lua: Prepare for standalone build

src/lua/bcc-probe

@@ -14,30 +14,8 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 ]]
-function setup_path()
- local str = require("debug").getinfo(2, "S").source:sub(2)
- local script_path = str:match("(.*/)").."/?.lua;"
- package.path = script_path..package.path
-end
-
-setup_path()
-local BCC = require("bcc.init")
-local BPF = BCC.BPF
-
-BPF.script_root(arg[1])
-
-local utils = {
- argparse = require("bcc.vendor.argparse"),
- posix = require("bcc.vendor.posix"),
- sym = BCC.sym
-}
-
-local tracefile = table.remove(arg, 1)
-local command = dofile(tracefile)
-local res, err = pcall(command, BPF, utils)
-
-if not res then
- io.stderr:write("[ERROR] "..err.."\n")
-end
-
-BPF.cleanup_probes()
+local str = require("debug").getinfo(1, "S").source:sub(2)
+local script_path = str:match("(.*/)").."/?.lua;"
+package.path = script_path..package.path
+rawset(_G, "BCC_STANDALONE", false)
+require("bcc.run")()

src/lua/bcc/init.lua

@@ -13,10 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 ]]
-require("bcc.vendor.strict")
 require("bcc.vendor.helpers")
-class = require("bcc.vendor.middleclass")
-
 return {
  BPF = require("bcc.bpf"),
  sym = require("bcc.sym"),

src/lua/bcc/libbcc.lua

@@ -98,5 +98,4 @@ int perf_reader_fd(struct perf_reader *reader);
 void perf_reader_set_fd(struct perf_reader *reader, int fd);
 ]]
 
-local libbcc = ffi.load("bcc")
-return libbcc
+return rawget(_G, "BCC_STANDALONE") and ffi.C or ffi.load("bcc")

src/lua/bcc/run.lua

@@ -0,0 +1,39 @@
+--[[
+Copyright 2016 GitHub, Inc
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http:https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+]]
+
+return function()
+ local BCC = require("bcc.init")
+ local BPF = BCC.BPF
+
+ BPF.script_root(arg[1])
+
+ local utils = {
+ argparse = require("bcc.vendor.argparse"),
+ posix = require("bcc.vendor.posix"),
+ sym = BCC.sym
+ }
+
+ local tracefile = table.remove(arg, 1)
+ local command = dofile(tracefile)
+ local res, err = pcall(command, BPF, utils)
+
+ if not res then
+ io.stderr:write("[ERROR] "..err.."\n")
+ end
+
+ BPF.cleanup_probes()
+ return res, err
+end

src/lua/bcc/vendor/helpers.lua

@@ -156,4 +156,14 @@ local function logline(...)
  os.date("%H:%M:%S"), c_clear, line, msg))
 end
 
-log = { info = logline, enabled = true }
+setmetatable(_G, {
+ __newindex = function (_, n)
+ error("attempt to write to undeclared variable "..n, 2)
+ end,
+ __index = function (_, n)
+ error("attempt to read undeclared variable "..n, 2)
+ end,
+})
+
+rawset(_G, "log", { info = logline, enabled = true })
+rawset(_G, "class", require("bcc.vendor.middleclass"))