On Sun, Apr 21, 2013 at 02:28:09AM -0400, Ted Unangst wrote:
> For whatever reason, I found myself looking at the m4 code. In eval.c,
> there are some funny functions. I figure if you have to cast every
> instance of a variable to a different type, maybe the problem is
> you're starting with the wrong type. Switching to unsigned char *
> inputs makes these functions much simpler.
>
> Also simplify and eliminate statics. I can't see any reason frombis
> needs to be static, and in the case of mapvec being static just means
> more work to undo writes to it.
>
> (I changed seen to int to make clear it's not used for character data.)
>
> Index: eval.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/m4/eval.c,v
> retrieving revision 1.70
> diff -u -p -r1.70 eval.c
> --- eval.c 12 Apr 2012 17:00:11 -0000 1.70
> +++ eval.c 21 Apr 2013 06:26:41 -0000
> @@ -67,8 +67,10 @@ static void dom4wrap(const char *);
> static void dodiv(int);
> static void doundiv(const char *[], int);
> static void dosub(const char *[], int);
> -static void map(char *, const char *, const char *, const char *);
> -static const char *handledash(char *, char *, const char *);
> +static void map(unsigned char *, const unsigned char *,
> + const unsigned char *, const unsigned char *);
> +static const unsigned char *handledash(unsigned char *, unsigned char *,
> + const unsigned char *);
> static void expand_builtin(const char *[], int, int);
> static void expand_macro(const char *[], int);
> static void dump_one_def(const char *, struct macro_definition *);
> @@ -892,34 +894,15 @@ dosub(const char *argv[], int argc)
> * which means that those characters dissapear altogether.
> */
> static void
> -map(char *dest, const char *src, const char *from, const char *to)
> +map(unsigned char *dest, const unsigned char *src, const unsigned char *from,
> + const unsigned char *to)
> {
> - const char *tmp;
> unsigned char sch, dch;
> - static char frombis[257];
> - static char tobis[257];
> + unsigned char frombis[257];
> + unsigned char tobis[257];
> + unsigned char mapvec[256];
> + int seen[256];
> int i;
> - char seen[256];
> - static unsigned char mapvec[256] = {
> - 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18,
> - 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
> - 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
> - 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69,
> - 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86,
> - 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102,
> - 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
> - 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128,
> - 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141,
> - 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154,
> - 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167,
> - 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180,
> - 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193,
> - 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206,
> - 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,
> - 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232,
> - 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245,
> - 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
> - };
>
> if (*src) {
> if (mimic_gnu) {
> @@ -929,17 +912,17 @@ map(char *dest, const char *src, const c
> from = handledash(frombis, frombis + 256, from);
> to = handledash(tobis, tobis + 256, to);
> }
> - tmp = from;
> - /*
> - * create a mapping between "from" and
> - * "to"
> - */
> - for (i = 0; i < 256; i++)
> + /*
> + * create a mapping between "from" and "to"
> + */
> + for (i = 0; i < 256; i++) {
> + mapvec[i] = i;
> seen[i] = 0;
> + }
> while (*from) {
> - if (!seen[(unsigned char)(*from)]) {
> - mapvec[(unsigned char)(*from)] = (unsigned
> char)(*to);
> - seen[(unsigned char)(*from)] = 1;
> + if (!seen[*from]) {
> + mapvec[*from] = *to;
> + seen[*from] = 1;
> }
> from++;
> if (*to)
> @@ -947,18 +930,11 @@ map(char *dest, const char *src, const c
> }
>
> while (*src) {
> - sch = (unsigned char)(*src++);
> + sch = *src++;
> dch = mapvec[sch];
> - if ((*dest = (char)dch))
> + if ((*dest = dch))
> dest++;
> }
> - /*
> - * restore all the changed characters
> - */
> - while (*tmp) {
> - mapvec[(unsigned char)(*tmp)] = (unsigned char)(*tmp);
> - tmp++;
> - }
> }
> *dest = '\0';
> }
> @@ -969,18 +945,18 @@ map(char *dest, const char *src, const c
> * use buffer to copy the src string, expanding character ranges
> * on the way.
> */
> -static const char *
> -handledash(char *buffer, char *end, const char *src)
> +static const unsigned char *
> +handledash(unsigned char *buffer, unsigned char *end,
> + const unsigned char *src)
> {
> - char *p;
> + unsigned char *p;
>
> p = buffer;
> while(*src) {
> if (src[1] == '-' && src[2]) {
> unsigned char i;
> - if ((unsigned char)src[0] <= (unsigned char)src[2]) {
> - for (i = (unsigned char)src[0];
> - i <= (unsigned char)src[2]; i++) {
> + if (src[0] <= src[2]) {
> + for (i = src[0]; i <= src[2]; i++) {
> *p++ = i;
> if (p == end) {
> *p = '\0';
> @@ -988,8 +964,7 @@ handledash(char *buffer, char *end, cons
> }
> }
> } else {
> - for (i = (unsigned char)src[0];
> - i >= (unsigned char)src[2]; i--) {
> + for (i = src[0]; i >= src[2]; i--) {
> *p++ = i;
> if (p == end) {
> *p = '\0';
This would require at least a full bulk build.
Those functions are vital to autoconf.
