ash: add bash-compatible EPOCH variables

Bash 5.0 added the dynamic variable EPOCHSECONDS and EPOCHREALTIME
which return the number of seconds since the Unix Epoch as an
integer or float.  These are useful for logging or tracing.

function                                             old     new   delta
change_epoch                                           -      78     +78
.rodata                                           175167  175235     +68
varinit_data                                         264     312     +48
change_seconds                                         -      24     +24
change_realtime                                        -      24     +24
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 2/0 up/down: 242/0)             Total: 242 bytes
   text	   data	    bss	    dec	    hex	filename
 938508	   4203	   1888	 944599	  e69d7	busybox_old
 938702	   4203	   1888	 944793	  e6a99	busybox_unstripped

v2: Cast tv_sec and tv_usec to unsigned quantities.
    Add brackets to macros.

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Ron Yorston 2019-04-15 10:52:05 +01:00 committed by Denys Vlasenko
parent d96c69d876
commit 1d37186fe2

View File

@ -220,6 +220,7 @@
#define BASH_SOURCE ENABLE_ASH_BASH_COMPAT
#define BASH_PIPEFAIL ENABLE_ASH_BASH_COMPAT
#define BASH_HOSTNAME_VAR ENABLE_ASH_BASH_COMPAT
#define BASH_EPOCH_VARS ENABLE_ASH_BASH_COMPAT
#define BASH_SHLVL_VAR ENABLE_ASH_BASH_COMPAT
#define BASH_XTRACEFD ENABLE_ASH_BASH_COMPAT
#define BASH_READ_D ENABLE_ASH_BASH_COMPAT
@ -2053,6 +2054,10 @@ static void changepath(const char *) FAST_FUNC;
#if ENABLE_ASH_RANDOM_SUPPORT
static void change_random(const char *) FAST_FUNC;
#endif
#if BASH_EPOCH_VARS
static void change_seconds(const char *) FAST_FUNC;
static void change_realtime(const char *) FAST_FUNC;
#endif
static const struct {
int flags;
@ -2079,6 +2084,10 @@ static const struct {
#if ENABLE_ASH_RANDOM_SUPPORT
{ VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random },
#endif
#if BASH_EPOCH_VARS
{ VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "EPOCHSECONDS", change_seconds },
{ VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "EPOCHREALTIME", change_realtime },
#endif
#if ENABLE_LOCALE_SUPPORT
{ VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL" , change_lc_all },
{ VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE" , change_lc_ctype },
@ -2110,26 +2119,26 @@ extern struct globals_var *BB_GLOBAL_CONST ash_ptr_to_globals_var;
#define linenovar (G_var.linenovar )
#define vifs varinit[0]
#if ENABLE_ASH_MAIL
# define vmail (&vifs)[1]
# define vmpath (&vmail)[1]
# define vpath (&vmpath)[1]
#else
# define vpath (&vifs)[1]
# define vmail varinit[1]
# define vmpath varinit[2]
#endif
#define vps1 (&vpath)[1]
#define vps2 (&vps1)[1]
#define vps4 (&vps2)[1]
#define VAR_OFFSET1 (ENABLE_ASH_MAIL*2)
#define vpath varinit[VAR_OFFSET1 + 1]
#define vps1 varinit[VAR_OFFSET1 + 2]
#define vps2 varinit[VAR_OFFSET1 + 3]
#define vps4 varinit[VAR_OFFSET1 + 4]
#if ENABLE_ASH_GETOPTS
# define voptind (&vps4)[1]
# define vlineno (&voptind)[1]
# if ENABLE_ASH_RANDOM_SUPPORT
# define vrandom (&vlineno)[1]
# endif
#else
# define vlineno (&vps4)[1]
# if ENABLE_ASH_RANDOM_SUPPORT
# define vrandom (&vlineno)[1]
# endif
# define voptind varinit[VAR_OFFSET1 + 5]
#endif
#define VAR_OFFSET2 (VAR_OFFSET1 + ENABLE_ASH_GETOPTS)
#define vlineno varinit[VAR_OFFSET2 + 5]
#if ENABLE_ASH_RANDOM_SUPPORT
# define vrandom varinit[VAR_OFFSET2 + 6]
#endif
#define VAR_OFFSET3 (VAR_OFFSET2 + ENABLE_ASH_RANDOM_SUPPORT)
#if BASH_EPOCH_VARS
# define vepochs varinit[VAR_OFFSET3 + 6]
# define vepochr varinit[VAR_OFFSET3 + 7]
#endif
#define INIT_G_var() do { \
unsigned i; \
@ -2268,7 +2277,7 @@ lookupvar(const char *name)
v = *findvar(hashvar(name), name);
if (v) {
#if ENABLE_ASH_RANDOM_SUPPORT
#if ENABLE_ASH_RANDOM_SUPPORT || BASH_EPOCH_VARS
/*
* Dynamic variables are implemented roughly the same way they are
* in bash. Namely, they're "special" so long as they aren't unset.
@ -2364,7 +2373,7 @@ setvareq(char *s, int flags)
}
flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
#if ENABLE_ASH_RANDOM_SUPPORT
#if ENABLE_ASH_RANDOM_SUPPORT || BASH_EPOCH_VARS
if (flags & VUNSET)
flags &= ~VDYNAMIC;
#endif
@ -11249,6 +11258,32 @@ change_random(const char *value)
}
#endif
#if BASH_EPOCH_VARS
static void FAST_FUNC
change_epoch(struct var *vepoch, const char *fmt)
{
struct timeval tv;
char buffer[sizeof("%lu.nnnnnn") + sizeof(long)*3];
gettimeofday(&tv, NULL);
sprintf(buffer, fmt, (unsigned long)tv.tv_sec, (unsigned)tv.tv_usec);
setvar(vepoch->var_text, buffer, VNOFUNC);
vepoch->flags &= ~VNOFUNC;
}
static void FAST_FUNC
change_seconds(const char *value UNUSED_PARAM)
{
change_epoch(&vepochs, "%lu");
}
static void FAST_FUNC
change_realtime(const char *value UNUSED_PARAM)
{
change_epoch(&vepochr, "%lu.%06u");
}
#endif
#if ENABLE_ASH_GETOPTS
static int
getopts(char *optstr, char *optvar, char **optfirst)