api: auto generate api function wrappers for viml

scripts/gendispatch.lua

@@ -41,18 +41,20 @@ c_proto = Ct(
   )
 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)
+-- we need at least 3 arguments since the last two are output files
+assert(#arg >= 2)
 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]
+-- output c file(dispatch function + metadata serialized with msgpack)
+outputf = arg[#arg-1]
+-- output mpack file (metadata)
+mpack_outputf = arg[#arg]
 
 -- read each input file, parse and append to the api metadata
-for i = 1, #arg - 1 do
+for i = 1, #arg - 2 do
   local full_path = arg[i]
   local parts = {}
   for part in string.gmatch(full_path, '[^/]+') do
@@ -165,7 +167,7 @@ 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('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
@@ -311,3 +313,7 @@ MsgpackRpcRequestHandler msgpack_rpc_get_handler_for(const char *name,
 ]])
 
 output:close()
+
+mpack_output = io.open(mpack_outputf, 'wb')
+mpack_output:write(packed)
+mpack_output:close()

scripts/geneval.lua

@@ -1,5 +1,8 @@
+mpack = require('mpack')
+
 local nvimsrcdir = arg[1]
 local autodir = arg[2]
+local metadata_file = arg[3]
 
 if nvimsrcdir == '--help' then
   print([[
@@ -18,9 +21,20 @@ local funcsfname = autodir .. '/funcs.generated.h'
 
 local funcspipe = io.open(funcsfname .. '.hsh', 'w')
 
-local funcs = require('eval')
+local funcs = require('eval').funcs
 
-for name, def in pairs(funcs.funcs) do
+local metadata = mpack.unpack(io.open(arg[3], 'rb'):read("*all"))
+
+for i,fun in ipairs(metadata) do
+  funcs['api_'..fun.name] = {
+    args=#fun.parameters,
+    func='api_wrapper',
+    data='handle_'..fun.name,
+  }
+end
+
+
+for name, def in pairs(funcs) do
   args = def.args or 0
   if type(args) == 'number' then
     args = {args, args}
@@ -28,7 +42,8 @@ for name, def in pairs(funcs.funcs) do
     args[2] = 'MAX_FUNC_ARGS'
   end
   func = def.func or ('f_' .. name)
-  local val = ('{ %s, %s, &%s }'):format(args[1], args[2], func)
+  data = def.data or "NULL"
+  local val = ('{ %s, %s, &%s, %s }'):format(args[1], args[2], func, data)
   funcspipe:write(name .. '\n' .. val .. '\n')
 end
 funcspipe:close()

src/nvim/CMakeLists.txt

@@ -14,6 +14,7 @@ set(GENERATED_DIR ${PROJECT_BINARY_DIR}/src/nvim/auto)
 set(DISPATCH_GENERATOR ${PROJECT_SOURCE_DIR}/scripts/gendispatch.lua)
 file(GLOB API_HEADERS api/*.h)
 file(GLOB MSGPACK_RPC_HEADERS msgpack_rpc/*.h)
+set(API_METADATA ${PROJECT_BINARY_DIR}/api_metadata.mpack)
 set(HEADER_GENERATOR ${PROJECT_SOURCE_DIR}/scripts/gendeclarations.lua)
 set(GENERATED_INCLUDES_DIR ${PROJECT_BINARY_DIR}/include)
 set(GENERATED_API_DISPATCH ${GENERATED_DIR}/api/private/dispatch.c)
@@ -192,8 +193,8 @@ add_custom_command(OUTPUT ${GENERATED_UNICODE_TABLES}
     ${EASTASIANWIDTH_FILE}
 )
 
-add_custom_command(OUTPUT ${GENERATED_API_DISPATCH}
-  COMMAND ${LUA_PRG} ${DISPATCH_GENERATOR} ${API_HEADERS} ${GENERATED_API_DISPATCH}
+add_custom_command(OUTPUT ${GENERATED_API_DISPATCH} ${API_METADATA}
+  COMMAND ${LUA_PRG} ${DISPATCH_GENERATOR} ${API_HEADERS} ${GENERATED_API_DISPATCH} ${API_METADATA}
   DEPENDS
     ${API_HEADERS}
     ${MSGPACK_RPC_HEADERS}
@@ -220,10 +221,10 @@ add_custom_command(OUTPUT ${GENERATED_EX_CMDS_ENUM} ${GENERATED_EX_CMDS_DEFS}
 
 add_custom_command(OUTPUT ${GENERATED_FUNCS}
   COMMAND ${LUA_PRG} ${FUNCS_GENERATOR}
-    ${PROJECT_SOURCE_DIR}/src/nvim ${GENERATED_DIR}
+    ${PROJECT_SOURCE_DIR}/src/nvim ${GENERATED_DIR} ${API_METADATA}
   COMMAND $<TARGET_FILE:genhash>
     ${GENERATED_FUNCS_HASH_INPUT} ${GENERATED_FUNCS} functions functions VimLFuncDef "NOFUNC"
-  DEPENDS ${FUNCS_GENERATOR} ${EVAL_DEFS_FILE} genhash
+    DEPENDS ${FUNCS_GENERATOR} ${EVAL_DEFS_FILE} ${API_METADATA} genhash
 )
 
 add_custom_command(OUTPUT ${GENERATED_EVENTS_ENUM} ${GENERATED_EVENTS_NAMES_MAP}

src/nvim/api/private/dispatch.h

@@ -3,13 +3,15 @@
 
 #include "nvim/api/private/defs.h"
 
