Factor recipe to separate header/source files

8 files changed, 86 insertions, 58 deletions

diff --git a/libbuild2/action.hxx b/libbuild2/action.hxx
index ec2701f..c1e4697 100644
--- a/libbuild2/action.hxx
+++ b/libbuild2/action.hxx
@@ -40,9 +40,10 @@ namespace build2
   // it via rule/recipe override but that didn't end up well, to put it
   // mildly). While the outer operation normally "directs" the inner, inner
   // rules can still be matched/executed directly, without outer's involvement
-  // (e.g., because of other inner rules). A typical implementation of an
-  // outer rule either returns noop or delegates to the inner rule. In
-  // particular, it should not replace or override the inner's logic.
+  // (e.g., because of dependencies in other inner rules). A typical
+  // implementation of an outer rule either returns noop or delegates to the
+  // inner rule. In particular, it should not replace or override the inner's
+  // logic.
   //
   // While most of the relevant target state is duplicated, certain things are
   // shared among the inner/outer rules, such as the target data pad and the
diff --git a/libbuild2/algorithm.hxx b/libbuild2/algorithm.hxx
index ad4ee74..390516a 100644
--- a/libbuild2/algorithm.hxx
+++ b/libbuild2/algorithm.hxx
@@ -10,6 +10,7 @@
 
 #include <libbuild2/action.hxx>
 #include <libbuild2/target.hxx>
+#include <libbuild2/recipe.hxx>
 
 #include <libbuild2/export.hxx>
 
@@ -673,12 +674,18 @@ namespace build2
   LIBBUILD2_SYMEXPORT target_state
   noop_action (action, const target&);
 
-  // Default action implementation which forwards to the prerequisites.
-  // Use default_recipe instead of using this function directly.
+  // Default action implementation which forwards to the prerequisites.  Use
+  // default_recipe instead of using this function directly.
   //
   LIBBUILD2_SYMEXPORT target_state
   default_action (action, const target&);
 
+  // Group action which calls the group's recipe. Use group_recipe instead of
+  // using this function directly.
+  //
+  LIBBUILD2_SYMEXPORT target_state
+  group_action (action, const target&);
+
   // Standard perform(clean) action implementation for the file target
   // (or derived).
   //
diff --git a/libbuild2/recipe.cxx b/libbuild2/recipe.cxx
new file mode 100644
index 0000000..3720059
--- /dev/null
+++ b/libbuild2/recipe.cxx
@@ -0,0 +1,14 @@
+// file      : libbuild2/target.cxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#include <libbuild2/target.hxx>
+
+#include <libbuild2/algorithm.hxx>
+
+namespace build2
+{
+  const recipe empty_recipe;
+  const recipe noop_recipe (&noop_action);
+  const recipe default_recipe (&default_action);
+  const recipe group_recipe (&group_action);
+}
diff --git a/libbuild2/recipe.hxx b/libbuild2/recipe.hxx
new file mode 100644
index 0000000..508c059
--- /dev/null
+++ b/libbuild2/recipe.hxx
@@ -0,0 +1,53 @@
+// file      : libbuild2/recipe.hxx -*- C++ -*-
+// license   : MIT; see accompanying LICENSE file
+
+#ifndef LIBBUILD2_RECIPE_HXX
+#define LIBBUILD2_RECIPE_HXX
+
+#include <libbuild2/types.hxx>
+#include <libbuild2/forward.hxx>
+#include <libbuild2/utility.hxx>
+
+#include <libbuild2/action.hxx>
+#include <libbuild2/target-state.hxx>
+
+#include <libbuild2/export.hxx>
+
+namespace build2
+{
+  // The returned target state is normally changed or unchanged. If there is
+  // an error, then the recipe should throw failed rather than returning (this
+  // is the only exception that a recipe can throw).
+  //
+  // The return value of the recipe is used to update the target state. If it
+  // is target_state::group then the target's state is the group's state.
+  //
+  // The recipe may also return postponed in which case the target state is
+  // assumed to be unchanged (normally this means a prerequisite was postponed
+  // and while the prerequisite will be re-examined via another dependency,
+  // this target is done).
+  //
+  // Note that max size for the "small capture optimization" in std::function
+  // ranges (in pointer sizes) from 0 (GCC prior to 5) to 2 (GCC 5) to 6 (VC
+  // 14.2). With the size ranging (in bytes for 64-bit target) from 32 (GCC)
+  // to 64 (VC).
+  //
+  using recipe_function = target_state (action, const target&);
+  using recipe = function<recipe_function>;
+
+  // Commonly-used recipes.
+  //
+  // The default recipe executes the action on all the prerequisites in a
+  // loop, skipping ignored. Specifically, for actions with the "first"
+  // execution mode, it calls execute_prerequisites() while for those with
+  // "last" -- reverse_execute_prerequisites() (see <libbuild2/operation.hxx>,
+  // <libbuild2/algorithm.hxx> for details). The group recipe calls the
+  // group's recipe.
+  //
+  LIBBUILD2_SYMEXPORT extern const recipe empty_recipe;
+  LIBBUILD2_SYMEXPORT extern const recipe noop_recipe;
+  LIBBUILD2_SYMEXPORT extern const recipe default_recipe;
+  LIBBUILD2_SYMEXPORT extern const recipe group_recipe;
+}
+
+#endif // LIBBUILD2_RECIPE_HXX
diff --git a/libbuild2/rule.hxx b/libbuild2/rule.hxx
index e5e53d1..9eab1f6 100644
--- a/libbuild2/rule.hxx
+++ b/libbuild2/rule.hxx
@@ -10,6 +10,7 @@
 
