cmake(common): scope config.cpp/yaml-cpp to tools; add LLAMA_ENABLE_CONFIG_YAML guards

- Wrap --config option definition with LLAMA_ENABLE_CONFIG_YAML in arg.cpp
- Guard all YAML-dependent code sections in config.cpp and config.h
- Ensures yaml-cpp is only compiled when LLAMA_BUILD_TOOLS=ON
- Prevents platform builds that don't need tools from pulling yaml-cpp dependencies

Co-Authored-By: Jaime Mizrachi <[email protected]>

Author: devin-ai-integration[bot]

common/arg.cpp

@@ -1341,13 +1341,15 @@ common_params_context common_params_parser_init(common_params & params, llama_ex
         }
     ));
 
+#ifdef LLAMA_ENABLE_CONFIG_YAML
     add_opt(common_arg(
         {"--config"},
         "<path/to/config.yaml>",
         "Load parameters from a YAML config file; flags passed on the command line override values from the YAML file.",
         [](common_params &, const std::string &) {
         }
     ));
+#endif
     add_opt(common_arg(
         {"--verbose-prompt"},
         string_format("print a verbose prompt before generation (default: %s)", params.verbose_prompt ? "true" : "false"),

common/config.cpp

@@ -1,3 +1,5 @@
+#ifdef LLAMA_ENABLE_CONFIG_YAML
+
 #include "config.h"
 #include "log.h"
 
@@ -6,6 +8,8 @@
 #include <set>
 #include <sstream>
 #include <stdexcept>
+#include <cstdint>
+#include <limits>
 
 namespace fs = std::filesystem;
 
@@ -335,3 +339,5 @@ bool common_load_yaml_config(const std::string & path, common_params & params) {
         throw std::invalid_argument("Config loading error: " + std::string(e.what()));
     }
 }
+
+#endif // LLAMA_ENABLE_CONFIG_YAML

common/config.h

@@ -3,5 +3,7 @@
 #include "common.h"
 #include <string>
 
+#ifdef LLAMA_ENABLE_CONFIG_YAML
 bool common_load_yaml_config(const std::string & path, common_params & params);
 std::string common_yaml_valid_keys_help();
+#endif