[llvm] fdd18e8 - [llvm][TableGen][Jupyter] Show llvm-tblgen not found error in notebook

[David Spickett via llvm-commits]

Author: David Spickett
Date: 2023-02-13T09:26:48Z
New Revision: fdd18e866b050ed89e59c214bf559d81ed90d57f

URL: https://github.com/llvm/llvm-project/commit/fdd18e866b050ed89e59c214bf559d81ed90d57f
DIFF: https://github.com/llvm/llvm-project/commit/fdd18e866b050ed89e59c214bf559d81ed90d57f.diff

LOG: [llvm][TableGen][Jupyter] Show llvm-tblgen not found error in notebook

Previously this message was only shown on the command line,
which is not much help if you can't see that.
(you've full screened the browser or you aren't running Jupyter
on the same machine)

Instead return the error as stderr which will get printed in
the notebook just like stderr from llvm-tblgen would.

I've refactored the message sending along the way. Note that
even when we do not send a stream, we still need to send the
status reply. The send_... methods will do that for you.

Reviewed By: jpienaar

Differential Revision: https://reviews.llvm.org/D142531

Added: 
    

Modified: 
    llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py

Removed: 
    


################################################################################
diff  --git a/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py b/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
index 074d58a4caaca..e1a05d936c892 100644
--- a/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
+++ b/llvm/utils/TableGen/jupyter/tablegen_kernel/kernel.py
@@ -64,8 +64,7 @@ def __init__(self, **kwargs):
     def banner(self):
         return "llvm-tblgen kernel %s" % __version__
 
-    @property
-    def executable(self):
+    def get_executable(self):
         """If this is the first run, search for llvm-tblgen.
         Otherwise return the cached path to it."""
         if self._executable is None:
@@ -75,7 +74,10 @@ def executable(self):
             else:
                 path = shutil.which("llvm-tblgen")
                 if path is None:
-                    raise OSError("llvm-tblgen not found, please see README")
+                    raise OSError(
+                        "llvm-tblgen not found. Put it on your PATH or set the"
+                        " environment variable LLVM_TBLGEN_EXECUTABLE to point to it."
+                    )
                 self._executable = path
 
         return self._executable
@@ -157,17 +159,43 @@ def get_code_and_args(self, new_code):
 
         return self._previous_code, self._previous_magic.get("args", [])
 
+    def make_status(self):
+        return {
+            "status": "ok",
+            "execution_count": self.execution_count,
+            "payload": [],
+            "user_expressions": {},
+        }
+
+    def send_stream(self, name, content):
+        self.send_response(self.iopub_socket, "stream", {"name": name, "text": content})
+
+        return self.make_status()
+
+    def send_stderr(self, stderr):
+        return self.send_stream("stderr", stderr)
+
+    def send_stdout(self, stdout):
+        return self.send_stream("stdout", stdout)
+
     def do_execute(
         self, code, silent, store_history=True, user_expressions=None, allow_stdin=False
     ):
         """Execute user code using llvm-tblgen binary."""
         all_code, args = self.get_code_and_args(code)
 
+        # If we cannot find llvm-tblgen, propogate the error to the notebook.
+        # (in case the user is not able to see the output from the Jupyter server)
+        try:
+            executable = self.get_executable()
+        except Exception as e:
+            return self.send_stderr(str(e))
+
         with tempfile.TemporaryFile("w+") as f:
             f.write(all_code)
             f.seek(0)
             got = subprocess.run(
-                [self.executable, *args],
+                [executable, *args],
                 stdin=f,
                 stderr=subprocess.PIPE,
                 stdout=subprocess.PIPE,
@@ -176,20 +204,11 @@ def do_execute(
 
         if not silent:
             if got.stderr:
-                self.send_response(
-                    self.iopub_socket, "stream", {"name": "stderr", "text": got.stderr}
-                )
+                return self.send_stderr(got.stderr)
             else:
-                self.send_response(
-                    self.iopub_socket, "stream", {"name": "stdout", "text": got.stdout}
-                )
-
-        return {
-            "status": "ok",
-            "execution_count": self.execution_count,
-            "payload": [],
-            "user_expressions": {},
-        }
+                return self.send_stdout(got.stdout)
+        else:
+            return self.make_status()
 
 
 if __name__ == "__main__":