Allow building build module in multiple configurations if they belong to different configuration clusters

5 files changed, 88 insertions, 14 deletions

diff --git a/bpkg/database.cxx b/bpkg/database.cxx
index dd6790a..4f3b102 100644
--- a/bpkg/database.cxx
+++ b/bpkg/database.cxx
@@ -936,6 +936,39 @@ namespace bpkg
                                empty_string /* type */);
   }
 
+  linked_databases database::
+  cluster_configs (bool sys_rep)
+  {
+    linked_databases r;
+
+    // If the database is not in the resulting list, then add it and its
+    // dependent and dependency configurations, recursively.
+    //
+    auto add = [&r, sys_rep] (database& db, const auto& add)
+    {
+      if (std::find (r.begin (), r.end (), db) != r.end ())
+        return;
+
+      r.push_back (db);
+
+      {
+        linked_databases cs (db.dependency_configs ());
+        for (auto i (cs.begin_linked ()); i != cs.end (); ++i)
+          add (*i, add);
+      }
+
+      {
+        linked_databases cs (db.dependent_configs (sys_rep));
+        for (auto i (cs.begin_linked ()); i != cs.end (); ++i)
+          add (*i, add);
+      }
+    };
+
+    add (*this, add);
+
+    return r;
+  }
+
   database& database::
   find_attached (uint64_t id, bool s)
   {
diff --git a/bpkg/database.hxx b/bpkg/database.hxx
index c9ef590..cfd2645 100644
--- a/bpkg/database.hxx
+++ b/bpkg/database.hxx
@@ -214,7 +214,7 @@ namespace bpkg
     //
     // Note that we skip dangling links without any warning since they can be
     // quite common. Think of a shared host configuration with a bunch of
-    // implicitly linked configurations, which are removed and potentially
+    // implicitly linked configurations which are removed and potentially
     // recreated later during the host configuration lifetime. Note however,
     // that we remove the dangling implicit links during migration (see
     // migrate() on details).
@@ -297,6 +297,12 @@ namespace bpkg
     linked_databases
     dependent_configs (bool sys_rep = false);
 
+    // Return configurations of the linked cluster which the current
+    // configuration belongs to.
+    //
+    linked_databases
+    cluster_configs (bool sys_rep = false);
+
     // The following find_*() functions assume that the main database has been
     // created with the pre_attach flag set to true.
     //
diff --git a/bpkg/pkg-build.cli b/bpkg/pkg-build.cli
index f9cee12..b1415fe 100644
--- a/bpkg/pkg-build.cli
+++ b/bpkg/pkg-build.cli
@@ -412,7 +412,7 @@ namespace bpkg
       "<dir>",
       "Assume current configuration is in <dir> rather than in the current
        working directory. Repeat this option to specify multiple current
-       configurations. If multiple configurations are specified, they must
+       configurations. If multiple configurations are specified, they need not
        belong to the same linked configuration cluster."
     }
   };
diff --git a/bpkg/pkg-build.cxx b/bpkg/pkg-build.cxx
index 51bd224..dd48440 100644
--- a/bpkg/pkg-build.cxx
+++ b/bpkg/pkg-build.cxx
@@ -6218,15 +6218,18 @@ namespace bpkg
                                  verify_dependencies);
 
           // Now, verify that none of the build2 modules may simultaneously be
-          // built in multiple configurations, accross all (potentially
-          // unrelated) dependency trees.
+          // built in multiple configurations which belong to the same linked
+          // configuration cluster.
           //
           // For that we use the `package_prereqs` map: its key set refers to
           // all the packages potentially involved into the build (explicitly
           // or implicitly).
           //
           {
-            map<package_name, database&> build2_mods;
+            // List of module packages together with the linked configuration
+            // clusters they belong to.
+            //
+            vector<pair<config_package, linked_databases>> build2_mods;
 
             for (const auto& pp: package_prereqs)
             {
@@ -6249,22 +6252,33 @@ namespace bpkg
                   continue;
               }
 
-              auto i (build2_mods.emplace (cp.name, cp.db));
-
-              if (!i.second)
+              // Make sure the module's database doesn't belong to any other
+              // cluster this module is also configured in.
+              //
+              for (const auto& m: build2_mods)
               {
-                database& db (i.first->second);
+                if (m.first.name != cp.name)
+                  continue;
 
                 // The `package_prereqs` map can only contain the same package
                 // twice if databases differ.
                 //
-                assert (db != cp.db);
+                assert (m.first.db != cp.db);
+
+                const linked_databases& lcc (m.second);
 
-                fail << "building build system module " << cp.name << " in "
-                     << "multiple configurations" <<
-                  info << db.config_orig <<
-                  info << cp.db.config_orig;
+                if (find (lcc.begin (), lcc.end (), cp.db) != lcc.end ())
+                {
+                  fail << "building build system module " << cp.name
+                       << " in multiple configurations" <<
+                    info << m.first.db.config_orig <<
+                    info << cp.db.config_orig;
+                }
               }
+
+              // Add the module and its cluster to the list.
+              //
+              build2_mods.emplace_back (cp, cp.db.cluster_configs ());
             }
           }
         }
diff --git a/tests/pkg-build.testscript b/tests/pkg-build.testscript
index 4da7747..48fea7b 100644
--- a/tests/pkg-build.testscript
+++ b/tests/pkg-build.testscript
@@ -6465,6 +6465,27 @@ else
           libbaz configured 1.0.0
         EOO
     }
+
+    : build2-module-different-clusters
+    :
+    : Test that the same module can successfully be built in 2 configurations
+    : if they belong to different linked configuration clusters.
+    :
+    {
+      $cfg_create -d cfg  --uuid $cfg_uuid  &cfg/***;
+      $cfg_create -d cfg2 --uuid $cfg2_uuid &cfg2/***;
+
+      test.arguments += -d cfg2; # Now refers 2 current dirs: cfg/ and cfg2/.
+
+      $* "libbiz@$rep/t7a" +{ --config-uuid $cfg_uuid  } \
+         "libbuz@$rep/t7a" +{ --config-uuid $cfg2_uuid } --yes --trust-yes 2>>~%EOE%
+        %(added|fetching) .+%{4}
+        %(fetched|unpacked) .+%{26}
+        %configured .+%{13}
+        %info: .+ is up to date%{2}
+        %updated .+%{2}
+        EOE
+    }
   }
 
   : system