SBFile::GetFile: convert SBFile back into python native files.

Summary:
This makes SBFile::GetFile public and adds a SWIG typemap to convert
the result back into a python native file.

If the underlying File itself came from a python file, it is returned
identically.   Otherwise a new python file object is created using
the file descriptor.

Reviewers: JDevlieghere, jasonmolenda, labath

Reviewed By: labath

Subscribers: lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D68737

llvm-svn: 374911

2 files changed, 33 insertions, 0 deletions

diff --git a/lldb/scripts/Python/python-typemaps.swig b/lldb/scripts/Python/python-typemaps.swig
index 9428c7c92ff..b9389022512 100644
--- a/lldb/scripts/Python/python-typemaps.swig
+++ b/lldb/scripts/Python/python-typemaps.swig
@@ -434,6 +434,22 @@ bool SetNumberFromPyObject<double>(double &number, PyObject *obj) {
   }
 }
 
+%typemap(out) lldb::FileSP {
+  using namespace lldb_private;
+  $result = nullptr;
+  lldb::FileSP &sp = $1;
+  if (sp) {
+    PythonFile pyfile = unwrapOrSetPythonException(PythonFile::FromFile(*sp));
+    if (!pyfile.IsValid())
+      return nullptr;
+    $result = pyfile.release();
+  }
+  if (!$result)
+  {
+      $result = Py_None;
+      Py_INCREF(Py_None);
+  }
+}
 
 // FIXME both of these paths wind up calling fdopen() with no provision for ever calling
 // fclose() on the result.  SB interfaces that use FILE* should be deprecated for scripting
diff --git a/lldb/scripts/interface/SBFile.i b/lldb/scripts/interface/SBFile.i
index 179446d5a53..27b83641338 100644
--- a/lldb/scripts/interface/SBFile.i
+++ b/lldb/scripts/interface/SBFile.i
@@ -77,6 +77,23 @@ public:
     operator bool() const;
 
     SBError Close();
+
+    %feature("docstring", "
+    Convert this SBFile into a python io.IOBase file object.
+
+    If the SBFile is itself a wrapper around a python file object,
+    this will return that original object.
+
+    The file returned from here should be considered borrowed,
+    in the sense that you may read and write to it, and flush it,
+    etc, but you should not close it.   If you want to close the
+    SBFile, call SBFile.Close().
+
+    If there is no underlying python file to unwrap, GetFile will
+    use the file descriptor, if availble to create a new python
+    file object using `open(fd, mode=..., closefd=False)`
+    ");
+    FileSP GetFile();
 };
 
 } // namespace lldb