diff options
Diffstat (limited to 'source/luametatex/source/luacore/lua54/src/lapi.h')
-rw-r--r-- | source/luametatex/source/luacore/lua54/src/lapi.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/source/luametatex/source/luacore/lua54/src/lapi.h b/source/luametatex/source/luacore/lua54/src/lapi.h new file mode 100644 index 000000000..9e99cc448 --- /dev/null +++ b/source/luametatex/source/luacore/lua54/src/lapi.h @@ -0,0 +1,49 @@ +/* +** $Id: lapi.h $ +** Auxiliary functions from Lua API +** See Copyright Notice in lua.h +*/ + +#ifndef lapi_h +#define lapi_h + + +#include "llimits.h" +#include "lstate.h" + + +/* Increments 'L->top', checking for stack overflows */ +#define api_incr_top(L) {L->top++; api_check(L, L->top <= L->ci->top, \ + "stack overflow");} + + +/* +** If a call returns too many multiple returns, the callee may not have +** stack space to accommodate all results. In this case, this macro +** increases its stack space ('L->ci->top'). +*/ +#define adjustresults(L,nres) \ + { if ((nres) <= LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; } + + +/* Ensure the stack has at least 'n' elements */ +#define api_checknelems(L,n) api_check(L, (n) < (L->top - L->ci->func), \ + "not enough elements in the stack") + + +/* +** To reduce the overhead of returning from C functions, the presence of +** to-be-closed variables in these functions is coded in the CallInfo's +** field 'nresults', in a way that functions with no to-be-closed variables +** with zero, one, or "all" wanted results have no overhead. Functions +** with other number of wanted results, as well as functions with +** variables to be closed, have an extra check. +*/ + +#define hastocloseCfunc(n) ((n) < LUA_MULTRET) + +/* Map [-1, inf) (range of 'nresults') into (-inf, -2] */ +#define codeNresults(n) (-(n) - 3) +#define decodeNresults(n) (-(n) - 3) + +#endif |