[Mlir-commits] [mlir] 554e40d - Add a message to mlir-opt when reading from stdin to avoid being waiting for nothing

[Mehdi Amini]

Author: Mehdi Amini
Date: 2023-03-13T14:28:11+01:00
New Revision: 554e40d6ba1cdeef1c0b82469bce3978fabc84a9

URL: https://github.com/llvm/llvm-project/commit/554e40d6ba1cdeef1c0b82469bce3978fabc84a9
DIFF: https://github.com/llvm/llvm-project/commit/554e40d6ba1cdeef1c0b82469bce3978fabc84a9.diff

LOG: Add a message to mlir-opt when reading from stdin to avoid being waiting for nothing

It happens from time to time that one may run mlir-opt expecting something to
happen, but the process is waiting on stdin. Print a message when reading from
stdin to warn developers.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D145469

Added: 
    

Modified: 
    mlir/lib/Tools/mlir-opt/MlirOptMain.cpp

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp b/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
index d1c56375e3fda..a9d165b117b48 100644
--- a/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
+++ b/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Support/FileUtilities.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/Process.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/StringSaver.h"
@@ -338,6 +339,14 @@ LogicalResult mlir::MlirOptMain(int argc, char **argv, llvm::StringRef toolName,
   MlirOptMainConfig config = MlirOptMainConfig::createFromCLOptions();
   config.preloadDialectsInContext(preloadDialectsInContext);
 
+  // When reading from stdin and the input is a tty, it is often a user mistak
+  // and the process "appears to be stuck". Print a message to let the user know
+  // about it!
+  if (inputFilename == "-" &&
+      sys::Process::FileDescriptorIsDisplayed(fileno(stdin)))
+    llvm::errs() << "(processing input from stdin now, hit ctrl-c/ctrl-d to "
+                    "interrupt)\n";
+
   // Set up the input file.
   std::string errorMessage;
   auto file = openInputFile(inputFilename, &errorMessage);