feat(audiocpp_server): support --list-devices

CMakeLists.txt

@@ -1848,6 +1848,20 @@ endif()
 if (ENGINE_BUILD_TESTS)
     enable_testing()
 
+    add_test(
+        NAME audiocpp_cli_list_devices
+        COMMAND audiocpp_cli --list-devices
+    )
+    add_test(
+        NAME audiocpp_server_list_devices
+        COMMAND audiocpp_server --list-devices
+    )
+    set_tests_properties(
+        audiocpp_cli_list_devices
+        audiocpp_server_list_devices
+        PROPERTIES PASS_REGULAR_EXPRESSION "available_devices=[0-9]+"
+    )
+
     set(ENGINE_UNITTEST_ASSET_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/tests/unittests/assets")
 
     function(add_engine_unittest target source)

app/cli/main.cpp

@@ -648,16 +648,7 @@ int audiocpp_cli_main(int argc, char ** argv) {
             return 0;
         }
         if (has_arg(argc, argv, "--list-devices")) {
-            const auto devices = engine::core::list_backend_devices();
-            std::cout << "available_devices=" << devices.size() << "\n";
-            for (const auto & device : devices) {
-                std::cout << device.backend << ":" << device.index;
-                if (!device.name.empty()) {
-                    std::cout << " \"" << device.name << "\"";
-                }
-                std::cout << " [" << device.type << "]\n";
-            }
-            std::cout << "select with: --backend <cuda|hip|vulkan|metal|cpu> --device <index>\n";
+            engine::core::print_backend_devices(std::cout);
             return 0;
         }
         if (has_arg(argc, argv, "--list-loaders")) {

app/server/main.cpp

@@ -2,6 +2,7 @@
 #include "http.h"
 #include "runtime.h"
 
+#include "engine/framework/core/backend.h"
 #include "engine/framework/debug/trace.h"
 
 #include <csignal>
@@ -60,7 +61,8 @@ std::filesystem::path executable_directory(const char * argv0) {
 void print_help() {
     std::cout
         << "audiocpp_server [--config <server.json>] [--ui] [--host <ip>] [--port <port>] [--backend <backend>]\n"
-        << "                [--device <id>] [--threads <n>] [--busy-timeout-ms <ms>] [--max-loaded-models <n>]\n"
+        << "                [--device <id>] [--list-devices] [--threads <n>] [--busy-timeout-ms <ms>]\n"
+        << "                [--max-loaded-models <n>]\n"
         << "                [--model-spec-override <json-or-directory>] [--voice-dir <directory>]\n"
         << "                [--log] [--log-file <path>]\n"
         << "                [--cors-origins <origins>]\n"
@@ -69,6 +71,7 @@ void print_help() {
         << "  --ui-management                  allow WebUI model management and downloads; requires\n"
         << "                                   AUDIOCPP_BUILD_NATIVE_MODEL_MANAGER=ON at build time\n"
         << "  --backend cpu|cuda|hip|rocm|vulkan|metal  default cuda (rocm is an alias for hip)\n"
+        << "  --list-devices                   list available backend devices and exit\n"
         << "  --busy-timeout-ms <ms>           fail a request with 503 when the model has been\n"
         << "                                   busy this long; default 300000, 0 disables\n"
         << "  --max-loaded-models <n>          keep at most n models resident in memory, unloading\n"
@@ -110,6 +113,10 @@ void print_help() {
 
 int main(int argc, char ** argv) {
     try {
+        if (has_arg(argc, argv, "--list-devices")) {
+            engine::core::print_backend_devices(std::cout);
+            return 0;
+        }
         if (has_arg(argc, argv, "--help") || has_arg(argc, argv, "-h")) {
             print_help();
             return 0;

include/engine/framework/core/backend.h

@@ -7,6 +7,7 @@
 
 #include <cstddef>
 #include <cstdint>
+#include <iosfwd>
 #include <string>
 #include <vector>
 
@@ -29,6 +30,7 @@ struct BackendDeviceInfo {
 
 // Enumerates every device of every loaded ggml backend registry, in registry order.
 std::vector<BackendDeviceInfo> list_backend_devices();
+void print_backend_devices(std::ostream & out);
 
 struct BackendMemorySnapshot {
     bool available = false;

src/framework/core/backend.cpp

@@ -4,6 +4,7 @@
 #include <algorithm>
 #include <cstdlib>
 #include <cstring>
+#include <ostream>
 #include <stdexcept>
 #include <string>
 
@@ -209,6 +210,19 @@ std::vector<BackendDeviceInfo> list_backend_devices() {
     return devices;
 }
 
+void print_backend_devices(std::ostream & out) {
+    const auto devices = list_backend_devices();
+    out << "available_devices=" << devices.size() << "\n";
+    for (const auto & device : devices) {
+        out << device.backend << ":" << device.index;
+        if (!device.name.empty()) {
+            out << " \"" << device.name << "\"";
+        }
+        out << " [" << device.type << "]\n";
+    }
+    out << "select with: --backend <cuda|hip|vulkan|metal|cpu> --device <index>\n";
+}
+
 ggml_backend_t init_backend(const BackendConfig & config) {
     ensure_backends_loaded();
     switch (config.type) {