commit 82f9f3e552fe3adcf5b1e585f3c99fde4c21936a
parent c96ad1c9455b59ea3ff25660549b0e2ad222791e
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Fri, 20 Sep 1996 09:50:56 -0300
better structure to control stack interface lua-C.
beginblock-endblock keeps better control over stack
Diffstat:
M | opcode.c | | | 108 | +++++++++++++++++++++++++++++++++++++++---------------------------------------- |
1 file changed, 53 insertions(+), 55 deletions(-)
diff --git a/opcode.c b/opcode.c
@@ -3,7 +3,7 @@
** TecCGraf - PUC-Rio
*/
-char *rcs_opcode="$Id: opcode.c,v 3.72 1996/08/15 18:40:55 roberto Exp roberto $";
+char *rcs_opcode="$Id: opcode.c,v 3.73 1996/09/02 21:57:51 roberto Exp roberto $";
#include <setjmp.h>
#include <stdio.h>
@@ -50,10 +50,14 @@ static Object *top = &initial_stack;
*/
#define incr_top if (++top >= stackLimit) growstack()
-static StkId CBase = 0; /* when Lua calls C or C calls Lua, points to */
- /* the first slot after the last parameter. */
-static int CnResults = 0; /* when Lua calls C, has the number of parameters; */
- /* when C calls Lua, has the number of results. */
+struct C_Lua_Stack {
+ StkId base; /* when Lua calls C or C calls Lua, points to */
+ /* the first slot after the last parameter. */
+ int num; /* when Lua calls C, has the number of parameters; */
+ /* when C calls Lua, has the number of results. */
+};
+
+static struct C_Lua_Stack CLS_current = {0, 0};
static jmp_buf *errorJmp = NULL; /* current error recover point */
@@ -178,7 +182,7 @@ static void adjust_top (StkId newtop)
top = nt; /* top could be bigger than newtop */
}
-#define adjustC(nParams) adjust_top(CBase+nParams)
+#define adjustC(nParams) adjust_top(CLS_current.base+nParams)
/*
@@ -198,14 +202,12 @@ static void open_stack (int nelems)
*/
static void lineHook (int line)
{
- StkId oldBase = CBase;
- int oldCnResults = CnResults;
- StkId old_top = CBase = top-stack;
- CnResults = 0;
+ struct C_Lua_Stack oldCLS = CLS_current;
+ StkId old_top = CLS_current.base = top-stack;
+ CLS_current.num = 0;
(*lua_linehook)(line);
top = stack+old_top;
- CnResults = oldCnResults;
- CBase = oldBase;
+ CLS_current = oldCLS;
}
@@ -215,10 +217,9 @@ static void lineHook (int line)
*/
static void callHook (StkId base, lua_Type type, int isreturn)
{
- StkId oldBase = CBase;
- int oldCnResults = CnResults;
- StkId old_top = CBase = top-stack;
- CnResults = 0;
+ struct C_Lua_Stack oldCLS = CLS_current;
+ StkId old_top = CLS_current.base = top-stack;
+ CLS_current.num = 0;
if (isreturn)
(*lua_callhook)(LUA_NOOBJECT, "(return)", 0);
else
@@ -230,32 +231,29 @@ static void callHook (StkId base, lua_Type type, int isreturn)
(*lua_callhook)(Ref(f), "(C)", -1);
}
top = stack+old_top;
- CnResults = oldCnResults;
- CBase = oldBase;
+ CLS_current = oldCLS;
}
/*
-** Call a C function. CBase will point to the top of the stack,
-** and CnResults is the number of parameters. Returns an index
+** Call a C function. CLS_current.base will point to the top of the stack,
+** and CLS_current.num is the number of parameters. Returns an index
** to the first result from C.
*/
static StkId callC (lua_CFunction func, StkId base)
{
- StkId oldBase = CBase;
- int oldCnResults = CnResults;
+ struct C_Lua_Stack oldCLS = CLS_current;
StkId firstResult;
- CnResults = (top-stack) - base;
+ CLS_current.num = (top-stack) - base;
/* incorporate parameters on the stack */
- CBase = base+CnResults; /* == top-stack */
+ CLS_current.base = base+CLS_current.num; /* == top-stack */
if (lua_callhook)
callHook(base, LUA_T_CMARK, 0);
(*func)();
if (lua_callhook) /* func may have changed lua_callhook */
callHook(base, LUA_T_CMARK, 1);
- firstResult = CBase;
- CBase = oldBase;
- CnResults = oldCnResults;
+ firstResult = CLS_current.base;
+ CLS_current = oldCLS;
return firstResult;
}
@@ -450,27 +448,27 @@ int lua_setlocal (lua_Function func, int local_number)
/*
-** Execute a protected call. Assumes that function is at CBase and
-** parameters are on top of it. Leave nResults on the stack.
+** Execute a protected call. Assumes that function is at CLS_current.base and
+** parameters are on top of it. Leave nResults on the stack.
