[vcpkg] Improve vcpkg help -- now has per-command help!

toolsrc/include/vcpkg/base/cstringview.h

@@ -63,6 +63,8 @@ namespace vcpkg
 
     inline bool operator!=(const std::string& l, const CStringView& r) { return l != r.c_str(); }
 
+    inline std::string operator+(std::string&& l, const CStringView& r) { return std::move(l) + r.c_str(); }
+
     inline const char* to_printf_arg(const CStringView string_view) { return string_view.c_str(); }
 
     static_assert(sizeof(CStringView) == sizeof(void*), "CStringView must be a simple wrapper around char*");

toolsrc/include/vcpkg/export.h

@@ -4,6 +4,8 @@
 
 namespace vcpkg::Export
 {
+    extern const CommandStructure COMMAND_STRUCTURE;
+
     void perform_and_exit(const VcpkgCmdArguments& args, const VcpkgPaths& paths, const Triplet& default_triplet);
 
     void export_integration_files(const fs::path& raw_exported_dir_path, const VcpkgPaths& paths);

toolsrc/include/vcpkg/help.h

@@ -7,13 +7,13 @@
 
 namespace vcpkg::Help
 {
+    extern const CommandStructure COMMAND_STRUCTURE;
+
     void perform_and_exit(const VcpkgCmdArguments& args, const VcpkgPaths& paths);
 
     void help_topic_valid_triplet(const VcpkgPaths& paths);
 
     void print_usage();
 
-    void print_example(const std::string& command_and_arguments);
-
     std::string create_example_string(const std::string& command_and_arguments);
 }

toolsrc/include/vcpkg/vcpkgcmdarguments.h

@@ -49,6 +49,8 @@ namespace vcpkg
         std::vector<std::string> (*valid_arguments)(const VcpkgPaths& paths);
     };
 
+    void display_usage(const CommandStructure& command_structure);
+
 #if defined(_WIN32)
     using CommandLineCharType = wchar_t;
 #else

toolsrc/src/vcpkg/export.cpp

@@ -4,6 +4,7 @@
 #include <vcpkg/base/util.h>
 #include <vcpkg/commands.h>
 #include <vcpkg/dependencies.h>
+#include <vcpkg/export.h>
 #include <vcpkg/export.ifw.h>
 #include <vcpkg/help.h>
 #include <vcpkg/input.h>
@@ -289,7 +290,7 @@ namespace vcpkg::Export
         {OPTION_IFW_INSTALLER_FILE_PATH, ""},
     }};
 
-    const CommandStructure COMMAND_STRUCTURE = {
+    const CommandStructure vcpkg::Export::COMMAND_STRUCTURE = {
         Help::create_example_string("export zlib zlib:x64-windows boost --nuget"),
         0,
         SIZE_MAX,

toolsrc/src/vcpkg/help.cpp

@@ -2,15 +2,68 @@
 
 #include <vcpkg/base/system.h>
 #include <vcpkg/commands.h>
+#include <vcpkg/export.h>
+#include <vcpkg/help.h>
+#include <vcpkg/install.h>
+#include <vcpkg/remove.h>
 
 namespace vcpkg::Help
 {
-    void help_topics()
+    struct Topic
+    {
+        using topic_function = void (*)(const VcpkgPaths& paths);
+
+        constexpr Topic(CStringView n, topic_function fn) : name(n), print(fn) {}
+
+        CStringView name;
+        topic_function print;
+    };
+
+    template<const CommandStructure& S>
+    static void command_topic_fn(const VcpkgPaths&)
+    {
+        display_usage(S);
+    }
+
+    static void integrate_topic_fn(const VcpkgPaths&)
+    {
+        System::print("Commands:\n"
+                      "%s",
+                      Commands::Integrate::INTEGRATE_COMMAND_HELPSTRING);
+    }
+
+    static void help_topics(const VcpkgPaths&);
+
+    const CommandStructure COMMAND_STRUCTURE = {
+        Help::create_example_string("help"),
+        0,
+        1,
+        {},
+        nullptr,
+    };
+
+    static constexpr std::array<Topic, 12> topics = {{
+        {"create", command_topic_fn<Commands::Create::COMMAND_STRUCTURE>},
+        {"edit", command_topic_fn<Commands::Edit::COMMAND_STRUCTURE>},
+        {"env", command_topic_fn<Commands::Env::COMMAND_STRUCTURE>},
+        {"export", command_topic_fn<Export::COMMAND_STRUCTURE>},
+        {"help", command_topic_fn<Help::COMMAND_STRUCTURE>},
+        {"install", command_topic_fn<Install::COMMAND_STRUCTURE>},
+        {"integrate", integrate_topic_fn},
+        {"list", command_topic_fn<Commands::List::COMMAND_STRUCTURE>},
+        {"owns", command_topic_fn<Commands::Owns::COMMAND_STRUCTURE>},
+        {"remove", command_topic_fn<Remove::COMMAND_STRUCTURE>},
+        {"search", command_topic_fn<Commands::Search::COMMAND_STRUCTURE>},
+        {"topics", help_topics},
+    }};
+
+    static void help_topics(const VcpkgPaths&)
     {
         System::println("Available help topics:\n"
                         "  triplet\n"
-                        "  integrate\n"
+                        "  integrate"
-                        "  export");
+                        "%s",
+                        Strings::join("", topics, [](const Topic& topic) { return std::string("\n  ") + topic.name; }));
     }
 
     void help_topic_valid_triplet(const VcpkgPaths& paths)
@@ -22,21 +75,6 @@ namespace vcpkg::Help
         }
     }
 
