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Merge branch 'str-at-semantics' into develop

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This commit is contained in:
Murphy Berzish 2017-03-13 14:40:40 -04:00
commit 94d5f242b8
35 changed files with 799 additions and 66 deletions
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2
src/ast/rewriter/rewriter.h
View file

@ -315,6 +315,8 @@ protected:
template<bool ProofGen>
void process_app(app * t, frame & fr);
bool constant_fold(app* t, frame& fr);
template<bool ProofGen>
void process_quantifier(quantifier * q, frame & fr);

37
src/ast/rewriter/rewriter_def.h
View file

@ -174,6 +174,38 @@ bool rewriter_tpl<Config>::visit(expr * t, unsigned max_depth) {
}
}
template<typename Config>
bool rewriter_tpl<Config>::constant_fold(app * t, frame & fr) {
if (fr.m_i == 1 && m().is_ite(t)) {
expr * cond = result_stack()[fr.m_spos].get();
expr* arg = 0;
if (m().is_true(cond)) {
arg = t->get_arg(1);
}
else if (m().is_false(cond)) {
arg = t->get_arg(2);
}
if (arg) {
result_stack().shrink(fr.m_spos);
result_stack().push_back(arg);
fr.m_state = REWRITE_BUILTIN;
unsigned max_depth = fr.m_max_depth;
if (visit<false>(arg, fr.m_max_depth)) {
m_r = result_stack().back();
result_stack().pop_back();
result_stack().pop_back();
result_stack().push_back(m_r);
cache_result<false>(t, m_r, m_pr, fr.m_cache_result);
frame_stack().pop_back();
set_new_child_flag(t);
}
m_r = 0;
return true;
}
}
return false;
}
template<typename Config>
template<bool ProofGen>
void rewriter_tpl<Config>::process_app(app * t, frame & fr) {
@ -183,10 +215,15 @@ void rewriter_tpl<Config>::process_app(app * t, frame & fr) {
case PROCESS_CHILDREN: {
unsigned num_args = t->get_num_args();
while (fr.m_i < num_args) {
if (!ProofGen && constant_fold(t, fr)) {
return;
}
expr * arg = t->get_arg(fr.m_i);
fr.m_i++;
if (!visit<ProofGen>(arg, fr.m_max_depth))
return;
}
func_decl * f = t->get_decl();

19
src/ast/rewriter/seq_rewriter.cpp
View file

@ -632,14 +632,25 @@ br_status seq_rewriter::mk_seq_contains(expr* a, expr* b, expr_ref& result) {
return BR_FAILED;
}
/*
* (str.at s i), constants s/i, i < 0 or i >= |s| ==> (str.at s i) = ""
*/
br_status seq_rewriter::mk_seq_at(expr* a, expr* b, expr_ref& result) {
zstring c;
rational r;
if (m_util.str.is_string(a, c) && m_autil.is_numeral(b, r) && r.is_unsigned()) {
unsigned j = r.get_unsigned();
if (j < c.length()) {
result = m_util.str.mk_string(c.extract(j, 1));
if (m_util.str.is_string(a, c) && m_autil.is_numeral(b, r)) {
if (r.is_neg()) {
result = m_util.str.mk_string(symbol(""));
return BR_DONE;
} else if (r.is_unsigned()) {
unsigned j = r.get_unsigned();
if (j < c.length()) {
result = m_util.str.mk_string(c.extract(j, 1));
return BR_DONE;
} else {
result = m_util.str.mk_string(symbol(""));
return BR_DONE;
}
}
}
return BR_FAILED;