kconfig: implement KCONFIG_PROBABILITY for randconfig

Currently the odds to set each symbol is (rounded):
    booleans:   y: 50%          n: 50%
    tristates:  y: 33%  m: 33%  n: 33%

Introduce a KCONFIG_PROBABILITY environment variable to tweak the
probabilities (in percentage), as such:
    KCONFIG_PROBABILITY     y:n split           yⓂ️n split
    -----------------------------------------------------------------
[1] unset or empty          50  : 50            33  : 33  : 34
[2] N                        N  : 100-N         N/2 : N/2 : 100-N
    N:M                     N+M : 100-(N+M)      N  :  M  : 100-(N+M)
    N:M:L                    N  : 100-N          M  :  L  : 100-(M+L)

[1] The current behaviour is kept as default, for backward compatibility
[2] The solution initially implemented by Peter for Buildroot, see:
    http://git.buildroot.org/buildroot/commit/?id=3435c1afb5

Signed-off-by: Peter Korsgaard <jacmet@uclibc.org>
[yann.morin.1998@free.fr: add to Documentation/]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
This commit is contained in:
Yann E. MORIN 2013-04-13 17:18:36 +02:00
parent 0d8024c6eb
commit e43956e607
2 changed files with 81 additions and 3 deletions

View File

@ -98,6 +98,33 @@ You can set this to the integer value used to seed the RNG, if you want
to somehow debug the behaviour of the kconfig parser/frontends.
If not set, the current time will be used.
KCONFIG_PROBABILITY
--------------------------------------------------
This variable can be used to skew the probabilities. This variable can
be unset or empty, or set to three different formats:
KCONFIG_PROBABILITY y:n split y:m:n split
-----------------------------------------------------------------
unset or empty 50 : 50 33 : 33 : 34
N N : 100-N N/2 : N/2 : 100-N
[1] N:M N+M : 100-(N+M) N : M : 100-(N+M)
[2] N:M:L N : 100-N M : L : 100-(M+L)
where N, M and L are integers (in base 10) in the range [0,100], and so
that:
[1] N+M is in the range [0,100]
[2] M+L is in the range [0,100]
Examples:
KCONFIG_PROBABILITY=10
10% of booleans will be set to 'y', 90% to 'n'
5% of tristates will be set to 'y', 5% to 'm', 90% to 'n'
KCONFIG_PROBABILITY=15:25
40% of booleans will be set to 'y', 60% to 'n'
15% of tristates will be set to 'y', 25% to 'm', 60% to 'n'
KCONFIG_PROBABILITY=10:15:15
10% of booleans will be set to 'y', 90% to 'n'
15% of tristates will be set to 'y', 15% to 'm', 70% to 'n'
______________________________________________________________________
Environment variables for 'silentoldconfig'

View File

@ -1107,7 +1107,51 @@ static void set_all_choice_values(struct symbol *csym)
void conf_set_all_new_symbols(enum conf_def_mode mode)
{
struct symbol *sym, *csym;
int i, cnt;
int i, cnt, pby, pty, ptm; /* pby: probability of boolean = y
* pty: probability of tristate = y
* ptm: probability of tristate = m
*/
pby = 50; pty = ptm = 33; /* can't go as the default in switch-case
* below, otherwise gcc whines about
* -Wmaybe-uninitialized */
if (mode == def_random) {
int n, p[3];
char *env = getenv("KCONFIG_PROBABILITY");
n = 0;
while( env && *env ) {
char *endp;
int tmp = strtol( env, &endp, 10 );
if( tmp >= 0 && tmp <= 100 ) {
p[n++] = tmp;
} else {
errno = ERANGE;
perror( "KCONFIG_PROBABILITY" );
exit( 1 );
}
env = (*endp == ':') ? endp+1 : endp;
if( n >=3 ) {
break;
}
}
switch( n ) {
case 1:
pby = p[0]; ptm = pby/2; pty = pby-ptm;
break;
case 2:
pty = p[0]; ptm = p[1]; pby = pty + ptm;
break;
case 3:
pby = p[0]; pty = p[1]; ptm = p[2];
break;
}
if( pty+ptm > 100 ) {
errno = ERANGE;
perror( "KCONFIG_PROBABILITY" );
exit( 1 );
}
}
for_all_symbols(i, sym) {
if (sym_has_value(sym) || (sym->flags & SYMBOL_VALID))
@ -1126,8 +1170,15 @@ void conf_set_all_new_symbols(enum conf_def_mode mode)
sym->def[S_DEF_USER].tri = no;
break;
case def_random:
cnt = sym->type == S_TRISTATE ? 3 : 2;
sym->def[S_DEF_USER].tri = (tristate)(rand() % cnt);
sym->def[S_DEF_USER].tri = no;
cnt = rand() % 100;
if (sym->type == S_TRISTATE) {
if (cnt < pty)
sym->def[S_DEF_USER].tri = yes;
else if (cnt < (pty+ptm))
sym->def[S_DEF_USER].tri = mod;
} else if (cnt < pby)
sym->def[S_DEF_USER].tri = yes;
break;
default:
continue;