Introduce live tracing facility

Set LIBSASS_TRACE to any value
in the environment to watch
a very verbose output live.

Conflicts:
	Makefile
	Makefile.am
	src/debug.hpp
	src/util.cpp
	win/libsass.vcxproj

Makefile.conf

@@ -8,6 +8,7 @@ SOURCES = \
 	constants.cpp \
 	context.cpp \
 	cssize.cpp \
+	debug.cpp \
 	emitter.cpp \
 	environment.cpp \
 	error_handling.cpp \

src/debug.cpp

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <sstream>
+
+#include "debug.hpp"
+
+namespace Sass {
+
+  Log::Log() {} 
+
+  std::ostringstream& Log::Get(TLogLevel level, void *p, const char *f, const char *filen, int lineno)
+  {
+	 os << "[LIBSASS] " << p << ":" << f << " " << filen << ":" << lineno << " ";
+	 messageLevel = level;
+	 return os;
+  }
+  std::ostringstream& Log::Get(TLogLevel level, const char *f, const char *filen, int lineno)
+  {
+	 os << "[LIBSASS] " << f << " " << filen << ":" << lineno << " ";
+	 messageLevel = level;
+	 return os;
+  }
+  Log::~Log()
+  {
+	 os << std::endl;
+	 fprintf(stderr, "%s", os.str().c_str());
+	 fflush(stderr);
+  }
+}

src/debug.hpp

@@ -1,6 +1,7 @@
 #ifndef SASS_DEBUG_H
 #define SASS_DEBUG_H
 
+#define __STDC_LIMIT_MACROS
 #include <stdint.h>
 
 enum dbg_lvl_t : uint32_t {
@@ -16,6 +17,40 @@ enum dbg_lvl_t : uint32_t {
   ALL = UINT32_MAX
 };
 
+namespace Sass {
+  enum TLogLevel {logINFO, logTRACE};
+  static TLogLevel LibsassLogReportingLevel = getenv("LIBSASS_TRACE") ? logTRACE : logINFO;
+  class Log
+  {
+  public:
+	Log();
+	virtual ~Log();
+	std::ostringstream& Get(TLogLevel level, void *p, const char *f, const char *filen, int lineno);
+	std::ostringstream& Get(TLogLevel level, const char *f, const char *filen, int lineno);
+  public:
+  protected:
+	std::ostringstream os;
+  private:
+	Log(const Log&);
+	Log& operator =(const Log&);
+  private:
+	TLogLevel messageLevel;
+  };
+}
+
+// Visual Studio 2013 does not like __func__
+#if _MSC_VER < 1900
+#define __func__ __FUNCTION__
+#endif
+
+#define TRACE() \
+  if (logTRACE > Sass::LibsassLogReportingLevel) ; \
+  else Sass::Log().Get(Sass::logTRACE, __func__, __FILE__, __LINE__)
+
+#define TRACEINST(obj) \
+  if (logTRACE > Sass::LibsassLogReportingLevel) ; \
+  else Sass::Log().Get(Sass::logTRACE, (obj), __func__, __FILE__, __LINE__)
+
 #ifdef DEBUG
 
 #ifndef DEBUG_LVL

src/util.cpp

@@ -1,13 +1,14 @@
 #include "sass.h"
+#define __STDC_LIMIT_MACROS
+#include <stdint.h>
+
 #include "ast.hpp"
 #include "util.hpp"
 #include "lexer.hpp"
 #include "prelexer.hpp"
 #include "constants.hpp"
 #include "utf8/checked.h"
 
-#include <stdint.h>
-
 namespace Sass {
 
   #define out_of_memory() do {                    \

win/libsass.vcxproj

@@ -202,6 +202,7 @@
     <ClCompile Include="..\src\color_maps.cpp" />
     <ClCompile Include="..\src\constants.cpp" />
     <ClCompile Include="..\src\context.cpp" />
+    <ClCompile Include="..\src\debug.cpp" />
     <ClCompile Include="..\src\environment.cpp" />
     <ClCompile Include="..\src\error_handling.cpp" />
     <ClCompile Include="..\src\eval.cpp" />