[Lldb-commits] [PATCH] D38829: Python: SetOutputFileHandle doesn't work with IOBase

[Pavel Labath via Phabricator via lldb-commits]

labath added inline comments.


================
Comment at: lldb/trunk/source/Plugins/ScriptInterpreter/Python/PythonDataObjects.cpp:1075-1096
+static int readfn(void *ctx, char *buffer, int n)
+{
+  auto state = PyGILState_Ensure();
+  auto *file = (PyObject *) ctx;
+  int result = -1;
+  auto pybuffer = PyBuffer_FromMemory(buffer, n);
+  PyObject *pyresult = NULL;
----------------
lawrence_danna wrote:
> zturner wrote:
> > I am still pretty unhappy about these functions, and passing function pointers into the `File` class.
> > 
> > I think another approach would be this:
> > 
> > 1) Make the `File` class contain a member `std::unique_ptr<IOObject> LowLevelIo;`
> > 
> > 2) In `File.cpp`, define something called `class DefaultLowLevelIo : public IOObject` that implements the virtual methods against an fd.
> > 
> > 3) In `PythonDataObjects`, define `PythonFileIo : public IOObject` and implement the virtual methods against a `PyObject`.
> > 
> > 4) Add an additional constructor to `File` which takes a `std::unique_ptr<IOObject> LowLevelIo`, which we can use when creating one of these from a python file.
> > 
> > One advantage of this method is that it allows the `PythonFileIo` class to be easily tested.
> > 
> > (Also, sorry for not getting back to reviewing this several weeks ago)
> I don't see how this approach gets around the problem that the interfaces in SBDebugger use FILE *, not IOObject 
> 
> The only way I can see to do it the way you are saying is to also add a SBIOObject, with swig wrappers to that, and variants of the SBDebugger  
> interfaces that take IOObject instead of FILE *
> 
> Do you want to do it that way?
What's the final use case here. In the patch itself I don't see anything that would necessitate a FILE * conversion, but I don't know what do you actually intend to use this for. We can always return a null FILE * if the File object is backed by a a python file (we do the same for file descriptors, as there is no way to convert those into FILE*, not without going the fopencookie way).


Repository:
  rL LLVM

https://reviews.llvm.org/D38829