diff options
| -rw-r--r-- | lcode.c | 14 | ||||
| -rw-r--r-- | ldo.c | 16 | ||||
| -rw-r--r-- | lparser.h | 5 | ||||
| -rw-r--r-- | manual/manual.of | 13 |
4 files changed, 30 insertions, 18 deletions
@@ -753,7 +753,7 @@ void luaK_setoneret (FuncState *fs, expdesc *e) { /* -** Ensure that expression 'e' is not a variable (nor a constant). +** Ensure that expression 'e' is not a variable (nor a <const>). ** (Expression still may have jump lists.) */ void luaK_dischargevars (FuncState *fs, expdesc *e) { @@ -805,8 +805,8 @@ void luaK_dischargevars (FuncState *fs, expdesc *e) { /* -** Ensures expression value is in register 'reg' (and therefore -** 'e' will become a non-relocatable expression). +** Ensure expression value is in register 'reg', making 'e' a +** non-relocatable expression. ** (Expression still may have jump lists.) */ static void discharge2reg (FuncState *fs, expdesc *e, int reg) { @@ -860,7 +860,8 @@ static void discharge2reg (FuncState *fs, expdesc *e, int reg) { /* -** Ensures expression value is in any register. +** Ensure expression value is in a register, making 'e' a +** non-relocatable expression. ** (Expression still may have jump lists.) */ static void discharge2anyreg (FuncState *fs, expdesc *e) { @@ -946,8 +947,11 @@ int luaK_exp2anyreg (FuncState *fs, expdesc *e) { exp2reg(fs, e, e->u.info); /* put final result in it */ return e->u.info; } + /* else expression has jumps and cannot change its register + to hold the jump values, because it is a local variable. + Go through to the default case. */ } - luaK_exp2nextreg(fs, e); /* otherwise, use next available register */ + luaK_exp2nextreg(fs, e); /* default: use next available register */ return e->u.info; } @@ -534,11 +534,11 @@ CallInfo *luaD_precall (lua_State *L, StkId func, int nresults) { /* -** Call a function (C or Lua). 'inc' can be 1 (increment number -** of recursive invocations in the C stack) or nyci (the same plus -** increment number of non-yieldable calls). +** Call a function (C or Lua) through C. 'inc' can be 1 (increment +** number of recursive invocations in the C stack) or nyci (the same +** plus increment number of non-yieldable calls). */ -static void docall (lua_State *L, StkId func, int nResults, int inc) { +static void ccall (lua_State *L, StkId func, int nResults, int inc) { CallInfo *ci; L->nCcalls += inc; if (unlikely(getCcalls(L) >= LUAI_MAXCCALLS)) @@ -552,10 +552,10 @@ static void docall (lua_State *L, StkId func, int nResults, int inc) { /* -** External interface for 'docall' +** External interface for 'ccall' */ void luaD_call (lua_State *L, StkId func, int nResults) { - return docall(L, func, nResults, 1); + ccall(L, func, nResults, 1); } @@ -563,7 +563,7 @@ void luaD_call (lua_State *L, StkId func, int nResults) { ** Similar to 'luaD_call', but does not allow yields during the call. */ void luaD_callnoyield (lua_State *L, StkId func, int nResults) { - return docall(L, func, nResults, nyci); + ccall(L, func, nResults, nyci); } @@ -678,7 +678,7 @@ static void resume (lua_State *L, void *ud) { StkId firstArg = L->top - n; /* first argument */ CallInfo *ci = L->ci; if (L->status == LUA_OK) /* starting a coroutine? */ - docall(L, firstArg - 1, LUA_MULTRET, 1); /* just call its body */ + ccall(L, firstArg - 1, LUA_MULTRET, 1); /* just call its body */ else { /* resuming from previous yield */ lua_assert(L->status == LUA_YIELD); L->status = LUA_OK; /* mark that it is running (again) */ @@ -23,7 +23,7 @@ /* kinds of variables/expressions */ typedef enum { - VVOID, /* when 'expdesc' describes the last expression a list, + VVOID, /* when 'expdesc' describes the last expression of a list, this kind means an empty list (so, no expression) */ VNIL, /* constant nil */ VTRUE, /* constant true */ @@ -38,7 +38,8 @@ typedef enum { VLOCAL, /* local variable; var.sidx = stack index (local register); var.vidx = relative index in 'actvar.arr' */ VUPVAL, /* upvalue variable; info = index of upvalue in 'upvalues' */ - VCONST, /* compile-time constant; info = absolute index in 'actvar.arr' */ + VCONST, /* compile-time <const> variable; + info = absolute index in 'actvar.arr' */ VINDEXED, /* indexed variable; ind.t = table register; ind.idx = key's R index */ diff --git a/manual/manual.of b/manual/manual.of index 86631bbc..606771f4 100644 --- a/manual/manual.of +++ b/manual/manual.of @@ -2516,7 +2516,8 @@ Lua's garbage collection can free or move internal memory and then invalidate pointers to internal strings. To allow a safe use of these pointers, The API guarantees that any pointer to a string in a stack index -is valid while the value at that index is neither modified nor popped. +is valid while the string value at that index is not removed from the stack. +(It can be moved to another index, though.) When the index is a pseudo-index (referring to an upvalue), the pointer is valid while the corresponding call is active and the corresponding upvalue is not modified. @@ -3744,10 +3745,13 @@ except that it allows the called function to yield @see{continuations}. } @APIEntry{void lua_pop (lua_State *L, int n);| -@apii{n,0,-} +@apii{n,0,e} Pops @id{n} elements from the stack. +This function can run arbitrary code when removing an index +marked as to-be-closed from the stack. + } @APIEntry{void lua_pushboolean (lua_State *L, int b);| @@ -4227,7 +4231,7 @@ for the @Q{newindex} event @see{metatable}. } @APIEntry{void lua_settop (lua_State *L, int index);| -@apii{?,?,-} +@apii{?,?,e} Accepts any index, @N{or 0}, and sets the stack top to this index. @@ -4235,6 +4239,9 @@ If the new top is greater than the old one, then the new elements are filled with @nil. If @id{index} @N{is 0}, then all stack elements are removed. +This function can run arbitrary code when removing an index +marked as to-be-closed from the stack. + } @APIEntry{void lua_setwarnf (lua_State *L, lua_WarnFunction f, void *ud);| |