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GCC switch range: don't enumerate elements #5724

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Merged
merged 1 commit into from
Jan 8, 2021
Merged

GCC switch range: don't enumerate elements #5724

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7 changes: 6 additions & 1 deletion regression/cbmc/gcc_switch_case_range1/main.c
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Original file line number Diff line number Diff line change
@@ -1,3 +1,5 @@
#include <limits.h>

int main()
{
int x;
Expand All @@ -18,9 +20,12 @@ int main()
#endif
__CPROVER_assert(0, "... works");
break;
case 13:
case 14:
__CPROVER_assert(0, "13 works");
break;
case 15 ... INT_MAX:
__CPROVER_assert(0, "large range works");
break;
default:
__CPROVER_assert(0, "default works");
break;
Expand Down
2 changes: 1 addition & 1 deletion regression/cbmc/gcc_switch_case_range1/test.desc
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Expand Up @@ -4,6 +4,6 @@ main.c
^EXIT=10$
^SIGNAL=0$
^VERIFICATION FAILED$
^\*\* 4 of 4 failed
^\*\* 5 of 5 failed
--
^warning: ignoring
35 changes: 22 additions & 13 deletions src/goto-programs/goto_convert.cpp
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Expand Up @@ -416,10 +416,10 @@ void goto_convertt::convert_gcc_switch_case_range(
targets.cases_map.insert({target, --targets.cases.end()}).first;
}

exprt::operandst &case_op_dest = cases_entry->second->second;

for(mp_integer i = *lb; i <= *ub; ++i)
case_op_dest.push_back(from_integer(i, code.lower().type()));
// create a skeleton for case_guard
cases_entry->second->second.push_back(
and_exprt{binary_relation_exprt{code.lower(), ID_le, nil_exprt{}},
binary_relation_exprt{nil_exprt{}, ID_le, code.upper()}});
}

/// converts 'code' and appends the result to 'dest'
Expand Down Expand Up @@ -1100,18 +1100,27 @@ exprt goto_convertt::case_guard(
{
PRECONDITION(!case_op.empty());

if(case_op.size() == 1)
return equal_exprt(value, case_op.at(0));
else
{
exprt::operandst disjuncts;
disjuncts.reserve(case_op.size());
exprt::operandst disjuncts;
disjuncts.reserve(case_op.size());

for(const auto &op : case_op)
for(const auto &op : case_op)
{
// could be a skeleton generated by convert_gcc_switch_case_range
if(op.id() == ID_and)
{
const binary_exprt &and_expr = to_binary_expr(op);
PRECONDITION(to_binary_expr(and_expr.op0()).op1().is_nil());
PRECONDITION(to_binary_expr(and_expr.op1()).op0().is_nil());
binary_exprt skeleton = and_expr;
to_binary_expr(skeleton.op0()).op1() = value;
to_binary_expr(skeleton.op1()).op0() = value;
disjuncts.push_back(skeleton);
}
else
disjuncts.push_back(equal_exprt(value, op));

return disjunction(disjuncts);
}

return disjunction(disjuncts);
}

void goto_convertt::convert_switch(
Expand Down