save-load-state : refactor tests and improve readability (#23196)

* save-load-state : refactor into separate phase functions

- Split monolithic main() into 4 self-contained phase functions, each
  managing its own context/sampler/batch lifecycle
- Each function tokenizes internally using its local ctx instance
- main() is now a clean orchestrator: init -> run phases -> assert results
- Proper resource cleanup on every exit path (return {} on error)

Assisted-by: llama.cpp:local pi

* save-load-state : use params.out_file instead of separate state_file

- Remove state_file parameter from all phase functions
- Each function accesses params.out_file directly
- Initialize params.out_file in main alongside params.prompt

Assisted-by: llama.cpp:local pi

* save-load-state : use smart pointers for ctx and smpl

- Replace raw llama_context* with llama_context_ptr
- Replace raw llama_sampler* with llama_sampler_ptr
- Remove all manual llama_free() and llama_sampler_free() calls
- Keep llama_batch as raw (managed manually with llama_batch_free)

Assisted-by: llama.cpp:local pi

* save-load-state : add local llama_batch_ptr RAII wrapper

- Add llama_batch_ptr struct holding llama_batch by value
- Calls llama_batch_free() in destructor
- Eliminates all manual llama_batch_free() calls

Assisted-by: llama.cpp:local pi

* save-load-state : replace printf/fprintf with logging macros

- Add log.h include
- Replace fprintf(stderr, ...) errors with LOG_ERR
- Replace fprintf(stderr, ...) info with LOG_TRC
- Replace printf output with LOG

Assisted-by: llama.cpp:local pi

* save-load-state : refactor tests to check results inline

Each follow-up phase now accepts an expected result and performs
the comparison internally instead of collecting results in main().

Assisted-by: llama.cpp:local pi

* save-load-state : improve test output readability

Add phase labels, remove redundant run prefixes, and show
PASS after each test.

Assisted-by: llama.cpp:local pi

* pi : add rule about git signing

* save-load-state : simplify llama_batch_ptr

Change get() to return a reference and remove operator*().
Use batch.get() throughout for consistency.

Assisted-by: llama.cpp:local pi

* save-load-state : extract generate_tokens helper

Factor out the repeated token generation loop into a shared
helper function used by all phases.

Assisted-by: llama.cpp:local pi

* save-load-state : update comments to use test terminology

Replace "Phase" with "Test" and list each test's steps
as bullet points.

Assisted-by: llama.cpp:local pi

* save-load-state : rename test functions

Rename to test_baseline, test_state_load, test_seq_cp_host,
test_seq_cp_device. Update comments and logs accordingly.

Assisted-by: llama.cpp:local pi

* pi : add rule to never git push without confirmation

Assisted-by: llama.cpp:local pi

* common : add model_only option to common_init_from_params

Add bool model_only parameter to skip context creation,
sampler init, and context-dependent setup.

Use in save-load-state to initialize only the model,
with each test creating its own context.

Assisted-by: llama.cpp:local pi

---------

Co-authored-by: ggerganov <ggerganov@users.noreply.github.com>

common/common.cpp

@@ -1160,7 +1160,7 @@ struct common_init_result::impl {
     std::vector<llama_sampler_seq_config> samplers_seq_config;
 };
 
-common_init_result::common_init_result(common_params & params) :
+common_init_result::common_init_result(common_params & params, bool model_only) :
     pimpl(new impl{}) {
     auto mparams = common_model_params_to_llama(params);
     auto cparams = common_context_params_to_llama(params);
@@ -1183,6 +1183,10 @@ common_init_result::common_init_result(common_params & params) :
 
     pimpl->model.reset(model);
 
+    if (model_only) {
+        return;
+    }
+
     const llama_vocab * vocab = llama_model_get_vocab(model);
 
     // load and optionally apply lora adapters
@@ -1309,8 +1313,8 @@ std::vector<llama_adapter_lora_ptr> & common_init_result::lora() {
     return pimpl->lora;
 }
 
-common_init_result_ptr common_init_from_params(common_params & params) {
-    common_init_result_ptr res(new common_init_result(params));
+common_init_result_ptr common_init_from_params(common_params & params, bool model_only) {
+    common_init_result_ptr res(new common_init_result(params, model_only));
 
     llama_model * model = res->model();
     if (model == NULL) {
@@ -1318,6 +1322,10 @@ common_init_result_ptr common_init_from_params(common_params & params) {
         return res;
     }
 
+    if (model_only) {
+        return res;
+    }
+
     llama_context * lctx = res->context();
     if (lctx == NULL) {
         LOG_ERR("%s: failed to create context with model '%s'\n", __func__, params.model.path.c_str());

common/common.h

@@ -857,7 +857,7 @@ struct common_sampler;
 
 // note: defines the model, context, samplers, ets. lifetimes
 struct common_init_result {
-    common_init_result(common_params & params);
+    common_init_result(common_params & params, bool model_only = false);
     ~common_init_result();
 
     llama_model * model();
@@ -875,7 +875,7 @@ private:
 
 using common_init_result_ptr = std::unique_ptr<common_init_result>;
 
-common_init_result_ptr common_init_from_params(common_params & params);
+common_init_result_ptr common_init_from_params(common_params & params, bool model_only = false);
 
 struct llama_model_params     common_model_params_to_llama  (      common_params & params);
 struct llama_context_params   common_context_params_to_llama(const common_params & params);