[chirp_devel] [PATCH 1 of 2] [RFC] Add ability to define structure types in bitwise

[Dan Smith]

# HG changeset patch
# User Dan Smith <dsmith at danplanet.com>
# Date 1334113255 25200
# Node ID ce7239963bc4dd7bef2b8dc1a3bdb6fbe26aab75
# Parent  c3b8a85d6e235eb493c790ddac982683414dd251
[RFC] Add ability to define structure types in bitwise

This adds the ability to define structure types in bitwise formats
and then use them in multiple places. Right now, we have a few places where
this is needed and it's badly faked like this:

  struct_format = "struct { u8 foo; u8 bar; }"
  mem_format =
    struct_format + "struct1;" +
    struct_format + "struct2;"

This new change to bitwise will allow us to behave more like C and do:

  mem_format = """
    struct mytype { u8 foo; u8 bar; };
    struct mytype struct1;
    struct mytype struct2;
  """

The bitwise grammar changed a little, but it's still compatible with the
existing definitions and all of the tests still pass.

#93

diff -r c3b8a85d6e23 -r ce7239963bc4 chirp/bitwise.py
--- a/chirp/bitwise.py	Tue Apr 10 19:10:20 2012 -0700
+++ b/chirp/bitwise.py	Tue Apr 10 20:00:55 2012 -0700
@@ -590,6 +590,7 @@
         self._data = data
         self._offset = offset
         self._obj = None
+        self._user_types = {}
 
     def do_symbol(self, symdef, gen):
         name = symdef[1]
@@ -647,8 +648,11 @@
             else:
                 self._generators[name] = res
 
-    def parse_struct(self, struct):
+    def parse_struct_decl(self, struct):
         block = struct[:-1]
+        if block[0][0] == "symbol":
+            # This is a pre-defined struct
+            block = self._user_types[block[0][1]]
         deftype = struct[-1]
         if deftype[0] == "array":
             name = deftype[1][0][1]
@@ -672,6 +676,19 @@
         else:
             self._generators[name] = result
 
+    def parse_struct_defn(self, struct):
+        name = struct[0][1]
+        block = struct[1:]
+        self._user_types[name] = block
+
+    def parse_struct(self, struct):
+        if struct[0][0] == "struct_defn":
+            return self.parse_struct_defn(struct[0][1])
+        elif struct [0][0] == "struct_decl":
+            return self.parse_struct_decl(struct[0][1])
+        else:
+            raise Exception("Internal error: What is `%s'?" % struct[0][0])
+
     def parse_directive(self, directive):
         name = directive[0][0]
         if name == "seekto":
@@ -713,6 +730,8 @@
 
 if __name__ == "__main__":
     defn = """
+struct mytype { u8 foo; };
+struct mytype bar;
 struct {
   u8 foo;
   u8 highbit:1,
@@ -722,9 +741,11 @@
   bbcd fourdigits[2];
 } mystruct;
 """
-    data = "\x7F\x81abc\x12\x34"
+    data = "\xab\x7F\x81abc\x12\x34"
     tree = parse(defn, data)
 
+    print repr(tree)
+
     print "Foo %i" % tree.mystruct.foo
     print "Highbit: %i SixZeros: %i: Lowbit: %i" % (tree.mystruct.highbit,
                                                     tree.mystruct.sixzeros,
diff -r c3b8a85d6e23 -r ce7239963bc4 chirp/bitwise_grammar.py
--- a/chirp/bitwise_grammar.py	Tue Apr 10 19:10:20 2012 -0700
+++ b/chirp/bitwise_grammar.py	Tue Apr 10 20:00:55 2012 -0700
@@ -64,8 +64,14 @@
 def _block():
     return "{", _block_inner, "}"
 
+def struct_defn():
+    return symbol, _block
+
+def struct_decl():
+    return [symbol, _block], [array, symbol]
+
 def struct():
-    return keyword("struct"), _block, [array, symbol], ";"
+    return keyword("struct"), [struct_defn, struct_decl], ";"
 
 def _language():
     return _block_inner