From 8a82f67e2cb3366ab6988bcb56eb06c1d56fdc5d Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Sat, 28 Apr 2018 18:04:08 +0200
Subject: Use rmsymlink() to portably remove symlinks

---
 build2/algorithm.cxx  | 23 +++++++++++++++--------
 build2/filesystem.cxx | 27 +++++++++++++++++++++++++++
 build2/filesystem.hxx |  3 +++
 3 files changed, 45 insertions(+), 8 deletions(-)

diff --git a/build2/algorithm.cxx b/build2/algorithm.cxx
index 6f756e4..924935c 100644
--- a/build2/algorithm.cxx
+++ b/build2/algorithm.cxx
@@ -973,7 +973,12 @@ namespace build2
 
     try
     {
-      try_rmfile (l); // Normally will be there.
+      // Normally will be there.
+      //
+      if (l.to_directory ())
+        try_rmsymlink (l, true /* directory */);
+      else
+        try_rmfile (l);
 
       // Skip (ad hoc) targets that don't exist.
       //
@@ -1014,10 +1019,10 @@ namespace build2
   void
   clean_backlink (const path& l, uint16_t verbosity)
   {
-    // Assuming this works for directories (which can only be symlinked). See
-    // also try_rmfile() calls in ~backlink() and update_backlink().
-    //
-    rmfile (l, verbosity);
+    if (l.to_directory ())
+      rmsymlink (l, true /* directory */, verbosity);
+    else
+      rmfile (l, verbosity); // Should work for symbolic and hard file links.
   }
 
   // If target/link path are syntactically to a directory, then the backlink
@@ -1039,9 +1044,11 @@ namespace build2
     {
       if (active)
       {
-        // Assuming this works for both file and directory (sym)links.
-        //
-        try_rmfile (path, true /* ignore_errors */);
+        if (path.to_directory ())
+          try_rmsymlink (path, true /* directory */, true /* ignore_errors */);
+        else
+          try_rmfile (path, true /* ignore_errors */);
+
         active = false;
       }
     }
diff --git a/build2/filesystem.cxx b/build2/filesystem.cxx
index 58e3037..bfda1c4 100644
--- a/build2/filesystem.cxx
+++ b/build2/filesystem.cxx
@@ -85,6 +85,33 @@ namespace build2
     return ms;
   }
 
+  fs_status<rmfile_status>
+  rmsymlink (const path& p, bool d, uint16_t v)
+  {
+    auto print = [&p, v] ()
+    {
+      if (verb >= v)
+        text << "rm " << p.string ();
+    };
+
+    rmfile_status rs;
+
+    try
+    {
+      rs = try_rmsymlink (p, d);
+    }
+    catch (const system_error& e)
+    {
+      print ();
+      fail << "unable to remove symlink " << p.string () << ": " << e << endf;
+    }
+
+    if (rs == rmfile_status::success)
+      print ();
+
+    return rs;
+  }
+
   fs_status<butl::rmdir_status>
   rmdir_r (const dir_path& d, bool dir, uint16_t v)
   {
diff --git a/build2/filesystem.hxx b/build2/filesystem.hxx
index 4c118a1..bbdc560 100644
--- a/build2/filesystem.hxx
+++ b/build2/filesystem.hxx
@@ -76,6 +76,9 @@ namespace build2
     return rmfile (f, f, verbosity);
   }
 
+  fs_status<rmfile_status>
+  rmsymlink (const path&, bool dir, uint16_t verbosity);
+
   // Similar to rmfile() but for directories (note: not -r).
   //
   using rmdir_status = butl::rmdir_status;
-- 
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