neovim/scripts/msgpack-gen.lua

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lpeg = require('lpeg')
mpack = require('mpack')
-- 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
P, R, S = lpeg.P, lpeg.R, lpeg.S
C, Ct, Cc, Cg = lpeg.C, lpeg.Ct, lpeg.Cc, lpeg.Cg
any = P(1) -- (consume one character)
letter = R('az', 'AZ') + S('_$')
alpha = letter + R('09')
nl = P('\r\n') + P('\n')
not_nl = any - nl
ws = S(' \t') + nl
fill = ws ^ 0
c_comment = P('//') * (not_nl ^ 0)
c_preproc = P('#') * (not_nl ^ 0)
typed_container =
(P('ArrayOf(') + P('DictionaryOf(')) * ((any - P(')')) ^ 1) * P(')')
c_id = (
typed_container +
(letter * (alpha ^ 0))
)
c_void = P('void')
c_param_type = (
((P('Error') * fill * P('*') * fill) * Cc('error')) +
(C(c_id) * (ws ^ 1))
)
c_type = (C(c_void) * (ws ^ 1)) + c_param_type
c_param = Ct(c_param_type * C(c_id))
c_param_list = c_param * (fill * (P(',') * fill * c_param) ^ 0)
c_params = Ct(c_void + c_param_list)
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_ATTR_ASYNC') * Cc(true)), 'async') ^ -1) *
fill * P(';')
)
grammar = Ct((c_proto + c_comment + c_preproc + ws) ^ 1)
-- we need at least 2 arguments since the last one is the output file
assert(#arg >= 1)
functions = {}
-- names of all headers relative to the source root(for inclusion in the
-- generated file)
headers = {}
-- output file(dispatch function + metadata serialized with msgpack)
outputf = arg[#arg]
-- read each input file, parse and append to the api metadata
for i = 1, #arg - 1 do
local full_path = arg[i]
local parts = {}
for part in string.gmatch(full_path, '[^/]+') do
parts[#parts + 1] = part
end
headers[#headers + 1] = parts[#parts - 1]..'/'..parts[#parts]
local input = io.open(full_path, 'rb')
local tmp = grammar:match(input:read('*all'))
for i = 1, #tmp do
functions[#functions + 1] = tmp[i]
local fn = tmp[i]
if #fn.parameters ~= 0 and fn.parameters[1][2] == 'channel_id' then
-- this function should receive the channel id
fn.receives_channel_id = true
-- remove the parameter since it won't be passed by the api client
table.remove(fn.parameters, 1)
end
if #fn.parameters ~= 0 and fn.parameters[#fn.parameters][1] == 'error' then
-- function can fail if the last parameter type is 'Error'
fn.can_fail = true
-- remove the error parameter, msgpack has it's own special field
-- for specifying errors
fn.parameters[#fn.parameters] = nil
end
end
input:close()
end
-- start building the output
output = io.open(outputf, 'wb')
output:write([[
2014-10-22 06:16:52 -07:00
#include <inttypes.h>
#include <stdbool.h>
#include <stdint.h>
2014-06-22 22:40:35 -07:00
#include <assert.h>
#include <msgpack.h>
#include "nvim/map.h"
#include "nvim/log.h"
#include "nvim/vim.h"
#include "nvim/msgpack_rpc/helpers.h"
#include "nvim/msgpack_rpc/defs.h"
#include "nvim/api/private/helpers.h"
#include "nvim/api/private/defs.h"
]])
for i = 1, #headers do
if headers[i]:sub(-12) ~= '.generated.h' then
output:write('\n#include "nvim/'..headers[i]..'"')
end
end
output:write([[
static const uint8_t msgpack_metadata[] = {
]])
-- serialize the API metadata using msgpack and embed into the resulting
-- binary for easy querying by clients
packed = mpack.pack(functions)
for i = 1, #packed do
output:write(string.byte(packed, i)..', ')
if i % 10 == 0 then
output:write('\n ')
end
end
output:write([[
};
void msgpack_rpc_init_function_metadata(Dictionary *metadata)
{
msgpack_unpacked unpacked;
msgpack_unpacked_init(&unpacked);
if (msgpack_unpack_next(&unpacked,
(const char *)msgpack_metadata,
sizeof(msgpack_metadata),
NULL) != MSGPACK_UNPACK_SUCCESS) {
abort();
}
Object functions;
msgpack_rpc_to_object(&unpacked.data, &functions);
msgpack_unpacked_destroy(&unpacked);
PUT(*metadata, "functions", functions);
}
]])
local function real_type(type)
local rv = type
if typed_container:match(rv) then
if rv:match('Array') then
rv = 'Array'
else
rv = 'Dictionary'
end
end
return rv
end
-- start the handler functions. Visit each function metadata to build the
-- handler function with code generated for validating arguments and calling to
-- the real API.
