Utils/Logger: Fix SENF_LOG_CONF to support top-level areas and streams

Utils/Logger: Add some internal implementation documentation concerning SENF_LOG_CLASS_AREA()

Utils/Logger/AreaRegistry.test.cc

@@ -37,7 +37,8 @@
 
 BOOST_AUTO_UNIT_TEST(areaRegistry)
 {
-    char const * areas[] = { "senf::log::DefaultArea", 
+    char const * areas[] = { "GlobalTestArea",
+                             "senf::log::DefaultArea", 
                              "senf::log::test::Foo", 
                              "senf::log::test::myArea" };
 

Utils/Logger/Config.hh

@@ -152,7 +152,7 @@ namespace log {
             <tr><td>stream</td>       <td>::= \e scope_seq \n</td></tr>
             <tr><td>optional_area</td><td>::= <tt>(_)</tt> | \e scope_seq \n</td></tr>
             <tr><td>level</td>        <td>::= \c VERBOSE | \c NOTICE | \c MESSAGE | \c IMPORTANT | \c CRITICAL | \c DISABLED \n</td></tr>
-            <tr><td>scope_seq</td>    <td>::= \e scope \e scope \e scope* \n</td></tr>
+            <tr><td>scope_seq</td>    <td>::= \e scope \e scope* \n</td></tr>
             <tr><td>scope</td>        <td>::= <tt>(</tt> \e name <tt>)</tt> \n</td></tr>
             <tr><td>name</td>         <td>::= arbitrary C++ identifier</td></tr>
             </table>

Utils/Logger/Config.ih

@@ -41,17 +41,19 @@ namespace senf {
 namespace log {
 namespace detail {
 
+    struct na {};
+
     /// Internal: Compile time configuration for given \a Stream and \a Area
     template <class Stream, class Area>
     struct Config
     {
-        typedef typename Config<Stream,void>::compileLimit compileLimit;
+        typedef typename Config<Stream,na>::compileLimit compileLimit;
     };
 
 #   ifndef DOXYGEN
 
     template <class Stream>
-    struct Config<Stream, void>
+    struct Config<Stream, na>
     {
         typedef typename Stream::compileLimit compileLimit;
     };
@@ -68,35 +70,40 @@ namespace detail {
 #define SENF_LOG_PREDECL_(s, state, elem)                                                         \
     namespace elem { state }
 
-#define SENF_LOG_PREDECL(seq)                                                                     \
+#define SENF_LOG_PREDECL_long(seq)                                                                \
     BOOST_PP_SEQ_FOLD_RIGHT( SENF_LOG_PREDECL_,                                                   \
                              class SENF_PP_SEQ_BACK(seq);,                                        \
                              BOOST_PP_SEQ_POP_BACK(seq) )
 
+#define SENF_LOG_PREDECL_short(seq)                                                               \
+        class SENF_PP_SEQ_BACK(seq);
+
+#define SENF_LOG_PREDECL(seq)                                                                     \
+    BOOST_PP_CAT(SENF_LOG_PREDECL_,                                                               \
+                 BOOST_PP_IF(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(seq)),long,short))(seq)
+
 #define SENF_LOG_NIL(x)
 
 #define SENF_LOG_CONF_DEFINE(stream, area, level)                                                 \
     SENF_LOG_PREDECL(stream)                                                                      \
-    BOOST_PP_IF(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(area)),                                            \
-                SENF_LOG_PREDECL,                                                                 \
-                SENF_LOG_NIL)(area)                                                               \
+    SENF_LOG_PREDECL(area)                                                                        \
     namespace senf { namespace log { namespace detail {                                           \
         template <>                                                                               \
         struct Config< SENF_LOG_SEQ_TO_NAME(stream),                                              \
-                       BOOST_PP_IF(BOOST_PP_DEC(BOOST_PP_SEQ_SIZE(area)),                         \
-                                   SENF_LOG_SEQ_TO_NAME(area),                                    \
-                                   void) >                                                        \
+                       SENF_LOG_SEQ_TO_NAME(area) >                                               \
         { typedef senf::log::level compileLimit; };                                               \
     }}}
 
 #ifdef SENF_LOG_CONF
 
+#   define _ senf::log::detail::na
 #   define SLC_elt(r, data, elt) \
         SENF_LOG_CONF_DEFINE elt
 
     BOOST_PP_SEQ_FOR_EACH(SLC_elt, none, SENF_LOG_CONF)
 
