1 files changed, 119 insertions, 0 deletions
diff --git a/bpkg/package-configuration.hxx b/bpkg/package-configuration.hxx
new file mode 100644
index 0000000..55a43a5
--- /dev/null
+++ b/bpkg/package-configuration.hxx
@@ -0,0 +1,119 @@
+// file      : bpkg/package-configuration.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef BPKG_PACKAGE_CONFIGURATION_HXX
+#define BPKG_PACKAGE_CONFIGURATION_HXX
+
+#include <map>
+
+#include <libbuild2/types.hxx>        // build2::names
+#include <libbuild2/config/types.hxx> // build2::config::variable_origin
+
+#include <bpkg/types.hxx>
+#include <bpkg/utility.hxx>
+
+#include <bpkg/package.hxx>
+
+using namespace std;
+
+namespace bpkg
+{
+  class package_skeleton;
+
+  struct config_variable_value
+  {
+    string name;
+
+    // The variable_origin values have the following meaning:
+    //
+    // default    -- default value from the config directive
+    // buildfile  -- dependent configuration (config_source::dependent)
+    // override   -- user configuration      (config_source::user)
+    // undefined  -- none of the above
+    //
+    build2::config::variable_origin origin;
+
+    // If origin is not undefined, then this is the reversed variable value
+    // with absent signifying NULL.
+    //
+    optional<build2::names> value;
+
+    // Variable type name with absent signifying untyped.
+    //
+    optional<string> type;
+
+    // If origin is buildfile, then this is the "originating dependent" which
+    // first set this variable to this value.
+    //
+    optional<package_key> dependent;
+
+    // Value version (used internally by package_skeleton).
+    //
+    size_t version;
+  };
+
+  class package_configuration: public vector<config_variable_value>
+  {
+  public:
+    config_variable_value*
+    find (const string& name)
+    {
+      auto i (find_if (begin (), end (),
+                       [&name] (const config_variable_value& v)
+                       {
+                         return v.name == name;
+                       }));
+      return i != end () ? &*i : nullptr;
+    }
+
+    const config_variable_value*
+    find (const string& name) const
+    {
+      auto i (find_if (begin (), end (),
+                       [&name] (const config_variable_value& v)
+                       {
+                         return v.name == name;
+                       }));
+      return i != end () ? &*i : nullptr;
+    }
+  };
+
+
+  // @@ Maybe redo as small_vector?
+  //
+  using package_configurations = map<package_key, package_configuration>;
+
+
+  // A subset of config_variable_value for variable values set by the
+  // dependents (origin is buildfile). Used to track change history.
+  //
+  struct dependent_config_variable_value
+  {
+    string                  name;
+    optional<build2::names> value;
+    package_key             dependent;
+  };
+
+  class dependent_config_variable_values:
+    public small_vector<dependent_config_variable_value, 1>
+  {
+  public:
+    /*
+      @@
+    void
+    sort ();
+    */
+  };
+
+  // Up-negotiate the configuration for the specified dependencies of the
+  // specified dependent. Return true if the configuration has changed.
+  //
+  bool
+  up_negotiate_configuration (
+    package_configurations&,
+    package_skeleton& dependent,
+    pair<size_t, size_t> position,
+    const small_vector<reference_wrapper<package_skeleton>, 1>& dependencies);
+}
+
+#endif // BPKG_PACKAGE_CONFIGURATION_HXX