12 @@ class Parser(object):
         print("static inline void\n%s_pack(__gen_user_data *data, void * restrict dst,\n%sconst struct %s * restrict values)\n{" %
               (name, ' ' * (len(name) + 6), name))
 
-        # Cast dst to make header C++ friendly
-        print("   uint32_t * restrict dw = (uint32_t * restrict) dst;")
+        (dwords, length) = group.collect_dwords_and_length()
+        if length:
+            # Cast dst to make header C++ friendly
+            print("   uint32_t * restrict dw = (uint32_t * restrict) dst;")
 
-        group.emit_pack_function()
+            group.emit_pack_function(dwords, length)
 
         print("}\n")
 
-- 
git-series 0.9.1