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, 6 insertions, 0 deletions

diff --git a/src/syntax.c b/src/syntax.c
index 59453bca..ace55ce2 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -18,6 +18,7 @@
 
 #include "serd/serd.h"
 
+#include <assert.h>
 #include <stdbool.h>
 #include <string.h>
 
@@ -38,17 +39,22 @@ static const Syntax syntaxes[] = {
 SerdSyntax
 serd_syntax_by_name(const char* const name)
 {
+  assert(name);
+
   for (const Syntax* s = syntaxes; s->name; ++s) {
     if (!serd_strncasecmp(s->name, name, strlen(name))) {
       return s->syntax;
     }
   }
+
   return SERD_SYNTAX_EMPTY;
 }
 
 SerdSyntax
 serd_guess_syntax(const char* const filename)
 {
+  assert(filename);
+
   const char* ext = strrchr(filename, '.');
   if (ext) {
     for (const Syntax* s = syntaxes; s->name; ++s) {