A few more improvements in 'luaO_pushvfstring'

- 'L' added to the 'BuffFS' structure - '%c' does not handle control characters (it is not its business. This now is done by the lexer, who is the one in charge of that kind of errors.) - avoid the direct use of 'l_sprintf' in the Lua kernel
6 years ago · 7c5786479c
4 changed files with 52 additions and 35 deletions
--- a/llex.c
+++ b/llex.c
@ -82,7 +82,10 @@ void luaX_init (lua_State *L) {
 const char *luaX_token2str (LexState *ls, int token) {
  if (token < FIRST_RESERVED) {  /* single-byte symbols? */
    lua_assert(token == cast_uchar(token));
-    return luaO_pushfstring(ls->L, "'%c'", token);
+    if (lisprint(token))
+      return luaO_pushfstring(ls->L, "'%c'", token);
+    else  /* control character */
+      return luaO_pushfstring(ls->L, "'<\\%d>'", token);
  }
  else {
    const char *s = luaX_tokens[token - FIRST_RESERVED];
--- a/lobject.c
+++ b/lobject.c
@ -392,11 +392,20 @@ void luaO_tostring (lua_State *L, TValue *obj) {
 }


+
+
+/*
+** {==================================================================
+** 'luaO_pushvfstring'
+** ===================================================================
+*/
+
 /* size for buffer space used by 'luaO_pushvfstring' */
 #define BUFVFS		400

 /* buffer used by 'luaO_pushvfstring' */
 typedef struct BuffFS {
+  lua_State *L;
  int pushed;  /* number of string pieces already on the stack */
  int blen;  /* length of partial string in 'space' */
  char space[BUFVFS];  /* holds last part of the result */
@ -407,7 +416,8 @@ typedef struct BuffFS {
 ** Push given string to the stack, as part of the buffer. If the stack
 ** is almost full, join all partial strings in the stack into one.
 */
-static void pushstr (lua_State *L, BuffFS *buff, const char *str, size_t l) {
+static void pushstr (BuffFS *buff, const char *str, size_t l) {
+  lua_State *L = buff->L;
  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  L->top++;
  buff->pushed++;
@ -421,8 +431,8 @@ static void pushstr (lua_State *L, BuffFS *buff, const char *str, size_t l) {
 /*
 ** empty the buffer space into the stack
 */
-static void clearbuff (lua_State *L, BuffFS *buff) {
-  pushstr(L, buff, buff->space, buff->blen);  /* push buffer contents */
+static void clearbuff (BuffFS *buff) {
+  pushstr(buff, buff->space, buff->blen);  /* push buffer contents */
  buff->blen = 0;  /* space now is empty */
 }

@ -431,10 +441,10 @@ static void clearbuff (lua_State *L, BuffFS *buff) {
 ** Get a space of size 'sz' in the buffer. If buffer has not enough
 ** space, empty it. 'sz' must fit in an empty space.
 */
-static char *getbuff (lua_State *L, BuffFS *buff, size_t sz) {
+static char *getbuff (BuffFS *buff, size_t sz) {
  lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);
  if (sz > BUFVFS - cast_sizet(buff->blen))  /* string does not fit? */
-    clearbuff(L, buff);
+    clearbuff(buff);
  return buff->space + buff->blen;
 }

@ -446,16 +456,15 @@ static char *getbuff (lua_State *L, BuffFS *buff, size_t sz) {
 ** Add 'str' to the buffer. If string is larger than the buffer space,
 ** push the string directly to the stack.
 */
-static void addstr2buff (lua_State *L, BuffFS *buff, const char *str,
-                                                     size_t slen) {
+static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {
  if (slen <= BUFVFS) {  /* does string fit into buffer? */
-    char *bf = getbuff(L, buff, slen);
+    char *bf = getbuff(buff, slen);
    memcpy(bf, str, slen);  /* add string to buffer */
    addsize(buff, slen);
  }
  else {  /* string larger than buffer */
-    clearbuff(L, buff);  /* string comes after buffer's content */
-    pushstr(L, buff, str, slen);  /* push string */
+    clearbuff(buff);  /* string comes after buffer's content */
+    pushstr(buff, str, slen);  /* push string */
  }
 }

