includes: add xalloc.h to unify memory allocations

The xalloc.h provides necessary error checking.

Signed-off-by: Jim Warner <james.warner@comcast.net>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

include/xalloc.h

@@ -0,0 +1,56 @@
+/*
+ * General memory allocation wrappers for malloc, realloc, calloc
+ * and strdup.
+ */
+
+#ifndef PROCPS_NG_XALLOC_H
+#define PROCPS_NG_XALLOC_H
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "c.h"
+
+#ifndef XALLOC_EXIT_CODE
+# define XALLOC_EXIT_CODE EXIT_FAILURE
+#endif
+
+static inline __ul_alloc_size(1)
+void *xmalloc(const size_t size)
+{
+	void *ret = malloc(size);
+	if (!ret && size)
+		err(XALLOC_EXIT_CODE, "cannot allocate %zu bytes", size);
+	return ret;
+}
+
+static inline __ul_alloc_size(2)
+void *xrealloc(void *ptr, const size_t size)
+{
+	void *ret = realloc(ptr, size);
+	if (!ret && size)
+		err(XALLOC_EXIT_CODE, "cannot allocate %zu bytes", size);
+	return ret;
+}
+
+static inline __ul_calloc_size(1, 2)
+void *xcalloc(const size_t nelems, const size_t size)
+{
+	void *ret = calloc(nelems, size);
+	if (!ret && size && nelems)
+		err(XALLOC_EXIT_CODE, "cannot allocate %zu bytes", size);
+	return ret;
+}
+
+static inline char *xstrdup(const char *str)
+{
+	char *ret;
+	if (!str)
+		return NULL;
+	ret = strdup(str);
+	if (!ret)
+		err(XALLOC_EXIT_CODE, "cannot duplicate string");
+	return ret;
+}
+
+#endif /* PROCPS_NG_XALLOC_H */