From 1308eb0d740a687161641d52dabad8c0f849db08 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Mon, 10 Apr 2023 14:28:23 +0200
Subject: Add support for negation in config.install.filter

---
 doc/manual.cli                | 22 ++++++++++++++--------
 libbuild2/install/utility.cxx | 22 ++++++++++++++++++----
 libbuild2/install/utility.hxx |  2 +-
 3 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/doc/manual.cli b/doc/manual.cli
index 101493c..7f6b730 100644
--- a/doc/manual.cli
+++ b/doc/manual.cli
@@ -6328,14 +6328,20 @@ modifier to only apply to symlink filesystem entries. For example:
 $ b config.install.filter='\"*.so\"@false,symlink'
 \
 
-Note that this mechanism only affects what gets physically copied to the
-installation directory without affecting what gets built for install or the
-view of what gets installed at the \c{buildfile} level. For example,
-given the \c{include/@false *.a@false} filters, static libraries will still be
-built (unless arranged not to with \c{config.bin.lib}) and the \c{pkg-config}
-files will still end up with \c{-I} options pointing to the header
-installation directory. Note also that this mechanism applies to both
-\c{install} and \c{uninstall} operations.
+A filter can be negated by specifying \c{!} as the first pair. For example:
+
+\
+$ b install config.install.filter='! include/@false \"*.a\"@false'
+\
+
+Note that the filtering mechanism only affects what gets physically copied to
+the installation directory without affecting what gets built for install or
+the view of what gets installed at the \c{buildfile} level. For example, given
+the \c{include/@false *.a@false} filters, static libraries will still be built
+(unless arranged not to with \c{config.bin.lib}) and the \c{pkg-config} files
+will still end up with \c{-I} options pointing to the header installation
+directory. Note also that this mechanism applies to both \c{install} and
+\c{uninstall} operations.
 
 \N|If you are familiar with the Debian or Fedora packaging, this mechanism is
 somewhat similar to (and can be used for a similar purpose as) the Debian's
diff --git a/libbuild2/install/utility.cxx b/libbuild2/install/utility.cxx
index c8e1699..c8b6a92 100644
--- a/libbuild2/install/utility.cxx
+++ b/libbuild2/install/utility.cxx
@@ -57,10 +57,21 @@ namespace build2
       // If redoing all this work for every entry proves too slow, we can
       // consider some form of caching (e.g., on the per-project basis).
       //
+      auto i (fs->begin ());
+
+      bool negate (false);
+      if (i->first == "!")
+      {
+        negate = true;
+        ++i;
+      }
+
       size_t limit (0); // See below.
 
-      for (const pair<string, string>& kv: *fs)
+      for (auto e (fs->end ()); i != e; ++i)
       {
+        const pair<string, optional<string>>& kv (*i);
+
         path k;
         try
         {
@@ -77,7 +88,7 @@ namespace build2
 
         bool v;
         {
-          const string& s (kv.second);
+          const string& s (kv.second ? *kv.second : string ());
 
           size_t p (s.find (','));
 
@@ -269,13 +280,16 @@ namespace build2
           }
         }
 
+        if (negate)
+          v = !v;
+
         l4 ([&]{trace << (base / leaf)
                       << (v ? " included by " : " excluded by ")
-                      << kv.first << '@' << kv.second;});
+                      << kv.first << '@' << *kv.second;});
         return v;
       }
 
-      return true;
+      return !negate;
     }
   }
 }
diff --git a/libbuild2/install/utility.hxx b/libbuild2/install/utility.hxx
index dca8eb4..fc40ebe 100644
--- a/libbuild2/install/utility.hxx
+++ b/libbuild2/install/utility.hxx
@@ -113,7 +113,7 @@ namespace build2
     //
     // If entry type is a directory, then leaf must be empty.
     //
-    using filters = vector<pair<string, string>>;
+    using filters = vector<pair<string, optional<string>>>;
 
     LIBBUILD2_SYMEXPORT bool
     filter_entry (const scope& rs,
-- 
cgit v1.1