Add assertions for all non-null pointers in the public API

Clang issues warnings at build time based on the SERD_NONNULL annotations,
which is a much better approach in general.  However, it does not cover cases
where the API is being used with another compiler, or without a compiler that
can statically check things at all (such as Python or other dynamic language
bindings).

In those situations, getting a clear assertion message is a lot less confusing
than a random crash somewhere in serd, and it makes it clear that the bug is in
the caller, so I think it's worth the tedious verbosity.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/node_syntax.c b/src/node_syntax.c
index 626648f6..ff8c32d4 100644
--- a/src/node_syntax.c
+++ b/src/node_syntax.c
@@ -18,6 +18,7 @@
 
 #include "serd/serd.h"
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -38,6 +39,8 @@ serd_node_from_syntax_in(const char* const str,
                          const SerdSyntax  syntax,
                          SerdEnv* const    env)
 {
+  assert(str);
+
   static const char* const prelude =
     "_:s <http://www.w3.org/2000/01/rdf-schema#object>";
 
@@ -72,6 +75,8 @@ serd_node_from_syntax(const char* const str,
                       const SerdSyntax  syntax,
                       SerdEnv* const    env)
 {
+  assert(str);
+
   if (env) {
     return serd_node_from_syntax_in(str, syntax, env);
   }
@@ -110,6 +115,8 @@ serd_node_to_syntax(const SerdNode* const node,
                     const SerdSyntax      syntax,
                     const SerdEnv* const  env)
 {
+  assert(node);
+
   if (env) {
     return serd_node_to_syntax_in(node, syntax, env);
   }