Refactor configuration builtins

Gives them a tagged type that simplifies use and aglutinates default,
description, checks, which were previously not formally required or scattered.

src/alire/alire-builds.adb

@@ -1,5 +1,6 @@
 with AAA.Strings;
 
+with Alire.Config.Builtins;
 with Alire.Config.Edit;
 with Alire.Directories;
 with Alire.OS_Lib.Subprocess;
@@ -18,8 +19,7 @@ package body Alire.Builds is
    ----------------------------
 
    function Sandboxed_Dependencies return Boolean
-   is (not Config.DB.Get (Config.Keys.Dependencies_Shared,
-                          Config.Defaults.Dependencies_Shared));
+   is (not Config.Builtins.Dependencies_Shared.Get);
 
    -------------------
    -- To_Msys2_Path --

src/alire/alire-config-builtins.ads

@@ -0,0 +1,149 @@
+package Alire.Config.Builtins is
+
+   subtype Builtin is Builtin_Option;
+
+   --------------
+   -- Builtins --
+   --------------
+
+   Dependencies_Shared : constant Builtin := New_Builtin
+     (Key  => "dependencies.shared",
+      Def  => False,
+      Help =>
+        "When true, dependencies are downloaded and built in a shared "
+      & "location inside the global cache. When false (default), "
+      & "dependencies are sandboxed in each workspace.");
+
+   Distribution_Disable_Detection : constant Builtin := New_Builtin
+     (Key  => "distribution.disable_detection",
+      Def  => False,
+      Help =>
+        "If true, Alire will report an unknown distribution and will not"
+      & " attempt to use the system package manager.");
+
+   --  EDITOR
+
+   Editor_Cmd : constant Builtin := New_Builtin
+     (Key  => "editor.cmd",
+      Kind => Cfg_String,
+      Def  => "gnatstudio -P ${GPR_FILE}",
+      Help =>
+        "Editor command and arguments for editing crate code (alr edit)." &
+        " The executables and arguments are separated by a single space" &
+        " character. The token ${GPR_FILE} is replaced by" &
+        " a path to the project file to open.");
+
+   --  INDEX
+
+   Index_Auto_Community : constant Builtin := New_Builtin
+     (Key => "index.auto_community",
+      Def => True,
+      Help =>
+        "When unset or true, the community index will be added " &
+        "automatically when required if no other index is configured.");
+
+   Index_Host : constant Builtin := New_Builtin
+     (Key  => "index.host",
+      Kind => Cfg_String,
+      Def  => "https://github.com",
+      Help => "URL of the community index host");
+
+   Index_Owner : constant Builtin := New_Builtin
+     (Key  => "index.owner",
+      Kind => Cfg_String,
+      Def  => "alire-project",
+      Help => "Owner of the index repository (GitHub user/org).");
+
+   Index_Repository_Name : constant Builtin := New_Builtin
+     (Key  => "index.repository_name",
+      Kind => Cfg_String,
+      Def  => "alire-index",
+      Help => "Name of the index repository.");
+
+   --  SOLVER
+
+   Solver_Autonarrow : constant Builtin := New_Builtin
+     (Key => "solver.autonarrow",
+      Def => True,
+      Help =>
+        "If true, `alr with` will replace 'any' dependencies with the"
+      & " appropriate caret/tilde dependency.");
+
+   --  TOOLCHAIN
+
+   Toolchain_Assistant : constant Builtin := New_Builtin
+     (Key  => "toolchain.assistant",
+      Def  => True,
+      Help =>
+        "If true, and assistant to select the default toolchain will run "
+      & "when first needed.");
+
+   Toolchain_External : constant Builtin := New_Builtin
+     (Key    => "toolchain.external",
+      Def    => True,
+      Public => False);
+   --  We use this key to store whether a tool in the toolchain requires
+   --  external detection. It stores a boolean per tool, e.g, for gprbuild:
+   --  toolchain.external.gprbuild
+
+   Toolchain_Use : constant Builtin := New_Builtin
+     (Key    => "toolchain.use",
+      Def    => True,
+      Public => False);
+   --  We use this key internally to store the configured tools picked
+   --  up by the user. Not really intended to be set up by users, so
+   --  not listed as a built-in. Each tool is a child of this key,
+   --  e.g.: toolchain.use.gnat, toolchain.use.gprbuild
+
+   --  UPDATE
+
+   Update_Manually_Only : constant Builtin := New_Builtin
+     (Key  => "update.manually_only",
+      Def  => False,
+      Help =>
+        "If true, Alire will not attempt to update dependencies even after "
+      & "the manifest is manually edited, or when no valid solution has "
+      & "been ever computed. All updates have to be manually requested "
+      & "through `alr update`");
+
+   --  USER
+
+   User_Email : constant Builtin := New_Builtin
+     (Key  => "user.email",
+      Kind => Cfg_Email,
+      Help =>
+        "User email address. Used for the authors and" &
+        " maintainers field of a new crate.");
+
+   User_Name : constant Builtin := New_Builtin
+     (Key  => "user.name",
+      Kind => Cfg_String,
+      Help =>
+        "User full name. Used for the authors and " &
+        "maintainers field of a new crate.");
+
+   User_Github_Login : constant Builtin := New_Builtin
+     (Key  => "user.github_login",
+      Kind => Cfg_GitHub_Login,
+      Help =>
+        "User GitHub login/username. Used to for the maintainers-logins " &
+        "field of a new crate.");
+
+   --  WARNINGS
+
+   Warning_Caret : constant Builtin := New_Builtin
+     (Key  => "warning.caret",
+      Def  => True,
+      Help =>
+        "If true, Alire will warn about the use of caret (^) for pre-1 "
+      & "dependencies, for which tilde (~) is recommended instead.");
+
+   Warning_Old_Index : constant Builtin := New_Builtin
+     (Key  => "warning.old_index",
+      Def  => True,
+      Help =>
+        "If unset or true, a warning will be emitted when " &
+        "using a compatible index with a lower version than the newest" &
+        " known.");
+
+end Alire.Config.Builtins;

