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| author | drh <drh@noemail.net> | 2012-01-07 15:17:18 +0000 |
|---|---|---|
| committer | drh <drh@noemail.net> | 2012-01-07 15:17:18 +0000 |
| commit | 7dd1ac600e7e82f5faabe51b05e67b0e68e8ef79 (patch) | |
| tree | 906b707516d1937d9da153052692f92fa2bb991a /tool/lemon.c | |
| parent | 60e4a7487976a3b300a1ec13e54d107f5ae19047 (diff) | |
| download | sqlite-7dd1ac600e7e82f5faabe51b05e67b0e68e8ef79.tar.gz sqlite-7dd1ac600e7e82f5faabe51b05e67b0e68e8ef79.zip | |
Fix a bug in lemon in computation of which non-terminals can generate an
empty string. This bug and the fix make absolutely no difference for the
grammar used by SQLite, but it can make a difference when lemon is used
in other grammars.
FossilOrigin-Name: ce32775b232da894343f62deefaf19b0ec484636
Diffstat (limited to 'tool/lemon.c')
| -rw-r--r-- | tool/lemon.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tool/lemon.c b/tool/lemon.c index 1fb0308be..a089bc7ba 100644 --- a/tool/lemon.c +++ b/tool/lemon.c @@ -686,8 +686,9 @@ void FindFirstSets(struct lemon *lemp) for(rp=lemp->rule; rp; rp=rp->next){ if( rp->lhs->lambda ) continue; for(i=0; i<rp->nrhs; i++){ - struct symbol *sp = rp->rhs[i]; - if( sp->type!=TERMINAL || sp->lambda==LEMON_FALSE ) break; + struct symbol *sp = rp->rhs[i]; + assert( sp->type==NONTERMINAL || sp->lambda==LEMON_FALSE ); + if( sp->lambda==LEMON_FALSE ) break; } if( i==rp->nrhs ){ rp->lhs->lambda = LEMON_TRUE; |