no-nonsense debug information about tail calls

This commit is contained in:
Roberto Ierusalimschy 2003-02-27 08:52:30 -03:00
parent 5cd99b82b7
commit 92f6e0c1bf
7 changed files with 102 additions and 74 deletions

View File

@ -1,5 +1,5 @@
/*
** $Id: lbaselib.c,v 1.122 2003/02/24 16:50:41 roberto Exp roberto $
** $Id: lbaselib.c,v 1.123 2003/02/24 16:54:20 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
@ -123,6 +123,9 @@ static void getfunc (lua_State *L) {
if (lua_getstack(L, level, &ar) == 0)
luaL_argerror(L, 1, "invalid level");
lua_getinfo(L, "f", &ar);
if (lua_isnil(L, -1))
luaL_error(L, "cannot get/set environment (tail call at level %d)",
level);
}
}

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@ -1,5 +1,5 @@
/*
** $Id: ldblib.c,v 1.76 2002/12/19 11:11:55 roberto Exp roberto $
** $Id: ldblib.c,v 1.77 2002/12/20 10:26:33 roberto Exp roberto $
** Interface from Lua to its debug API
** See Copyright Notice in lua.h
*/
@ -137,7 +137,8 @@ static const char KEY_HOOK = 'h';
static void hookf (lua_State *L, lua_Debug *ar) {
static const char *const hooknames[] = {"call", "return", "line", "count"};
static const char *const hooknames[] =
{"call", "return", "line", "count", "tail return"};
lua_pushlightuserdata(L, (void *)&KEY_HOOK);
lua_rawget(L, LUA_REGISTRYINDEX);
if (lua_isfunction(L, -1)) {
@ -259,8 +260,8 @@ static int errorfb (lua_State *L) {
default: {
if (*ar.what == 'm') /* main? */
lua_pushfstring(L, " in main chunk");
else if (*ar.what == 'C') /* C function? */
lua_pushfstring(L, "%s", ar.short_src);
else if (*ar.what == 'C' || *ar.what == 't')
lua_pushliteral(L, " ?"); /* C function or tail call */
else
lua_pushfstring(L, " in function <%s:%d>",
ar.short_src, ar.linedefined);

