Some .proto files contain complex syntax that does not be described in protobuf official site
(https://developers.google.com/protocol-buffers/docs/reference/proto3-spec).
1. Update 'epan/protobuf_lang_parser.lemon' to:
1) Support complex option names format (EBNF):
optionName = ( ident | "(" fullIdent ")" ) { "." ( ident | "(" fullIdent ")" ) }
for example, "option (complex_opt2).(grault) = 654;".
2) Make enum body support 'reserved' section (EBNF):
enumBody = "{" { reserved | option | enumField | emptyStatement } "}"
3) Allow the value of field or enumValue option to be "{ ... }" other than constant:
enumValueOption = optionName "=" ( constant | customOptionValue ) ";"
fieldOption = optionName "=" ( constant | customOptionValue ) ";"
4) Allow 'group' section missing 'label' (for example, in 'oneof' section).
5) Make 'oneof' section support 'option' and 'group' sections (BNF):
oneof = "oneof" oneofName "{" { oneofField | option | group | emptyStatement } "}"
6) Ignore unused 'extend' section.
7) Fix the bug of one string being splitted into multi-lines.
2. Update 'epan/protobuf_lang_tree.c' to:
8) Fix the bug of parsing repeated option.
3. Update 'test/suite_dissection.py' to add test case for parsing complex syntax .proto files:
test/protobuf_lang_files/complex_proto_files/unittest_custom_options.proto
test/protobuf_lang_files/complex_proto_files/complex_syntax.proto
and dependency files:
test/protobuf_lang_files/well_know_types/google/protobuf/any.proto
test/protobuf_lang_files/well_know_types/google/protobuf/descriptor.proto
Refer to issue #17046
In order to avoid Bison's compatibility problem (like
https://code.wireshark.org/review/#/c/33771/),
the *.proto file parser is rewritten with lemon. (rename
protobuf_lang.y.in to protobuf_lang_parser.lemon)
Also improved the mechanism of recording line number of
message, field, and enum names.
Gerald Combs