1 files changed, 39 insertions, 0 deletions
diff --git a/src/shared/dlfcn-util.h b/src/shared/dlfcn-util.h
new file mode 100644
index 0000000..7d8cb4c
--- /dev/null
+++ b/src/shared/dlfcn-util.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <dlfcn.h>
+
+#include "macro.h"
+
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(void*, dlclose, NULL);
+
+int dlsym_many_or_warn_sentinel(void *dl, int log_level, ...) _sentinel_;
+int dlopen_many_sym_or_warn_sentinel(void **dlp, const char *filename, int log_level, ...) _sentinel_;
+
+#define dlsym_many_or_warn(dl, log_level, ...) \
+        dlsym_many_or_warn_sentinel(dl, log_level, __VA_ARGS__, NULL)
+#define dlopen_many_sym_or_warn(dlp, filename, log_level, ...) \
+        dlopen_many_sym_or_warn_sentinel(dlp, filename, log_level, __VA_ARGS__, NULL)
+
+#define DLSYM_PROTOTYPE(symbol)                 \
+        extern typeof(symbol)* sym_##symbol
+#define DLSYM_FUNCTION(symbol)                  \
+        typeof(symbol)* sym_##symbol = NULL
+
+/* Macro useful for putting together variable/symbol name pairs when calling dlsym_many_or_warn(). Assumes
+ * that each library symbol to resolve will be placed in a variable with the "sym_" prefix, i.e. a symbol
+ * "foobar" is loaded into a variable "sym_foobar". */
+#define DLSYM_ARG(arg) \
+        ({ assert_cc(__builtin_types_compatible_p(typeof(sym_##arg), typeof(&arg))); &sym_##arg; }), STRINGIFY(arg)
+
+/* libbpf is a bit confused about type-safety and API compatibility. Provide a macro that can tape over that mess. Sad. */
+#define DLSYM_ARG_FORCE(arg) \
+        &sym_##arg, STRINGIFY(arg)
+
+static inline void *safe_dlclose(void *p) {
+        if (!p)
+                return NULL;
+
+        assert_se(dlclose(p) == 0);
+        return NULL;
+}