124
ldebug.c
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@ -1,5 +1,5 @@
/*
** $Id: ldebug.c,v 1.144 2003/02/11 10:46:24 roberto Exp roberto $
** $Id: ldebug.c,v 1.145 2003/02/19 10:28:58 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@ -93,13 +93,21 @@ LUA_API int lua_gethookcount (lua_State *L) {
LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
int status;
int ci;
CallInfo *ci;
lua_lock(L);
ci = (L->ci - L->base_ci) - level;
if (ci <= 0) status = 0; /* there is no such level */
else {
ar->i_ci = ci;
for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) {
level--;
if (!(ci->state & CI_C)) /* Lua function? */
level -= ci->u.l.tailcalls; /* skip lost tail calls */
}
if (level > 0 || ci == L->base_ci) status = 0; /* there is no such level */
else if (level < 0) { /* level is of a lost tail call */
status = 1;
ar->i_ci = 0;
}
else {
status = 1;
ar->i_ci = ci - L->base_ci;
}
lua_unlock(L);
return status;
@ -150,31 +158,19 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
}
static void infoLproto (lua_Debug *ar, Proto *f) {
ar->source = getstr(f->source);
ar->linedefined = f->lineDefined;
ar->what = "Lua";
}
static void funcinfo (lua_State *L, lua_Debug *ar, StkId func) {
Closure *cl;
if (ttisfunction(func))
cl = clvalue(func);
else {
luaG_runerror(L, "value for `lua_getinfo' is not a function");
cl = NULL; /* to avoid warnings */
}
Closure *cl = clvalue(func);
if (cl->c.isC) {
ar->source = "=[C]";
ar->linedefined = -1;
ar->what = "C";
}
else
infoLproto(ar, cl->l.p);
else {
ar->source = getstr(cl->l.p->source);
ar->linedefined = cl->l.p->lineDefined;
ar->what = (ar->linedefined == 0) ? "main" : "Lua";
}
luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
if (ar->linedefined == 0)
ar->what = "main";
}
@ -190,29 +186,20 @@ static const char *travglobals (lua_State *L, const TObject *o) {
}
static void getname (lua_State *L, const TObject *f, lua_Debug *ar) {
/* try to find a name for given function */
if ((ar->name = travglobals(L, f)) != NULL)
ar->namewhat = "global";
else ar->namewhat = ""; /* not found */
static void info_tailcall (lua_State *L, lua_Debug *ar) {
ar->name = ar->namewhat = "";
ar->what = "tail";
ar->linedefined = ar->currentline = -1;
ar->source = "=(tail call)";
luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
ar->nups = 0;
setnilvalue(L->top);
}
LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
StkId f;
CallInfo *ci;
static int getinfo (lua_State *L, const char *what, lua_Debug *ar,
StkId f, CallInfo *ci) {
int status = 1;
lua_lock(L);
if (*what != '>') { /* function is active? */
ci = L->base_ci + ar->i_ci;
f = ci->base - 1;
}
else {
what++; /* skip the `>' */
ci = NULL;
f = L->top - 1;
}
for (; *what; what++) {
switch (*what) {
case 'S': {
@ -224,25 +211,48 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
break;
}
case 'u': {
ar->nups = (ttisfunction(f)) ? clvalue(f)->c.nupvalues : 0;
ar->nups = clvalue(f)->c.nupvalues;
break;
}
case 'n': {
ar->namewhat = (ci) ? getfuncname(ci, &ar->name) : NULL;
if (ar->namewhat == NULL)
getname(L, f, ar);
if (ar->namewhat == NULL) {
/* try to find a global name */
if ((ar->name = travglobals(L, f)) != NULL)
ar->namewhat = "global";
else ar->namewhat = ""; /* not found */
}
break;
}
case 'f': {
setobj2s(L->top, f);
status = 2;
break;
}
default: status = 0; /* invalid option */
}
}
if (!ci) L->top--; /* pop function */
if (status == 2) incr_top(L);
return status;
}
LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
int status = 1;
lua_lock(L);
if (*what == '>') {
StkId f = L->top - 1;
if (!ttisfunction(f))
luaG_runerror(L, "value for `lua_getinfo' is not a function");
status = getinfo(L, what + 1, ar, f, NULL);
L->top--; /* pop function */
}
else if (ar->i_ci != 0) { /* no tail call? */
CallInfo *ci = L->base_ci + ar->i_ci;
lua_assert(ttisfunction(ci->base - 1));
status = getinfo(L, what, ar, ci->base - 1, ci);
}
else
info_tailcall(L, ar);
if (strchr(what, 'f')) incr_top(L);
lua_unlock(L);
return status;
}
@ -480,18 +490,16 @@ static const char *getobjname (CallInfo *ci, int stackpos, const char **name) {
}
static Instruction getcurrentinstr (CallInfo *ci) {
return (!isLua(ci)) ? (Instruction)(-1) :
ci_func(ci)->l.p->code[currentpc(ci)];
}
static const char *getfuncname (CallInfo *ci, const char **name) {
Instruction i;
if ((isLua(ci) && ci->u.l.tailcalls > 0) || !isLua(ci - 1))
return NULL; /* calling function is not Lua (or is unknown) */
ci--; /* calling function */
i = getcurrentinstr(ci);
return (GET_OPCODE(i) == OP_CALL ? getobjname(ci, GETARG_A(i), name)
: NULL); /* no useful name found */
i = ci_func(ci)->l.p->code[currentpc(ci)];
if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL)
return getobjname(ci, GETARG_A(i), name);
else
return NULL; /* no useful name can be found */
}

