add configuration header (#8)

Add a config.h header file that provides version information.

Generated from a config.h.in template.

Version information is read from the VERSION file.

Add a --version flag to the CLI tool.

meson.build

@@ -46,6 +46,8 @@ lib_dep = declare_dependency(
         include_directories: lib_inc
 )
 
+subdir('src/uenv')
+
 # the uenv executable
 if uenv_cli
     uenv_src = [

src/cli/ls.cpp

@@ -26,7 +26,8 @@ void image_ls_args::add_cli(CLI::App& cli,
                        "comma separated list of uenv to mount.");
     ls_cli->add_flag("--no-header", no_header,
                      "print only the matching records, with no header.");
-    ls_cli->callback([&settings]() { settings.mode = uenv::mode_image_ls; });
+    ls_cli->callback(
+        [&settings]() { settings.mode = uenv::cli_mode::image_ls; });
 }
 
 int image_ls(const image_ls_args& args, const global_settings& settings) {

src/cli/run.cpp

@@ -34,7 +34,7 @@ void run_args::add_cli(CLI::App& cli, global_settings& settings) {
         ->add_option("commands", commands,
                      "the command to run, including with arguments")
         ->required();
-    run_cli->callback([&settings]() { settings.mode = uenv::mode_run; });
+    run_cli->callback([&settings]() { settings.mode = uenv::cli_mode::run; });
 }
 
 int run(const run_args& args, const global_settings& globals) {

src/cli/start.cpp

@@ -31,7 +31,8 @@ void start_args::add_cli(CLI::App& cli,
         ->add_option("uenv", uenv_description,
                      "comma separated list of uenv to mount")
         ->required();
-    start_cli->callback([&settings]() { settings.mode = uenv::mode_start; });
+    start_cli->callback(
+        [&settings]() { settings.mode = uenv::cli_mode::start; });
 }
 
 int start(const start_args& args,

src/cli/uenv.cpp

@@ -7,6 +7,7 @@
 
 #include <uenv/log.h>
 
+#include <uenv/config.h>
 #include <uenv/parse.h>
 #include <uenv/repository.h>
 #include <util/expected.h>
@@ -16,17 +17,15 @@
 #include "start.h"
 #include "uenv.h"
 
-void help() {
-    fmt::println("usage main");
-}
-
 int main(int argc, char** argv) {
     uenv::global_settings settings;
+    bool print_version = false;
 
-    CLI::App cli("uenv");
+    CLI::App cli(fmt::format("uenv {}", UENV_VERSION));
     cli.add_flag("-v,--verbose", settings.verbose, "enable verbose output");
     cli.add_flag("--no-color", settings.no_color, "disable color output");
     cli.add_flag("--repo", settings.repo_, "the uenv repository");
+    cli.add_flag("--version", print_version, "print version");
 
     uenv::start_args start;
     uenv::run_args run;
@@ -50,6 +49,12 @@ int main(int argc, char** argv) {
     }
     uenv::init_log(console_log_level, spdlog::level::trace);
 
+    // print the version and exit if the --version flag was passed
+    if (print_version) {
+        fmt::print("{}\n", UENV_VERSION);
+        return 0;
+    }
+
     // if a repo was not provided as a flag, look at environment variables
     if (!settings.repo_) {
         if (const auto p = uenv::default_repo_path()) {
@@ -73,21 +78,27 @@ int main(int argc, char** argv) {
     }
 
     if (settings.repo) {
-        spdlog::info("repo is set {}", *settings.repo);
+        spdlog::info("using repo {}", *settings.repo);
     }
 
     spdlog::info("{}", settings);
 
     switch (settings.mode) {
-    case uenv::mode_start:
+    case settings.start:
         return uenv::start(start, settings);
-    case uenv::mode_run:
+    case settings.run:
         return uenv::run(run, settings);
-    case uenv::mode_image_ls:
+    case settings.image_ls:
         return uenv::image_ls(image.ls_args, settings);
-    case uenv::mode_none:
+    case settings.unset:
+        fmt::println("uenv version {}", UENV_VERSION);
+        fmt::println("call '{} --help' for help", argv[0]);
+        return 0;
     default:
-        help();
+        spdlog::warn("{}", (int)settings.mode);
+        spdlog::error("internal error, missing implementation for mode {}",
+                      settings.mode);
+        return 1;
     }
 
     return 0;

src/cli/uenv.h

@@ -1,6 +1,7 @@
 // vim: ts=4 sts=4 sw=4 et
 #pragma once
 
+#include <cstdint>
 #include <filesystem>
 #include <optional>
 #include <string>
@@ -11,17 +12,15 @@
 
 namespace uenv {
 
-extern int mode;
-
-constexpr int mode_none = 0;
-constexpr int mode_start = 1;
-constexpr int mode_run = 2;
-constexpr int mode_image_ls = 3;
+enum class cli_mode : std::uint32_t { unset, start, run, image_ls };
 
 struct global_settings {
+    using enum cli_mode;
+
     int verbose = 0;
     bool no_color = false;
-    int mode = mode_none;
+    // int mode = mode_none;
+    cli_mode mode = unset;
 
     // repo_ is the unverified string description of the repo path that is
     // either read from an environment variable or as a --repo CLI argument. the
@@ -33,6 +32,30 @@ struct global_settings {
 
 } // namespace uenv
 
+template <> class fmt::formatter<uenv::cli_mode> {
+  public:
+    // parse format specification and store it:
+    constexpr auto parse(format_parse_context& ctx) {
+        return ctx.end();
+    }
+    // format a value using stored specification:
+    template <typename FmtContext>
+    constexpr auto format(uenv::cli_mode mode, FmtContext& ctx) const {
+        using enum uenv::cli_mode;
+        switch (mode) {
+        case unset:
+            return format_to(ctx.out(), "unset");
+        case start:
+            return format_to(ctx.out(), "start");
+        case run:
+            return format_to(ctx.out(), "run");
+        case image_ls:
+            return format_to(ctx.out(), "image-ls");
+        }
+        return format_to(ctx.out(), "unknown");
+    }
+};
+
 template <> class fmt::formatter<uenv::global_settings> {
   public:
     // parse format specification and store it:

src/uenv/config.h.in

@@ -0,0 +1,7 @@
+#pragma once
+
+#define UENV_VERSION "@version@"
+#define UENV_VERSION_MAJOR @version_major@
+#define UENV_VERSION_MINOR @version_minor@
+#define UENV_VERSION_PATCH @version_patch@
+#define UENV_VERSION_PRERELEASE "@version_prerelease@"

src/uenv/meson.build

@@ -0,0 +1,28 @@
+version_path = meson.current_build_dir()+'config.h'
+fs = import('fs')
+if not fs.is_file(version_path)
+  uenv_version = meson.project_version()
+  uenv_version_array = uenv_version.split('-')
+  if uenv_version_array.length()==2
+    uenv_version_prerelease = uenv_version_array[1]
+  else
+    uenv_version_prerelease = ''
+  endif
+  uenv_version_array = uenv_version_array[0].split('.')
+  uenv_version_major = uenv_version_array[0].to_int()
+  uenv_version_minor = uenv_version_array[1].to_int()
+  uenv_version_patch = uenv_version_array[2].to_int()
+
+  conf = configuration_data()
+
+  conf.set('version', uenv_version)
+  conf.set('version_major', uenv_version_major)
+  conf.set('version_minor', uenv_version_minor)
+  conf.set('version_patch', uenv_version_patch)
+  conf.set('version_prerelease', uenv_version_prerelease)
+
+  configure_file(input : 'config.h.in',
+                 output : 'config.h',
+                 configuration : conf)
+endif
+