initial commit
diff --git a/src/common.h b/src/common.h
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--- /dev/null
+++ b/src/common.h
@@ -0,0 +1,100 @@
+/**
+ * @file common.h
+ * @author Radek Krejci <rkrejci@cesnet.cz>
+ * @brief common internal definitions for libyang
+ *
+ * Copyright (c) 2015 - 2018 CESNET, z.s.p.o.
+ *
+ * This source code is licensed under BSD 3-Clause License (the "License").
+ * You may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://opensource.org/licenses/BSD-3-Clause
+ */
+
+#ifndef LY_COMMON_H_
+#define LY_COMMON_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "libyang.h"
+
+#define UNUSED(x) UNUSED_ ## x __attribute__((__unused__))
+
+#if __STDC_VERSION__ >= 201112 && !defined __STDC_NO_THREADS__
+# define THREAD_LOCAL _Thread_local
+#elif defined __GNUC__ || \
+ defined __SUNPRO_C || \
+ defined __xlC__
+# define THREAD_LOCAL __thread
+#else
+# error "Cannot define THREAD_LOCAL"
+#endif
+
+#define GETMACRO2(_1, _2, NAME, ...) NAME
+#define GETMACRO3(_1, _2, _3, NAME, ...) NAME
+#define GETMACRO4(_1, _2, _3, _4, NAME, ...) NAME
+
+/*
+ * logger
+ */
+
+/* internal logging options */
+enum int_log_opts {
+ ILO_LOG = 0, /* log normally */
+ ILO_STORE, /* only store any messages, they will be processed higher on stack */
+ ILO_IGNORE, /* completely ignore messages */
+ ILO_ERR2WRN, /* change errors to warnings */
+};
+
+extern THREAD_LOCAL enum int_log_opts log_opt;
+extern volatile uint8_t ly_log_level;
+extern volatile uint8_t ly_log_opts;
+
+void ly_log(const struct ly_ctx *ctx, LY_LOG_LEVEL level, LY_ERR no, const char *format, ...);
+
+#define LOGERR(ctx, errno, str, args...) ly_log(ctx, LY_LLERR, errno, str, ##args)
+#define LOGWRN(ctx, str, args...) ly_log(ctx, LY_LLWRN, 0, str, ##args)
+#define LOGVRB(str, args...) ly_log(NULL, LY_LLVRB, 0, str, ##args)
+
+#define LOGMEM(CTX) LOGERR(CTX, LY_EMEM, "Memory allocation failed (%s()).", __func__)
+#define LOGINT(CTX) LOGERR(CTX, LY_EINT, "Internal error (%s:%d).", __FILE__, __LINE__)
+#define LOGARG(CTX, ARG) LOGERR(CTX, LY_EINVAL, "Invalid argument %s (%s()).", #ARG, __func__)
+
+/*
+ * Common code to check return value and perform appropriate action.
+ */
+#define LY_CHECK_GOTO(COND, GOTO) if (COND) {goto GOTO;}
+#define LY_CHECK_ERR_GOTO(COND, ERR, GOTO) if (COND) {ERR; goto GOTO;}
+#define LY_CHECK_RETURN(COND, RETVAL) if (COND) {return RETVAL;}
+#define LY_CHECK_ERR_RETURN(COND, ERR, RETVAL) if (COND) {ERR; return RETVAL;}
+
+#define LY_CHECK_ARG_NON_NULL_GOTO1(CTX, ARG, GOTO) if (!ARG) {LOGARG(CTX, ARG);goto GOTO;}
