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/*
** $Id: ldblib.c $
** Interface from Lua to its debug API
** See Copyright Notice in lua.h
*/
#define ldblib_c
#define LUA_LIB
#include "lprefix.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
/*
** The hook table at registry[HOOKKEY] maps threads to their current
** hook function.
*/
static const char *const HOOKKEY
= "_HOOKKEY";
/*
** If L1 != L, L1 can be in any state, and therefore there are no
** guarantees about its stack space; any push in L1 must be
** checked.
*/
static void checkstack
(lua_State
*L
, lua_State
*L1
, int n
) {
if (l_unlikely
(L
!= L1
&& !lua_checkstack
(L1
, n
)))
luaL_error
(L
, "stack overflow");
}
static int db_getregistry
(lua_State
*L
) {
lua_pushvalue
(L
, LUA_REGISTRYINDEX
);
return 1;
}
static int db_getmetatable
(lua_State
*L
) {
luaL_checkany
(L
, 1);
if (!lua_getmetatable
(L
, 1)) {
lua_pushnil
(L
); /* no metatable */
}
return 1;
}
static int db_setmetatable
(lua_State
*L
) {
int t
= lua_type
(L
, 2);
luaL_argexpected
(L
, t
== LUA_TNIL
|| t
== LUA_TTABLE
, 2, "nil or table");
lua_settop
(L
, 2);
lua_setmetatable
(L
, 1);
return 1; /* return 1st argument */
}
static int db_getuservalue
(lua_State
*L
) {
int n
= (int)luaL_optinteger
(L
, 2, 1);
if (lua_type
(L
, 1) != LUA_TUSERDATA
)
luaL_pushfail
(L
);
else if (lua_getiuservalue
(L
, 1, n
) != LUA_TNONE
) {
lua_pushboolean
(L
, 1);
return 2;
}
return 1;
}
static int db_setuservalue
(lua_State
*L
) {
int n
= (int)luaL_optinteger
(L
, 3, 1);
luaL_checktype
(L
, 1, LUA_TUSERDATA
);
luaL_checkany
(L
, 2);
lua_settop
(L
, 2);
if (!lua_setiuservalue
(L
, 1, n
))
luaL_pushfail
(L
);
return 1;
}
/*
** Auxiliary function used by several library functions: check for
** an optional thread as function's first argument and set 'arg' with
** 1 if this argument is present (so that functions can skip it to
** access their other arguments)
*/
static lua_State
*getthread
(lua_State
*L
, int *arg
) {
if (lua_isthread
(L
, 1)) {
*arg
= 1;
return lua_tothread
(L
, 1);
}
else {
*arg
= 0;
return L
; /* function will operate over current thread */
}
}
/*
** Variations of 'lua_settable', used by 'db_getinfo' to put results
** from 'lua_getinfo' into result table. Key is always a string;
** value can be a string, an int, or a boolean.
*/
static void settabss
(lua_State
*L
, const char *k
, const char *v
) {
lua_pushstring
(L
, v
);
lua_setfield
(L
, -2, k
);
}
static void settabsi
(lua_State
*L
, const char *k
, int v
) {
lua_pushinteger
(L
, v
);
lua_setfield
(L
, -2, k
);
}
static void settabsb
(lua_State
*L
, const char *k
, int v
) {
lua_pushboolean
(L
, v
);
lua_setfield
(L
, -2, k
);
}
/*
** In function 'db_getinfo', the call to 'lua_getinfo' may push
** results on the stack; later it creates the result table to put
** these objects. Function 'treatstackoption' puts the result from
** 'lua_getinfo' on top of the result table so that it can call
** 'lua_setfield'.
*/
static void treatstackoption
(lua_State
*L
, lua_State
*L1
, const char *fname
) {
if (L
== L1
)
