From 10c611a3f1e2cb6c796a3eb1b3aaf77b69b3466b Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Fri, 13 Dec 2013 12:22:36 -0800
Subject: [PATCH] Add a check that we've made it into the C runtime when doing
 dlopen().

This should give us a more informative failure mode than the one
mentioned in the README.
---
 src/dispatch_common.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/dispatch_common.c b/src/dispatch_common.c
index 8d7c1d1..03d08fc 100644
--- a/src/dispatch_common.c
+++ b/src/dispatch_common.c
@@ -157,12 +157,29 @@ static struct api api = {
 };
 
 #ifndef _WIN32
+static bool library_initialized;
+
+static void
+library_init(void) __attribute__((constructor));
+
+static void
+library_init(void)
+{
+    library_initialized = true;
+}
+
 static void
 get_dlopen_handle(void **handle, const char *lib_name, bool exit_on_fail)
 {
     if (*handle)
         return;
 
+    if (!library_initialized) {
+        fprintf(stderr,
+                "Attempting to dlopen() while in the dynamic linker.\n");
+        abort();
+    }
+
     pthread_mutex_lock(&api.mutex);
     if (!*handle) {
         *handle = dlopen(lib_name, RTLD_LAZY | RTLD_LOCAL);