+#define LY_CHECK_ARG_NON_NULL_GOTO2(CTX, ARG1, ARG2, GOTO) LY_CHECK_ARG_NON_NULL_GOTO1(CTX, ARG1, GOTO);LY_CHECK_ARG_NON_NULL_GOTO1(CTX, ARG2, GOTO)
+#define LY_CHECK_ARG_NON_NULL_GOTO3(CTX, ARG1, ARG2, ARG3, GOTO) LY_CHECK_ARG_NON_NULL_GOTO2(CTX, ARG1, ARG2, GOTO);LY_CHECK_ARG_NON_NULL_GOTO1(CTX, ARG3, GOTO)
+#define LY_CHECK_ARG_NON_NULL_GOTO(CTX, ...) GETMACRO4(__VA_ARGS__, LY_CHECK_ARG_NON_NULL_GOTO3, LY_CHECK_ARG_NON_NULL_GOTO2, LY_CHECK_ARG_NON_NULL_GOTO1)(CTX, __VA_ARGS__)
+
+#define LY_CHECK_ARG_NON_NULL_RETURN1(CTX, ARG, RETVAL) if (!ARG) {LOGARG(CTX, ARG);return RETVAL;}
+#define LY_CHECK_ARG_NON_NULL_RETURN2(CTX, ARG1, ARG2, RETVAL) LY_CHECK_ARG_NON_NULL_RETURN1(CTX, ARG1, RETVAL);LY_CHECK_ARG_NON_NULL_RETURN1(CTX, ARG2, RETVAL)
+#define LY_CHECK_ARG_NON_NULL_RETURN3(CTX, ARG1, ARG2, ARG3, RETVAL) LY_CHECK_ARG_NON_NULL_RETURN2(CTX, ARG1, ARG2, RETVAL);LY_CHECK_ARG_NON_NULL_RETURN1(CTX, ARG3, RETVAL)
+#define LY_CHECK_ARG_NON_NULL_RETURN(CTX, ...) GETMACRO4(__VA_ARGS__, LY_CHECK_ARG_NON_NULL_RETURN3, LY_CHECK_ARG_NON_NULL_RETURN2, LY_CHECK_ARG_NON_NULL_RETURN1)(CTX, __VA_ARGS__)
+
+#define LY_CHECK_ARG_NULL_GOTO1(CTX, ARG, GOTO) if (ARG) {LOGARG(CTX, ARG);goto GOTO;}
+#define LY_CHECK_ARG_NULL_GOTO2(CTX, ARG1, ARG2, GOTO) LY_CHECK_ARG_NULL_GOTO1(CTX, ARG1, GOTO);LY_CHECK_ARG_NULL_GOTO1(CTX, ARG2, GOTO)
+#define LY_CHECK_ARG_NULL_GOTO3(CTX, ARG1, ARG2, ARG3, GOTO) LY_CHECK_ARG_NULL_GOTO2(CTX, ARG1, ARG2, GOTO);LY_CHECK_ARG_NULL_GOTO1(CTX, ARG3, GOTO)
+#define LY_CHECK_ARG_NULL_GOTO(CTX, ...) GETMACRO4(__VA_ARGS__, LY_CHECK_ARG_NULL_GOTO3, LY_CHECK_ARG_NULL_GOTO2, LY_CHECK_ARG_NULL_GOTO1)(CTX, __VA_ARGS__)
+
+#define LY_CHECK_ARG_NULL_RETURN1(CTX, ARG, RETVAL) if (ARG) {LOGARG(CTX, ARG);return RETVAL;}
+#define LY_CHECK_ARG_NULL_RETURN2(CTX, ARG1, ARG2, RETVAL) LY_CHECK_ARG_NULL_RETURN1(CTX, ARG1, RETVAL);LY_CHECK_ARG_NULL_RETURN1(CTX, ARG2, RETVAL)
+#define LY_CHECK_ARG_NULL_RETURN3(CTX, ARG1, ARG2, ARG3, RETVAL) LY_CHECK_ARG_NULL_RETURN2(CTX, ARG1, ARG2, RETVAL);LY_CHECK_ARG_NULL_RETURN1(CTX, ARG3, RETVAL)
+#define LY_CHECK_ARG_NULL_RETURN(CTX, ...) GETMACRO4(__VA_ARGS__, LY_CHECK_ARG_NULL_RETURN3, LY_CHECK_ARG_NULL_RETURN2, LY_CHECK_ARG_NULL_RETURN1)(CTX, __VA_ARGS__)
+
+/*
+ * If the compiler supports attribute to mark objects as hidden, mark all
+ * objects as hidden and export only objects explicitly marked to be part of
+ * the public API.
+ */
+#define API __attribute__((visibility("default")))
+
+#endif /* LY_COMMON_H_ */