lua_rotate
(L
, -2, 1); /* exchange object and table */
else
lua_xmove
(L1
, L
, 1); /* move object to the "main" stack */
lua_setfield
(L
, -2, fname
); /* put object into table */
}
/*
** Calls 'lua_getinfo' and collects all results in a new table.
** L1 needs stack space for an optional input (function) plus
** two optional outputs (function and line table) from function
** 'lua_getinfo'.
*/
static int db_getinfo
(lua_State
*L
) {
lua_Debug ar
;
int arg
;
lua_State
*L1
= getthread
(L
, &arg
);
const char *options
= luaL_optstring
(L
, arg
+2, "flnSrtu");
checkstack
(L
, L1
, 3);
luaL_argcheck
(L
, options
[0] != '>', arg
+ 2, "invalid option '>'");
if (lua_isfunction
(L
, arg
+ 1)) { /* info about a function? */
options
= lua_pushfstring
(L
, ">%s", options
); /* add '>' to 'options' */
lua_pushvalue
(L
, arg
+ 1); /* move function to 'L1' stack */
lua_xmove
(L
, L1
, 1);
}
else { /* stack level */
if (!lua_getstack
(L1
, (int)luaL_checkinteger
(L
, arg
+ 1), &ar
)) {
luaL_pushfail
(L
); /* level out of range */
return 1;
}
}
if (!lua_getinfo
(L1
, options
, &ar
))
return luaL_argerror
(L
, arg
+2, "invalid option");
lua_newtable
(L
); /* table to collect results */
if (strchr(options
, 'S')) {
lua_pushlstring
(L
, ar.
source, ar.
srclen);
lua_setfield
(L
, -2, "source");
settabss
(L
, "short_src", ar.
short_src);
settabsi
(L
, "linedefined", ar.
linedefined);
settabsi
(L
, "lastlinedefined", ar.
lastlinedefined);
settabss
(L
, "what", ar.
what);
}
if (strchr(options
, 'l'))
settabsi
(L
, "currentline", ar.
currentline);
if (strchr(options
, 'u')) {
settabsi
(L
, "nups", ar.
nups);
settabsi
(L
, "nparams", ar.
nparams);
settabsb
(L
, "isvararg", ar.
isvararg);
}
if (strchr(options
, 'n')) {
settabss
(L
, "name", ar.
name);
settabss
(L
, "namewhat", ar.
namewhat);
}
if (strchr(options
, 'r')) {
settabsi
(L
, "ftransfer", ar.
ftransfer);
settabsi
(L
, "ntransfer", ar.
ntransfer);
}
if (strchr(options
, 't'))
settabsb
(L
, "istailcall", ar.
istailcall);
if (strchr(options
, 'L'))
treatstackoption
(L
, L1
, "activelines");
if (strchr(options
, 'f'))
treatstackoption
(L
, L1
, "func");
return 1; /* return table */
}
static int db_getlocal
(lua_State
*L
) {
int arg
;
lua_State
*L1
= getthread
(L
, &arg
);
int nvar
= (int)luaL_checkinteger
(L
, arg
+ 2); /* local-variable index */
if (lua_isfunction
(L
, arg
+ 1)) { /* function argument? */
lua_pushvalue
(L
, arg
+ 1); /* push function */
lua_pushstring
(L
, lua_getlocal
(L
, NULL
, nvar
)); /* push local name */
return 1; /* return only name (there is no value) */
}
else { /* stack-level argument */
lua_Debug ar
;
const char *name
;
int level
= (int)luaL_checkinteger
(L
, arg
+ 1);
if (l_unlikely
(!lua_getstack
(L1
, level
, &ar
))) /* out of range? */
return luaL_argerror
(L
, arg
+1, "level out of range");
checkstack
(L
, L1
, 1);
name
= lua_getlocal
(L1
, &ar
, nvar
);
if (name
) {
lua_xmove
(L1
, L
, 1); /* move local value */
lua_pushstring
(L
, name
); /* push name */
lua_rotate
(L
, -2, 1); /* re-order */
return 2;
}
else {
luaL_pushfail
(L
); /* no name (nor value) */
return 1;
}
}
}
static int db_setlocal
(lua_State
*L
) {
int arg
;
const char *name
;
lua_State
*L1
= getthread
(L
, &arg
);
lua_Debug ar
;
int level
= (int)luaL_checkinteger
(L
, arg
+ 1);
int nvar
= (int)luaL_checkinteger
(L
, arg
+ 2);
