Added field 'srclen' to structure 'lua_Debug'

This new field gets the length of 'source' in the same structure.
Unlike the other strings in that structure, 'source' can be
relatively large, and Lua already has its length readily available.

ldblib.c

@@ -167,7 +167,8 @@ static int db_getinfo (lua_State *L) {
     return luaL_argerror(L, arg+2, "invalid option");
   lua_newtable(L);  /* table to collect results */
   if (strchr(options, 'S')) {
-    settabss(L, "source", ar.source);
+    lua_pushlstring(L, ar.source, ar.srclen);
+    lua_setfield(L, -2, "source");
     settabss(L, "short_src", ar.short_src);
     settabsi(L, "linedefined", ar.linedefined);
     settabsi(L, "lastlinedefined", ar.lastlinedefined);

ldebug.c

@@ -262,18 +262,26 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
 static void funcinfo (lua_Debug *ar, Closure *cl) {
   if (noLuaClosure(cl)) {
     ar->source = "=[C]";
+    ar->srclen = LL("=[C]");
     ar->linedefined = -1;
     ar->lastlinedefined = -1;
     ar->what = "C";
   }
   else {
     const Proto *p = cl->l.p;
-    ar->source = p->source ? getstr(p->source) : "=?";
+    if (p->source) {
+      ar->source = getstr(p->source);
+      ar->srclen = tsslen(p->source);
+    }
+    else {
+      ar->source = "=?";
+      ar->srclen = LL("=?");
+    }
     ar->linedefined = p->linedefined;
     ar->lastlinedefined = p->lastlinedefined;
     ar->what = (ar->linedefined == 0) ? "main" : "Lua";
   }
-  luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
+  luaO_chunkid(ar->short_src, ar->source, ar->srclen);
 }
 
 
@@ -750,7 +758,7 @@ const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
                                         int line) {
   char buff[LUA_IDSIZE];
   if (src)
-    luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
+    luaO_chunkid(buff, getstr(src), tsslen(src));
   else {  /* no source available; use "?" instead */
     buff[0] = '?'; buff[1] = '\0';
   }

llimits.h

@@ -65,6 +65,10 @@ typedef signed char ls_byte;
 #define ispow2(x)	(((x) & ((x) - 1)) == 0)
 
 
+/* number of chars of a literal string without the ending \0 */
+#define LL(x)   (sizeof(x)/sizeof(char) - 1)
+
+
 /*
 ** conversion of pointer to unsigned integer:
 ** this is for hashing only; there is no problem if the integer

lobject.c

@@ -473,45 +473,42 @@ const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
 }
 
 
-/* number of chars of a literal string without the ending \0 */
-#define LL(x)	(sizeof(x)/sizeof(char) - 1)
-
 #define RETS	"..."
 #define PRE	"[string \""
 #define POS	"\"]"
 
 #define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )
 
-void luaO_chunkid (char *out, const char *source, size_t bufflen) {
-  size_t l = strlen(source);
+void luaO_chunkid (char *out, const char *source, size_t srclen) {
+  size_t bufflen = LUA_IDSIZE;  /* free space in buffer */
   if (*source == '=') {  /* 'literal' source */
-    if (l <= bufflen)  /* small enough? */
-      memcpy(out, source + 1, l * sizeof(char));
+    if (srclen <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, srclen * sizeof(char));
     else {  /* truncate it */
       addstr(out, source + 1, bufflen - 1);
       *out = '\0';
     }
   }
   else if (*source == '@') {  /* file name */
-    if (l <= bufflen)  /* small enough? */
-      memcpy(out, source + 1, l * sizeof(char));
+    if (srclen <= bufflen)  /* small enough? */
+      memcpy(out, source + 1, srclen * sizeof(char));
     else {  /* add '...' before rest of name */
       addstr(out, RETS, LL(RETS));
       bufflen -= LL(RETS);
-      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
+      memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char));
     }
   }
   else {  /* string; format as [string "source"] */
     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
     addstr(out, PRE, LL(PRE));  /* add prefix */
     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
-    if (l < bufflen && nl == NULL) {  /* small one-line source? */
-      addstr(out, source, l);  /* keep it */
+    if (srclen < bufflen && nl == NULL) {  /* small one-line source? */
+      addstr(out, source, srclen);  /* keep it */
     }
     else {
-      if (nl != NULL) l = nl - source;  /* stop at first newline */
-      if (l > bufflen) l = bufflen;
-      addstr(out, source, l);
+      if (nl != NULL) srclen = nl - source;  /* stop at first newline */
+      if (srclen > bufflen) srclen = bufflen;
+      addstr(out, source, srclen);
       addstr(out, RETS, LL(RETS));
     }
     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));

lobject.h

@@ -747,7 +747,7 @@ LUAI_FUNC void luaO_tostring (lua_State *L, TValue *obj);
 LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt,
                                                        va_list argp);
 LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...);
-LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len);
+LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t srclen);
 
 
 #endif

lua.h

@@ -469,6 +469,7 @@ struct lua_Debug {
   const char *namewhat;	/* (n) 'global', 'local', 'field', 'method' */
   const char *what;	/* (S) 'Lua', 'C', 'main', 'tail' */
   const char *source;	/* (S) */
+  size_t srclen;	/* (S) */
   int currentline;	/* (l) */
   int linedefined;	/* (S) */
   int lastlinedefined;	/* (S) */