nit: more informative crash when grammar sampler fails (ggml-org#11593)

ochafik · web-flow · commit 90f9b88afb64 · 2025-02-02T19:58:34.000Z
diff --git a/src/llama-grammar.cpp b/src/llama-grammar.cpp
@@ -1213,5 +1213,7 @@ void llama_grammar_accept_str(struct llama_grammar & grammar, const std::string
     }
 
     grammar.partial_utf8 = decoded.second;
-    GGML_ASSERT(!grammar.stacks.empty());
+    if (grammar.stacks.empty()) {
+        throw std::runtime_error("Unexpected empty grammar stack after accepting piece: " + piece);
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -1213,5 +1213,7 @@ void llama_grammar_accept_str(struct llama_grammar & grammar, const std::string`
`1213`	`1213`	`}`
`1214`	`1214`
`1215`	`1215`	`grammar.partial_utf8 = decoded.second;`
`1216`		`- GGML_ASSERT(!grammar.stacks.empty());`
	`1216`	`+ if (grammar.stacks.empty()) {`
	`1217`	`+ throw std::runtime_error("Unexpected empty grammar stack after accepting piece: " + piece);`
	`1218`	`+ }`
`1217`	`1219`	`}`