if (l_unlikely
(!lua_getstack
(L1
, level
, &ar
))) /* out of range? */
return luaL_argerror
(L
, arg
+1, "level out of range");
luaL_checkany
(L
, arg
+3);
lua_settop
(L
, arg
+3);
checkstack
(L
, L1
, 1);
lua_xmove
(L
, L1
, 1);
name
= lua_setlocal
(L1
, &ar
, nvar
);
if (name
== NULL
)
lua_pop
(L1
, 1); /* pop value (if not popped by 'lua_setlocal') */
lua_pushstring
(L
, name
);
return 1;
}
/*
** get (if 'get' is true) or set an upvalue from a closure
*/
static int auxupvalue
(lua_State
*L
, int get
) {
const char *name
;
int n
= (int)luaL_checkinteger
(L
, 2); /* upvalue index */
luaL_checktype
(L
, 1, LUA_TFUNCTION
); /* closure */
name
= get
? lua_getupvalue
(L
, 1, n
) : lua_setupvalue
(L
, 1, n
);
if (name
== NULL
) return 0;
lua_pushstring
(L
, name
);
lua_insert
(L
, -(get
+1)); /* no-op if get is false */
return get
+ 1;
}
static int db_getupvalue
(lua_State
*L
) {
return auxupvalue
(L
, 1);
}
static int db_setupvalue
(lua_State
*L
) {
luaL_checkany
(L
, 3);
return auxupvalue
(L
, 0);
}
/*
** Check whether a given upvalue from a given closure exists and
** returns its index
*/
static void *checkupval
(lua_State
*L
, int argf
, int argnup
, int *pnup
) {
void *id
;
int nup
= (int)luaL_checkinteger
(L
, argnup
); /* upvalue index */
luaL_checktype
(L
, argf
, LUA_TFUNCTION
); /* closure */
id
= lua_upvalueid
(L
, argf
, nup
);
if (pnup
) {
luaL_argcheck
(L
, id
!= NULL
, argnup
, "invalid upvalue index");
*pnup
= nup
;
}
return id
;
}
static int db_upvalueid
(lua_State
*L
) {
void *id
= checkupval
(L
, 1, 2, NULL
);
if (id
!= NULL
)
lua_pushlightuserdata
(L
, id
);
else
luaL_pushfail
(L
);
return 1;
}
static int db_upvaluejoin
(lua_State
*L
) {
int n1
, n2
;
checkupval
(L
, 1, 2, &n1
);
checkupval
(L
, 3, 4, &n2
);
luaL_argcheck
(L
, !lua_iscfunction
(L
, 1), 1, "Lua function expected");
luaL_argcheck
(L
, !lua_iscfunction
(L
, 3), 3, "Lua function expected");
lua_upvaluejoin
(L
, 1, n1
, 3, n2
);
return 0;
}
/*
** Call hook function registered at hook table for the current
** thread (if there is one)
*/
static void hookf
(lua_State
*L
, lua_Debug
*ar
) {
static const char *const hooknames
[] =
{"call", "return", "line", "count", "tail call"};
lua_getfield
(L
, LUA_REGISTRYINDEX
, HOOKKEY
);
lua_pushthread
(L
);
if (lua_rawget
(L
, -2) == LUA_TFUNCTION
) { /* is there a hook function? */
lua_pushstring
(L
, hooknames
[(int)ar
->event
]); /* push event name */
if (ar
->currentline
>= 0)
lua_pushinteger
(L
, ar
->currentline
); /* push current line */
else lua_pushnil
(L
);
lua_assert
(lua_getinfo
(L
, "lS", ar
));
lua_call
(L
, 2, 0); /* call hook function */
}
}
/*
** Convert a string mask (for 'sethook') into a bit mask
*/
static int makemask
(const char *smask
, int count
) {
int mask
= 0;
if (strchr(smask
, 'c')) mask
|= LUA_MASKCALL
;
if (strchr(smask
, 'r')) mask
|= LUA_MASKRET
;
if (strchr(smask
, 'l')) mask
|= LUA_MASKLINE
;
if (count
> 0) mask
|= LUA_MASKCOUNT
;
return mask
;
}
/*
** Convert a bit mask (for 'gethook') into a string mask
*/
static char *unmakemask
(int mask
, char *smask
) {
int i
= 0;
if (mask
& LUA_MASKCALL
) smask
[i
++] = 'c';
if (mask
& LUA_MASKRET
) smask
[i
++] = 'r';
if (mask
& LUA_MASKLINE
) smask
[i
++] = 'l';
smask
[i
] = '\0';
return smask
;
}
static int db_sethook
(lua_State
*L
) {
int arg
, mask
, count
;
lua_Hook func
