dwarflint: Support composed messages

- This should be used like this:
   bool whether = false;
   wr_message (where, cat).id (this, whether) << stuff stuff;
   wr_message (where2, cat2).when (whether) << stuffy stuff;

2 files changed, 42 insertions, 16 deletions

diff --git a/dwarflint/messages.cc b/dwarflint/messages.cc
index 04519197..4d63e2e8 100644
--- a/dwarflint/messages.cc
+++ b/dwarflint/messages.cc
@@ -328,17 +328,6 @@ message_count_filter::should_emit (void const *key)
     return 1;
 }
 
-std::ostream &
-message_context::emit (char const *str)
-{
-  ++error_count;
-  std::ostream &ret = get_stream ();
-  ret << _m_prefix;
-  if (_m_where)
-    ret << *_m_where << ": ";
-  return ret << str;
-}
-
 message_context::message_context (message_count_filter *filter,
 				  where const *where, char const *prefix)
   : _m_filter (filter)
@@ -347,22 +336,50 @@ message_context::message_context (message_count_filter *filter,
 {}
 
 std::ostream &
-message_context::operator << (char const *message)
+message_context::when (bool whether)
+{
+  if (whether)
+    return get_stream ();
+  else
+    return nostream;
+}
+
+std::ostream &
+message_context::id (void const *key, bool &whether)
 {
   if (_m_filter == NULL)
     return nostream;
-  else if (int status = _m_filter->should_emit (message))
+  else if (int status = _m_filter->should_emit (key))
     {
+      ++error_count;
       if (status == -1)
 	get_stream () << "(threshold reached for the following message)"
 		      << std::endl;
-      return emit (message);
+      whether = true;
+      return get_stream ();
     }
   else
     return nostream;
 }
 
 std::ostream &
+message_context::id (void const *key)
+{
+  bool whether;
+  return id (key, whether);
+}
+
+std::ostream &
+message_context::operator << (char const *message)
+{
+  std::ostream &ret = id (message);
+  ret << _m_prefix;
+  if (_m_where)
+    ret << *_m_where << ": ";
+  return ret << message;
+}
+
+std::ostream &
 message_context::operator << (std::string const &message)
 {
   return *this << message.c_str ();
diff --git a/dwarflint/messages.hh b/dwarflint/messages.hh
index 0efc9d36..bd945c42 100644
--- a/dwarflint/messages.hh
+++ b/dwarflint/messages.hh
@@ -187,8 +187,6 @@ class message_context
   friend message_context wr_message (where const &wh, message_category cat);
   friend message_context wr_message (message_category cat);
 
-  std::ostream &emit (char const *str);
-
   message_context (message_count_filter *filter,
 		   where const *where, char const *prefix);
 
@@ -207,6 +205,17 @@ public:
     ss << t;
     return (*this) << ss.str ();
   }
+
+  // Use KEY for count filtering.
+  std::ostream &id (void const *key);
+
+  // Use KEY for count filtering.  WHETHER is true if the message will
+  // be emitted.  It doesn't touch that value otherwise, so WHETHER
+  // must be pre-initialized to false.
+  std::ostream &id (void const *key, bool &whether);
+
+  // Return either the full stream, or a sink, depending on WHETHER.
+  std::ostream &when (bool whether);
 };
 
 std::ostream &wr_error (where const &wh);