From 7b06ee81ab0e8a2199c4dce07ec67282c4f52f62 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Tue, 4 Apr 2023 08:05:21 +0200
Subject: Add support for installation filtering (GH issue #147)

---
 libbuild2/install/functions.cxx | 67 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

(limited to 'libbuild2/install/functions.cxx')

diff --git a/libbuild2/install/functions.cxx b/libbuild2/install/functions.cxx
index 9f5fa44..d62b578 100644
--- a/libbuild2/install/functions.cxx
+++ b/libbuild2/install/functions.cxx
@@ -5,6 +5,7 @@
 #include <libbuild2/variable.hxx>
 
 #include <libbuild2/install/utility.hxx>
+#include <libbuild2/install/operation.hxx>
 
 namespace build2
 {
@@ -17,6 +18,8 @@ namespace build2
 
       // $install.resolve(<dir>[, <rel_base>])
       //
+      // @@ TODO: add overload to call resolve_file().
+      //
       // Resolve potentially relative install.* value to an absolute and
       // normalized directory based on (other) install.* values visible from
       // the calling scope.
@@ -80,6 +83,70 @@ namespace build2
                             move (dir),
                             rel_base ? move (*rel_base) : dir_path ());
       };
+
+      // @@ TODO: add $install.chroot().
+
+      // $install.filter(<path>[, <type>])
+      //
+      // Apply filters from config.install.filter and return true if the
+      // specified filesystem entry should be installed/uninstalled. Note that
+      // the entry is specified as an absolute and normalized installation
+      // path (so not $path($>) but $install.resolve($>)).
+      //
+      // The type argument can be one of `regular`, `directory`, or `symlink`.
+      // If unspecified, either `directory` or `regular` is assumed, based on
+      // whether path is syntactially a directory (ends with a directory
+      // separator).
+      //
+      // Note that this function is not pure and can only be called from a
+      // install or uninstall operation recipe.
+      //
+      f.insert (".filter", false) += [] (const scope* s,
+                                         path p,
+                                         optional<names> ot)
+      {
+        if (s == nullptr)
+          fail << "install.filter() called out of scope" << endf;
+
+        context& ctx (s->ctx);
+
+        if (ctx.phase != run_phase::match &&
+            ctx.phase != run_phase::execute)
+          fail << "install.filter() can only be called from recipe";
+
+        if (ctx.current_inner_oif != &op_install &&
+            ctx.current_inner_oif != &op_uninstall)
+          fail << "install.filter() can only be called during install/uninstall";
+
+        entry_type t;
+        if (ot)
+        {
+          string v (convert<string> (move (*ot)));
+
+          if      (v == "regular")   t = entry_type::regular;
+          else if (v == "directory") t = entry_type::directory;
+          else if (v == "symlink")   t = entry_type::symlink;
+          else throw invalid_argument ("unknown type '" + v + '\'');
+        }
+        else
+          t = p.to_directory () ? entry_type::directory : entry_type::regular;
+
+        // Split into directory and leaf.
+        //
+        dir_path d;
+        if (t == entry_type::directory)
+        {
+          d = path_cast<dir_path> (move (p));
+          p = path (); // No leaf.
+        }
+        else
+        {
+          d = p.directory ();
+          p.make_leaf ();
+        }
+
+        return context_data::filter (*s->root_scope (), d, p, t);
+      };
     }
   }
 }
-- 
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