 #include <libbuild2/action.hxx>
 #include <libbuild2/target.hxx>
+#include <libbuild2/recipe.hxx>
 
 #include <libbuild2/export.hxx>
 
diff --git a/libbuild2/target.cxx b/libbuild2/target.cxx
index d313b05..83ed4a5 100644
--- a/libbuild2/target.cxx
+++ b/libbuild2/target.cxx
@@ -82,13 +82,6 @@ namespace build2
     return os << target_state_[static_cast<uint8_t> (ts)];
   }
 
-  // recipe
-  //
-  const recipe empty_recipe;
-  const recipe noop_recipe (&noop_action);
-  const recipe default_recipe (&default_action);
-  const recipe group_recipe (&group_action);
-
   // target
   //
   const target::prerequisites_type target::empty_prerequisites_;
diff --git a/libbuild2/target.hxx b/libbuild2/target.hxx
index 8adaa2c..eea43df 100644
--- a/libbuild2/target.hxx
+++ b/libbuild2/target.hxx
@@ -16,6 +16,7 @@
 
 #include <libbuild2/scope.hxx>
 #include <libbuild2/action.hxx>
+#include <libbuild2/recipe.hxx>
 #include <libbuild2/context.hxx>
 #include <libbuild2/variable.hxx>
 #include <libbuild2/target-key.hxx>
@@ -52,51 +53,6 @@ namespace build2
     value v_;
   };
 
-  // Recipe.
-  //
-  // The returned target state is normally changed or unchanged. If there is
-  // an error, then the recipe should throw failed rather than returning (this
-  // is the only exception that a recipe can throw).
-  //
-  // The return value of the recipe is used to update the target state. If it
-  // is target_state::group then the target's state is the group's state.
-  //
-  // The recipe may also return postponed in which case the target state is
-  // assumed to be unchanged (normally this means a prerequisite was postponed
-  // and while the prerequisite will be re-examined via another dependency,
-  // this target is done).
-  //
-  // Note that max size for the "small capture optimization" in std::function
-  // ranges (in pointer sizes) from 0 (GCC prior to 5) to 2 (GCC 5) to 6 (VC
-  // 14.2). With the size ranging (in bytes for 64-bit target) from 32 (GCC)
-  // to 64 (VC).
-  //
-  using recipe_function = target_state (action, const target&);
-  using recipe = function<recipe_function>;
-
-  // Commonly-used recipes. The default recipe executes the action on
-  // all the prerequisites in a loop, skipping ignored. Specifically,
-  // for actions with the "first" execution mode, it calls
-  // execute_prerequisites() while for those with the "last" mode --
-  // reverse_execute_prerequisites(); see <libbuild2/operation.hxx>,
-  // <libbuild2/algorithm.hxx> for details. The group recipe call's the
-  // group's recipe.
-  //
-  LIBBUILD2_SYMEXPORT extern const recipe empty_recipe;
-  LIBBUILD2_SYMEXPORT extern const recipe noop_recipe;
-  LIBBUILD2_SYMEXPORT extern const recipe default_recipe;
-  LIBBUILD2_SYMEXPORT extern const recipe group_recipe;
-
-  // Defined in <libbuild2/algorithm.hxx>.
-  //
-  LIBBUILD2_SYMEXPORT target_state
-  noop_action (action, const target&);
-
-  // Defined in <libbuild2/algorithm.hxx>.
-  //
-  LIBBUILD2_SYMEXPORT target_state
-  group_action (action, const target&);
-
   // A view of target group members.
   //
   struct group_view
@@ -484,7 +440,7 @@ namespace build2
     static const size_t offset_executed = 5; // Recipe has been executed.
     static const size_t offset_busy     = 6; // Match/execute in progress.
 
-    // Inner/outer operation state. See <libbuild2/operation.hxx> for details.
+    // Inner/outer operation state. See <libbuild2/action.hxx> for details.
     //
     class LIBBUILD2_SYMEXPORT opstate
     {
diff --git a/libbuild2/target.ixx b/libbuild2/target.ixx
index 5f53f3d..4717800 100644
--- a/libbuild2/target.ixx
+++ b/libbuild2/target.ixx
@@ -87,6 +87,9 @@ namespace build2
     return c >= offset_matched;
   }
 
+  LIBBUILD2_SYMEXPORT target_state
+  group_action (action, const target&); // <libbuild2/algorithm.hxx>
+
   inline bool target::
   group_state (action a) const
   {