1 files changed, 385 insertions, 0 deletions
diff --git a/src/lua/ldo.c b/src/lua/ldo.c
new file mode 100644
index 00000000..5f23bfd9
--- /dev/null
+++ b/src/lua/ldo.c
@@ -0,0 +1,385 @@
+/*
+** $Id: ldo.c,v 1.7 2004/06/04 13:42:10 neil Exp $
+** Stack and Call structure of Lua
+** See Copyright Notice in lua.h
+*/
+
+
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lparser.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "ltm.h"
+#include "lundump.h"
+#include "lvm.h"
+#include "lzio.h"
+
+
+/* space to handle stack overflow errors */
+#define EXTRA_STACK	(2*LUA_MINSTACK)
+
+
+void luaD_init (lua_State *L, int stacksize) {
+  L->stack = luaM_newvector(L, stacksize+EXTRA_STACK, TObject);
+  L->nblocks += stacksize*sizeof(TObject);
+  L->stack_last = L->stack+(stacksize-1);
+  L->stacksize = stacksize;
+  L->Cbase = L->top = L->stack;
+}
+
+
+void luaD_checkstack (lua_State *L, int n) {
+  if (L->stack_last - L->top <= n) {  /* stack overflow? */
+    if (L->stack_last-L->stack > (L->stacksize-1)) {
+      /* overflow while handling overflow */
+      luaD_breakrun(L, LUA_ERRERR);  /* break run without error message */
+    }
+    else {
+      L->stack_last += EXTRA_STACK;  /* to be used by error message */
+      lua_error(L, "stack overflow");
+    }
+  }
+}
+
+
+static void restore_stack_limit (lua_State *L) {
+  if (L->top - L->stack < L->stacksize - 1)
+    L->stack_last = L->stack + (L->stacksize-1);
+}
+
+
+/*
+** Adjust stack. Set top to base+extra, pushing NILs if needed.
+** (we cannot add base+extra unless we are sure it fits in the stack;
+**  otherwise the result of such operation on pointers is undefined)
+*/
+void luaD_adjusttop (lua_State *L, StkId base, int extra) {
+  int diff = extra-(L->top-base);
+  if (diff <= 0)
+    L->top = base+extra;
+  else {
+    luaD_checkstack(L, diff);
+    while (diff--)
+      ttype(L->top++) = LUA_TNIL;
+  }
+}
+
+
+/*
+** Open a hole inside the stack at `pos'
+*/
+static void luaD_openstack (lua_State *L, StkId pos) {
+  int i = L->top-pos; 
+  while (i--) pos[i+1] = pos[i];
+  incr_top;
+}
+
+
+static void dohook (lua_State *L, lua_Debug *ar, lua_Hook hook) {
+  StkId old_Cbase = L->Cbase;
+  StkId old_top = L->Cbase = L->top;
+  luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
+  L->allowhooks = 0;  /* cannot call hooks inside a hook */
+  (*hook)(L, ar);
+  LUA_ASSERT(L->allowhooks == 0, "invalid allow");
+  L->allowhooks = 1;
+  L->top = old_top;
+  L->Cbase = old_Cbase;
+}
+
+
+void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook) {
+  if (L->allowhooks) {
+    lua_Debug ar;
+    ar._func = func;
+    ar.event = "line";
+    ar.currentline = line;
+    dohook(L, &ar, linehook);
+  }
+}
+
+
+static void luaD_callHook (lua_State *L, StkId func, lua_Hook callhook,
+                    const char *event) {
+  if (L->allowhooks) {
+    lua_Debug ar;
+    ar._func = func;
+    ar.event = event;
+    infovalue(func)->pc = NULL;  /* function is not active */
+    dohook(L, &ar, callhook);
+  }
+}
+
+
+static StkId callCclosure (lua_State *L, const struct Closure *cl, StkId base) {
+  int nup = cl->nupvalues;  /* number of upvalues */
+  StkId old_Cbase = L->Cbase;
+  int n;
+  L->Cbase = base;       /* new base for C function */
+  luaD_checkstack(L, nup+LUA_MINSTACK);  /* ensure minimum stack size */
+  for (n=0; n<nup; n++)  /* copy upvalues as extra arguments */
+    *(L->top++) = cl->upvalue[n];
+  n = (*cl->f.c)(L);  /* do the actual call */
+  L->Cbase = old_Cbase;  /* restore old C base */
+  return L->top - n;  /* return index of first result */
+}
+
+
+void luaD_callTM (lua_State *L, Closure *f, int nParams, int nResults) {
+  StkId base = L->top - nParams;
+  luaD_openstack(L, base);
+  clvalue(base) = f;
+  ttype(base) = LUA_TFUNCTION;
+  luaD_call(L, base, nResults);
+}
+
+
+/*
+** Call a function (C or Lua). The function to be called is at *func.
