diff options
| -rw-r--r-- | shell/ash.c | 77 |
1 files changed, 43 insertions, 34 deletions
diff --git a/shell/ash.c b/shell/ash.c index a31cee259..a63d40d7e 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -1168,6 +1168,12 @@ struct strpush { struct alias *ap; /* if push was associated with an alias */ #endif char *string; /* remember the string since it may change */ + + /* Remember last two characters for pungetc. */ + int lastc[2]; + + /* Number of outstanding calls to pungetc. */ + int unget; }; struct parsefile { @@ -1180,6 +1186,12 @@ struct parsefile { char *buf; /* input buffer */ struct strpush *strpush; /* for pushing strings at this level */ struct strpush basestrpush; /* so pushing one is fast */ + + /* Remember last two characters for pungetc. */ + int lastc[2]; + + /* Number of outstanding calls to pungetc. */ + int unget; }; static struct parsefile basepf; /* top level input file */ @@ -9715,6 +9727,8 @@ pushstring(char *s, struct alias *ap) g_parsefile->strpush = sp; sp->prev_string = g_parsefile->next_to_pgetc; sp->prev_left_in_line = g_parsefile->left_in_line; + sp->unget = g_parsefile->unget; + memcpy(sp->lastc, g_parsefile->lastc, sizeof(sp->lastc)); #if ENABLE_ASH_ALIAS sp->ap = ap; if (ap) { @@ -9724,6 +9738,7 @@ pushstring(char *s, struct alias *ap) #endif g_parsefile->next_to_pgetc = s; g_parsefile->left_in_line = len; + g_parsefile->unget = 0; INT_ON; } @@ -9751,6 +9766,8 @@ popstring(void) #endif g_parsefile->next_to_pgetc = sp->prev_string; g_parsefile->left_in_line = sp->prev_left_in_line; + g_parsefile->unget = sp->unget; + memcpy(g_parsefile->lastc, sp->lastc, sizeof(sp->lastc)); g_parsefile->strpush = sp->prev; if (sp != &(g_parsefile->basestrpush)) free(sp); @@ -9846,13 +9863,14 @@ preadfd(void) */ //#define pgetc_debug(...) bb_error_msg(__VA_ARGS__) #define pgetc_debug(...) ((void)0) +static int pgetc(void); static int preadbuffer(void) { char *q; int more; - while (g_parsefile->strpush) { + if (g_parsefile->strpush) { #if ENABLE_ASH_ALIAS if (g_parsefile->left_in_line == -1 && g_parsefile->strpush->ap @@ -9864,13 +9882,7 @@ preadbuffer(void) } #endif popstring(); - /* try "pgetc" now: */ - pgetc_debug("preadbuffer internal pgetc at %d:%p'%s'", - g_parsefile->left_in_line, - g_parsefile->next_to_pgetc, - g_parsefile->next_to_pgetc); - if (--g_parsefile->left_in_line >= 0) - return (unsigned char)(*g_parsefile->next_to_pgetc++); + return pgetc(); } /* on both branches above g_parsefile->left_in_line < 0. * "pgetc" needs refilling. @@ -9949,27 +9961,28 @@ preadbuffer(void) return (unsigned char)*g_parsefile->next_to_pgetc++; } -#define pgetc_as_macro() \ - (--g_parsefile->left_in_line >= 0 \ - ? (unsigned char)*g_parsefile->next_to_pgetc++ \ - : preadbuffer() \ - ) - static int pgetc(void) { - pgetc_debug("pgetc_fast at %d:%p'%s'", + int c; + + pgetc_debug("pgetc at %d:%p'%s'", g_parsefile->left_in_line, g_parsefile->next_to_pgetc, g_parsefile->next_to_pgetc); - return pgetc_as_macro(); -} + if (g_parsefile->unget) + return g_parsefile->lastc[--g_parsefile->unget]; -#if ENABLE_ASH_OPTIMIZE_FOR_SIZE -# define pgetc_fast() pgetc() -#else -# define pgetc_fast() pgetc_as_macro() -#endif + if (--g_parsefile->left_in_line >= 0) + c = (signed char)*g_parsefile->next_to_pgetc++; + else + c = preadbuffer(); + + g_parsefile->lastc[1] = g_parsefile->lastc[0]; + g_parsefile->lastc[0] = c; + + return c; +} #if ENABLE_ASH_ALIAS static int @@ -9977,11 +9990,11 @@ pgetc_without_PEOA(void) { int c; do { - pgetc_debug("pgetc_fast at %d:%p'%s'", + pgetc_debug("pgetc at %d:%p'%s'", g_parsefile->left_in_line, g_parsefile->next_to_pgetc, g_parsefile->next_to_pgetc); - c = pgetc_fast(); + c = pgetc(); } while (c == PEOA); return c; } @@ -10015,18 +10028,13 @@ pfgets(char *line, int len) } /* - * Undo the last call to pgetc. Only one character may be pushed back. + * Undo a call to pgetc. Only two characters may be pushed back. * PEOF may be pushed back. */ static void pungetc(void) { - g_parsefile->left_in_line++; - g_parsefile->next_to_pgetc--; - pgetc_debug("pushed back to %d:%p'%s'", - g_parsefile->left_in_line, - g_parsefile->next_to_pgetc, - g_parsefile->next_to_pgetc); + g_parsefile->unget++; } /* @@ -10043,6 +10051,7 @@ pushfile(void) pf->pf_fd = -1; /*pf->strpush = NULL; - ckzalloc did it */ /*pf->basestrpush.prev = NULL;*/ + /*pf->unget = 0;*/ g_parsefile = pf; } @@ -11451,7 +11460,7 @@ readtoken1(int c, int syntax, char *eofmark, int striptabs) IF_ASH_ALIAS(if (c != PEOA)) USTPUTC(c, out); } - c = pgetc_fast(); + c = pgetc(); } /* for (;;) */ endword: @@ -11945,7 +11954,7 @@ xxreadtoken(void) setprompt_if(needprompt, 2); startlinno = g_parsefile->linno; for (;;) { /* until token or start of word found */ - c = pgetc_fast(); + c = pgetc(); if (c == ' ' || c == '\t' IF_ASH_ALIAS( || c == PEOA)) continue; @@ -12008,7 +12017,7 @@ xxreadtoken(void) setprompt_if(needprompt, 2); startlinno = g_parsefile->linno; for (;;) { /* until token or start of word found */ - c = pgetc_fast(); + c = pgetc(); switch (c) { case ' ': case '\t': IF_ASH_ALIAS(case PEOA:) |