;
lua_State
*L1
= getthread
(L
, &arg
);
if (lua_isnoneornil
(L
, arg
+1)) { /* no hook? */
lua_settop
(L
, arg
+1);
func
= NULL
; mask
= 0; count
= 0; /* turn off hooks */
}
else {
const char *smask
= luaL_checkstring
(L
, arg
+2);
luaL_checktype
(L
, arg
+1, LUA_TFUNCTION
);
count
= (int)luaL_optinteger
(L
, arg
+ 3, 0);
func
= hookf
; mask
= makemask
(smask
, count
);
}
if (!luaL_getsubtable
(L
, LUA_REGISTRYINDEX
, HOOKKEY
)) {
/* table just created; initialize it */
lua_pushliteral
(L
, "k");
lua_setfield
(L
, -2, "__mode"); /** hooktable.__mode = "k" */
lua_pushvalue
(L
, -1);
lua_setmetatable
(L
, -2); /* metatable(hooktable) = hooktable */
}
checkstack
(L
, L1
, 1);
lua_pushthread
(L1
); lua_xmove
(L1
, L
, 1); /* key (thread) */
lua_pushvalue
(L
, arg
+ 1); /* value (hook function) */
lua_rawset
(L
, -3); /* hooktable[L1] = new Lua hook */
lua_sethook
(L1
, func
, mask
, count
);
return 0;
}
static int db_gethook
(lua_State
*L
) {
int arg
;
lua_State
*L1
= getthread
(L
, &arg
);
char buff
[5];
int mask
= lua_gethookmask
(L1
);
lua_Hook hook
= lua_gethook
(L1
);
if (hook
== NULL
) { /* no hook? */
luaL_pushfail
(L
);
return 1;
}
else if (hook
!= hookf
) /* external hook? */
lua_pushliteral
(L
, "external hook");
else { /* hook table must exist */
lua_getfield
(L
, LUA_REGISTRYINDEX
, HOOKKEY
);
checkstack
(L
, L1
, 1);
lua_pushthread
(L1
); lua_xmove
(L1
, L
, 1);
lua_rawget
(L
, -2); /* 1st result = hooktable[L1] */
lua_remove
(L
, -2); /* remove hook table */
}
lua_pushstring
(L
, unmakemask
(mask
, buff
)); /* 2nd result = mask */
lua_pushinteger
(L
, lua_gethookcount
(L1
)); /* 3rd result = count */
return 3;
}
static int db_debug
(lua_State
*L
) {
for (;;) {
char buffer
[250];
lua_writestringerror
("%s", "lua_debug> ");
if (fgets(buffer
, sizeof(buffer
), stdin
) == NULL
||
strcmp(buffer
, "cont\n") == 0)
return 0;
if (luaL_loadbuffer
(L
, buffer
, strlen(buffer
), "=(debug command)") ||
lua_pcall
(L
, 0, 0, 0))
lua_writestringerror
("%s\n", luaL_tolstring
(L
, -1, NULL
));
lua_settop
(L
, 0); /* remove eventual returns */
}
}
static int db_traceback
(lua_State
*L
) {
int arg
;
lua_State
*L1
= getthread
(L
, &arg
);
const char *msg
= lua_tostring
(L
, arg
+ 1);
if (msg
== NULL
&& !lua_isnoneornil
(L
, arg
+ 1)) /* non-string 'msg'? */
lua_pushvalue
(L
, arg
+ 1); /* return it untouched */
else {
int level
= (int)luaL_optinteger
(L
, arg
+ 2, (L
== L1
) ? 1 : 0);
luaL_traceback
(L
, L1
, msg
, level
);
}
return 1;
}
static int db_setcstacklimit
(lua_State
*L
) {
int limit
= (int)luaL_checkinteger
(L
, 1);
int res
= lua_setcstacklimit
(L
, limit
);
lua_pushinteger
(L
, res
);
return 1;
}
static const luaL_Reg dblib
[] = {
{"debug", db_debug
},
{"getuservalue", db_getuservalue
},
{"gethook", db_gethook
},
{"getinfo", db_getinfo
},
{"getlocal", db_getlocal
},
{"getregistry", db_getregistry
},
{"getmetatable", db_getmetatable
},
{"getupvalue", db_getupvalue
},
{"upvaluejoin", db_upvaluejoin
},
{"upvalueid", db_upvalueid
},
{"setuservalue", db_setuservalue
},
{"sethook", db_sethook
},
{"setlocal", db_setlocal
},
{"setmetatable", db_setmetatable
},
{"setupvalue", db_setupvalue
},
{"traceback", db_traceback
},
{"setcstacklimit", db_setcstacklimit
},
{NULL
, NULL
}
};
LUAMOD_API
int luaopen_debug
(lua_State
*L
) {
luaL_newlib
(L
, dblib
);
return 1;
}