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ash: undo "tokname hack"

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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>
This commit is contained in:
Denys Vlasenko 2016-10-02 16:54:17 +02:00
parent bc1a00843f
commit 888527ccee
1 changed files with 82 additions and 40 deletions
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122
shell/ash.c
View File

@ -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",
"function",
#endif
"\0if",
"\0in",
"\1then",
"\0until",
"\0while",
"\0{",
"\1}",
"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;
}