Introduce explicit declaration of function parameters

lang/lua-ast.lua

@@ -66,6 +66,17 @@ function AST.function_decl(ast, path, args, body, proto)
    return func_decl(path, body, args, proto.varargs, false, proto.firstline, proto.lastline)
 end
 
+function AST.func_parameters_decl(ast, args, vararg)
+    local params = {}
+    for i = 1, #args do
+        params[i] = ast:var_declare(args[i])
+    end
+    if vararg then
+        params[#params + 1] = ast:expr_vararg()
+    end
+    return params
+end
+
 function AST.chunk(ast, body, chunkname, firstline, lastline)
     return build("Chunk", { body = body, chunkname = chunkname, firstline = firstline, lastline = lastline })
 end

lang/parser.lua

@@ -479,26 +479,26 @@ end
 local function parse_params(ast, ls, needself)
     lex_check(ls, "(")
     local args = { }
+    local vararg = false
     if needself then
-        args[1] = ast:var_declare("self")
+        args[1] = "self"
     end
     if ls.token ~= ")" then
         repeat
             if ls.token == 'TK_name' or (not LJ_52 and ls.token == 'TK_goto') then
                 local name = lex_str(ls)
-                args[#args+1] = ast:var_declare(name)
+                args[#args+1] = name
             elseif ls.token == 'TK_dots' then
                 ls:next()
-                ls.fs.varargs = true
-                args[#args + 1] = ast:expr_vararg()
+                vararg = true
                 break
             else
                 err_syntax(ls, "<name> or \"...\" expected")
             end
         until not lex_opt(ls, ',')
     end
     lex_check(ls, ")")
-    return args
+    return args, vararg
 end
 
 local function new_proto(ls, varargs)
@@ -528,7 +528,9 @@ function parse_body(ast, ls, line, needself)
     ls.fs = new_proto(ls, false)
     ast:fscope_begin()
     ls.fs.firstline = line
-    local args = parse_params(ast, ls, needself)
+    local args, vararg = parse_params(ast, ls, needself)
+    local params = ast:func_parameters_decl(args, vararg)
+    ls.fs.varargs = vararg
     local body = parse_block(ast, ls)
     ast:fscope_end()
     local proto = ls.fs
@@ -538,7 +540,7 @@ function parse_body(ast, ls, line, needself)
     ls.fs.lastline = ls.linenumber
     ls:next()
     ls.fs = pfs
-    return args, body, proto
+    return params, body, proto
 end
 
 function parse_block(ast, ls, firstline)