From d575f579bcd604910847219c64c9a5e79af1dd17 Mon Sep 17 00:00:00 2001
From: Snaipe <franklinmathieu@gmail.com>
Date: Mon, 9 Mar 2015 02:36:09 +0100
Subject: [PATCH] Added logging facilities

---
 Makefile.am                 |  2 ++
 include/criterion/common.h  |  6 ++++++
 include/criterion/logging.h | 19 +++++++++++++++++++
 src/logging.c               | 16 ++++++++++++++++
 4 files changed, 43 insertions(+)
 create mode 100644 include/criterion/logging.h
 create mode 100644 src/logging.c

diff --git a/Makefile.am b/Makefile.am
index 00a090d..e889c93 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -28,6 +28,7 @@ subdirinclude_HEADERS = \
 	include/criterion/criterion.h \
 	include/criterion/event.h \
 	include/criterion/hooks.h \
+	include/criterion/logging.h \
 	include/criterion/stats.h
 
 libcriterion_la_SOURCES = \
@@ -41,4 +42,5 @@ libcriterion_la_SOURCES = \
 	src/process.h \
 	src/stats.c \
 	src/stats.h \
+	src/logging.c \
 	src/main.c
diff --git a/include/criterion/common.h b/include/criterion/common.h
index a2ae32a..30995eb 100644
--- a/include/criterion/common.h
+++ b/include/criterion/common.h
@@ -27,4 +27,10 @@
 # define SECTION_(Name) __attribute__((section(Name)))
 # define UNUSED __attribute__((unused))
 
+# ifdef __GNUC__
+#  define FORMAT(Archetype, Index, Ftc) __attribute__((format(Archetype, Index, Ftc)))
+# else
+#  define FORMAT(Archetype, Index, Ftc)
+# endif
+
 #endif /* !CRITERION_COMMON_H_ */
diff --git a/include/criterion/logging.h b/include/criterion/logging.h
new file mode 100644
index 0000000..dfc6c53
--- /dev/null
+++ b/include/criterion/logging.h
@@ -0,0 +1,19 @@
+#ifndef CRITERION_LOGGING_H_
+# define CRITERION_LOGGING_H_
+
+#include "common.h"
+
+enum criterion_logging_level {
+    CRITERION_INFO = 1,
+    CRITERION_IMPORTANT,
+};
+
+extern enum criterion_logging_level logging_threshold;
+
+FORMAT(printf, 2, 3)
+void criterion_log(enum criterion_logging_level level, const char *msg, ...);
+
+# define criterion_info(...) criterion_log(CRITERION_INFO, __VA_ARGS__)
+# define criterion_important(...) criterion_log(CRITERION_IMPORTANT, __VA_ARGS__)
+
+#endif /* !CRITERION_LOGGING_H_ */
diff --git a/src/logging.c b/src/logging.c
new file mode 100644
index 0000000..803a717
--- /dev/null
+++ b/src/logging.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <stdarg.h>
+#include "criterion/logging.h"
+
+enum criterion_logging_level logging_threshold = CRITERION_IMPORTANT;
+
+void criterion_log(enum criterion_logging_level level, const char *msg, ...) {
+    va_list args;
+
+    if (level < logging_threshold)
+        return;
+
+    va_start(args, msg);
+    vfprintf(stderr, msg, args);
+    va_end(args);
+}