Error handling cleanup in expr_initializer.cpp (and implied changes)

Author: danpoe

src/ansi-c/ansi_c_entry_point.cpp

@@ -177,8 +177,7 @@ bool ansi_c_entry_point(
     return false; // give up
   }
 
-  if(static_lifetime_init(symbol_table, symbol.location, message_handler))
-    return true;
+  static_lifetime_init(symbol_table, symbol.location, message_handler);
 
   return generate_ansi_c_start_function(symbol, symbol_table, message_handler);
 }

src/linking/static_lifetime_init.cpp

@@ -117,16 +117,10 @@ bool static_lifetime_init(
 
     if(symbol.value.is_nil())
     {
-      try
-      {
-        namespacet ns(symbol_table);
-        rhs=zero_initializer(symbol.type, symbol.location, ns, message_handler);
-        assert(rhs.is_not_nil());
-      }
-      catch(...)
-      {
-        return true;
-      }
+      namespacet ns(symbol_table);
+      rhs = zero_initializer(symbol.type, symbol.location, ns, message_handler);
+      INVARIANT(
+        rhs.is_not_nil(), "result of zero-initialization must be non-nil");
     }
     else
       rhs=symbol.value;

src/util/expr_initializer.cpp

@@ -56,6 +56,10 @@ exprt expr_initializert<nondet>::expr_initializer_rec(
 {
   const irep_idt &type_id=type.id();
 
+  PRECONDITION(
+    type_id != ID_code,
+    source_location.as_string() + ": cannot initialize code type");
+
   if(type_id==ID_unsignedbv ||
      type_id==ID_signedbv ||
      type_id==ID_pointer ||
@@ -119,12 +123,6 @@ exprt expr_initializert<nondet>::expr_initializer_rec(
     result.add_source_location()=source_location;
     return result;
   }
-  else if(type_id==ID_code)
-  {
-    error().source_location=source_location;
-    error() << "cannot initialize code-type" << eom;
-    throw 0;
-  }
   else if(type_id==ID_array)
   {
     const array_typet &array_type=to_array_type(type);
@@ -160,10 +158,15 @@ exprt expr_initializert<nondet>::expr_initializer_rec(
         if(nondet)
           return side_effect_expr_nondett(type, source_location);
 
-        error().source_location=source_location;
-        error() << "failed to zero-initialize array of non-fixed size `"
-                << format(array_type.size()) << "'" << eom;
-        throw 0;
+        std::ostringstream oss;
+        oss << format(array_type.size());
+
+        INVARIANT(
+          false,
+          "non-infinite array size expression must be convertible to an "
+          "integer",
+          source_location.as_string() +
+            ": failed to zero-initialize array of size `" + oss.str() + "'");
       }
 
       DATA_INVARIANT(
@@ -188,10 +191,14 @@ exprt expr_initializert<nondet>::expr_initializer_rec(
       if(nondet)
         return side_effect_expr_nondett(type, source_location);
 
-      error().source_location=source_location;
-      error() << "failed to zero-initialize vector of non-fixed size `"
-              << format(vector_type.size()) << "'" << eom;
-      throw 0;
+      std::ostringstream oss;
+      oss << format(vector_type.size());
+
+      INVARIANT(
+        false,
+        "vector size must be convertible to an integer",
+        source_location.as_string() +
+          ": failed to zero-initialize vector of size `" + oss.str() + "'");
     }
 
     DATA_INVARIANT(
@@ -323,9 +330,12 @@ exprt expr_initializert<nondet>::expr_initializer_rec(
   }
   else
   {
-    error().source_location=source_location;
-    error() << "failed to initialize `" << format(type) << "'" << eom;
-    throw 0;
+    std::ostringstream oss;
+    oss << format(type);
+
+    PRECONDITION(
+      false,
+      source_location.as_string() + ": cannot initialize " + oss.str() + "'");
   }
 }
 
@@ -354,35 +364,17 @@ exprt zero_initializer(
   const source_locationt &source_location,
   const namespacet &ns)
 {
-  std::ostringstream oss;
-  stream_message_handlert mh(oss);
-
-  try
-  {
-    expr_initializert<false> z_i(ns, mh);
-    return z_i(type, source_location);
-  }
-  catch(int)
-  {
-    throw oss.str();
-  }
+  null_message_handlert null_message_handler;
+  expr_initializert<false> z_i(ns, null_message_handler);
+  return z_i(type, source_location);
 }
 
 exprt nondet_initializer(
   const typet &type,
   const source_locationt &source_location,
   const namespacet &ns)
 {
-  std::ostringstream oss;
-  stream_message_handlert mh(oss);
-
-  try
-  {
-    expr_initializert<true> z_i(ns, mh);
-    return z_i(type, source_location);
-  }
-  catch(int)
-  {
-    throw oss.str();
-  }
+  null_message_handlert null_message_handler;
+  expr_initializert<true> z_i(ns, null_message_handler);
+  return z_i(type, source_location);
 }