for i = 1, #functions do
local fn = functions[i]
local args = {}
output:write('static Object handle_'..fn.name..'(uint64_t channel_id, uint64_t request_id, Array args, Error *error)')
output:write('\n{')
output:write('\n Object ret = NIL;')
-- Declare/initialize variables that will hold converted arguments
for j = 1, #fn.parameters do
local param = fn.parameters[j]
local converted = 'arg_'..j
output:write('\n '..param[1]..' '..converted..' api_init_'..string.lower(real_type(param[1]))..';')
end
output:write('\n')
output:write('\n if (args.size != '..#fn.parameters..') {')
output:write('\n snprintf(error->msg, sizeof(error->msg), "Wrong number of arguments: expecting '..#fn.parameters..' but got %zu", args.size);')
output:write('\n error->set = true;')
output:write('\n goto cleanup;')
output:write('\n }\n')
-- Validation/conversion for each argument
for j = 1, #fn.parameters do
local converted, convert_arg, param, arg
param = fn.parameters[j]
converted = 'arg_'..j
local rt = real_type(param[1])
if rt ~= 'Object' then
output:write('\n if (args.items['..(j - 1)..'].type == kObjectType'..rt..') {')
output:write('\n '..converted..' = args.items['..(j - 1)..'].data.'..rt:lower()..';')
if rt:match('^Buffer$') or rt:match('^Window$') or rt:match('^Tabpage$') or rt:match('^Boolean$') then
-- accept positive integers for Buffers, Windows and Tabpages
output:write('\n } else if (args.items['..(j - 1)..'].type == kObjectTypeInteger && args.items['..(j - 1)..'].data.integer > 0) {')
output:write('\n '..converted..' = (unsigned)args.items['..(j - 1)..'].data.integer;')
end
output:write('\n } else {')
output:write('\n snprintf(error->msg, sizeof(error->msg), "Wrong type for argument '..j..', expecting '..param[1]..'");')
output:write('\n error->set = true;')
output:write('\n goto cleanup;')
output:write('\n }\n')
else
output:write('\n '..converted..' = args.items['..(j - 1)..'];\n')
end
args[#args + 1] = converted
end
-- function call
local call_args = table.concat(args, ', ')
output:write('\n ')
if fn.return_type ~= 'void' then
-- has a return value, prefix the call with a declaration
output:write(fn.return_type..' rv = ')
end
-- write the function name and the opening parenthesis
output:write(fn.name..'(')
if fn.receives_channel_id then
-- if the function receives the channel id, pass it as first argument
if #args > 0 then
output:write('channel_id, '..call_args)
else
output:write('channel_id')
end
else
output:write(call_args)
end
if fn.can_fail then
-- if the function can fail, also pass a pointer to the local error object
if #args > 0 then
output:write(', error);\n')
else
output:write('error);\n')
end
-- and check for the error
output:write('\n if (error->set) {')
output:write('\n goto cleanup;')
output:write('\n }\n')
else
output:write(');\n')
end
if fn.return_type ~= 'void' then
output:write('\n ret = '..string.upper(real_type(fn.return_type))..'_OBJ(rv);')
end
-- Now generate the cleanup label for freeing memory allocated for the
-- arguments
output:write('\n\ncleanup:');
for j = 1, #fn.parameters do
local param = fn.parameters[j]
output:write('\n api_free_'..string.lower(real_type(param[1]))..'(arg_'..j..');')
end
output:write('\n return ret;\n}\n\n');
end
-- Generate a function that initializes method names with handler functions
output:write([[
static Map(String, MsgpackRpcRequestHandler) *methods = NULL;
void msgpack_rpc_add_method_handler(String method, MsgpackRpcRequestHandler handler)
{
map_put(String, MsgpackRpcRequestHandler)(methods, method, handler);
}
void msgpack_rpc_init_method_table(void)
{
methods = map_new(String, MsgpackRpcRequestHandler)();
]])
-- Keep track of the maximum method name length in order to avoid walking
-- strings longer than that when searching for a method handler
local max_fname_len = 0
for i = 1, #functions do
local fn = functions[i]
output:write(' msgpack_rpc_add_method_handler('..
'(String) {.data = "'..fn.name..'", '..
'.size = sizeof("'..fn.name..'") - 1}, '..
'(MsgpackRpcRequestHandler) {.fn = handle_'.. fn.name..
', .async = '..tostring(fn.async)..'});\n')
if #fn.name > max_fname_len then
max_fname_len = #fn.name
end
end
output:write('\n}\n\n')
output:write([[
MsgpackRpcRequestHandler msgpack_rpc_get_handler_for(const char *name,
size_t name_len)
{
String m = {
.data=(char *)name,
.size=MIN(name_len, ]]..max_fname_len..[[)
};
MsgpackRpcRequestHandler rv =
map_get(String, MsgpackRpcRequestHandler)(methods, m);
if (!rv.fn) {
rv.fn = msgpack_rpc_handle_missing_method;
}
return rv;
}
]])
output:close()