 #   undef SLC_elt
+#   undef _
 
 #endif
 

Utils/Logger/Definitions.hh

@@ -56,7 +56,7 @@ namespace log {
 
         \hideinitializer
      */
-#   define SENF_LOG_DEFINE_STREAM(stream, defaultLevel_, runtimeLimit_, compileLimit_)               \
+#   define SENF_LOG_DEFINE_STREAM(stream, defaultLevel_, runtimeLimit_, compileLimit_)            \
         struct stream                                                                             \
             : public senf::log::detail::StreamBase, public senf::singleton<stream>                \
         {                                                                                         \
@@ -86,8 +86,9 @@ namespace log {
 
         \hideinitializer
      */
+    // See Definitions.ih for implementation details on SENF_LOG_CLASS_AREA
 #   define SENF_LOG_CLASS_AREA()                                                                  \
-        SENF_LOG_DEFINE_AREA_I(                                                                      \
+        SENF_LOG_DEFINE_AREA_I(                                                                   \
             SENFLogArea,                                                                          \
             std::string v_name() const                                                            \
                 { std::string s (fullName()); return std::string(s,0,s.size()-13); });            \
@@ -101,7 +102,7 @@ namespace log {
 
         \hideinitializer
      */
-#   define SENF_LOG_DEFINE_ALIAS(alias,args)                                                         \
+#   define SENF_LOG_DEFINE_ALIAS(alias,args)                                                      \
         struct alias : public senf::log::detail::AliasBase                                        \
         {                                                                                         \
             template <class Base>                                                                 \

Utils/Logger/Definitions.ih

@@ -30,7 +30,42 @@
 
 ///////////////////////////////ih.p////////////////////////////////////////
 
-#define SENF_LOG_DEFINE_AREA_I(area, decls)                                                          \
+// Implementation details concerning SENF_LOG_CLASS_AREA
+//
+// The SENF_LOG_CLASS_AREA statement shall declare the containing class as it's own default area. Of
+// course, we cannot make the containing class into an area. Therefor we need to trick around a bit:
+//
+// We begin by defining an area SENFLogArea with in the class. This area however is hacked, so that
+// it's name() member will return the name of the containing class (which is simple: just cut of the
+// last couple of characters of the name since the name will always end in '::SENFLogArea').
+//
+// This however does not allow the use of the containing class as an area. There are several places
+// which need to be adjusted to allow using the containing class as an area: The logging statements
+// (SENF_LOG), the compile time configuration via SENF_LOG_CONF and the runtime configuration via
+// route statements.
+//
+// Lets begin with the compile time configuration. The compile time configuration is done using
+// specialization of the senf::log::detail::Config template. This doesn't care, what the area
+// template argument really is. Therefore, compile-time configuration just uses the containing class
+// as is. So we need to make sure, that the logging statements use the containing class when
+// checking the compile-time limit whereas they need to use the nested SENFLogArea when calling the
+// targets.
+//
+// So let's look at the logging statements. The central logic for parsing the logging parameters is
+// in SENF_LOG_MERGE_PARAMETERS in Parameters.ih. Here we have a special case which detects classes
+// with a SENFLogArea member and then set's things up correctly: It uses the containing class for
+// compile time checking (this is, what 'area_base' typedef is for) while using the nested
+// SENFLogArea for routing (this is, what the 'area' typedef is for).
+//
+// So the last thing which needs to be adjusted is the routing which is part of the Target
+// class. Here for each template taking an area as an argument we really provide TWO templates, one
+// taking the area directly, the other checking for a nested SENFLogArea member. We can
+// differentiate these overloads using boost::enable_if and friends.
+//
+// This setup makes a class with SENF_LOG_CLASS_AREA() look like an ordinary area even though the
+// implementation is somewhat different.
+
+#define SENF_LOG_DEFINE_AREA_I(area, decls)                                                       \
     struct area                                                                                   \
         : public senf::log::detail::AreaBase, public senf::singleton<area>                        \
     {                                                                                             \

Utils/Logger/main.test.hh

@@ -33,6 +33,7 @@
 #endif
 
 #define SENF_LOG_CONF (( (senf)(log)(Debug), (_), NOTICE )) \
+                      (( (senf)(log)(test)(myStream), (GlobalTestArea), IMPORTANT )) \
                       (( (senf)(log)(test)(myStream), (senf)(log)(test)(Foo), VERBOSE ))
 
 #include "Logger.hh"
@@ -40,6 +41,8 @@
 //#include "main.test.mpp"
 ///////////////////////////////hh.p////////////////////////////////////////
 
+SENF_LOG_DEFINE_AREA(GlobalTestArea);
+
 namespace senf {
 namespace log {
 namespace test {

senf.dict

@@ -124,6 +124,7 @@ ForwardingRoute
 fraunhofer
 FroblizerArea
 GlobalScope
+GlobalTestArea
 gre
 GREPacket
 GREPacketParser