ash: undo "tokname hack"

dash has tokendlist[] array to decide which tokens end lists.
We store it as first byte of each tokname_array[i].

Switch to bit array, name it like dash (tokendlist), drop special
1st byte of tokname_array[i]. This brings us closer to dash, and
shrinks the binary, because many more string aliasing opportunities
are now open:

function                                             old     new   delta
pstrcmp1                                               -      16     +16
readtoken1                                          2852    2858      +6
list                                                 326     327      +1
pstrcmp                                               16      15      -1
tokname                                               45      42      -3
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/2 up/down: 23/-4)              Total: 19 bytes
   text	   data	    bss	    dec	    hex	filename
 943556	    916	  14292	 958764	  ea12c	busybox_old
 943463	    916	  14292	 958671	  ea0cf	busybox_unstripped
^^^^^^^ note this!

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 83 insertions, 41 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 41ae5cbd2..421639e8b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -7881,49 +7881,86 @@ enum {
 };
 typedef smallint token_id_t;
 
-/* first char is indicating which tokens mark the end of a list */
+/* Nth bit indicates if token marks the end of a list */
+enum {
+        tokendlist = 0
+        /*  0 */ | (1u << TEOF)
+        /*  1 */ | (0u << TNL)
+        /*  2 */ | (0u << TREDIR)
+        /*  3 */ | (0u << TWORD)
+        /*  4 */ | (0u << TSEMI)
+        /*  5 */ | (0u << TBACKGND)
+        /*  6 */ | (0u << TAND)
+        /*  7 */ | (0u << TOR)
+        /*  8 */ | (0u << TPIPE)
+        /*  9 */ | (0u << TLP)
+        /* 10 */ | (1u << TRP)
+        /* 11 */ | (1u << TENDCASE)
+        /* 12 */ | (1u << TENDBQUOTE)
+        /* 13 */ | (0u << TNOT)
+        /* 14 */ | (0u << TCASE)
+        /* 15 */ | (1u << TDO)
+        /* 16 */ | (1u << TDONE)
+        /* 17 */ | (1u << TELIF)
+        /* 18 */ | (1u << TELSE)
+        /* 19 */ | (1u << TESAC)
+        /* 20 */ | (1u << TFI)
+        /* 21 */ | (0u << TFOR)
+#if ENABLE_ASH_BASH_COMPAT
+        /* 22 */ | (0u << TFUNCTION)
+#endif  
+        /* 23 */ | (0u << TIF)
+        /* 24 */ | (0u << TIN)
+        /* 25 */ | (1u << TTHEN)
+        /* 26 */ | (0u << TUNTIL)
+        /* 27 */ | (0u << TWHILE)
+        /* 28 */ | (0u << TBEGIN)
+        /* 29 */ | (1u << TEND)
+        , /* thus far 29 bits used */
+};
+
 static const char *const tokname_array[] = {
-        "\1end of file",
-        "\0newline",
-        "\0redirection",
-        "\0word",
-        "\0;",
-        "\0&",
-        "\0&&",
-        "\0||",
-        "\0|",
-        "\0(",
-        "\1)",
-        "\1;;",
-        "\1`",
+        "end of file",
+        "newline",
+        "redirection",
+        "word",
+        ";",
+        "&",
+        "&&",
+        "||",
+        "|",
+        "(",
+        ")",
+        ";;",
+        "`",
 #define KWDOFFSET 13
         /* the following are keywords */
-        "\0!",
-        "\0case",
-        "\1do",
-        "\1done",
-        "\1elif",
-        "\1else",
-        "\1esac",
-        "\1fi",
-        "\0for",
+        "!",
+        "case",
+        "do",
+        "done",
+        "elif",
+        "else",
+        "esac",
+        "fi",
+        "for",
 #if ENABLE_ASH_BASH_COMPAT
-        "\0function",
-#endif
-        "\0if",
-        "\0in",
-        "\1then",
-        "\0until",
-        "\0while",
-        "\0{",
-        "\1}",
+        "function",
+#endif
+        "if",
+        "in",
+        "then",
+        "until",
+        "while",
+        "{",
+        "}",
 };
 
 /* Wrapper around strcmp for qsort/bsearch/... */
 static int
 pstrcmp(const void *a, const void *b)
 {
-        return strcmp((char*) a, (*(char**) b) + 1);
+        return strcmp((char*)a, *(char**)b);
 }
 
 static const char *const *
@@ -9339,6 +9376,11 @@ static const struct builtincmd builtintab[] = {
 /*
  * Search the table of builtin commands.
  */
+static int
+pstrcmp1(const void *a, const void *b)
+{
+        return strcmp((char*)a, *(char**)b + 1);
+}
 static struct builtincmd *
 find_builtin(const char *name)
 {
@@ -9346,7 +9388,7 @@ find_builtin(const char *name)
 
         bp = bsearch(
                 name, builtintab, ARRAY_SIZE(builtintab), sizeof(builtintab[0]),
-                pstrcmp
+                pstrcmp1
         );
         return bp;
 }
@@ -10669,8 +10711,8 @@ static const char *
 tokname(char *buf, int tok)
 {
         if (tok < TSEMI)
-                return tokname_array[tok] + 1;
-        sprintf(buf, "\"%s\"", tokname_array[tok] + 1);
+                return tokname_array[tok];
+        sprintf(buf, "\"%s\"", tokname_array[tok]);
         return buf;
 }
 
@@ -10727,7 +10769,7 @@ list(int nlflag)
                 }
 
                 checkkwd = CHKNL | CHKKWD | CHKALIAS;
-                if (nlflag == 2 && tokname_array[peektoken()][0])
+                if (nlflag == 2 && ((1 << peektoken()) & tokendlist))
                         return n1;
                 nlflag |= 2;
 
@@ -11109,7 +11151,7 @@ parse_command(void)
                 n1->nbinary.ch1 = list(0);
                 got = readtoken();
                 if (got != TDO) {
-                        TRACE(("expecting DO got '%s' %s\n", tokname_array[got] + 1,
+                        TRACE(("expecting DO got '%s' %s\n", tokname_array[got],
                                         got == TWORD ? wordtext : ""));
                         raise_error_unexpected_syntax(TDO);
                 }
@@ -12156,7 +12198,7 @@ readtoken(void)
                 pp = findkwd(wordtext);
                 if (pp) {
                         lasttoken = t = pp - tokname_array;
-                        TRACE(("keyword '%s' recognized\n", tokname_array[t] + 1));
+                        TRACE(("keyword '%s' recognized\n", tokname_array[t]));
                         goto out;
                 }
         }
@@ -12177,9 +12219,9 @@ readtoken(void)
         checkkwd = 0;
 #if DEBUG
         if (!alreadyseen)
-                TRACE(("token '%s' %s\n", tokname_array[t] + 1, t == TWORD ? wordtext : ""));
+                TRACE(("token '%s' %s\n", tokname_array[t], t == TWORD ? wordtext : ""));
         else
-                TRACE(("reread token '%s' %s\n", tokname_array[t] + 1, t == TWORD ? wordtext : ""));
+                TRACE(("reread token '%s' %s\n", tokname_array[t], t == TWORD ? wordtext : ""));
 #endif
         return t;
 }