Use extended interpretation of "is constant"

Author: tautschnig

regression/goto-analyzer/constant_propagation_09/test.desc

@@ -1,9 +1,8 @@
-FUTURE
+KNOWNBUG
 main.c
---constants --simplify out.gb
+--constants --verify
 ^EXIT=0$
 ^SIGNAL=0$
-^Simplified:  assert: 1, assume: 0, goto: 3, assigns: 4, function calls: 0$
-^Unmodified:  assert: 0, assume: 0, goto: 0, assigns: 11, function calls: 2$
+^\[main.assertion.1\] line 9 assertion a\[(\(signed( long)? long int\))?0\] == 0: FAILURE \(if reachable\)$
 --
 ^warning: ignoring

regression/goto-analyzer/constant_propagation_10/test.desc

@@ -1,8 +1,8 @@
-FUTURE
+CORE
 main.c
 --constants --verify
 ^EXIT=0$
 ^SIGNAL=0$
-^\[main.assertion.1\] file main.c line 10 function main, assertion a\[(\(signed( long)? long int\))?0\] == 2: FAILURE$
+^\[main.assertion.1\] line 10 assertion a\[(\(signed( long)? long int\))?0\] == 2: FAILURE \(if reachable\)$
 --
 ^warning: ignoring

regression/goto-analyzer/constant_propagation_11/test.desc

@@ -1,9 +1,8 @@
-FUTURE
+KNOWNBUG
 main.c
---constants --simplify out.gb
+--constants --verify
 ^EXIT=0$
 ^SIGNAL=0$
-^Simplified:  assert: 1, assume: 0, goto: 0, assigns: 0, function calls: 0$
-^Unmodified:  assert: 0, assume: 0, goto: 0, assigns: 0, function calls: 0$
+^\[main.assertion.1\] line 9 assertion a\[(\(signed( long)? long int\))?0\] == 1: SUCCESS$
 --
 ^warning: ignoring

regression/goto-analyzer/constant_propagation_15/test.desc

@@ -1,8 +1,8 @@
-FUTURE
+CORE
 main.c
 --constants --verify
 ^EXIT=0$
 ^SIGNAL=0$
-^\[main.assertion.1\] file main.c line 9 function main, assertion a\[(\(signed( long)? long int\))?0\] == 2: FAILURE$
+^\[main.assertion.1\] line 9 assertion a\[(\(signed( long)? long int\))?0\] == 2: FAILURE \(if reachable\)$
 --
 ^warning: ignoring

src/analyses/constant_propagator.cpp

@@ -47,7 +47,7 @@ void constant_propagator_domaint::assign_rec(
   exprt tmp=rhs;
   partial_evaluate(dest_values, tmp, ns);
 
-  if(tmp.is_constant())
+  if(dest_values.is_constant(tmp))
   {
     DATA_INVARIANT(
       base_type_eq(ns.lookup(s).type, tmp.type(), ns),