Add nonnull and nullable attributes to API

This will warn if NULL is passed to any nonnull-annotated parameter, and is
also supported by sanitizers which can check for violations at runtime.

Unfortunately, it is currently only supported by clang.  GCC has a similar
feature in the nonnull attribute, but this has a different syntax (it's a
function attribute) and is more dangerous since it is used by the optimizer to
assume a null pointer is undefined behavior.  This one just warns and still
allows code to handle the situation gracefully, which I think is more
appropriate for a library API.

Note that this optimization behavior is not some unlikely edge case: switching
these attributes to the GCC one will break release builds.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/env.c b/src/env.c
index 3813391c..431fef41 100644
--- a/src/env.c
+++ b/src/env.c
@@ -70,6 +70,7 @@ serd_env_get_base_uri(const SerdEnv* env,
 	return &env->base_uri_node;
 }
 
+// TODO: Make env nonnull in next major release
 SerdStatus
 serd_env_set_base_uri(SerdEnv*        env,
                       const SerdNode* uri)