[PATCH] decodetree: Allow custom var width load functions

[Luis Pires <luis.pires@eldorado.org.br>]

This is useful in situations where you want decodetree
to handle variable width instructions but you want to
provide custom code to load the instructions. Suppressing
the generation of the load function is necessary to avoid
compilation errors due to the load function being unused.

This will be used by the PowerPC decodetree code.

Signed-off-by: Luis Pires <luis.pires@eldorado.org.br>
---
 scripts/decodetree.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/scripts/decodetree.py b/scripts/decodetree.py
index fef5eeaf42..c88dbdb4c3 100644
--- a/scripts/decodetree.py
+++ b/scripts/decodetree.py
@@ -1277,9 +1277,10 @@ def main():
     global anyextern
 
     decode_scope = 'static '
+    noloadfunc = False
 
     long_opts = ['decode=', 'translate=', 'output=', 'insnwidth=',
-                 'static-decode=', 'varinsnwidth=']
+                 'static-decode=', 'varinsnwidth=', 'noloadfunc']
     try:
         (opts, args) = getopt.gnu_getopt(sys.argv[1:], 'o:vw:', long_opts)
     except getopt.GetoptError as err:
@@ -1311,6 +1312,8 @@ def main():
                 deposit_function = 'deposit64'
             elif insnwidth != 32:
                 error(0, 'cannot handle insns of width', insnwidth)
+        elif o == '--noloadfunc':
+            noloadfunc = True
         else:
             assert False, 'unhandled option'
 
@@ -1400,12 +1403,13 @@ def main():
     output(i4, 'return false;\n')
     output('}\n')
 
-    if variablewidth:
-        output('\n', decode_scope, insntype, ' ', decode_function,
-               '_load(DisasContext *ctx)\n{\n',
-               '    ', insntype, ' insn = 0;\n\n')
-        stree.output_code(4, 0, 0, 0)
-        output('}\n')
+    if not noloadfunc:
+        if variablewidth:
+            output('\n', decode_scope, insntype, ' ', decode_function,
+                   '_load(DisasContext *ctx)\n{\n',
+                   '    ', insntype, ' insn = 0;\n\n')
+            stree.output_code(4, 0, 0, 0)
+            output('}\n')
 
     if output_file:
         output_fd.close()
-- 
2.25.1