-    void help_topic_export()
-    {
-        System::println("Summary:\n"
-                        "  vcpkg export [options] <pkgs>...\n"
-                        "\n"
-                        "Options:\n"
-                        "  --7zip                          Export to a 7zip (.7z) file\n"
-                        "  --dry-run                       Do not actually export\n"
-                        "  --nuget                         Export a NuGet package\n"
-                        "  --nuget-id=<id>                 Specify the id for the exported NuGet package\n"
-                        "  --nuget-version=<ver>           Specify the version for the exported NuGet package\n"
-                        "  --raw                           Export to an uncompressed directory\n"
-                        "  --zip                           Export to a zip file");
-    }
-
     void print_usage()
     {
         System::println(
@@ -86,19 +124,6 @@ namespace vcpkg::Help
         return cs;
     }
 
-    void print_example(const std::string& command_and_arguments)
-    {
-        System::println(create_example_string(command_and_arguments));
-    }
-
-    const CommandStructure COMMAND_STRUCTURE = {
-        Help::create_example_string("help"),
-        0,
-        1,
-        {},
-        nullptr,
-    };
-
     void perform_and_exit(const VcpkgCmdArguments& args, const VcpkgPaths& paths)
     {
         args.parse_arguments(COMMAND_STRUCTURE);
@@ -112,27 +137,18 @@ namespace vcpkg::Help
         if (topic == "triplet" || topic == "triplets" || topic == "triple")
         {
             help_topic_valid_triplet(paths);
+            Checks::exit_success(VCPKG_LINE_INFO);
         }
-        else if (topic == "export")
+
+        auto it_topic = Util::find_if(topics, [&](const Topic& t) { return t.name == topic; });
+        if (it_topic != topics.end())
         {
-            help_topic_export();
+            it_topic->print(paths);
+            Checks::exit_success(VCPKG_LINE_INFO);
         }
-        else if (topic == "integrate")
+
-        {
+        System::println(System::Color::error, "Error: unknown topic %s", topic);
-            System::print("Commands:\n"
+        help_topics(paths);
-                          "%s",
+        Checks::exit_fail(VCPKG_LINE_INFO);
-                          Commands::Integrate::INTEGRATE_COMMAND_HELPSTRING);
-        }
-        else if (topic == "topics")
-        {
-            help_topics();
-        }
-        else
-        {
-            System::println(System::Color::error, "Error: unknown topic %s", topic);
-            help_topics();
-            Checks::exit_fail(VCPKG_LINE_INFO);
-        }
-        Checks::exit_success(VCPKG_LINE_INFO);
     }
 }

toolsrc/src/vcpkg/vcpkgcmdarguments.cpp

@@ -250,26 +250,32 @@ namespace vcpkg
 
         if (failed)
         {
-            if (!command_structure.example_text.empty())
+            display_usage(command_structure);
-            {
-                System::println("%s", command_structure.example_text);
-            }
-
-            System::println("Options:", this->command);
-            for (auto&& option : command_structure.options.switches)
-            {
-                System::println("    %-40s %s", option.name, option.short_help_text);
-            }
-            for (auto&& option : command_structure.options.settings)
-            {
-                System::println("    %-40s %s", (option.name + "=..."), option.short_help_text);
-            }
-            System::println("    --triplet <t>");
-            System::println("    --vcpkg-root <path>");
-
             Checks::exit_fail(VCPKG_LINE_INFO);
         }
 
         return output;
     }
+
+    void display_usage(const CommandStructure& command_structure)
+    {
+        if (!command_structure.example_text.empty())
+        {
+            System::println("%s", command_structure.example_text);
+        }
+
+        System::println("Options:");
+        for (auto&& option : command_structure.options.switches)
+        {
+            System::println("    %-40s %s", option.name, option.short_help_text);
+        }
+        for (auto&& option : command_structure.options.settings)
+        {
+            System::println("    %-40s %s", (option.name + "=..."), option.short_help_text);
+        }
+        System::println("    %-40s %s", "--triplet <t>", "Set the default triplet for unqualified packages");
+        System::println("    %-40s %s",
+                        "--vcpkg-root <path>",
+                        "Specify the vcpkg directory to use instead of current directory or tool directory");
+    }
 }