1 files changed, 45 insertions, 0 deletions
diff --git a/libc-top-half/musl/src/misc/dl.c b/libc-top-half/musl/src/misc/dl.c
new file mode 100644
index 0000000..266594f
--- /dev/null
+++ b/libc-top-half/musl/src/misc/dl.c
@@ -0,0 +1,45 @@
+/* This file is used to build libdl.so with stub versions of `dlopen`, `dlsym`,
+ * etc.  The intention is that this stubbed libdl.so can be used to build
+ * libraries and applications which use `dlopen` without committing to a
+ * specific runtime implementation.  Later, it can be replaced with a real,
+ * working libdl.so (e.g. at runtime or component composition time).
+ * 
+ * For example, the `wasm-tools component link` subcommand can be used to create
+ * a component that bundles any `dlopen`-able libraries in such a way that their
+ * function exports can be resolved symbolically at runtime using an
+ * implementation of libdl.so designed for that purpose.  In other cases, a
+ * runtime might provide Emscripten-style dynamic linking via URLs or else a
+ * more traditional, filesystem-based implementation.  Finally, even this
+ * stubbed version of libdl.so can be used at runtime in cases where dynamic
+ * library resolution cannot or should not be supported (and the application can
+ * handle this situation gracefully). */
+
+#include <stddef.h>
+#include <dlfcn.h>
+
+static const char *error = NULL;
+
+weak int dlclose(void *library)
+{
+	error = "dlclose not implemented";
+	return -1;
+}
+
+weak char *dlerror(void)
+{
+	const char *var = error;
+	error = NULL;
+	return (char*) var;
+}
+
+weak void *dlopen(const char *name, int flags)
+{
+	error = "dlopen not implemented";
+	return NULL;
+}
+
+weak void *dlsym(void *library, const char *name)
+{
+	error = "dlsym not implemented";
+	return NULL;
+}