rework on PROGMEMSTRING feature

On those systems not needing such a feature, the macro substitutes to
the string constant, only. Nevertheless, the ProgmemString is usable  as
well on such systems. Furthermore, some glitches with not well behaving
compilers are workaround. One thing is the placement of the logging
strings within special section beginning with ".progmem.logging-cpp.".
This allows selective removing of messages through the linker by garbage
collecting unused sections. Doing not so, leading to have all log
messages in one section. Disabling some levels would work, but despite
this the messages of disabled level would be part of the executable, but
this needs to be avoided.

include/logging/OutputStream.h

@@ -41,7 +41,7 @@
 #define __OutputStream_h__
 
 #include "logging/Logger.h"
-#include "logging/ProgramMemoryStringImpl.h"
+#include "logging/ProgramMemoryString.h"
 
 namespace logging {
 
@@ -137,7 +137,7 @@ namespace logging {
              * \param string the character string, that is output
              * \return %OutputStream& allows for chaining of operators
              */
-            OutputStream& operator << ( PROGMEMSTRINGTYPE pms) {
+            OutputStream& operator << ( PROGMEMSTRINGTYPE& pms) {
                 while ( *pms ) {
                     put(*pms);
                     ++pms;

include/logging/ProgramMemoryString.h

@@ -40,6 +40,9 @@
 #ifndef __ProgramMemoryString_h__
 #define __ProgramMemoryString_h__
 
+#define __STRINGIFICATION__(x) #x
+#define __TOSTR__(x) __STRINGIFICATION__(x)
+
 /*!
  * \def PROGMEMSTRING
  * \brief A %PROGMEMSTRING enables the placement of string constants in the
@@ -61,14 +64,23 @@
  *
  * \param s the string constant
  */
-#define PROGMEMSTRING(s)                                            \
-    (__extension__({                                                \
-        static PROGMEMTYPE __str[] = (s);                           \
-        const ::logging::ProgramMemoryString __pms = {&__str[0]};   \
-        __pms;                                                      \
+#define PROGMEMSTRING(S)                                                    \
+    (__extension__({                                                        \
+        static                                                              \
+           char __attribute__  ((                                           \
+                            section(                                        \
+                                __TOSTR__(                                  \
+                                    __TOSTR__(.progmem.logging-cpp.S)       \
+                                )                                           \
+                            )                                               \
+                        ))  __str[] = (S);                                  \
+        const ::logging::ProgramMemoryString __pms = {&__str[0]};           \
+        __pms;                                                              \
     }))
 
 #define PROGMEMSTRINGTYPE const ::logging::ProgramMemoryString
 
+#include "logging/ProgramMemoryStringImpl.h"
+
 #endif // __ProgramMemoryString_h__
 

include/logging/ProgramMemoryStringImpl.h

@@ -40,16 +40,14 @@
 #ifndef __ProgramMemoryStringImpl_h__
 #define __ProgramMemoryStringImpl_h__
 
-#include "logging/ProgramMemoryString.h"
-
 #ifdef __AVR__
 
 #include <avr/pgmspace.h>
-#define PROGMEMTYPE char __attribute__((section(".progmem.logging-cpp")))
 
 #else /* !__AVR__ */
 
-#define PROGMEMTYPE char
+#undef PROGMEMSTRING
+#define PROGMEMSTRING(S) S
 
 static inline char pgm_read_byte_far(const char* t) {
     return *t;

tst/Makefile

@@ -41,6 +41,8 @@ CXXFLAGS=-I../include -Wall -Os
 
 filtered=$(filter-out %.cc %.h %.py %.impl %Makefile,$(shell find . -maxdepth 1 -type f))
 
+LDFLAGS=-Wl,--gc-sections
+
 .phony: all clean
 
 all:

tst/logging-ProgmemStringFeature.cc

@@ -0,0 +1,70 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2008, 2009 Michael Schulze <mschulze@ivs.cs.uni-magdeburg.de>
+ * All rights reserved.
+ *
+ *    Redistribution and use in source and binary forms, with or without
+ *    modification, are permitted provided that the following conditions
+ *    are met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *    * Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in
+ *      the documentation and/or other materials provided with the
+ *      distribution.
+ *
+ *    * Neither the name of the copyright holders nor the names of
+ *      contributors may be used to endorse or promote products derived
+ *      from this software without specific prior written permission.
+ *
+ *
+ *    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ *    IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ *    TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+ *    PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * $Id$
+ *
+ ******************************************************************************/
+
+// for at90can128 with 16MHz CPU clock
+#define CPU_FREQUENCY 16000000
+
+//#define LOGGING_DISABLE
+#include "logging/logging.h"
+using namespace ::logging;
+
+// logging levels can be disabled at compile time
+//LOGGING_DISABLE_LEVEL(::logging::Error);
+
+
+struct Test {
+    Test() {
+        ::logging::log::emit< ::logging::Info>() << PROGMEMSTRING("Test::Test()")
+            << ::logging::log::endl;
+    }
+    ~Test() {
+        ::logging::log::emit< ::logging::Info>() << PROGMEMSTRING("~Test::Test()")
+            << ::logging::log::endl;
+    }
+};
+
+int main(int, char**) {
+    ::logging::log::emit() << "Hello World! with the logging framework"
+        << ::logging::log::endl << ::logging::log::endl;
+
+    ::logging::log::emit< ::logging::Error>()
+        << PROGMEMSTRING("Logging an Error")
+        << ::logging::log::endl;
+    return 0;
+}