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ash: [EXPAND] Removed herefd hack

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Upstream commit:

    Date: Sun, 11 Nov 2007 15:00:06 +0800
    [EXPAND] Removed herefd hack

    The herefd hack goes back more than a decade.  it limits the amount of
    memory we have to allocate when expanding here-documents by writing the
    result out from time to time.  However, it's no longer safe because the
    stack is used to place intermediate results too and there we certainly
    don't want to write them out should we be short on memory.

    In any case, with today's computers we can afford to keep the entire
    result in memory and write them out at the end.

function                                             old     new   delta
redirect                                            1268    1264      -4
ash_main                                            1485    1478      -7
subevalvar                                          1157    1132     -25
growstackstr                                          54      24     -30
argstr                                              1192    1154     -38
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-104)           Total: -104 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-10-25 21:10:20 +02:00
parent caee80cd3d
commit 579ad107a6
1 changed files with 22 additions and 39 deletions
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27
shell/ash.c
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@ -1399,7 +1399,6 @@ struct globals_memstack {
char *g_stacknxt; // = stackbase.space; char *g_stacknxt; // = stackbase.space;
char *sstrend; // = stackbase.space + MINSIZE; char *sstrend; // = stackbase.space + MINSIZE;
size_t g_stacknleft; // = MINSIZE; size_t g_stacknleft; // = MINSIZE;
int herefd; // = -1;
struct stack_block stackbase; struct stack_block stackbase;
}; };
extern struct globals_memstack *const ash_ptr_to_globals_memstack; extern struct globals_memstack *const ash_ptr_to_globals_memstack;
@ -1408,7 +1407,6 @@ extern struct globals_memstack *const ash_ptr_to_globals_memstack;
#define g_stacknxt (G_memstack.g_stacknxt ) #define g_stacknxt (G_memstack.g_stacknxt )
#define sstrend (G_memstack.sstrend ) #define sstrend (G_memstack.sstrend )
#define g_stacknleft (G_memstack.g_stacknleft) #define g_stacknleft (G_memstack.g_stacknleft)
#define herefd (G_memstack.herefd )
#define stackbase (G_memstack.stackbase ) #define stackbase (G_memstack.stackbase )
#define INIT_G_memstack() do { \ #define INIT_G_memstack() do { \
(*(struct globals_memstack**)&ash_ptr_to_globals_memstack) = xzalloc(sizeof(G_memstack)); \ (*(struct globals_memstack**)&ash_ptr_to_globals_memstack) = xzalloc(sizeof(G_memstack)); \
@ -1417,7 +1415,6 @@ extern struct globals_memstack *const ash_ptr_to_globals_memstack;
g_stacknxt = stackbase.space; \ g_stacknxt = stackbase.space; \
g_stacknleft = MINSIZE; \ g_stacknleft = MINSIZE; \
sstrend = stackbase.space + MINSIZE; \ sstrend = stackbase.space + MINSIZE; \
herefd = -1; \
} while (0) } while (0)
@ -1605,10 +1602,6 @@ static void *
growstackstr(void) growstackstr(void)
{ {
size_t len = stackblocksize(); size_t len = stackblocksize();
if (herefd >= 0 && len >= 1024) {
full_write(herefd, stackblock(), len);
return stackblock();
}
growstackblock(); growstackblock();
return (char *)stackblock() + len; return (char *)stackblock() + len;
} }
@ -5893,21 +5886,16 @@ static int evaltree(union node *, int);
static void FAST_FUNC static void FAST_FUNC
evalbackcmd(union node *n, struct backcmd *result) evalbackcmd(union node *n, struct backcmd *result)
{ {
int saveherefd; int pip[2];
struct job *jp;
result->fd = -1; result->fd = -1;
result->buf = NULL; result->buf = NULL;
result->nleft = 0; result->nleft = 0;
result->jp = NULL; result->jp = NULL;
if (n == NULL) if (n == NULL) {
goto out; goto out;
}
saveherefd = herefd;
herefd = -1;
{
int pip[2];
struct job *jp;
if (pipe(pip) < 0) if (pipe(pip) < 0)
ash_msg_and_raise_error("pipe call failed"); ash_msg_and_raise_error("pipe call failed");
@ -5935,8 +5923,7 @@ evalbackcmd(union node *n, struct backcmd *result)
close(pip[1]); close(pip[1]);
result->fd = pip[0]; result->fd = pip[0];
result->jp = jp; result->jp = jp;
}
herefd = saveherefd;
out: out:
TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
result->fd, result->buf, result->nleft, result->jp)); result->fd, result->buf, result->nleft, result->jp));
@ -6343,7 +6330,6 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
char *str; char *str;
IF_ASH_BASH_COMPAT(char *repl = NULL;) IF_ASH_BASH_COMPAT(char *repl = NULL;)
IF_ASH_BASH_COMPAT(int pos, len, orig_len;) IF_ASH_BASH_COMPAT(int pos, len, orig_len;)
int saveherefd = herefd;
int amount, resetloc; int amount, resetloc;
IF_ASH_BASH_COMPAT(int workloc;) IF_ASH_BASH_COMPAT(int workloc;)
int zero; int zero;
@ -6352,12 +6338,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
//bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)", //bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)",
// p, varname, strloc, subtype, startloc, varflags, quotes); // p, varname, strloc, subtype, startloc, varflags, quotes);
herefd = -1;
argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ? argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ?
(flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0), (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0),
var_str_list); var_str_list);
STPUTC('\0', expdest); STPUTC('\0', expdest);
herefd = saveherefd;
argbackq = saveargbackq; argbackq = saveargbackq;
startp = (char *)stackblock() + startloc; startp = (char *)stackblock() + startloc;
@ -7391,7 +7375,6 @@ expandarg(union node *arg, struct arglist *arglist, int flag)
static void static void
expandhere(union node *arg, int fd) expandhere(union node *arg, int fd)
{ {
herefd = fd;
expandarg(arg, (struct arglist *)NULL, EXP_QUOTED); expandarg(arg, (struct arglist *)NULL, EXP_QUOTED);
full_write(fd, stackblock(), expdest - (char *)stackblock()); full_write(fd, stackblock(), expdest - (char *)stackblock());
} }