commit b0f2b288a6b860374b9578d4c51329fc9cd43022
parent 2b25489b47ad94e6f970f5d9150937734322f24c
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 25 Nov 2009 13:27:27 -0200
new scheme for debug info about tail calls: no more 'fake' stack entries,
but stack entry knows whether it was tail called
Diffstat:
9 files changed, 60 insertions(+), 79 deletions(-)
diff --git a/lauxlib.c b/lauxlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lauxlib.c,v 1.192 2009/09/28 12:36:40 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.193 2009/10/05 16:44:33 roberto Exp roberto $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -97,7 +97,7 @@ static void pushfuncname (lua_State *L, lua_Debug *ar) {
lua_remove(L, -2); /* remove name */
}
else
- lua_pushliteral(L, "?"); /* C function or tail call */
+ lua_pushliteral(L, "?");
}
else
lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
@@ -133,12 +133,14 @@ LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
level = numlevels - LEVELS2; /* and skip to last ones */
}
else {
- lua_getinfo(L1, "Sln", &ar);
+ lua_getinfo(L1, "Slnt", &ar);
lua_pushfstring(L, "\n\t%s:", ar.short_src);
if (ar.currentline > 0)
lua_pushfstring(L, "%d:", ar.currentline);
lua_pushliteral(L, " in ");
pushfuncname(L, &ar);
+ if (ar.istailcall)
+ lua_pushliteral(L, "\n\t(...tail calls...)");
lua_concat(L, lua_gettop(L) - top);
}
}
diff --git a/lbaselib.c b/lbaselib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lbaselib.c,v 1.225 2009/11/19 16:26:29 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.226 2009/11/24 12:05:44 roberto Exp roberto $
** Basic library
** See Copyright Notice in lua.h
*/
@@ -119,8 +119,6 @@ static void getfunc (lua_State *L, int opt) {
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, "no function environment for tail call at level %d", level);
}
}
diff --git a/ldblib.c b/ldblib.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldblib.c,v 1.116 2009/11/18 15:50:18 roberto Exp roberto $
+** $Id: ldblib.c,v 1.117 2009/11/24 12:05:44 roberto Exp roberto $
** Interface from Lua to its debug API
** See Copyright Notice in lua.h
*/
@@ -100,7 +100,7 @@ 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, "flnSu");
+ const char *options = luaL_optstring(L, arg+2, "flnStu");
if (lua_isnumber(L, arg+1)) {
if (!lua_getstack(L1, (int)lua_tointeger(L, arg+1), &ar)) {
lua_pushnil(L); /* level out of range */
@@ -133,6 +133,10 @@ static int db_getinfo (lua_State *L) {
settabss(L, "name", ar.name);
settabss(L, "namewhat", ar.namewhat);
}
+ if (strchr(options, 't')) {
+ lua_pushboolean(L, ar.istailcall);
+ lua_setfield(L, -2, "istailcall");
+ }
if (strchr(options, 'L'))
treatstackoption(L, L1, "activelines");
if (strchr(options, 'f'))
@@ -232,7 +236,7 @@ static const char KEY_HOOK = 'h';
static void hookf (lua_State *L, lua_Debug *ar) {
static const char *const hooknames[] =
- {"call", "return", "line", "count", "tail return"};
+ {"call", "return", "line", "count", "tail call"};
lua_pushlightuserdata(L, (void *)&KEY_HOOK);
lua_rawget(L, LUA_REGISTRYINDEX);
lua_pushlightuserdata(L, L);
diff --git a/ldebug.c b/ldebug.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldebug.c,v 2.56 2009/09/28 16:32:50 roberto Exp roberto $
+** $Id: ldebug.c,v 2.57 2009/10/13 19:07:40 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@@ -83,23 +83,14 @@ LUA_API int lua_gethookcount (lua_State *L) {
LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
int status;
CallInfo *ci;
+ if (level < 0) return 0; /* invalid (negative) level */
lua_lock(L);
- for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous) {
+ for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
level--;
- if (isLua(ci)) /* Lua function? */
- level -= ci->u.l.tailcalls; /* skip lost tail calls */
- }
if (level == 0 && ci != &L->base_ci) { /* level found? */
status = 1;
ar->i_ci = ci;
}
- else if (level < 0) {
- if (ci == L->ci) status = 0; /* level was negative? */
- else { /* level is of a lost tail call */
- status = 1;
- ar->i_ci = NULL;
- }
- }
else status = 0; /* no such level */
lua_unlock(L);
return status;
@@ -110,7 +101,6 @@ static const char *findlocal (lua_State *L, CallInfo *ci, int n,
StkId *pos) {
const char *name = NULL;
StkId base;
- if (ci == NULL) return NULL; /* tail call? */
if (isLua(ci)) {
base = ci->u.l.base;
name = luaF_getlocalname(ci_func(ci)->l.p, n, currentpc(ci));
@@ -170,17 +160,6 @@ static void funcinfo (lua_Debug *ar, Closure *cl) {
