allow arbitrary python streams to be converted to SBFile

Summary:
This patch adds SWIG typemaps that can convert arbitrary python
file objects into lldb_private::File.

A SBFile may be initialized from a python file using the
constructor.   There are also alternate, tagged constructors
that allow python files to be borrowed, and for the caller
to control whether or not the python I/O methods will be
called even when a file descriptor is available.I

Reviewers: JDevlieghere, jasonmolenda, labath

Reviewed By: labath

Subscribers: zturner, amccarth, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D68188

llvm-svn: 374225

2 files changed, 107 insertions, 0 deletions

diff --git a/lldb/scripts/Python/python-typemaps.swig b/lldb/scripts/Python/python-typemaps.swig
index 77ca1156ec5..f963e37da6f 100644
--- a/lldb/scripts/Python/python-typemaps.swig
+++ b/lldb/scripts/Python/python-typemaps.swig
@@ -372,6 +372,69 @@ bool SetNumberFromPyObject<double>(double &number, PyObject *obj) {
   $1 = $1 || PyCallable_Check(reinterpret_cast<PyObject*>($input));
 }
 
+
+%typemap(in) lldb::FileSP {
+  using namespace lldb_private;
+  PythonFile py_file(PyRefType::Borrowed, $input);
+  if (!py_file) {
+    PyErr_SetString(PyExc_TypeError, "not a file");
+    return nullptr;
+  }
+  auto sp = unwrapOrSetPythonException(py_file.ConvertToFile());
+  if (!sp)
+    return nullptr;
+  $1 = sp;
+}
+
+%typemap(in) lldb::FileSP FORCE_IO_METHODS {
+  using namespace lldb_private;
+  PythonFile py_file(PyRefType::Borrowed, $input);
+  if (!py_file) {
+    PyErr_SetString(PyExc_TypeError, "not a file");
+    return nullptr;
+  }
+  auto sp = unwrapOrSetPythonException(py_file.ConvertToFileForcingUseOfScriptingIOMethods());
+  if (!sp)
+    return nullptr;
+  $1 = sp;
+}
+
+%typemap(in) lldb::FileSP BORROWED {
+ using namespace lldb_private;
+  PythonFile py_file(PyRefType::Borrowed, $input);
+  if (!py_file) {
+    PyErr_SetString(PyExc_TypeError, "not a file");
+    return nullptr;
+  }
+  auto sp = unwrapOrSetPythonException(py_file.ConvertToFile(/*borrowed=*/true));
+  if (!sp)
+    return nullptr;
+  $1 = sp;
+}
+
+%typemap(in) lldb::FileSP BORROWED_FORCE_IO_METHODS {
+  using namespace lldb_private;
+  PythonFile py_file(PyRefType::Borrowed, $input);
+  if (!py_file) {
+    PyErr_SetString(PyExc_TypeError, "not a file");
+    return nullptr;
+  }
+  auto sp = unwrapOrSetPythonException(py_file.ConvertToFileForcingUseOfScriptingIOMethods(/*borrowed=*/true));
+  if (!sp)
+    return nullptr;
+  $1 = sp;
+}
+
+%typecheck(SWIG_TYPECHECK_POINTER) lldb::FileSP {
+  if (lldb_private::PythonFile::Check($input)) {
+    $1 = 1;
+  } else {
+    PyErr_Clear();
+    $1 = 0;
+  }
+}
+
+
 // 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
 // use and this typemap should eventually be removed.
diff --git a/lldb/scripts/interface/SBFile.i b/lldb/scripts/interface/SBFile.i
index 6cdb192f26e..179446d5a53 100644
--- a/lldb/scripts/interface/SBFile.i
+++ b/lldb/scripts/interface/SBFile.i
@@ -15,9 +15,53 @@ namespace lldb {
 class SBFile
 {
 public:
+
     SBFile();
+
+    %feature("docstring", "
+    Initialize a SBFile from a file descriptor.  mode is
+    'r', 'r+', or 'w', like fdopen.");
     SBFile(int fd, const char *mode, bool transfer_ownership);
 
+    %feature("docstring", "initialize a SBFile from a python file object");
+    SBFile(FileSP file);
+
+    %extend {
+        static lldb::SBFile MakeBorrowed(lldb::FileSP BORROWED) {
+            return lldb::SBFile(BORROWED);
+        }
+        static lldb::SBFile MakeForcingIOMethods(lldb::FileSP FORCE_IO_METHODS) {
+            return lldb::SBFile(FORCE_IO_METHODS);
+        }
+        static lldb::SBFile MakeBorrowedForcingIOMethods(lldb::FileSP BORROWED_FORCE_IO_METHODS) {
+            return lldb::SBFile(BORROWED_FORCE_IO_METHODS);
+        }
+    }
+
+    %pythoncode {
+        @classmethod
+        def Create(cls, file, borrow=False, force_io_methods=False):
+            """
+            Create a SBFile from a python file object, with options.
+
+            If borrow is set then the underlying file will
+            not be closed when the SBFile is closed or destroyed.
+
+            If force_scripting_io is set then the python read/write
+            methods will be called even if a file descriptor is available.
+            """
+            if borrow:
+                if force_io_methods:
+                    return cls.MakeBorrowedForcingIOMethods(file)
+                else:
+                    return cls.MakeBorrowed(file)
+            else:
+                if force_io_methods:
+                    return cls.MakeForcingIOMethods(file)
+                else:
+                    return cls(file)
+    }
+
     ~SBFile ();
 
     %feature("autodoc", "Read(buffer) -> SBError, bytes_read") Read;