oldest known commit

1 files changed, 351 insertions, 0 deletions

diff --git a/table.c b/table.c
new file mode 100644
index 00000000..3bae7ebd
--- /dev/null
+++ b/table.c
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+/*
+** table.c
+** Module to control static tables
+** TeCGraf - PUC-Rio
+** 11 May 93
+*/
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "opcode.h"
+#include "hash.h"
+#include "inout.h"
+#include "table.h"
+#include "lua.h"
+
+#define streq(s1,s2)    (strcmp(s1,s2)==0)
+
+#ifndef MAXSYMBOL
+#define MAXSYMBOL       512
+#endif
+static Symbol           tablebuffer[MAXSYMBOL] = {
+                                    {"type",{T_CFUNCTION,{lua_type}}},
+                                    {"tonumber",{T_CFUNCTION,{lua_obj2number}}},
+                                    {"next",{T_CFUNCTION,{lua_next}}},
+                                    {"nextvar",{T_CFUNCTION,{lua_nextvar}}},
+                                    {"print",{T_CFUNCTION,{lua_print}}}
+                                                 };
+Symbol                 *lua_table=tablebuffer;
+Word                    lua_ntable=5;
+
+#ifndef MAXCONSTANT
+#define MAXCONSTANT     256
+#endif
+static char            *constantbuffer[MAXCONSTANT] = {"mark","nil","number",
+                                                       "string","table",
+                                                       "function","cfunction"
+                                                      };
+char                  **lua_constant = constantbuffer;
+Word                    lua_nconstant=T_CFUNCTION+1;
+
+#ifndef MAXSTRING
+#define MAXSTRING       512
+#endif
+static char            *stringbuffer[MAXSTRING];
+char                  **lua_string = stringbuffer;
+Word                    lua_nstring=0;
+
+#ifndef MAXARRAY
+#define MAXARRAY        512
+#endif
+static Hash             *arraybuffer[MAXARRAY];
+Hash                  **lua_array = arraybuffer;
+Word                    lua_narray=0;
+
+#define MAXFILE         20
+char                   *lua_file[MAXFILE];
+int                     lua_nfile;
+
+
+/*
+** Given a name, search it at symbol table and return its index. If not
+** found, allocate at end of table, checking oveflow and return its index.
+** On error, return -1.
+*/
+int lua_findsymbol (char *s)
+{
+ int i;
+ for (i=0; i<lua_ntable; i++)
+  if (streq(s,s_name(i)))
+   return i;
+ if (lua_ntable >= MAXSYMBOL-1)
+ {
+  lua_error ("symbol table overflow");
+  return -1;
+ }
+ s_name(lua_ntable) = strdup(s);
+ if (s_name(lua_ntable) == NULL)
+ {
+  lua_error ("not enough memory");
+  return -1;
+ }
+ s_tag(lua_ntable++) = T_NIL;
+ 
+ return (lua_ntable-1);
+}
+
+/*
+** Given a constant string, eliminate its delimeters (" or '), search it at 
+** constant table and return its index. If not found, allocate at end of 
+** the table, checking oveflow and return its index.
+**
+** For each allocation, the function allocate a extra char to be used to
+** mark used string (it's necessary to deal with constant and string 
+** uniformily). The function store at the table the second position allocated,
+** that represents the beginning of the real string. On error, return -1.
+** 
+*/
+int lua_findenclosedconstant (char *s)
+{
+ int i, j, l=strlen(s);
+ char *c = calloc (l, sizeof(char));    /* make a copy */
+ 
+ c++;           /* create mark space */
+
+ /* introduce scape characters */ 
+ for (i=1,j=0; i<l-1; i++)
+ {
+  if (s[i] == '\\')
+  {
+   switch (s[++i])
+   {
+    case 'n': c[j++] = '\n'; break;
+    case 't': c[j++] = '\t'; break;
+    case 'r': c[j++] = '\r'; break;
+    default : c[j++] = '\\'; c[j++] = c[i]; break;
+   }
+  }
+  else
+   c[j++] = s[i];
+ }
+ c[j++] = 0;
+ 
+ for (i=0; i<lua_nconstant; i++)
+  if (streq(c,lua_constant[i]))
+  {
+   free (c-1);
+   return i;
+  }
+ if (lua_nconstant >= MAXCONSTANT-1)
+ {
+  lua_error ("lua: constant string table overflow"); 
+  return -1;
+ }
+ lua_constant[lua_nconstant++] = c;
+ return (lua_nconstant-1);
+}
+
+/*
+** Given a constant string, search it at constant table and return its index.
+** If not found, allocate at end of the table, checking oveflow and return 
+** its index.
+**
+** For each allocation, the function allocate a extra char to be used to
+** mark used string (it's necessary to deal with constant and string 
+** uniformily). The function store at the table the second position allocated,
+** that represents the beginning of the real string. On error, return -1.
+** 
+*/
+int lua_findconstant (char *s)
+{
+ int i;
+ for (i=0; i<lua_nconstant; i++)
+  if (streq(s,lua_constant[i]))
+   return i;
+ if (lua_nconstant >= MAXCONSTANT-1)
+ {
+  lua_error ("lua: constant string table overflow"); 
+  return -1;
+ }
+ {
+  char *c = calloc(strlen(s)+2,sizeof(char));
+  c++;          /* create mark space */
+  lua_constant[lua_nconstant++] = strcpy(c,s);
+ }
+ return (lua_nconstant-1);
+}
+
+
+/*
+** Mark an object if it is a string or a unmarked array.