src/alire/alire-config-edit.adb

@@ -1,5 +1,6 @@
 with Ada.Text_IO;
 
+with Alire.Config.Builtins;
 with Alire.Environment;
 with Alire.Paths;
 with Alire.Platforms.Folders;
@@ -131,30 +132,6 @@ package body Alire.Config.Edit is
       end case;
    end Filepath;
 
-   ----------------
-   -- Is_Builtin --
-   ----------------
-
-   function Is_Builtin (Key : CLIC.Config.Config_Key) return Boolean
-   is (for some Cfg of Builtins => To_String (Cfg.Key) = Key);
-
-   ---------------------
-   -- Kind_Of_Builtin --
-   ---------------------
-
-   function Kind_Of_Builtin (Key : CLIC.Config.Config_Key)
-                             return Builtin_Kind
-   is
-   begin
-      for Ent of Builtins loop
-         if To_String (Ent.Key) = Key then
-            return Ent.Kind;
-         end if;
-      end loop;
-
-      Raise_Checked_Error ("Kind is only valid for builtin config key");
-   end Kind_Of_Builtin;
-
    -----------------
    -- Load_Config --
    -----------------
@@ -175,7 +152,7 @@ package body Alire.Config.Edit is
       --  Set variables elsewhere
 
       Platforms.Current.Disable_Distribution_Detection :=
-        DB.Get (Keys.Distribution_Disable_Detection, False);
+        Config.Builtins.Distribution_Disable_Detection.Get;
       if Platforms.Current.Disable_Distribution_Detection then
          Trace.Debug ("Distribution detection disabled by configuration");
       end if;
@@ -237,8 +214,11 @@ package body Alire.Config.Edit is
    is
       Result : Boolean := True;
    begin
-      for Ent of Builtins loop
+      for Ent of All_Builtins loop
          if To_String (Ent.Key) = Key then
+
+            --  Verify the type/specific constraints
+
             case Ent.Kind is
             when Cfg_Int =>
                Result := Value.Kind = TOML_Integer;
@@ -273,6 +253,19 @@ package body Alire.Config.Edit is
                  and then Utils.Is_Valid_GitHub_Username (Value.As_String);
             end case;
 
+            exit when not Result;
+
+            --  Apply the own builtin check if any.
+
+            if Result and then Ent.Check not in null then
+               if not Ent.Check (Key, Value) then
+                  Trace.Error
+                    ("Invalid value '" & CLIC.Config.Image (Value)  &
+                       "' for builtin configuration '" & Key & "'. " &
+                       "Specific builtin check failed.");
+               end if;
+            end if;
+
             exit;
          end if;
       end loop;
@@ -287,31 +280,17 @@ package body Alire.Config.Edit is
       return Result;
    end Valid_Builtin;
 
-   -----------
-   -- Image --
-   -----------
-
-   function Image (Kind : Builtin_Kind) return String
-   is (case Kind is
-          when Cfg_Int           => "Integer",
-          when Cfg_Float         => "Float",
-          when Cfg_Bool          => "Boolean",
-          when Cfg_String        => "String",
-          when Cfg_Absolute_Path => "Absolute path",
-          when Cfg_Existing_Absolute_Path => "Absolute path already existing",
-          when Cfg_Email         => "Email address",
-          when Cfg_GitHub_Login  => "GitHub login");
-
    -------------------
    -- Builtins_Info --
    -------------------
 
    function Builtins_Info return AAA.Strings.Vector is
       Results : AAA.Strings.Vector;
    begin
-      for Ent of Builtins loop
-         Results.Append (String'("- " & To_String (Ent.Key) &
-                           " [" & Image (Ent.Kind) & "]"));
+      for Ent of All_Builtins loop
+         Results.Append (String'("- " & To_String (Ent.Key)
+                         & " [" & Image (Ent.Kind) & "]"
+                         & "[Default:" & To_String (Ent.Def) & "]"));
          Results.Append (To_String (Ent.Help));
          Results.Append ("");
       end loop;
@@ -325,9 +304,10 @@ package body Alire.Config.Edit is
    procedure Print_Builtins_Doc is
       use Ada.Text_IO;
    begin
-      for Ent of Builtins loop
+      for Ent of All_Builtins loop
          Put (" - **`" & To_String (Ent.Key) & "`** ");
-         Put_Line ("[" & Image (Ent.Kind) & "]:");
+         Put ("[" & Image (Ent.Kind) & "]");
+         Put_Line ("[Default:" & To_String (Ent.Def) & "]:");
          Put_Line ("   " & To_String (Ent.Help));
          New_Line;
       end loop;