+** The arguments are on the stack, right after the function.
+** When returns, the results are on the stack, starting at the original
+** function position.
+** The number of results is nResults, unless nResults=LUA_MULTRET.
+*/ 
+void luaD_call (lua_State *L, StkId func, int nResults) {
+  lua_Hook callhook;
+  StkId firstResult;
+  CallInfo ci;
+  Closure *cl;
+  if (ttype(func) != LUA_TFUNCTION) {
+    /* `func' is not a function; check the `function' tag method */
+    Closure *tm = luaT_gettmbyObj(L, func, TM_FUNCTION);
+    if (tm == NULL)
+      luaG_typeerror(L, func, "call");
+    luaD_openstack(L, func);
+    clvalue(func) = tm;  /* tag method is the new function to be called */
+    ttype(func) = LUA_TFUNCTION;
+  }
+  cl = clvalue(func);
+  ci.func = cl;
+  infovalue(func) = &ci;
+  ttype(func) = LUA_TMARK;
+  callhook = L->callhook;
+  if (callhook)
+    luaD_callHook(L, func, callhook, "call");
+  firstResult = (cl->isC ? callCclosure(L, cl, func+1) :
+                           luaV_execute(L, cl, func+1));
+  if (callhook)  /* same hook that was active at entry */
+    luaD_callHook(L, func, callhook, "return");
+  LUA_ASSERT(ttype(func) == LUA_TMARK, "invalid tag");
+  /* move results to `func' (to erase parameters and function) */
+  if (nResults == LUA_MULTRET) {
+    while (firstResult < L->top)  /* copy all results */
+      *func++ = *firstResult++;
+    L->top = func;
+  }
+  else {  /* copy at most `nResults' */
+    for (; nResults > 0 && firstResult < L->top; nResults--)
+      *func++ = *firstResult++;
+    L->top = func;
+    for (; nResults > 0; nResults--) {  /* if there are not enough results */
+      ttype(L->top) = LUA_TNIL;  /* adjust the stack */
+      incr_top;  /* must check stack space */
+    }
+  }
+  luaC_checkGC(L);
+}
+
+
+/*
+** Execute a protected call.
+*/
+struct CallS {  /* data to `f_call' */
+  StkId func;
+  int nresults;
+};
+
+static void f_call (lua_State *L, void *ud) {
+  struct CallS *c = (struct CallS *)ud;
+  luaD_call(L, c->func, c->nresults);
+}
+
+
+LUA_API int lua_call (lua_State *L, int nargs, int nresults) {
+  StkId func = L->top - (nargs+1);  /* function to be called */
+  struct CallS c;
+  int status;
+  c.func = func; c.nresults = nresults;
+  status = luaD_runprotected(L, f_call, &c);
+  if (status != 0)  /* an error occurred? */
+    L->top = func;  /* remove parameters from the stack */
+  return status;
+}
+
+
+/*
+** Execute a protected parser.
