Add $filesystem.file_exists(), $filesystem.directory_exists()

3 files changed, 99 insertions, 2 deletions

diff --git a/libbuild2/functions-filesystem.cxx b/libbuild2/functions-filesystem.cxx
index 665a0f3..340c2bc 100644
--- a/libbuild2/functions-filesystem.cxx
+++ b/libbuild2/functions-filesystem.cxx
@@ -5,6 +5,7 @@
 
 #include <libbuild2/function.hxx>
 #include <libbuild2/variable.hxx>
+#include <libbuild2/filesystem.hxx>
 
 using namespace std;
 using namespace butl;
@@ -95,14 +96,60 @@ namespace build2
     return r;
   }
 
+  static bool
+  file_exists (path&& f)
+  {
+    if (f.relative () && path_traits::thread_current_directory () != nullptr)
+      f.complete ();
+
+    return exists (f);
+  }
+
+  static bool
+  directory_exists (dir_path&& d)
+  {
+    if (d.relative () && path_traits::thread_current_directory () != nullptr)
+      d.complete ();
+
+    return exists (d);
+  }
+
   void
   filesystem_functions (function_map& m)
   {
-    // @@ Maybe we should have the ability to mark the whole family as not
-    //    pure?
+    // NOTE: anything that depends on relative path must handle the
+    //       thread-specific curren directory override explicitly.
 
     function_family f (m, "filesystem");
 
+    // $file_exists(<path>)
+    //
+    // Return true if a filesystem entry at the specified path exists and is a
+    // regular file (or is a symlink to a regular file) and false otherwise.
+    //
+    // Note that this function is not pure.
+    //
+    {
+      auto e (f.insert ("file_exists", false));
+
+      e += [](path f) {return file_exists (move (f));};
+      e += [](names ns) {return file_exists (convert<path> (move (ns)));};
+    }
+
+    // $directory_exists(<path>)
+    //
+    // Return true if a filesystem entry at the specified path exists and is a
+    // directory (or is a symlink to a directory) and false otherwise.
+    //
+    // Note that this function is not pure.
+    //
+    {
+      auto e (f.insert ("directory_exists", false));
+
+      e += [](path f) {return directory_exists (path_cast<dir_path> (move (f)));};
+      e += [](names ns) {return directory_exists (convert<dir_path> (move (ns)));};
+    }
+
     // $path_search(<pattern>[, <start-dir>])
     //
     // Return filesystem paths that match the shell-like wildcard pattern. If
diff --git a/tests/function/filesystem/testscript b/tests/function/filesystem/testscript
index cf93b8b..c7c08f1 100644
--- a/tests/function/filesystem/testscript
+++ b/tests/function/filesystem/testscript
@@ -73,3 +73,51 @@
     EOE
   }
 }
+
+: file_exists
+:
+{
+  : file
+  :
+  touch f;
+  $* <'print $file_exists(f)' >'true'
+
+  : symlink
+  :
+  touch f && ln -s f s;
+  $* <'print $file_exists([path] s)' >'true'
+
+  : directory
+  :
+  mkdir d;
+  $* <'print $file_exists([dir_path] d)' >'false'
+
+  : testscript
+  :
+  touch f;
+  echo $file_exists(f) >'true'
+}
+
+: directory_exists
+:
+{
+  : directory
+  :
+  mkdir d;
+  $* <'print $directory_exists(d)' >'true'
+
+  : symlink
+  :
+  mkdir d && ln -s d s;
+  $* <'print $directory_exists([dir_path] d)' >'true'
+
+  : file
+  :
+  touch f;
+  $* <'print $directory_exists([path] f)' >'false'
+
+  : testscript
+  :
+  mkdir d;
+  echo $directory_exists(d) >'true'
+}
diff --git a/tests/function/path/testscript b/tests/function/path/testscript
index d49e9e5..6321b3d 100644
--- a/tests/function/path/testscript
+++ b/tests/function/path/testscript
@@ -210,6 +210,8 @@ s = ($posix ? '/' : '\')
   $* <'print $complete([path] a)'     >"$~$(s)a"     : path
   $* <'print $complete([dir_path] a)' >"$~$(s)a$(s)" : dir-path
   $* <'print $path.complete(a)'       >"$~$(s)a"     : untyped
+
+  echo $path.complete(a)              > "$~$(s)a"    : testscript
 }
 
 : canonicalize