@ -463,8 +472,8 @@ static void addstr2buff (lua_State *L, BuffFS *buff, const char *str,
 /*
 ** Add a number to the buffer.
 */
-static void addnum2buff (lua_State *L, BuffFS *buff, TValue *num) {
-  char *numbuff = getbuff(L, buff, MAXNUMBER2STR);
+static void addnum2buff (BuffFS *buff, TValue *num) {
+  char *numbuff = getbuff(buff, MAXNUMBER2STR);
  size_t len = tostringbuff(num, numbuff);  /* format number into 'numbuff' */
  addsize(buff, len);
 }
@ -478,58 +487,55 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  BuffFS buff;  /* holds last part of the result */
  const char *e;  /* points to next '%' */
  buff.pushed = buff.blen = 0;
+  buff.L = L;
  while ((e = strchr(fmt, '%')) != NULL) {
-    addstr2buff(L, &buff, fmt, e - fmt);  /* add 'fmt' up to '%' */
+    addstr2buff(&buff, fmt, e - fmt);  /* add 'fmt' up to '%' */
    switch (*(e + 1)) {  /* conversion specifier */
      case 's': {  /* zero-terminated string */
        const char *s = va_arg(argp, char *);
        if (s == NULL) s = "(null)";
-        addstr2buff(L, &buff, s, strlen(s));
+        addstr2buff(&buff, s, strlen(s));
        break;
      }
      case 'c': {  /* an 'int' as a character */
-        /* if non-printable character, print its code */
-        char *bf = getbuff(L, &buff, 10);
-        int c = va_arg(argp, int);
-        int len = (lisprint(c)) ? l_sprintf(bf, 10, "%c", c)
-                                : l_sprintf(bf, 10, "<\\%u>", c);
-        addsize(&buff, len);
+        char c = cast_uchar(va_arg(argp, int));
+        addstr2buff(&buff, &c, sizeof(char));
        break;
      }
      case 'd': {  /* an 'int' */
        TValue num;
        setivalue(&num, va_arg(argp, int));
-        addnum2buff(L, &buff, &num);
+        addnum2buff(&buff, &num);
        break;
      }
      case 'I': {  /* a 'lua_Integer' */
        TValue num;
        setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));
-        addnum2buff(L, &buff, &num);
+        addnum2buff(&buff, &num);
        break;
      }
      case 'f': {  /* a 'lua_Number' */
        TValue num;
        setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));
-        addnum2buff(L, &buff, &num);
+        addnum2buff(&buff, &num);
        break;
      }
      case 'p': {  /* a pointer */
        const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */
-        char *bf = getbuff(L, &buff, sz);
+        char *bf = getbuff(&buff, sz);
        void *p = va_arg(argp, void *);
-        int len = l_sprintf(bf, sz, "%p", p);
+        int len = lua_pointer2str(bf, sz, p);
        addsize(&buff, len);
        break;
      }
      case 'U': {  /* a 'long' as a UTF-8 sequence */
        char bf[UTF8BUFFSZ];
        int len = luaO_utf8esc(bf, va_arg(argp, long));
-        addstr2buff(L, &buff, bf + UTF8BUFFSZ - len, len);
+        addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);
        break;
      }
      case '%': {
-        addstr2buff(L, &buff, "%", 1);
+        addstr2buff(&buff, "%", 1);
        break;
      }
      default: {
@ -539,8 +545,8 @@ const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
    }
    fmt = e + 2;  /* skip '%' and the specifier */
  }
-  addstr2buff(L, &buff, fmt, strlen(fmt));  /* rest of 'fmt' */
-  clearbuff(L, &buff);  /* empty buffer into the stack */
+  addstr2buff(&buff, fmt, strlen(fmt));  /* rest of 'fmt' */
+  clearbuff(&buff);  /* empty buffer into the stack */
  if (buff.pushed > 1)
    luaV_concat(L, buff.pushed);  /* join all partial results */
  return svalue(s2v(L->top - 1));
@ -556,6 +562,8 @@ const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  return msg;
 }

+/* }================================================================== */
+

 #define RETS	"..."
 #define PRE	"[string \""
--- a/luaconf.h
+++ b/luaconf.h
@ -376,7 +376,7 @@
@@ lua_number2str converts a float to a string.
@@ l_mathop allows the addition of an 'l' or 'f' to all math operations.
@@ l_floor takes the floor of a float.
-@@ lua_str2number converts a decimal numeric string to a number.
+@@ lua_str2number converts a decimal numeral to a number.
 */


@ -568,7 +568,7 @@


 /*
-@@ lua_strx2number converts a hexadecimal numeric string to a number.
+@@ lua_strx2number converts a hexadecimal numeral to a number.
 ** In C99, 'strtod' does that conversion. Otherwise, you can
 ** leave 'lua_strx2number' undefined and Lua will provide its own
 ** implementation.
@ -579,7 +579,14 @@


 /*
-@@ lua_number2strx converts a float to a hexadecimal numeric string.
+@@ lua_pointer2str converts a pointer to a readable string in a
+** non-specified way.
+*/
+#define lua_pointer2str(buff,sz,p)	l_sprintf(buff,sz,"%p",p)
+
+
+/*
+@@ lua_number2strx converts a float to a hexadecimal numeral.
 ** In C99, 'sprintf' (with format specifiers '%a'/'%A') does that.
 ** Otherwise, you can leave 'lua_number2strx' undefined and Lua will
 ** provide its own implementation.
--- a/testes/strings.lua
+++ b/testes/strings.lua
@ -453,8 +453,7 @@ else

  str = "abc %c def"
  testpfs("I", str, string.byte("A"))
-  -- non-printable character
-  assert(callpfs("I", str, 255) == "abc <\\255> def")
+  testpfs("I", str, 255)

  str = string.rep("a", blen - 1) .. "%p" .. string.rep("cd", blen)
  testpfs("P", str, {})