*/
static int do_protectedrun (int nResults)
{
jmp_buf myErrorJmp;
int status;
- StkId oldCBase = CBase;
+ struct C_Lua_Stack oldCLS = CLS_current;
jmp_buf *oldErr = errorJmp;
errorJmp = &myErrorJmp;
if (setjmp(myErrorJmp) == 0)
{
- do_call(CBase+1, nResults);
- CnResults = (top-stack) - CBase; /* number of results */
- CBase += CnResults; /* incorporate results on the stack */
+ do_call(CLS_current.base+1, nResults);
+ CLS_current.num = (top-stack) - CLS_current.base; /* number of results */
+ CLS_current.base += CLS_current.num; /* incorporate results on the stack */
status = 0;
}
else
- { /* an error occurred: restore CBase and top */
- CBase = oldCBase;
- top = stack+CBase;
+ { /* an error occurred: restore CLS_current and top */
+ CLS_current = oldCLS;
+ top = stack+CLS_current.base;
status = 1;
}
errorJmp = oldErr;
@@ -481,8 +479,8 @@ int luaI_dorun (TFunc *tf)
{
int status;
adjustC(1); /* one slot for the pseudo-function */
- stack[CBase].tag = LUA_T_FUNCTION;
- stack[CBase].value.tf = tf;
+ stack[CLS_current.base].tag = LUA_T_FUNCTION;
+ stack[CLS_current.base].value.tf = tf;
status = do_protectedrun(0);
adjustC(0);
return status;
@@ -522,8 +520,8 @@ int lua_callfunction (lua_Object function)
return 1;
else
{
- open_stack((top-stack)-CBase);
- stack[CBase] = *Address(function);
+ open_stack((top-stack)-CLS_current.base);
+ stack[CLS_current.base] = *Address(function);
return do_protectedrun (MULT_RET);
}
}
@@ -532,8 +530,8 @@ int lua_callfunction (lua_Object function)
int lua_call (char *funcname)
{
Word n = luaI_findsymbolbyname(funcname);
- open_stack((top-stack)-CBase);
- stack[CBase] = s_object(n);
+ open_stack((top-stack)-CLS_current.base);
+ stack[CLS_current.base] = s_object(n);
return do_protectedrun(MULT_RET);
}
@@ -584,8 +582,8 @@ int lua_dostring (char *str)
lua_Object lua_setfallback (char *name, lua_CFunction fallback)
{
adjustC(1); /* one slot for the pseudo-function */
- stack[CBase].tag = LUA_T_CFUNCTION;
- stack[CBase].value.f = luaI_setfallback;
+ stack[CLS_current.base].tag = LUA_T_CFUNCTION;
+ stack[CLS_current.base].value.f = luaI_setfallback;
lua_pushstring(name);
lua_pushcfunction(fallback);
if (do_protectedrun(1) == 0)
@@ -603,7 +601,7 @@ lua_Object lua_getsubscript (void)
{
adjustC(2);
pushsubscript();
- CBase++; /* incorporate object in the stack */
+ CLS_current.base++; /* incorporate object in the stack */
return (Ref(top-1));
}
@@ -611,7 +609,7 @@ lua_Object lua_getsubscript (void)
#define MAX_C_BLOCKS 10
static int numCblocks = 0;
-static StkId Cblocks[MAX_C_BLOCKS];
+static struct C_Lua_Stack Cblocks[MAX_C_BLOCKS];
/*
** API: starts a new block
@@ -620,7 +618,7 @@ void lua_beginblock (void)
{
if (numCblocks >= MAX_C_BLOCKS)
lua_error("`lua_beginblock': too many nested blocks");
- Cblocks[numCblocks] = CBase;
+ Cblocks[numCblocks] = CLS_current;
numCblocks++;
}
@@ -630,7 +628,7 @@ void lua_beginblock (void)
void lua_endblock (void)
{
--numCblocks;
- CBase = Cblocks[numCblocks];
+ CLS_current = Cblocks[numCblocks];
adjustC(0);
}
@@ -652,7 +650,7 @@ lua_Object lua_createtable (void)
avalue(top) = lua_createarray(0);
tag(top) = LUA_T_ARRAY;
incr_top;
- CBase++; /* incorporate object in the stack */
+ CLS_current.base++; /* incorporate object in the stack */
return Ref(top-1);
}
@@ -662,10 +660,10 @@ lua_Object lua_createtable (void)
*/
lua_Object lua_getparam (int number)
{
- if (number <= 0 || number > CnResults) return LUA_NOOBJECT;
- /* Ref(stack+(CBase-CnResults+number-1)) ==
- stack+(CBase-CnResults+number-1)-stack+1 == */
- return CBase-CnResults+number;
+ if (number <= 0 || number > CLS_current.num) return LUA_NOOBJECT;
+ /* Ref(stack+(CLS_current.base-CLS_current.num+number-1)) ==
+ stack+(CLS_current.base-CLS_current.num+number-1)-stack+1 == */
+ return CLS_current.base-CLS_current.num+number;
}
int lua_isnumber (lua_Object object)
@@ -735,7 +733,7 @@ lua_Object lua_getref (int ref)
return LUA_NOOBJECT;
adjustC(0);
luaI_pushobject(o);
- CBase++; /* incorporate object in the stack */
+ CLS_current.base++; /* incorporate object in the stack */
return Ref(top-1);
}
@@ -764,7 +762,7 @@ lua_Object lua_getglobal (char *name)
{
adjustC(0);
getglobal(luaI_findsymbolbyname(name));
- CBase++; /* incorporate object in the stack */
+ CLS_current.base++; /* incorporate object in the stack */
return Ref(top-1);
}