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comparison third_party/luajit/src/jit/bc.lua @ 186:8cf4ec5e2191 hg-web

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Fixed merge conflict.
author MrJuneJune <me@mrjunejune.com>
date Fri, 23 Jan 2026 22:38:59 -0800
parents 94705b5986b3
children
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176:fed99fc04e12 186:8cf4ec5e2191
1 ----------------------------------------------------------------------------
2 -- LuaJIT bytecode listing module.
3 --
4 -- Copyright (C) 2005-2023 Mike Pall. All rights reserved.
5 -- Released under the MIT license. See Copyright Notice in luajit.h
6 ----------------------------------------------------------------------------
7 --
8 -- This module lists the bytecode of a Lua function. If it's loaded by -jbc
9 -- it hooks into the parser and lists all functions of a chunk as they
10 -- are parsed.
11 --
12 -- Example usage:
13 --
14 -- luajit -jbc -e 'local x=0; for i=1,1e6 do x=x+i end; print(x)'
15 -- luajit -jbc=- foo.lua
16 -- luajit -jbc=foo.list foo.lua
17 --
18 -- Default output is to stderr. To redirect the output to a file, pass a
19 -- filename as an argument (use '-' for stdout) or set the environment
20 -- variable LUAJIT_LISTFILE. The file is overwritten every time the module
21 -- is started.
22 --
23 -- This module can also be used programmatically:
24 --
25 -- local bc = require("jit.bc")
26 --
27 -- local function foo() print("hello") end
28 --
29 -- bc.dump(foo) --> -- BYTECODE -- [...]
30 -- print(bc.line(foo, 2)) --> 0002 KSTR 1 1 ; "hello"
31 --
32 -- local out = {
33 -- -- Do something with each line:
34 -- write = function(t, ...) io.write(...) end,
35 -- close = function(t) end,
36 -- flush = function(t) end,
37 -- }
38 -- bc.dump(foo, out)
39 --
40 ------------------------------------------------------------------------------
41
42 -- Cache some library functions and objects.
43 local jit = require("jit")
44 local jutil = require("jit.util")
45 local vmdef = require("jit.vmdef")
46 local bit = require("bit")
47 local sub, gsub, format = string.sub, string.gsub, string.format
48 local byte, band, shr = string.byte, bit.band, bit.rshift
49 local funcinfo, funcbc, funck = jutil.funcinfo, jutil.funcbc, jutil.funck
50 local funcuvname = jutil.funcuvname
51 local bcnames = vmdef.bcnames
52 local stdout, stderr = io.stdout, io.stderr
53
54 ------------------------------------------------------------------------------
55
56 local function ctlsub(c)
57 if c == "\n" then return "\\n"
58 elseif c == "\r" then return "\\r"
59 elseif c == "\t" then return "\\t"
60 else return format("\\%03d", byte(c))
61 end
62 end
63
64 -- Return one bytecode line.
65 local function bcline(func, pc, prefix)
66 local ins, m = funcbc(func, pc)
67 if not ins then return end
68 local ma, mb, mc = band(m, 7), band(m, 15*8), band(m, 15*128)
69 local a = band(shr(ins, 8), 0xff)
70 local oidx = 6*band(ins, 0xff)
71 local op = sub(bcnames, oidx+1, oidx+6)
72 local s = format("%04d %s %-6s %3s ",
73 pc, prefix or " ", op, ma == 0 and "" or a)
74 local d = shr(ins, 16)
75 if mc == 13*128 then -- BCMjump
76 return format("%s=> %04d\n", s, pc+d-0x7fff)
77 end
78 if mb ~= 0 then
79 d = band(d, 0xff)
80 elseif mc == 0 then
81 return s.."\n"
82 end
83 local kc
84 if mc == 10*128 then -- BCMstr
85 kc = funck(func, -d-1)
86 kc = format(#kc > 40 and '"%.40s"~' or '"%s"', gsub(kc, "%c", ctlsub))
87 elseif mc == 9*128 then -- BCMnum
88 kc = funck(func, d)
89 if op == "TSETM " then kc = kc - 2^52 end
90 elseif mc == 12*128 then -- BCMfunc
91 local fi = funcinfo(funck(func, -d-1))
92 if fi.ffid then
93 kc = vmdef.ffnames[fi.ffid]
94 else
95 kc = fi.loc
96 end
97 elseif mc == 5*128 then -- BCMuv
98 kc = funcuvname(func, d)
99 end
100 if ma == 5 then -- BCMuv
101 local ka = funcuvname(func, a)
102 if kc then kc = ka.." ; "..kc else kc = ka end
103 end
104 if mb ~= 0 then
105 local b = shr(ins, 24)
106 if kc then return format("%s%3d %3d ; %s\n", s, b, d, kc) end
107 return format("%s%3d %3d\n", s, b, d)
108 end
109 if kc then return format("%s%3d ; %s\n", s, d, kc) end
110 if mc == 7*128 and d > 32767 then d = d - 65536 end -- BCMlits
111 return format("%s%3d\n", s, d)
112 end
113
114 -- Collect branch targets of a function.
115 local function bctargets(func)
116 local target = {}
117 for pc=1,1000000000 do
118 local ins, m = funcbc(func, pc)
119 if not ins then break end
120 if band(m, 15*128) == 13*128 then target[pc+shr(ins, 16)-0x7fff] = true end
121 end
122 return target
123 end
124
125 -- Dump bytecode instructions of a function.
126 local function bcdump(func, out, all)
127 if not out then out = stdout end
128 local fi = funcinfo(func)
129 if all and fi.children then
130 for n=-1,-1000000000,-1 do
131 local k = funck(func, n)
132 if not k then break end
133 if type(k) == "proto" then bcdump(k, out, true) end
134 end
135 end
136 out:write(format("-- BYTECODE -- %s-%d\n", fi.loc, fi.lastlinedefined))
137 local target = bctargets(func)
138 for pc=1,1000000000 do
139 local s = bcline(func, pc, target[pc] and "=>")
140 if not s then break end
141 out:write(s)
142 end
143 out:write("\n")
144 out:flush()
145 end
146
147 ------------------------------------------------------------------------------
148
149 -- Active flag and output file handle.
150 local active, out
151
152 -- List handler.
153 local function h_list(func)
154 return bcdump(func, out)
155 end
156
157 -- Detach list handler.
158 local function bclistoff()
159 if active then
160 active = false
161 jit.attach(h_list)
162 if out and out ~= stdout and out ~= stderr then out:close() end
163 out = nil
164 end
165 end
166
167 -- Open the output file and attach list handler.
168 local function bcliston(outfile)
169 if active then bclistoff() end
170 if not outfile then outfile = os.getenv("LUAJIT_LISTFILE") end
171 if outfile then
172 out = outfile == "-" and stdout or assert(io.open(outfile, "w"))
173 else
174 out = stderr
175 end
176 jit.attach(h_list, "bc")
177 active = true
178 end
179
180 -- Public module functions.
181 return {
182 line = bcline,
183 dump = bcdump,
184 targets = bctargets,
185 on = bcliston,
186 off = bclistoff,
187 start = bcliston -- For -j command line option.
188 }
189