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z3str3: properly handle the case when an int.to.str term isn't fully assigned by string/arith theories

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This commit is contained in:
Murphy Berzish 2020-05-12 19:36:04 -04:00
parent 32055a31db
commit 22d0dd863b
1 changed files with 29 additions and 5 deletions
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34
src/smt/theory_str.cpp
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@ -8034,7 +8034,6 @@ namespace smt {
/* literal is_zero_l = */ mk_literal(is_zero);
axiomAdd = true;
TRACE("str", ctx.display(tout););
// NOT_IMPLEMENTED_YET();
}
bool S_hasEqcValue;
@ -8089,6 +8088,7 @@ namespace smt {
}
bool theory_str::finalcheck_int2str(app * a) {
SASSERT(u.str.is_itos(a));
bool axiomAdd = false;
ast_manager & m = get_manager();
@ -8108,7 +8108,7 @@ namespace smt {
// check for leading zeroes. if the first character is '0', the entire string must be "0"
char firstChar = (int)Sval[0];
if (firstChar == '0' && !(Sval == zstring("0"))) {
TRACE("str", tout << "str.to-int argument " << Sval << " contains leading zeroes" << std::endl;);
TRACE("str", tout << "str.from-int argument " << Sval << " contains leading zeroes" << std::endl;);
expr_ref axiom(m.mk_not(ctx.mk_eq_atom(a, mk_string(Sval))), m);
assert_axiom(axiom);
return true;
@ -8125,7 +8125,7 @@ namespace smt {
convertedRepresentation = (ten * convertedRepresentation) + rational(val);
} else {
// not a digit, invalid
TRACE("str", tout << "str.to-int argument contains non-digit character '" << digit << "'" << std::endl;);
TRACE("str", tout << "str.from-int argument contains non-digit character '" << digit << "'" << std::endl;);
conversionOK = false;
break;
}
@ -8149,7 +8149,31 @@ namespace smt {
}
} else {
TRACE("str", tout << "string theory has no assignment for " << mk_pp(a, m) << std::endl;);
NOT_IMPLEMENTED_YET();
// see if the integer theory has assigned N yet
arith_value v(m);
v.init(&ctx);
rational Nval;
if (v.get_value(N, Nval)) {
expr_ref premise(ctx.mk_eq_atom(N, mk_int(Nval)), m);
expr_ref conclusion(m);
if (Nval.is_neg()) {
// negative argument -> ""
conclusion = expr_ref(ctx.mk_eq_atom(a, mk_string("")), m);
} else {
// non-negative argument -> convert to string of digits
zstring Nval_str(Nval.to_string().c_str());
conclusion = expr_ref(ctx.mk_eq_atom(a, mk_string(Nval_str)), m);
}
expr_ref axiom(rewrite_implication(premise, conclusion), m);
assert_axiom(axiom);
axiomAdd = true;
} else {
TRACE("str", tout << "integer theory has no assignment for " << mk_pp(N, m) << std::endl;);
expr_ref is_zero(ctx.mk_eq_atom(N, m_autil.mk_int(0)), m);
/* literal is_zero_l = */ mk_literal(is_zero);
axiomAdd = true;
TRACE("str", ctx.display(tout););
}
}
return axiomAdd;
}
@ -8477,7 +8501,7 @@ namespace smt {
}
}
}
if (!needToAssignFreeVars) {
// check string-int terms