27
ldo.c
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@ -1,5 +1,5 @@
/*
** $Id: ldo.c,v 1.212 2003/01/23 11:31:38 roberto Exp roberto $
** $Id: ldo.c,v 1.213 2003/02/13 16:08:47 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@ -31,6 +31,7 @@
/*
** {======================================================
** Error-recovery functions (based on long jumps)
@ -161,7 +162,10 @@ void luaD_callhook (lua_State *L, int event, int line) {
lua_Debug ar;
ar.event = event;
ar.currentline = line;
ar.i_ci = L->ci - L->base_ci;
if (event == LUA_HOOKTAILRET)
ar.i_ci = 0; /* tail call; no debug information about it */
else
ar.i_ci = L->ci - L->base_ci;
luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
L->ci->top = L->top + LUA_MINSTACK;
L->allowhook = 0; /* cannot call hooks inside a hook */
@ -232,6 +236,7 @@ StkId luaD_precall (lua_State *L, StkId func) {
L->base = L->ci->base = restorestack(L, funcr) + 1;
ci->top = L->base + p->maxstacksize;
ci->u.l.savedpc = p->code; /* starting point */
ci->u.l.tailcalls = 0;
ci->state = CI_SAVEDPC;
while (L->top < ci->top)
setnilvalue(L->top++);
@ -261,13 +266,21 @@ StkId luaD_precall (lua_State *L, StkId func) {
}
static StkId callrethooks (lua_State *L, StkId firstResult) {
ptrdiff_t fr = savestack(L, firstResult); /* next call may change stack */
luaD_callhook(L, LUA_HOOKRET, -1);
if (!(L->ci->state & CI_C)) { /* Lua function? */
while (L->ci->u.l.tailcalls--) /* call hook for eventual tail calls */
luaD_callhook(L, LUA_HOOKTAILRET, -1);
}
return restorestack(L, fr);
}
void luaD_poscall (lua_State *L, int wanted, StkId firstResult) {
StkId res;
if (L->hookmask & LUA_MASKRET) {
ptrdiff_t fr = savestack(L, firstResult); /* next call may change stack */
luaD_callhook(L, LUA_HOOKRET, -1);
firstResult = restorestack(L, fr);
}
if (L->hookmask & LUA_MASKRET)
firstResult = callrethooks(L, firstResult);
res = L->base - 1; /* res == final position of 1st result */
L->ci--;
L->base = L->ci->base; /* restore base */

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@ -1,5 +1,5 @@
/*
** $Id: lstate.h,v 1.107 2002/11/22 18:01:46 roberto Exp roberto $
** $Id: lstate.h,v 1.108 2002/11/25 17:47:13 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@ -80,6 +80,7 @@ typedef struct CallInfo {
struct { /* for Lua functions */
const Instruction *savedpc;
const Instruction **pc; /* points to `pc' variable in `luaV_execute' */
int tailcalls; /* number of tail calls lost under this entry */
} l;
struct { /* for C functions */
int dummy; /* just to avoid an empty struct */

5
lua.h
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@ -1,5 +1,5 @@
/*
** $Id: lua.h,v 1.172 2003/02/18 16:13:15 roberto Exp roberto $
** $Id: lua.h,v 1.173 2003/02/24 16:54:20 roberto Exp roberto $
** Lua - An Extensible Extension Language
** Tecgraf: Computer Graphics Technology Group, PUC-Rio, Brazil
** http://www.lua.org mailto:info@lua.org
@ -317,6 +317,7 @@ LUA_API int lua_pushupvalues (lua_State *L);
#define LUA_HOOKRET 1
#define LUA_HOOKLINE 2
#define LUA_HOOKCOUNT 3
#define LUA_HOOKTAILRET 4
/*
@ -351,7 +352,7 @@ struct lua_Debug {
int event;
const char *name; /* (n) */
const char *namewhat; /* (n) `global', `local', `field', `method' */
const char *what; /* (S) `Lua' function, `C' function, Lua `main' */
const char *what; /* (S) `Lua', `C', `main', `tail' */
const char *source; /* (S) */
int currentline; /* (l) */
int nups; /* (u) number of upvalues */

3
lvm.c
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@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.275 2003/02/11 10:46:24 roberto Exp roberto $
** $Id: lvm.c,v 1.276 2003/02/18 16:02:56 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -648,6 +648,7 @@ StkId luaV_execute (lua_State *L) {
(L->ci - 1)->top = L->top = base+aux; /* correct top */
lua_assert(L->ci->state & CI_SAVEDPC);
(L->ci - 1)->u.l.savedpc = L->ci->u.l.savedpc;
(L->ci - 1)->u.l.tailcalls++; /* one more call lost */
(L->ci - 1)->state = CI_SAVEDPC;
L->ci--; /* remove new frame */
L->base = L->ci->base;