chat: add defensive IBM Granite Jinja compatibility (<tool_call> and <|tool_call|> support)

common/chat.cpp

@@ -2324,6 +2324,16 @@ static common_chat_params common_chat_params_init_granite(const common_chat_temp
     data.prompt = apply(tmpl, inputs, /* messages_override= */ std::nullopt, /* tools_override= */ std::nullopt, additional_context);
     data.format = COMMON_CHAT_FORMAT_GRANITE;
 
+    const auto & src = tmpl.source();
+    const bool has_pipe_tool_call = src.find("<|tool_call|>") != std::string::npos;
+    const bool has_plain_tool_call = src.find("<tool_call>") != std::string::npos;
+    const bool has_plain_tool_call_close = src.find("</tool_call>") != std::string::npos;
+    const bool use_plain_tool_call = !has_pipe_tool_call && has_plain_tool_call;
+
+    const std::string tool_call_tag = use_plain_tool_call ? "<tool_call>" : "<|tool_call|>";
+    const std::string tool_call_close_tag =
+        use_plain_tool_call && has_plain_tool_call_close ? "</tool_call>" : "";
+
     if (string_ends_with(data.prompt, "<think>\n") || string_ends_with(data.prompt, "<think>")) {
         if (!inputs.enable_thinking) {
             data.prompt += "</think>";
@@ -2333,9 +2343,23 @@ static common_chat_params common_chat_params_init_granite(const common_chat_temp
     }
 
     if (!inputs.tools.is_null()) {
-        // Granite uses <|tool_call|> followed by JSON list
+        // Granite uses a sentinel tag followed by a JSON list of tool calls
         data.grammar_lazy = inputs.tool_choice != COMMON_CHAT_TOOL_CHOICE_REQUIRED;
         data.grammar = build_grammar([&](const common_grammar_builder & builder) {
+            const auto quote_literal = [](const std::string & literal) {
+                std::string escaped;
+                escaped.reserve(literal.size() * 2 + 2);
+                escaped.push_back('"');
+                for (const char ch : literal) {
+                    if (ch == '"' || ch == '\\') {
+                        escaped.push_back('\\');
+                    }
+                    escaped.push_back(ch);
+                }
+                escaped.push_back('"');
+                return escaped;
+            };
+
             std::vector<std::string> tool_rules;
             foreach_function(inputs.tools, [&](const json & tool) {
                 const auto & function = tool.at("function");
@@ -2356,24 +2380,37 @@ static common_chat_params common_chat_params_init_granite(const common_chat_temp
             auto tool_call = builder.add_rule("tool_call", string_join(tool_rules, " | "));
             auto tool_list = builder.add_rule("tool_list", "\"[\" space " + tool_call + " (\",\" space " + tool_call + ")* space \"]\"");
 
+            const auto tool_call_literal = quote_literal(tool_call_tag);
+            const auto tool_call_close_literal =
+                tool_call_close_tag.empty() ? std::string{} : quote_literal(tool_call_close_tag);
+            const auto optional_close_segment = tool_call_close_literal.empty()
+                ? std::string{}
+                : " (space " + tool_call_close_literal + ")?";
+
             if (data.thinking_forced_open) {
-                builder.add_rule("root", "\"</think>\" space \"<response>\" space [^<]* \"</response>\" space \"<|tool_call|>\" space " + tool_list);
+                builder.add_rule(
+                    "root",
+                    "\"</think>\" space \"<response>\" space [^<]* \"</response>\" space " +
+                        tool_call_literal + " space " + tool_list + optional_close_segment);
             } else {
-                builder.add_rule("root", "\"<|tool_call|>\" space " + tool_list);
+                builder.add_rule("root", tool_call_literal + " space " + tool_list + optional_close_segment);
             }
 
             data.grammar_triggers.push_back({
                 COMMON_GRAMMAR_TRIGGER_TYPE_WORD,
-                "<|tool_call|>"
+                tool_call_tag
             });
 
             data.preserved_tokens = {
                 "<think>",
                 "</think>",
                 "<response>",
                 "</response>",
-                "<|tool_call|>",
+                tool_call_tag,
             };
+            if (!tool_call_close_tag.empty()) {
+                data.preserved_tokens.push_back(tool_call_close_tag);
+            }
         });
     } else {
         // Handle thinking tags for non-tool responses
@@ -2426,17 +2463,30 @@ static void common_chat_parse_granite(common_chat_msg_parser & builder) {
     }
 
     // Look for tool calls
-    static const common_regex tool_call_regex(regex_escape("<|tool_call|>"));
-    if (auto res = builder.try_find_regex(tool_call_regex)) {
-        builder.move_to(res->groups[0].end);
+    static const common_regex tool_call_regex_legacy(regex_escape("<|tool_call|>"));
+    static const common_regex tool_call_regex_plain(regex_escape("<tool_call>"));
 
-        // Expect JSON array of tool calls
-        if (auto tool_call = builder.try_consume_json_with_dumped_args({{{"arguments"}}})) {
-            if (!builder.add_tool_calls(tool_call->value) || tool_call->is_partial) {
-                throw common_chat_msg_partial_exception("incomplete tool call");
+    const auto try_parse_tool_calls = [&](const common_regex & regex, const std::string & close_tag) {
+        if (auto res = builder.try_find_regex(regex)) {
+            builder.move_to(res->groups[0].end);
+
+            // Expect JSON array of tool calls
+            if (auto tool_call = builder.try_consume_json_with_dumped_args({{{"arguments"}}})) {
+                if (!builder.add_tool_calls(tool_call->value) || tool_call->is_partial) {
+                    throw common_chat_msg_partial_exception("incomplete tool call");
+                }
+                builder.consume_spaces();
+                if (!close_tag.empty()) {
+                    builder.try_consume_literal(close_tag);
+                }
             }
+            return true;
         }
-    } else {
+        return false;
+    };
+
+    if (!try_parse_tool_calls(tool_call_regex_legacy, "") &&
+        !try_parse_tool_calls(tool_call_regex_plain, "</tool_call>")) {
         builder.add_content(builder.consume_rest());
     }
 }
@@ -2719,7 +2769,8 @@ static common_chat_params common_chat_templates_apply_jinja(
     }
 
     // Granite (IBM) - detects thinking / tools support
-    if (src.find("elif thinking") != std::string::npos && src.find("<|tool_call|>") != std::string::npos) {
+    if ((src.find("elif thinking") != std::string::npos || src.find("tools_system_message_prefix") != std::string::npos) &&
+        (src.find("<|tool_call|>") != std::string::npos || src.find("<tool_call>") != std::string::npos)) {
         return common_chat_params_init_granite(tmpl, params);
     }