}
-static void info_tailcall (lua_Debug *ar) {
- ar->name = NULL;
- ar->namewhat = "";
- ar->what = "tail";
- ar->lastlinedefined = ar->linedefined = ar->currentline = -1;
- ar->source = "=(tail call)";
- luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
- ar->nups = 0;
-}
-
-
static void collectvalidlines (lua_State *L, Closure *f) {
if (f == NULL || f->c.isC) {
setnilvalue(L->top);
@@ -201,10 +180,6 @@ static void collectvalidlines (lua_State *L, Closure *f) {
static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
Closure *f, CallInfo *ci) {
int status = 1;
- if (f == NULL) {
- info_tailcall(ar);
- return status;
- }
for (; *what; what++) {
switch (*what) {
case 'S': {
@@ -219,6 +194,10 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
ar->nups = f->c.nupvalues;
break;
}
+ case 't': {
+ ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
+ break;
+ }
case 'n': {
ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;
if (ar->namewhat == NULL) {
@@ -249,15 +228,14 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
f = clvalue(func);
L->top--; /* pop function */
}
- else if (ar->i_ci != NULL) { /* no tail call? */
+ else {
ci = ar->i_ci;
lua_assert(ttisfunction(ci->func));
f = clvalue(ci->func);
}
status = auxgetinfo(L, what, ar, f, ci);
if (strchr(what, 'f')) {
- if (f == NULL) setnilvalue(L->top);
- else setclvalue(L, L->top, f);
+ setclvalue(L, L->top, f);
incr_top(L);
}
if (strchr(what, 'L'))
@@ -379,7 +357,7 @@ static const char *getobjname (lua_State *L, CallInfo *ci, int reg,
static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
TMS tm = 0;
Instruction i;
- if ((isLua(ci) && ci->u.l.tailcalls > 0) || !isLua(ci->previous))
+ if ((ci->callstatus & CIST_TAIL) || !isLua(ci->previous))
return NULL; /* calling function is not Lua (or is unknown) */
ci = ci->previous; /* calling function */
i = ci_func(ci)->l.p->code[currentpc(ci)];
diff --git a/ldo.c b/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.71 2009/11/17 16:33:38 roberto Exp roberto $
+** $Id: ldo.c,v 2.72 2009/11/17 16:46:44 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -184,7 +184,7 @@ void luaD_shrinkstack (lua_State *L) {
}
-void luaD_callhook (lua_State *L, int event, int line) {
+void luaD_hook (lua_State *L, int event, int line) {
lua_Hook hook = L->hook;
if (hook && L->allowhook) {
CallInfo *ci = L->ci;
@@ -193,10 +193,7 @@ void luaD_callhook (lua_State *L, int event, int line) {
lua_Debug ar;
ar.event = event;
ar.currentline = line;
- if (event == LUA_HOOKTAILRET)
- ar.i_ci = NULL; /* tail call; no debug information about it */
- else
- ar.i_ci = ci;
+ ar.i_ci = ci;
luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
ci->top = L->top + LUA_MINSTACK;
lua_assert(ci->top <= L->stack_last);
@@ -214,6 +211,19 @@ void luaD_callhook (lua_State *L, int event, int line) {
}
+static void callhook (lua_State *L, CallInfo *ci) {
+ int hook = LUA_HOOKCALL;
+ ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
+ if (isLua(ci->previous) &&
+ GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
+ ci->callstatus |= CIST_TAIL;
+ hook = LUA_HOOKTAILCALL;
+ }
+ luaD_hook(L, hook, -1);
+ ci->u.l.savedpc--; /* correct 'pc' */
+}
+
+
static StkId adjust_varargs (lua_State *L, Proto *p, int actual) {
int i;
int nfixargs = p->numparams;
@@ -281,14 +291,10 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
ci->top = base + p->maxstacksize;
lua_assert(ci->top <= L->stack_last);
ci->u.l.savedpc = p->code; /* starting point */
- ci->u.l.tailcalls = 0;
ci->callstatus = CIST_LUA;
L->top = ci->top;
- if (L->hookmask & LUA_MASKCALL) {
- ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
- luaD_callhook(L, LUA_HOOKCALL, -1);
- ci->u.l.savedpc--; /* correct 'pc' */
- }
+ if (L->hookmask & LUA_MASKCALL)
+ callhook(L, ci);
return 0;
}
else { /* if is a C function, call it */
@@ -301,7 +307,7 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
lua_assert(ci->top <= L->stack_last);
ci->callstatus = 0;
if (L->hookmask & LUA_MASKCALL)
- luaD_callhook(L, LUA_HOOKCALL, -1);
+ luaD_hook(L, LUA_HOOKCALL, -1);
lua_unlock(L);
n = (*curr_func(L)->c.f)(L); /* do the actual call */
lua_lock(L);
@@ -311,25 +317,17 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
}
-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 (isLua(L->ci)) { /* Lua function? */
- while ((L->hookmask & LUA_MASKRET) && L->ci->u.l.tailcalls--)
- luaD_callhook(L, LUA_HOOKTAILRET, -1); /* ret. hooks for tail calls */
