tlv: add tlv field's type enums to header file

Version 1.1 of the lightning-rfc spec introduces TLVs for optional
data fields. This starts the process of updating our auto-gen'd
wireformat parsers to be able to understand TLV fields.

The general way to declare a new TLV field is to add a '+' to the
end of the fieldname. All field type declarations for that TLV set
should be added to a file in the same directory by the name
`gen_<field_name>_csv`.

Note that the FIXME included in this commit is difficult to fix, as
we currently pass in the csv files via stdin (so there's no easy
way to ascertain the originating directory of file)

tools/generate-wire.py

@@ -126,6 +126,16 @@ class Field(object):
         self.lenvar = None
         self.num_elems = 1
         self.optional = False
+        self.is_tlv = False
+
+        # field name appended with '+' means this field contains a tlv
+        if name.endswith('+'):
+            self.is_tlv = True
+            self.name = name[:-1]
+            if self.name not in tlv_fields:
+                # FIXME: use the rest of this
+                tlv_includes, tlv_messages, tlv_comments = parse_tlv_file(self.name)
+                tlv_fields[self.name] = tlv_messages
 
         # ? means optional field (not supported for arrays)
         if size.startswith('?'):
@@ -630,6 +640,43 @@ def find_message_with_option(messages, optional_messages, name, option):
     return m
 
 
+def get_directory_prefix():
+    # FIXME: use prefix of filename
+    return "wire/"
+
+
+def get_tlv_filename(field_name):
+    return 'gen_{}_csv'.format(field_name)
+
+
+def parse_tlv_file(tlv_field_name):
+    tlv_includes = []
+    tlv_messages = []
+    tlv_comments = []
+    with open(get_directory_prefix() + get_tlv_filename(tlv_field_name)) as f:
+        for line in f:
+            # #include gets inserted into header
+            if line.startswith('#include '):
+                tlv_includes.append(line)
+                continue
+
+            by_comments = line.rstrip().split('#')
+
+            # Emit a comment if they included one
+            if by_comments[1:]:
+                tlv_comments.append(' '.join(by_comments[1:]))
+
+            parts = by_comments[0].split(',')
+            if parts == ['']:
+                continue
+
+            if len(parts) == 2:
+                # eg commit_sig,132
+                tlv_messages.append(Message(parts[0], Enumtype("TLV_" + parts[0].upper(), parts[1]), tlv_comments))
+                tlv_comments = []
+        return tlv_includes, tlv_messages, tlv_comments
+
+
 parser = argparse.ArgumentParser(description='Generate C from CSV')
 parser.add_argument('--header', action='store_true', help="Create wire header")
 parser.add_argument('--bolt', action='store_true', help="Generate wire-format for BOLT")
@@ -644,6 +691,7 @@ messages = []
 messages_with_option = []
 comments = []
 includes = []
+tlv_fields = {}
 prevfield = None
 
 # Read csv lines.  Single comma is the message values, more is offset/len.
@@ -690,6 +738,38 @@ for line in fileinput.input(options.files):
             prevfield = parts[2]
         comments = []
 
+
+def construct_enums(msgs):
+    enums = ""
+    for m in msgs:
+        for c in m.comments:
+            enums += '\t/*{} */\n'.format(c)
+        enums += '\t{} = {},\n'.format(m.enum.name, m.enum.value)
+    return enums
+
+
+def enum_header(enums, enumname):
+    return enum_header_template.format(
+        enums=enums,
+        enumname=enumname)
+
+
+def build_enums(toplevel_enumname, toplevel_enums, tlv_fields):
+    enum_set = ""
+    enum_set += enum_header(toplevel_enums, toplevel_enumname)
+    for field_name, messages in tlv_fields.items():
+        enum_set += "\n"
+        enums = construct_enums(messages)
+        enum_set += enum_header(enums, field_name + '_type')
+    return enum_set
+
+
+enum_header_template = """enum {enumname} {{
+{enums}
+}};
+const char *{enumname}_name(int e);
+"""
+
 header_template = """/* This file was generated by generate-wire.py */
 /* Do not modify this file! Modify the _csv file it was generated from. */
 #ifndef LIGHTNING_{idem}
@@ -697,10 +777,7 @@ header_template = """/* This file was generated by generate-wire.py */
 #include <ccan/tal/tal.h>
 #include <wire/wire.h>
 {includes}
-enum {enumname} {{
-{enums}}};
-const char *{enumname}_name(int e);
-
+{formatted_enums}
 {func_decls}
 #endif /* LIGHTNING_{idem} */
 """
@@ -773,11 +850,8 @@ else:
     template = impl_template
 
 # Dump out enum, sorted by value order.
-enums = ""
-for m in messages:
-    for c in m.comments:
-        enums += '\t/*{} */\n'.format(c)
-    enums += '\t{} = {},\n'.format(m.enum.name, m.enum.value)
+enums = construct_enums(messages)
+built_enums = build_enums(options.enumname, enums, tlv_fields)
 includes = '\n'.join(includes)
 cases = ['case {enum.name}: return "{enum.name}";'.format(enum=m.enum) for m in messages]
 printcases = ['case {enum.name}: printf("{enum.name}:\\n"); printwire_{name}("{name}", msg); return;'.format(enum=m.enum, name=m.name) for m in messages]
@@ -797,4 +871,5 @@ print(template.format(
     includes=includes,
     enumname=options.enumname,
     enums=enums,
+    formatted_enums=built_enums,
     func_decls='\n'.join(decls)))