1 files changed, 50 insertions, 0 deletions
diff --git a/src/nvim/generators/c_grammar.lua b/src/nvim/generators/c_grammar.lua
new file mode 100644
index 0000000000..d3047e1a9c
--- /dev/null
+++ b/src/nvim/generators/c_grammar.lua
@@ -0,0 +1,50 @@
+lpeg = require('lpeg')
+
+-- lpeg grammar for building api metadata from a set of header files. It
+-- ignores comments and preprocessor commands and parses a very small subset
+-- of C prototypes with a limited set of types
+local P, R, S = lpeg.P, lpeg.R, lpeg.S
+local C, Ct, Cc, Cg = lpeg.C, lpeg.Ct, lpeg.Cc, lpeg.Cg
+
+local any = P(1) -- (consume one character)
+local letter = R('az', 'AZ') + S('_$')
+local num = R('09')
+local alpha = letter + num
+local nl = P('\r\n') + P('\n')
+local not_nl = any - nl
+local ws = S(' \t') + nl
+local fill = ws ^ 0
+local c_comment = P('//') * (not_nl ^ 0)
+local c_preproc = P('#') * (not_nl ^ 0)
+local typed_container =
+  (P('ArrayOf(') + P('DictionaryOf(')) * ((any - P(')')) ^ 1) * P(')')
+local c_id = (
+  typed_container +
+  (letter * (alpha ^ 0))
+)
+local c_void = P('void')
+local c_param_type = (
+  ((P('Error') * fill * P('*') * fill) * Cc('error')) +
+  (C(c_id) * (ws ^ 1))
+  )
+local c_type = (C(c_void) * (ws ^ 1)) + c_param_type
+local c_param = Ct(c_param_type * C(c_id))
+local c_param_list = c_param * (fill * (P(',') * fill * c_param) ^ 0)
+local c_params = Ct(c_void + c_param_list)
+local c_proto = Ct(
+  Cg(c_type, 'return_type') * Cg(c_id, 'name') *
+  fill * P('(') * fill * Cg(c_params, 'parameters') * fill * P(')') *
+  Cg(Cc(false), 'async') *
+  (fill * Cg((P('FUNC_API_SINCE(') * C(num ^ 1)) * P(')'), 'since') ^ -1) *
+  (fill * Cg((P('FUNC_API_DEPRECATED_SINCE(') * C(num ^ 1)) * P(')'),
+              'deprecated_since') ^ -1) *
+  (fill * Cg((P('FUNC_API_ASYNC') * Cc(true)), 'async') ^ -1) *
+  (fill * Cg((P('FUNC_API_NOEXPORT') * Cc(true)), 'noexport') ^ -1) *
+  (fill * Cg((P('FUNC_API_REMOTE_ONLY') * Cc(true)), 'remote_only') ^ -1) *
+  (fill * Cg((P('FUNC_API_REMOTE_IMPL') * Cc(true)), 'remote_impl') ^ -1) *
+  (fill * Cg((P('FUNC_API_BRIDGE_IMPL') * Cc(true)), 'bridge_impl') ^ -1) *
+  fill * P(';')
+  )
+
+local grammar = Ct((c_proto + c_comment + c_preproc + ws) ^ 1)
+return {grammar=grammar, typed_container=typed_container}