Improved allocation failure reporting

Now it reports file and line number of the function too.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

src/utils.c

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <sys/uio.h>
+
+#include "compiler.h"
+#include "string_utils.h"
+#include "utils.h"
+
+/// Report allocation failure without allocating memory
+void report_allocation_failure(const char *func, const char *file, unsigned int line) {
+	// Since memory allocation failed, we try to print this error message without any
+	// memory allocation. Since logging framework allocates memory (and might even
+	// have not been initialized yet), so we can't use it.
+	char buf[11];
+	int llen = uitostr(line, buf);
+	const char msg1[] = " has failed to allocate memory, ";
+	const char msg2[] = ". Aborting...\n";
+	const struct iovec v[] = {
+	    {.iov_base = (void *)func, .iov_len = strlen(func)},
+	    {.iov_base = "()", .iov_len = 2},
+	    {.iov_base = (void *)msg1, .iov_len = sizeof(msg1) - 1},
+	    {.iov_base = "at ", .iov_len = 3},
+	    {.iov_base = (void *)file, .iov_len = strlen(file)},
+	    {.iov_base = ":", .iov_len = 1},
+	    {.iov_base = buf, .iov_len = llen},
+	    {.iov_base = (void *)msg2, .iov_len = sizeof(msg2) - 1},
+	};
+
+	writev(STDERR_FILENO, v, ARR_SIZE(v));
+	abort();
+
+	unreachable;
+}
+
+// vim: set noet sw=8 ts=8 :