+*/
+void lua_markobject (Object *o)
+{
+ if (tag(o) == T_STRING)
+  lua_markstring (svalue(o)) = 1;
+ else if (tag(o) == T_ARRAY && markarray(avalue(o)) == 0)
+   lua_hashmark (avalue(o));
+}
+
+/*
+** Mark all strings and arrays used by any object stored at symbol table.
+*/
+static void lua_marktable (void)
+{
+ int i;
+ for (i=0; i<lua_ntable; i++)
+  lua_markobject (&s_object(i));
+} 
+
+/*
+** Simulate a garbage colection. When string table or array table overflows,
+** this function check if all allocated strings and arrays are in use. If
+** there are unused ones, pack (compress) the tables.
+*/
+static void lua_pack (void)
+{
+ lua_markstack ();
+ lua_marktable ();
+ 
+ { /* pack string */
+  int i, j;
+  for (i=j=0; i<lua_nstring; i++)
+   if (lua_markstring(lua_string[i]) == 1)
+   {
+    lua_string[j++] = lua_string[i];
+    lua_markstring(lua_string[i]) = 0;
+   }
+   else
+   {
+    free (lua_string[i]-1);
+   }
+  lua_nstring = j;
+ }
+
+ { /* pack array */
+  int i, j;
+  for (i=j=0; i<lua_narray; i++)
+   if (markarray(lua_array[i]) == 1)
+   {
+    lua_array[j++] = lua_array[i];
+    markarray(lua_array[i]) = 0;
+   }
+   else
+   {
+    lua_hashdelete (lua_array[i]);
+   }
+  lua_narray = j;
+ }
+}
+
+/*
+** Allocate a new string at string table. The given string is already 
+** allocated with mark space and the function puts it at the end of the
+** table, checking overflow, and returns its own pointer, or NULL on error.
+*/
+char *lua_createstring (char *s)
+{
+ if (s == NULL) return NULL;
+ 
+ if (lua_nstring >= MAXSTRING-1)
+ {
+  lua_pack ();
+  if (lua_nstring >= MAXSTRING-1)
+  {
+   lua_error ("string table overflow");
+   return NULL;
+  }
+ } 
+ lua_string[lua_nstring++] = s;
+ return s;
+}
+
+/*
+** Allocate a new array, already created, at array table. The function puts 
+** it at the end of the table, checking overflow, and returns its own pointer,
+** or NULL on error.
+*/
+void *lua_createarray (void *a)
+{
+ if (a == NULL) return NULL;
+ 
+ if (lua_narray >= MAXARRAY-1)
+ {
+  lua_pack ();
+  if (lua_narray >= MAXARRAY-1)
+  {
+   lua_error ("indexed table overflow");
+   return NULL;
+  }
+ } 
+ lua_array[lua_narray++] = a;
+ return a;
+}
+
+
+/*
+** Add a file name at file table, checking overflow. This function also set
+** the external variable "lua_filename" with the function filename set.
+** Return 0 on success or 1 on error.
+*/
+int lua_addfile (char *fn)
+{
+ if (lua_nfile >= MAXFILE-1)
+ {
+  lua_error ("too many files");
+  return 1;
+ }
+ if ((lua_file[lua_nfile++] = strdup (fn)) == NULL)
+ {
+  lua_error ("not enough memory");
+  return 1;
+ }
+ return 0;
+}
+
+/*
+** Return the last file name set.
+*/
+char *lua_filename (void)
+{
+ return lua_file[lua_nfile-1];
+}
+
+/*
+** Internal function: return next global variable
+*/
+void lua_nextvar (void)
+{
+ int index;
+ Object *o = lua_getparam (1);
+ if (o == NULL)
+ { lua_error ("too few arguments to function `nextvar'"); return; }
+ if (lua_getparam (2) != NULL)
+ { lua_error ("too many arguments to function `nextvar'"); return; }
+ if (tag(o) == T_NIL)
+ {
+  index = 0;
+ }
+ else if (tag(o) != T_STRING) 
+ { 
+  lua_error ("incorrect argument to function `nextvar'"); 
+  return;
+ }
+ else
+ {
+  for (index=0; index<lua_ntable; index++)
+   if (streq(s_name(index),svalue(o))) break;
+  if (index == lua_ntable) 
+  {
+   lua_error ("name not found in function `nextvar'");
+   return;
+  }
+  index++;
+  while (index < lua_ntable-1 && tag(&s_object(index)) == T_NIL) index++;
+  
+  if (index == lua_ntable-1)
+  {
+   lua_pushnil();
+   lua_pushnil();
+   return;
+  }
+ }
+ {
+  Object name;
+  tag(&name) = T_STRING;
+  svalue(&name) = lua_createstring(lua_strdup(s_name(index)));
+  if (lua_pushobject (&name)) return;
+  if (lua_pushobject (&s_object(index))) return;
+ }
+}