-/// The rpc_method_handlers table, used in msgpack_rpc_dispatch(), stores
-/// functions of this type.
-typedef struct {
-  Object (*fn)(uint64_t channel_id,
+typedef Object (*ApiDispatchWrapper)(uint64_t channel_id,
                                      uint64_t request_id,
                                      Array args,
                                      Error *error);
+
+/// The rpc_method_handlers table, used in msgpack_rpc_dispatch(), stores
+/// functions of this type.
+typedef struct {
+  ApiDispatchWrapper fn;
   bool async;  // function is always safe to run immediately instead of being
                // put in a request queue for handling when nvim waits for input.
 } MsgpackRpcRequestHandler;

src/nvim/eval.c

@@ -445,13 +445,14 @@ typedef struct {
 } timer_T;
 
 /// Prototype of C function that implements VimL function
-typedef void (*VimLFunc)(typval_T *args, typval_T *rvar);
+typedef void (*VimLFunc)(typval_T *args, typval_T *rvar, void *data);
 
 /// Structure holding VimL function definition
 typedef struct fst {
   uint8_t min_argc;  ///< Minimal number of arguments.
   uint8_t max_argc;  ///< Maximal number of arguments.
   VimLFunc func;     ///< Function implementation.
+  void *data;        ///< Userdata for function implementation.
 } VimLFuncDef;
 
 KHASH_MAP_INIT_STR(functions, VimLFuncDef)
@@ -6989,7 +6990,7 @@ call_func (
           error = ERROR_TOOMANY;
         } else {
           argvars[argcount].v_type = VAR_UNKNOWN;
-          fdef->func(argvars, rettv);
+          fdef->func(argvars, rettv, fdef->data);
           error = ERROR_NONE;
         }
       }
@@ -7100,13 +7101,10 @@ static inline int get_float_arg(typval_T *argvars, float_T *f)
 // Some versions of glibc on i386 have an optimization that makes it harder to
 // call math functions indirectly from inside an inlined function, causing
 // compile-time errors. Avoid `inline` in that case. #3072
-#ifndef ARCH_32
-inline
-#endif
-static void float_op_wrapper(typval_T *argvars, typval_T *rettv,
-                             float_T (*function)(float_T))
+static void float_op_wrapper(typval_T *argvars, typval_T *rettv, void *data)
 {
   float_T f;
+  float_T (*function)(float_T) = data;
 
   rettv->v_type = VAR_FLOAT;
   if (get_float_arg(argvars, &f) == OK) {
@@ -7116,6 +7114,34 @@ static void float_op_wrapper(typval_T *argvars, typval_T *rettv,
   }
 }
 
+static void api_wrapper(typval_T *argvars, typval_T *rettv, void *data)
+{
+  ApiDispatchWrapper fn = data;
+
+  Array args = ARRAY_DICT_INIT;
+
+  for (typval_T *tv = argvars; tv->v_type != VAR_UNKNOWN; tv++) {
+    ADD(args, vim_to_object(tv));
+  }
+
+  Error err = ERROR_INIT;
+  Object result = fn(-1, -1, args, &err);
+
+  if (err.set) {
+    vim_report_error(cstr_as_string(err.msg));
+    goto end;
+  }
+
+  if (!object_to_vim(result, rettv, &err)) {
+    EMSG2(_("Error converting the call result: %s"), err.msg);
+  }
+
+end:
+  // All arguments were freed already, but we still need to free the array
+  xfree(args.items);
+  api_free_object(result);
+}
+
 /*
  * "abs(expr)" function
  */
@@ -7515,14 +7541,6 @@ static void f_asin(typval_T *argvars, typval_T *rettv)
   float_op_wrapper(argvars, rettv, &asin);
 }
 
-/*
- * "atan()" function
- */
-static void f_atan(typval_T *argvars, typval_T *rettv)
-{
-  float_op_wrapper(argvars, rettv, &atan);
-}
-
 /*
  * "atan2()" function
  */

src/nvim/eval.lua

@@ -33,7 +33,7 @@ return {
     assert_notequal={args={2, 3}},
     assert_notmatch={args={2, 3}},
     assert_true={args={1, 2}},
-    atan={args=1},
+    atan={args=1, func="float_op_wrapper", data="atan"},
     atan2={args=2},
     browse={args=4},
     browsedir={args=2},