- }
- return restorestack(L, fr);
-}
-
-
int luaD_poscall (lua_State *L, StkId firstResult) {
StkId res;
int wanted, i;
CallInfo *ci = L->ci;
if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
- if (L->hookmask & LUA_MASKRET)
- firstResult = callrethooks(L, firstResult);
- L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for returning function */
+ if (L->hookmask & LUA_MASKRET) {
+ ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
+ luaD_hook(L, LUA_HOOKRET, -1);
+ firstResult = restorestack(L, fr);
+ }
+ L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
}
res = ci->func; /* res == final position of 1st result */
L->ci = ci = ci->previous; /* back to caller */
@@ -529,7 +527,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) {
}
lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */
lua_unlock(L);
- return 0; /* otherwise, return to 'luaD_callhook' */
+ return 0; /* return to 'luaD_hook' */
}
diff --git a/ldo.h b/ldo.h
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.h,v 2.15 2009/07/15 17:26:14 roberto Exp roberto $
+** $Id: ldo.h,v 2.16 2009/11/19 16:24:41 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -27,7 +27,7 @@
typedef void (*Pfunc) (lua_State *L, void *ud);
LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name);
-LUAI_FUNC void luaD_callhook (lua_State *L, int event, int line);
+LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults);
LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults,
int allowyield);
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 2.47 2009/10/23 19:12:19 roberto Exp roberto $
+** $Id: lstate.h,v 2.48 2009/11/18 13:13:47 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -80,7 +80,6 @@ typedef struct CallInfo {
struct { /* only for Lua functions */
StkId base; /* base for this function */
const Instruction *savedpc;
- int tailcalls; /* number of tail calls lost under this entry */
} l;
struct { /* only for C functions */
int ctx; /* context info. in case of yields */
@@ -104,6 +103,7 @@ typedef struct CallInfo {
#define CIST_YIELDED (1<<3) /* call reentered after suspension */
#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */
#define CIST_STAT (1<<5) /* call has an error status (pcall) */
+#define CIST_TAIL (1<<6) /* call was tail called */
#define curr_func(L) (clvalue(L->ci->func))
diff --git a/lua.h b/lua.h
@@ -1,5 +1,5 @@
/*
-** $Id: lua.h,v 1.249 2009/11/09 18:55:17 roberto Exp roberto $
+** $Id: lua.h,v 1.250 2009/11/09 19:10:48 roberto Exp roberto $
** Lua - A Scripting Language
** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
** See Copyright Notice at the end of this file
@@ -356,7 +356,7 @@ LUA_API void (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
#define LUA_HOOKRET 1
#define LUA_HOOKLINE 2
#define LUA_HOOKCOUNT 3
-#define LUA_HOOKTAILRET 4
+#define LUA_HOOKTAILCALL 4
/*
@@ -401,6 +401,7 @@ struct lua_Debug {
int nups; /* (u) number of upvalues */
int linedefined; /* (S) */
int lastlinedefined; /* (S) */
+ char istailcall; /* (t) */
char short_src[LUA_IDSIZE]; /* (S) */
/* private part */
struct CallInfo *i_ci; /* active function */
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.99 2009/09/30 15:38:37 roberto Exp roberto $
+** $Id: lvm.c,v 2.100 2009/10/28 12:20:07 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -62,7 +62,7 @@ static void traceexec (lua_State *L) {
lu_byte mask = L->hookmask;
if ((mask & LUA_MASKCOUNT) && L->hookcount == 0) {
resethookcount(L);
- luaD_callhook(L, LUA_HOOKCOUNT, -1);
+ luaD_hook(L, LUA_HOOKCOUNT, -1);
}
if (mask & LUA_MASKLINE) {
Proto *p = ci_func(ci)->l.p;
@@ -71,7 +71,7 @@ static void traceexec (lua_State *L) {
if (npc == 0 || /* call linehook when enter a new function, */
ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */
newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */
- luaD_callhook(L, LUA_HOOKLINE, newline);
+ luaD_hook(L, LUA_HOOKLINE, newline);
}
L->oldpc = ci->u.l.savedpc;
}
@@ -679,7 +679,7 @@ void luaV_execute (lua_State *L) {
oci->u.l.base = ofunc + (nci->u.l.base - nfunc); /* correct base */
oci->top = L->top = ofunc + (L->top - nfunc); /* correct top */
oci->u.l.savedpc = nci->u.l.savedpc;
- oci->u.l.tailcalls++; /* one more call lost */
+ oci->callstatus |= CIST_TAIL; /* function was tail called */
ci = L->ci = oci; /* remove new frame */
lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize);
break; /* restart luaV_execute over new Lua function */
