Add version status and args handling

CMakeLists.txt

@@ -19,9 +19,19 @@ include_directories(external/sokol)
 add_executable(emu
     src/main.c
     src/cli.c
+    ${CMAKE_CURRENT_BINARY_DIR}/version.c
 )
 target_include_directories(emu PRIVATE ${READLINE_INCLUDE_DIRS})
 target_link_libraries(emu
     PRIVATE ${READLINE_LIBRARIES}
     X11 Xi Xcursor EGL GLESv2 dl pthread m)
 target_compile_options(emu PRIVATE ${READLINE_CFLAGS_OTHER})
+
+# Add a custom command that produces version.c, plus
+# a dummy output that's not actually produced, in order
+# to force version.cmake to always be re-run before the build
+ADD_CUSTOM_COMMAND(
+    OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/version.c
+           ${CMAKE_CURRENT_BINARY_DIR}/_version.c
+    COMMAND ${CMAKE_COMMAND} -P
+            ${CMAKE_CURRENT_SOURCE_DIR}/version.cmake)

src/main.c

@@ -1,17 +1,25 @@
+#include <unistd.h>
+
 #define SOKOL_IMPL
 #define SOKOL_GLES3
 #define SOKOL_UNREACHABLE __builtin_unreachable()
 #include "sokol_app.h"
 #include "sokol_gfx.h"
 #include "sokol_glue.h"
 #include "sokol_log.h"
+#include "sokol_args.h"
 
 #include "icon.c"
 #include "cli.h"
 
+extern const char* GIT_TAG;
+extern const char* GIT_REV;
+extern const char* GIT_BRANCH;
+const char* APP_NAME = "X65 emu";
+
 sg_pass_action pass_action;
 
-void init(void) {
+static void init(void) {
     sg_setup(&(sg_desc){
         .environment = sglue_environment(),
         .logger.func = slog_func,
@@ -23,7 +31,7 @@ void init(void) {
     cli_init();
 }
 
-void frame(void) {
+static void frame(void) {
     float g = pass_action.colors[0].clear_value.g + 0.01f;
     pass_action.colors[0].clear_value.g = (g > 1.0f) ? 0.0f : g;
     sg_begin_pass(&(sg_pass){ .action = pass_action, .swapchain = sglue_swapchain() });
@@ -33,22 +41,32 @@ void frame(void) {
     cli_update();
 }
 
-void cleanup(void) {
+static void cleanup(void) {
     sg_shutdown();
+    sargs_shutdown();
 
     cli_cleanup();
 }
 
 sapp_desc sokol_main(int argc, char* argv[]) {
-    (void)argc;
-    (void)argv;
+    if (strlen(GIT_TAG))
+        printf("%s  %s\n", APP_NAME, GIT_TAG);
+    else
+        printf("%s  %s@%s\n", APP_NAME, GIT_REV, GIT_BRANCH);
+
+    sargs_setup(&(sargs_desc){
+        .argc = argc,
+        .argv = argv,
+        .buf_size = (int)sysconf(_SC_ARG_MAX),
+    });
+
     return (sapp_desc){
         .init_cb = init,
         .frame_cb = frame,
         .cleanup_cb = cleanup,
         .width = 400,
         .height = 300,
-        .window_title = "Clear (sokol app)",
+        .window_title = APP_NAME,
         .icon.images = { { .width = app_icon.width,
                            .height = app_icon.height,
                            .pixels = (sapp_range){ &app_icon.pixel_data, app_icon.width * app_icon.height * 4 } } },

version.cmake

@@ -0,0 +1,45 @@
+# Based on https://www.mattkeeter.com/blog/2018-01-06-versioning/
+
+execute_process(COMMAND git log --pretty=format:'%h' -n 1
+                OUTPUT_VARIABLE GIT_REV
+                ERROR_QUIET)
+
+# Check whether we got any revision (which isn't
+# always the case, e.g. when someone downloaded a zip
+# file from Github instead of a checkout)
+if ("${GIT_REV}" STREQUAL "")
+    set(GIT_REV "N/A")
+    set(GIT_DIFF "")
+    set(GIT_TAG "N/A")
+    set(GIT_BRANCH "N/A")
+else()
+    execute_process(
+        COMMAND bash -c "git diff --quiet --exit-code || echo +"
+        OUTPUT_VARIABLE GIT_DIFF)
+    execute_process(
+        COMMAND git describe --exact-match --tags
+        OUTPUT_VARIABLE GIT_TAG ERROR_QUIET)
+    execute_process(
+        COMMAND git rev-parse --abbrev-ref HEAD
+        OUTPUT_VARIABLE GIT_BRANCH)
+
+    string(STRIP "${GIT_REV}" GIT_REV)
+    string(SUBSTRING "${GIT_REV}" 1 7 GIT_REV)
+    string(STRIP "${GIT_DIFF}" GIT_DIFF)
+    string(STRIP "${GIT_TAG}" GIT_TAG)
+    string(STRIP "${GIT_BRANCH}" GIT_BRANCH)
+endif()
+
+set(VERSION "const char* GIT_REV=\"${GIT_REV}${GIT_DIFF}\";
+const char* GIT_TAG=\"${GIT_TAG}\";
+const char* GIT_BRANCH=\"${GIT_BRANCH}\";")
+
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/version.c)
+    file(READ ${CMAKE_CURRENT_SOURCE_DIR}/version.c VERSION_)
+else()
+    set(VERSION_ "")
+endif()
+
+if (NOT "${VERSION}" STREQUAL "${VERSION_}")
+    file(WRITE ${CMAKE_CURRENT_SOURCE_DIR}/version.c "${VERSION}")
+endif()