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hush: make getch/peek functions directly called

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Indirect calls are more difficult to predict.
Unfortunately, on x64 direct call is 5 bytes while indirect "call (reg+ofs)"
is 3 bytes:

function                                             old     new   delta
i_getch                                                -      82     +82
i_peek                                                 -      63     +63
parse_stream                                        2531    2579     +48
parse_dollar                                         771     797     +26
parse_redirect                                       296     321     +25
add_till_closing_bracket                             408     420     +12
encode_string                                        256     265      +9
i_peek_and_eat_bkslash_nl                             93      99      +6
add_till_backquote                                   110     114      +4
parse_and_run_stream                                 139     141      +2
expand_vars_to_list                                 1143    1144      +1
static_peek                                            6       -      -6
setup_string_in_str                                   39      18     -21
setup_file_in_str                                     40      19     -21
static_get                                            27       -     -27
file_peek                                             52       -     -52
file_get                                              65       -     -65
------------------------------------------------------------------------------
(add/remove: 2/4 grow/shrink: 9/2 up/down: 278/-192)           Total: 86 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-11-08 22:35:05 +01:00
parent 00a06b9715
commit 87e039d016
1 changed files with 24 additions and 27 deletions
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51
shell/hush.c
View File

@ -469,11 +469,7 @@ typedef struct in_str {
int peek_buf[2]; int peek_buf[2];
int last_char; int last_char;
FILE *file; FILE *file;
int (*get) (struct in_str *) FAST_FUNC;
int (*peek) (struct in_str *) FAST_FUNC;
} in_str; } in_str;
#define i_getch(input) ((input)->get(input))
#define i_peek(input) ((input)->peek(input))
/* The descrip member of this structure is only used to make /* The descrip member of this structure is only used to make
* debugging output pretty */ * debugging output pretty */
@ -2259,10 +2255,23 @@ static inline int fgetc_interactive(struct in_str *i)
} }
#endif /* INTERACTIVE */ #endif /* INTERACTIVE */
static int FAST_FUNC file_get(struct in_str *i) static int i_getch(struct in_str *i)
{ {
int ch; int ch;
if (!i->file) {
/* string-based in_str */
ch = (unsigned char)*i->p;
if (ch != '\0') {
i->p++;
i->last_char = ch;
return ch;
}
return EOF;
}
/* FILE-based in_str */
#if ENABLE_FEATURE_EDITING #if ENABLE_FEATURE_EDITING
/* This can be stdin, check line editing char[] buffer */ /* This can be stdin, check line editing char[] buffer */
if (i->p && *i->p != '\0') { if (i->p && *i->p != '\0') {
@ -2288,10 +2297,18 @@ static int FAST_FUNC file_get(struct in_str *i)
return ch; return ch;
} }
static int FAST_FUNC file_peek(struct in_str *i) static int i_peek(struct in_str *i)
{ {
int ch; int ch;
if (!i->file) {
/* string-based in_str */
/* Doesn't report EOF on NUL. None of the callers care. */
return (unsigned char)*i->p;
}
/* FILE-based in_str */
#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
/* This can be stdin, check line editing char[] buffer */ /* This can be stdin, check line editing char[] buffer */
if (i->p && *i->p != '\0') if (i->p && *i->p != '\0')
@ -2318,23 +2335,6 @@ static int FAST_FUNC file_peek(struct in_str *i)
return ch; return ch;
} }
static int FAST_FUNC static_get(struct in_str *i)
{
int ch = (unsigned char)*i->p;
if (ch != '\0') {
i->p++;
i->last_char = ch;
return ch;
}
return EOF;
}
static int FAST_FUNC static_peek(struct in_str *i)
{
/* Doesn't report EOF on NUL. None of the callers care. */
return (unsigned char)*i->p;
}
/* Only ever called if i_peek() was called, and did not return EOF. /* Only ever called if i_peek() was called, and did not return EOF.
* IOW: we know the previous peek saw an ordinary char, not EOF, not NUL, * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
* not end-of-line. Therefore we never need to read a new editing line here. * not end-of-line. Therefore we never need to read a new editing line here.
@ -2370,8 +2370,6 @@ static int i_peek2(struct in_str *i)
static void setup_file_in_str(struct in_str *i, FILE *f) static void setup_file_in_str(struct in_str *i, FILE *f)
{ {
memset(i, 0, sizeof(*i)); memset(i, 0, sizeof(*i));
i->get = file_get;
i->peek = file_peek;
/* i->promptmode = 0; - PS1 (memset did it) */ /* i->promptmode = 0; - PS1 (memset did it) */
i->file = f; i->file = f;
/* i->p = NULL; */ /* i->p = NULL; */
@ -2380,9 +2378,8 @@ static void setup_file_in_str(struct in_str *i, FILE *f)
static void setup_string_in_str(struct in_str *i, const char *s) static void setup_string_in_str(struct in_str *i, const char *s)
{ {
memset(i, 0, sizeof(*i)); memset(i, 0, sizeof(*i));
i->get = static_get;
i->peek = static_peek;
/* i->promptmode = 0; - PS1 (memset did it) */ /* i->promptmode = 0; - PS1 (memset did it) */
/*i->file = NULL */;
i->p = s; i->p = s;
} }