From 4e2024e2e6b8309f2db6548e04e920f565a84b0b Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 18 Mar 2021 15:47:49 +0200
Subject: Add try_rmfile_ignore_error()

---
 libbutl/filesystem.cxx |  6 ++++--
 libbutl/filesystem.ixx | 17 +++++++++++++++++
 libbutl/filesystem.mxx | 19 ++++++++++++++-----
 3 files changed, 35 insertions(+), 7 deletions(-)

(limited to 'libbutl')

diff --git a/libbutl/filesystem.cxx b/libbutl/filesystem.cxx
index 18be8a9..2147c6f 100644
--- a/libbutl/filesystem.cxx
+++ b/libbutl/filesystem.cxx
@@ -1063,8 +1063,8 @@ namespace butl
     }
   }
 
-  rmfile_status
-  try_rmfile (const path& p, bool ignore_error)
+  optional<rmfile_status>
+  try_rmfile_maybe_ignore_error (const path& p, bool ignore_error)
   {
     rmfile_status r (rmfile_status::success);
     const char* f (p.string ().c_str ());
@@ -1143,6 +1143,8 @@ namespace butl
         r = rmfile_status::not_exist;
       else if (!ignore_error)
         throw_generic_error (errno);
+      else
+        return nullopt;
     }
 
     return r;
diff --git a/libbutl/filesystem.ixx b/libbutl/filesystem.ixx
index f7c3777..8cd8456 100644
--- a/libbutl/filesystem.ixx
+++ b/libbutl/filesystem.ixx
@@ -38,6 +38,23 @@ namespace butl
     return e ? rmdir_status::success : rmdir_status::not_exist;
   }
 
+  LIBBUTL_SYMEXPORT optional<rmfile_status>
+  try_rmfile_maybe_ignore_error (const path&, bool ignore_error);
+
+  inline rmfile_status
+  try_rmfile (const path& p, bool ignore_error)
+  {
+    auto r (try_rmfile_maybe_ignore_error (p, ignore_error));
+    return r ? *r : rmfile_status::success;
+  }
+
+  inline optional<rmfile_status>
+  try_rmfile_ignore_error (const path& p)
+  {
+    return try_rmfile_maybe_ignore_error (p, true);
+  }
+
+
   inline path
   followsymlink (const path& p)
   {
diff --git a/libbutl/filesystem.mxx b/libbutl/filesystem.mxx
index 935fc3f..7506439 100644
--- a/libbutl/filesystem.mxx
+++ b/libbutl/filesystem.mxx
@@ -42,12 +42,14 @@ import std.core;
 #endif
 
 import butl.path;
+import butl.optional;
 import butl.timestamp;
 import butl.path_pattern; // path_match_flags
 
 import butl.utility; // operator<<(ostream,exception), throw_generic_error()
 #else
 #include <libbutl/path.mxx>
+#include <libbutl/optional.mxx>
 #include <libbutl/timestamp.mxx>
 #include <libbutl/path-pattern.mxx>
 
@@ -60,7 +62,8 @@ LIBBUTL_MODEXPORT namespace butl
 {
   // Return true if the path is to an existing regular file. Note that by
   // default this function follows symlinks. Underlying OS errors are reported
-  // by throwing std::system_error, unless ignore_error is true.
+  // by throwing std::system_error, unless ignore_error is true (in which case
+  // erroneous entries are treated as non-existent).
   //
   LIBBUTL_SYMEXPORT bool
   file_exists (const char*,
@@ -73,7 +76,8 @@ LIBBUTL_MODEXPORT namespace butl
 
   // Return true if the path is to an existing directory. Note that this
   // function follows symlinks. Underlying OS errors are reported by throwing
-  // std::system_error, unless ignore_error is true.
+  // std::system_error, unless ignore_error is true (in which case erroneous
+  // entries are treated as non-existent).
   //
   LIBBUTL_SYMEXPORT bool
   dir_exists (const char*, bool ignore_error = false);
@@ -84,7 +88,8 @@ LIBBUTL_MODEXPORT namespace butl
 
   // Return true if the path is to an existing file system entry. Note that by
   // default this function doesn't follow symlinks. Underlying OS errors are
-  // reported by throwing std::system_error, unless ignore_error is true.
+  // reported by throwing std::system_error, unless ignore_error is true (in
+  // which case erroneous entries are treated as non-existent).
   //
   LIBBUTL_SYMEXPORT bool
   entry_exists (const char*,
@@ -117,7 +122,8 @@ LIBBUTL_MODEXPORT namespace butl
   // Return a flag indicating if the path is to an existing filesystem entry
   // and its info if so. Note that by default this function doesn't follow
   // symlinks. Underlying OS errors are reported by throwing
-  // std::system_error, unless ignore_error is true.
+  // std::system_error, unless ignore_error is true (in which case erroneous
+  // entries are treated as non-existent).
   //
   LIBBUTL_SYMEXPORT std::pair<bool, entry_stat>
   path_entry (const char*,
@@ -206,9 +212,12 @@ LIBBUTL_MODEXPORT namespace butl
   // is not atomic. It is also not atomic for the directory-type reparse point
   // removal.
   //
-  LIBBUTL_SYMEXPORT rmfile_status
+  rmfile_status
   try_rmfile (const path&, bool ignore_error = false);
 
+  optional<rmfile_status>
+  try_rmfile_ignore_error (const path&);
+
   // Automatically try to remove a non-empty path on destruction unless
   // cancelled. Since the non-cancelled destruction will normally happen as a
   // result of an exception, the failure to remove the path is silently
-- 
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