Add 'hidden-version' pkg flag and tweak criteria

master_changes.md

@@ -105,6 +105,8 @@ New option are prefixed with ◈
 ## Solver
   * Fix Cudf generation for compat with external solvers [#4261 @AltGr]
   * Check for a solution before calling the solver [#4263 @AltGr]
+  * Add the package flag 'hidden-version' to discourage selection by the solver [#4281 @AltGr]
+  * Tweak the default criteria to handle 'missing-depexts' and 'hidden-version' flags [#4281 @AltGr]
 
 ## Test
   * Add show cram test [#4206 @rjbou]

src/format/opamTypes.mli

@@ -115,6 +115,8 @@ type package_flag =
   | Pkgflag_Compiler (** Package may be used for 'opam switch' *)
   | Pkgflag_Conf (** Virtual package: no source, no install or remove instructions,
                      .install, but likely has depexts *)
+  | Pkgflag_HiddenVersion (** This version of the package will only be installed if
+                              strictly required *)
   | Pkgflag_Unknown of string (** Used for error reporting, otherwise ignored *)
 
 (** At some point we want to abstract so that the same functions can be used

src/format/opamTypesBase.ml

@@ -136,6 +136,7 @@ let string_of_pkg_flag = function
   | Pkgflag_Plugin -> "plugin"
   | Pkgflag_Compiler -> "compiler"
   | Pkgflag_Conf -> "conf"
+  | Pkgflag_HiddenVersion -> "hidden-version"
   | Pkgflag_Unknown s -> s
 
 let pkg_flag_of_string = function
@@ -144,6 +145,7 @@ let pkg_flag_of_string = function
   | "plugin" -> Pkgflag_Plugin
   | "compiler" -> Pkgflag_Compiler
   | "conf" -> Pkgflag_Conf
+  | "hidden-version" -> Pkgflag_HiddenVersion
   | s -> Pkgflag_Unknown s
 
 let action_contents = function

src/solver/opamBuiltinMccs.ml.real

@@ -14,13 +14,20 @@ let name solver_backend = "builtin-"^Mccs.get_solver_id ~solver:solver_backend (
 
 let default_criteria = {
   crit_default = "-removed,\
+                  -count[hidden-version,changed],\
                   -count[version-lag,request],\
                   -count[version-lag,changed],\
+                  -count[missing-depexts,changed],\
                   -changed";
   crit_upgrade = "-removed,\
+                  -count[hidden-version,changed],\
                   -count[version-lag,solution],\
+                  -count[missing-depexts,changed],\
                   -new";
-  crit_fixup = "-changed,-count[version-lag:,false]";
+  crit_fixup = "-changed,\
+                -count[hidden-version:,true],\
+                -count[version-lag:,false],\
+                -count[missing-depexts:,true]";
   crit_best_effort_prefix = Some "+count[opam-query:,false],";
 }
 

src/solver/opamBuiltinZ3.ml.real

@@ -22,13 +22,20 @@ let command_name = None
 
 let default_criteria = {
   crit_default = "-removed,\
+                  -count[hidden-version,changed],\
                   -count[version-lag,request],\
                   -count[version-lag,changed],\
+                  -count[missing-depexts,changed],\
                   -changed";
   crit_upgrade = "-removed,\
+                  -count[hidden-version,changed],\
                   -count[version-lag,solution],\
+                  -count[missing-depexts,changed],\
                   -new";
-  crit_fixup = "-changed,-count[version-lag,solution]";
+  crit_fixup = "-changed,\
+                -count[hidden-version,changed],\
+                -count[version-lag,solution],\
+                -count[missing-depexts,changed]";
   crit_best_effort_prefix = Some "+count[opam-query,solution],";
 }
 

src/solver/opamCudfSolver.ml

@@ -125,16 +125,23 @@ module Aspcud_def = struct
   let default_criteria =
     {
       crit_default = "-count(removed),\
+                      -sum(solution,hidden-version),\
                       -sum(request,version-lag),\
                       -count(down),\
                       -sum(solution,version-lag),\
-                      -count(changed)";
+                      -count(changed),\
+                      -sum(solution,missing-depexts)";
       crit_upgrade = "-count(down),\
                       -count(removed),\
+                      -sum(solution,hidden-version),\
                       -sum(solution,version-lag),\
+                      -sum(solution,missing-depexts),\
                       -count(new)";
       crit_fixup = "-count(changed),\
-                    -notuptodate(solution),-sum(solution,version-lag)";
+                    -count[hidden-version:,true],\
+                    -notuptodate(solution),\
+                    -sum(solution,version-lag),\
+                    -count[missing-depexts:,true]";
       crit_best_effort_prefix = Some "+sum(solution,opam-query),";
     }
 end
@@ -170,14 +177,21 @@ module Mccs_def = struct
 
   let default_criteria =  {
     crit_default = "-removed,\
+                    -count[hidden-version:,true],\
                     -count[version-lag:,true],\
                     -changed,\
                     -count[version-lag:,false],\
+                    -count[missing-depexts:,true],\
                     -new";
     crit_upgrade = "-removed,\
+                    -count[hidden-version:,true],\
                     -count[version-lag:,false],\
+                    -count[missing-depexts:,true],\
                     -new";
-    crit_fixup = "-changed,-count[version-lag:,false]";
+    crit_fixup = "-changed,\
+                  -count[hidden-version:,true],\
+                  -count[version-lag:,false],\
+                  -count[missing-depexts:,true]";
     crit_best_effort_prefix = Some "+count[opam-query:,false],";
   }
 end

src/state/opamSwitchState.ml

@@ -882,6 +882,13 @@ let universe st
       (Lazy.force st.sys_packages)
       OpamPackage.Set.empty
   in
+  let hidden_versions =
+    OpamPackage.Map.fold (fun nv opam acc ->
+        if OpamFile.OPAM.has_flag Pkgflag_HiddenVersion opam
+        then OpamPackage.Set.add nv acc else acc)
+      st.opams
+      OpamPackage.Set.empty
+  in
   let u =
 {
   u_packages  = st.packages;
@@ -897,7 +904,8 @@ let universe st
   u_invariant;
   u_reinstall;
   u_attrs     = ["opam-query", requested_allpkgs;
-                 "missing-depexts", missing_depexts];
+                 "missing-depexts", missing_depexts;
+                 "hidden-version", hidden_versions];
 }
   in
   u