Catch parameter errors on startup and display option informations

2 files changed, 23 insertions, 6 deletions

diff --git a/src/main.cc b/src/main.cc
index 4a8421dc..721ee933 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -362,6 +362,18 @@ int main(int argc, char* argv[])
 
         kakoune(params);
     }
+    catch (Kakoune::parameter_error& error)
+    {
+        printf("Error: %s\n"
+               "Valid options:\n"
+               "    -e <commands>: execute commands on initialisation\n"
+               "    -c <session>: connect to the given session\n"
+               "    -s <session>: set session name\n"
+               "    -d: run as a headless session (requires -s)\n"
+               "    -n: do not source kakrc files on startup\n",
+               error.what());
+       return -1;
+    }
     catch (Kakoune::exception& error)
     {
         on_assert_failed(("uncaught exception:\n"_str + error.what()).c_str());
diff --git a/src/parameters_parser.hh b/src/parameters_parser.hh
index 2f7e5477..2230e3f2 100644
--- a/src/parameters_parser.hh
+++ b/src/parameters_parser.hh
@@ -12,21 +12,26 @@ namespace Kakoune
 
 using ParameterList = memoryview<String>;
 
-struct unknown_option : public runtime_error
+struct parameter_error : public runtime_error
+{
+    using runtime_error::runtime_error;
+};
+
+struct unknown_option : public parameter_error
 {
     unknown_option(const String& name)
-        : runtime_error("unknown option '" + name + "'") {}
+        : parameter_error("unknown option '" + name + "'") {}
 };
 
-struct missing_option_value: public runtime_error
+struct missing_option_value: public parameter_error
 {
     missing_option_value(const String& name)
-        : runtime_error("missing value for option '" + name + "'") {}
+        : parameter_error("missing value for option '" + name + "'") {}
 };
 
-struct wrong_argument_count : runtime_error
+struct wrong_argument_count : public parameter_error
 {
-    wrong_argument_count() : runtime_error("wrong argument count") {}
+    wrong_argument_count() : parameter_error("wrong argument count") {}
 };
 
 using OptionMap = std::unordered_map<String, bool>;