Merge pull request #6378 from diffblue/is_lvalue

rename is_lvalue -> is_assignable

Author: kroening

src/analyses/variable-sensitivity/abstract_environment.cpp

@@ -711,14 +711,14 @@ exprt assume_eq_unbounded(
   const left_and_right_valuest &operands,
   const namespacet &ns)
 {
-  if(operands.left->is_top() && is_lvalue(operands.lhs))
+  if(operands.left->is_top() && is_assignable(operands.lhs))
   {
     // TOP == x
     auto constrained = std::make_shared<interval_abstract_valuet>(
       operands.right_interval(), env, ns);
     prune_assign(env, operands.left, operands.lhs, constrained, ns);
   }
-  if(operands.right->is_top() && is_lvalue(operands.rhs))
+  if(operands.right->is_top() && is_assignable(operands.rhs))
   {
     // x == TOP
     auto constrained = std::make_shared<interval_abstract_valuet>(
@@ -746,9 +746,9 @@ exprt assume_eq(
   if(meet->is_bottom())
     return false_exprt();
 
-  if(is_lvalue(operands.lhs))
+  if(is_assignable(operands.lhs))
     prune_assign(env, operands.left, operands.lhs, meet, ns);
-  if(is_lvalue(operands.rhs))
+  if(is_assignable(operands.rhs))
     prune_assign(env, operands.right, operands.rhs, meet, ns);
   return true_exprt();
 }
@@ -781,7 +781,7 @@ exprt assume_less_than_unbounded(
   const left_and_right_valuest &operands,
   const namespacet &ns)
 {
-  if(operands.left->is_top() && is_lvalue(operands.lhs))
+  if(operands.left->is_top() && is_assignable(operands.lhs))
   {
     // TOP < x, so prune range is min->right.upper
     auto pruned_expr = constant_interval_exprt(
@@ -792,7 +792,7 @@ exprt assume_less_than_unbounded(
       std::make_shared<interval_abstract_valuet>(pruned_expr, env, ns);
     prune_assign(env, operands.left, operands.lhs, constrained, ns);
   }
-  if(operands.right->is_top() && is_lvalue(operands.rhs))
+  if(operands.right->is_top() && is_assignable(operands.rhs))
   {
     // x < TOP, so prune range is left.lower->max
     auto pruned_expr = constant_interval_exprt(
@@ -830,15 +830,15 @@ exprt assume_less_than(
   auto result = env.eval(reduced_le_expr, ns)->to_constant();
   if(result.is_true())
   {
-    if(is_lvalue(operands.lhs))
+    if(is_assignable(operands.lhs))
     {
       auto pruned_upper = constant_interval_exprt::get_min(
         left_interval.get_upper(), right_upper);
       auto constrained =
         as_value(operands.left)->constrain(left_lower, pruned_upper);
       prune_assign(env, operands.left, operands.lhs, constrained, ns);
     }
-    if(is_lvalue(operands.rhs))
+    if(is_assignable(operands.rhs))
     {
       auto pruned_lower = constant_interval_exprt::get_max(
         left_lower, right_interval.get_lower());

src/goto-programs/builtin_functions.cpp

@@ -597,7 +597,7 @@ exprt make_va_list(const exprt &expr)
   if(result.id() == ID_address_of)
   {
     const auto &address_of_expr = to_address_of_expr(result);
-    if(is_lvalue(address_of_expr.object()))
+    if(is_assignable(address_of_expr.object()))
       result = address_of_expr.object();
   }
 
@@ -1156,7 +1156,7 @@ void goto_convertt::do_function_call_symbol(
     exprt dest_expr=make_va_list(arguments[0]);
     const typecast_exprt src_expr(arguments[1], dest_expr.type());
 
-    if(!is_lvalue(dest_expr))
+    if(!is_assignable(dest_expr))
     {
       error().source_location=dest_expr.find_source_location();
       error() << "va_copy argument expected to be lvalue" << eom;
@@ -1179,7 +1179,7 @@ void goto_convertt::do_function_call_symbol(
 
     exprt dest_expr=make_va_list(arguments[0]);
 
-    if(!is_lvalue(dest_expr))
+    if(!is_assignable(dest_expr))
     {
       error().source_location=dest_expr.find_source_location();
       error() << "va_start argument expected to be lvalue" << eom;
@@ -1214,7 +1214,7 @@ void goto_convertt::do_function_call_symbol(
 
     exprt dest_expr=make_va_list(arguments[0]);
 
-    if(!is_lvalue(dest_expr))
+    if(!is_assignable(dest_expr))
     {
       error().source_location=dest_expr.find_source_location();
       error() << "va_end argument expected to be lvalue" << eom;

src/util/expr_util.cpp

@@ -18,19 +18,20 @@ Author: Daniel Kroening, kroening@kroening.com
 #include "pointer_expr.h"
 #include "std_expr.h"
 
-bool is_lvalue(const exprt &expr)
+bool is_assignable(const exprt &expr)
 {
   if(expr.id() == ID_index)
-    return is_lvalue(to_index_expr(expr).array());
+    return is_assignable(to_index_expr(expr).array());
   else if(expr.id() == ID_member)
-    return is_lvalue(to_member_expr(expr).compound());
+    return is_assignable(to_member_expr(expr).compound());
   else if(expr.id() == ID_dereference)
     return true;
   else if(expr.id() == ID_symbol)
     return true;
   else
     return false;
 }
+
 exprt make_binary(const exprt &expr)
 {
   const exprt::operandst &operands=expr.operands();

src/util/expr_util.h

@@ -29,8 +29,12 @@ class if_exprt;
 class typet;
 class namespacet;
 
-/// Returns true iff the argument is (syntactically) an lvalue.
-bool is_lvalue(const exprt &expr);
+/// Returns true iff the argument is one of the following:
+/// * a symbol
+/// * a dereference
+/// * an array element
+/// * a struct member
+bool is_assignable(const exprt &);
 
 /// splits an expression with >=3 operands into nested binary expressions
 exprt make_binary(const exprt &);

src/util/replace_symbol.cpp

@@ -335,7 +335,7 @@ bool address_of_aware_replace_symbolt::replace_symbol_expr(
   if(unchecked_replace_symbolt::replace_symbol_expr(s_copy))
     return true;
 
-  if(require_lvalue && !is_lvalue(s_copy))
+  if(require_lvalue && !is_assignable(s_copy))
     return true;
 
   // Note s_copy is no longer a symbol_exprt due to the replace operation,