From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Fri, 23 Feb 2018 12:29:03 +0000 (+0100)
Subject: basic/log: add an assert that does not recurse into logging functions
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=47271fd56eadbc451e3ef8b2692dcc8bd2d5d8c7;p=elogind.git

basic/log: add an assert that does not recurse into logging functions

Then it can be used in the asserts in logging functions without causing
infinite recursion. The error is just printed to stderr, it should be
good enough for the common case.
---

diff --git a/src/basic/log.c b/src/basic/log.c
index f3bb69855..719702054 100644
--- a/src/basic/log.c
+++ b/src/basic/log.c
@@ -85,6 +85,16 @@ static bool prohibit_ipc = false;
  * use here. */
 static char *log_abort_msg = NULL;
 
+/* An assert to use in logging functions that does not call recursively
+ * into our logging functions (since that might lead to a loop). */
+#define assert_raw(expr)                                                \
+        do {                                                            \
+                if (_unlikely_(!(expr))) {                              \
+                        fputs(#expr "\n", stderr);                      \
+                        abort();                                        \
+                }                                                       \
+        } while (false)
+
 static void log_close_console(void) {
 
         if (console_fd < 0)
@@ -543,7 +553,7 @@ static int log_do_header(
                      isempty(extra) ? "" : extra,
                      isempty(extra) ? "" : "\n",
                      program_invocation_short_name);
-        assert((size_t) r < size);
+        assert_raw((size_t) r < size);
 
         return 0;
 }
@@ -597,7 +607,7 @@ int log_dispatch_internal(
                 const char *extra,
                 char *buffer) {
 
-        assert(buffer);
+        assert_raw(buffer);
 
         if (error < 0)
                 error = -error;