+*/
+struct ParserS {  /* data to `f_parser' */
+  ZIO *z;
+  int bin;
+};
+
+static void f_parser (lua_State *L, void *ud) {
+  struct ParserS *p = (struct ParserS *)ud;
+  Proto *tf = p->bin ? luaU_undump(L, p->z) : luaY_parser(L, p->z);
+  luaV_Lclosure(L, tf, 0);
+}
+
+
+static int protectedparser (lua_State *L, ZIO *z, int bin) {
+  struct ParserS p;
+  unsigned long old_blocks;
+  int status;
+  p.z = z; p.bin = bin;
+  luaC_checkGC(L);
+  old_blocks = L->nblocks;
+  status = luaD_runprotected(L, f_parser, &p);
+  if (status == 0) {
+    /* add new memory to threshold (as it probably will stay) */
+    L->GCthreshold += (L->nblocks - old_blocks);
+  }
+  else if (status == LUA_ERRRUN)  /* an error occurred: correct error code */
+    status = LUA_ERRSYNTAX;
+  return status;
+}
+
+
+static int parse_file (lua_State *L, const char *filename) {
+  ZIO z;
+  int status;
+  int bin;  /* flag for file mode */
+  int c;    /* look ahead char */
+  FILE *f = (filename == NULL) ? stdin : fopen(filename, "r");
+  if (f == NULL) return LUA_ERRFILE;  /* unable to open file */
+  c = fgetc(f);
+  ungetc(c, f);
+  bin = (c == ID_CHUNK);
+  if (bin && f != stdin) {
+    f = freopen(filename, "rb", f);  /* set binary mode */
+    if (f == NULL) return LUA_ERRFILE;  /* unable to reopen file */
+  }
+  lua_pushstring(L, "@");
+  lua_pushstring(L, (filename == NULL) ? "(stdin)" : filename);
+  lua_concat(L, 2);
+  filename = lua_tostring(L, -1);  /* filename = '@'..filename */
+  lua_pop(L, 1);  /* OK: there is no GC during parser */
+  luaZ_Fopen(&z, f, filename);
+  status = protectedparser(L, &z, bin);
+  if (f != stdin)
+    fclose(f);
+  return status;
+}
+
+
+LUA_API int lua_dofile (lua_State *L, const char *filename) {
+  int status = parse_file(L, filename);
+  if (status == 0)  /* parse OK? */
+    status = lua_call(L, 0, LUA_MULTRET);  /* call main */
+  return status;
+}
+
+
+static int parse_buffer (lua_State *L, const char *buff, size_t size,
+                         const char *name) {
+  ZIO z;
+  if (!name) name = "?";
+  luaZ_mopen(&z, buff, size, name);
+  return protectedparser(L, &z, buff[0]==ID_CHUNK);
+}
+
+
+LUA_API int lua_dobuffer (lua_State *L, const char *buff, size_t size, const char *name) {
+  int status = parse_buffer(L, buff, size, name);
+  if (status == 0)  /* parse OK? */
+    status = lua_call(L, 0, LUA_MULTRET);  /* call main */
+  return status;
+}
+
+
+LUA_API int lua_dostring (lua_State *L, const char *str) {
+  return lua_dobuffer(L, str, strlen(str), str);
+}
+
+
+/*
+** {======================================================
+** Error-recover functions (based on long jumps)
+** =======================================================
+*/
+
+/* chain list of long jump buffers */
+struct lua_longjmp {
+  jmp_buf b;
+  struct lua_longjmp *previous;
+  volatile int status;  /* error code */
+};
+
+
+static void message (lua_State *L, const char *s) {
+  const TObject *em = luaH_getglobal(L, LUA_ERRORMESSAGE);
+  if (ttype(em) == LUA_TFUNCTION) {
+    *L->top = *em;
+    incr_top;
+    lua_pushstring(L, s);
+    luaD_call(L, L->top-2, 0);
+  }
+}
+
+
+/*
+** Reports an error, and jumps up to the available recovery label
+*/
+LUA_API void lua_error (lua_State *L, const char *s) {
+  if (s) message(L, s);
+  luaD_breakrun(L, LUA_ERRRUN);
+}
+
+
+void luaD_breakrun (lua_State *L, int errcode) {
+  if (L->errorJmp) {
+    L->errorJmp->status = errcode;
+    longjmp(L->errorJmp->b, 1);
+  }
+  else {
+    if (errcode != LUA_ERRMEM)
+      message(L, "unable to recover; exiting\n");
+    exit(EXIT_FAILURE);
+  }
+}
+
+
+int luaD_runprotected (lua_State *L, void (*f)(lua_State *, void *), void *ud) {
+  StkId oldCbase = L->Cbase;
+  StkId oldtop = L->top;
+  struct lua_longjmp lj;
+  int allowhooks = L->allowhooks;
+  lj.status = 0;
+  lj.previous = L->errorJmp;  /* chain new error handler */
+  L->errorJmp = &lj;
+  if (setjmp(lj.b) == 0)
+    (*f)(L, ud);
+  else {  /* an error occurred: restore the state */
+    L->allowhooks = allowhooks;
+    L->Cbase = oldCbase;
+    L->top = oldtop;
+    restore_stack_limit(L);
+  }
+  L->errorJmp = lj.previous;  /* restore old error handler */
+  return lj.status;
+}
+
+/* }====================================================== */
+