[MLIR][mlir-opt] add support for disabling diagnostics (#117669)

This PR adds a command line argument `--mlir-disable-diagnostic` for
disabling diagnostic information for mlir-opt.
When debugging with mlir-opt, some developers would like to disable the
diagnostic information and focus specifically on the dumped IR. For
example, triton-lang/triton#5250

Author: sfzhu93

mlir/include/mlir/Tools/mlir-opt/MlirOptMain.h

@@ -31,6 +31,13 @@ class DialectRegistry;
 class PassPipelineCLParser;
 class PassManager;
 
+/// enum class to indicate the verbosity level of the diagnostic filter.
+enum class VerbosityLevel {
+  ErrorsOnly = 0,
+  ErrorsAndWarnings,
+  ErrorsWarningsAndRemarks
+};
+
 /// Configuration options for the mlir-opt tool.
 /// This is intended to help building tools like mlir-opt by collecting the
 /// supported options.
@@ -74,6 +81,11 @@ class MlirOptMainConfig {
     dumpPassPipelineFlag = dump;
     return *this;
   }
+
+  VerbosityLevel getDiagnosticVerbosityLevel() const {
+    return diagnosticVerbosityLevelFlag;
+  }
+
   bool shouldDumpPassPipeline() const { return dumpPassPipelineFlag; }
 
   /// Set the output format to bytecode instead of textual IR.
@@ -82,10 +94,13 @@ class MlirOptMainConfig {
     return *this;
   }
   bool shouldEmitBytecode() const { return emitBytecodeFlag; }
+
   bool shouldElideResourceDataFromBytecode() const {
     return elideResourceDataFromBytecodeFlag;
   }
 
+  bool shouldShowNotes() const { return !disableDiagnosticNotesFlag; }
+
   /// Set the IRDL file to load before processing the input.
   MlirOptMainConfig &setIrdlFile(StringRef file) {
     irdlFileFlag = file;
@@ -209,6 +224,11 @@ class MlirOptMainConfig {
   /// Configuration for the debugging hooks.
   tracing::DebugConfig debugConfig;
 
+  /// Verbosity level of diagnostic information. 0: Errors only,
+  /// 1: Errors and warnings, 2: Errors, warnings and remarks.
+  VerbosityLevel diagnosticVerbosityLevelFlag =
+      VerbosityLevel::ErrorsWarningsAndRemarks;
+
   /// Print the pipeline that will be run.
   bool dumpPassPipelineFlag = false;
 
@@ -242,6 +262,11 @@ class MlirOptMainConfig {
   /// Show the registered dialects before trying to load the input file.
   bool showDialectsFlag = false;
 
+  /// Show the notes in diagnostic information. Notes can be included in
+  /// any diagnostic information, so it is not specified in the verbosity
+  /// level.
+  bool disableDiagnosticNotesFlag = true;
+
   /// Split the input file based on the given marker into chunks and process
   /// each chunk independently. Input is not split if empty.
   std::string splitInputFileFlag = "";

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

@@ -41,6 +41,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileUtilities.h"
 #include "llvm/Support/InitLLVM.h"
+#include "llvm/Support/LogicalResult.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/Process.h"
 #include "llvm/Support/Regex.h"
@@ -108,6 +109,23 @@ struct MlirOptMainConfigCLOptions : public MlirOptMainConfig {
         cl::desc("IRDL file to register before processing the input"),
         cl::location(irdlFileFlag), cl::init(""), cl::value_desc("filename"));
 
+    static cl::opt<VerbosityLevel, /*ExternalStorage=*/true>
+        diagnosticVerbosityLevel(
+            "mlir-diagnostic-verbosity-level",
+            cl::desc("Choose level of diagnostic information"),
+            cl::location(diagnosticVerbosityLevelFlag),
+            cl::init(VerbosityLevel::ErrorsWarningsAndRemarks),
+            cl::values(
+                clEnumValN(VerbosityLevel::ErrorsOnly, "errors", "Errors only"),
+                clEnumValN(VerbosityLevel::ErrorsAndWarnings, "warnings",
+                           "Errors and warnings"),
+                clEnumValN(VerbosityLevel::ErrorsWarningsAndRemarks, "remarks",
+                           "Errors, warnings and remarks")));
+
+    static cl::opt<bool, /*ExternalStorage=*/true> disableDiagnosticNotes(
+        "mlir-disable-diagnostic-notes", cl::desc("Disable diagnostic notes."),
+        cl::location(disableDiagnosticNotesFlag), cl::init(false));
+
     static cl::opt<bool, /*ExternalStorage=*/true> enableDebuggerHook(
         "mlir-enable-debugger-hook",
         cl::desc("Enable Debugger hook for debugging MLIR Actions"),
@@ -133,15 +151,17 @@ struct MlirOptMainConfigCLOptions : public MlirOptMainConfig {
         cl::location(showDialectsFlag), cl::init(false));
 
     static cl::opt<std::string, /*ExternalStorage=*/true> splitInputFile{
-        "split-input-file", llvm::cl::ValueOptional,
+        "split-input-file",
+        llvm::cl::ValueOptional,
         cl::callback([&](const std::string &str) {
           // Implicit value: use default marker if flag was used without value.
           if (str.empty())
             splitInputFile.setValue(kDefaultSplitMarker);
         }),
         cl::desc("Split the input file into chunks using the given or "
                  "default marker and process each chunk independently"),
-        cl::location(splitInputFileFlag), cl::init("")};
+        cl::location(splitInputFileFlag),
+        cl::init("")};
 
     static cl::opt<std::string, /*ExternalStorage=*/true> outputSplitMarker(
         "output-split-marker",
@@ -207,6 +227,44 @@ struct MlirOptMainConfigCLOptions : public MlirOptMainConfig {
   /// setDialectPluginsCallback(DialectRegistry&).
   cl::list<std::string> *dialectPlugins = nullptr;
 };
+
+/// A scoped diagnostic handler that suppresses certain diagnostics based on
+/// the verbosity level and whether the diagnostic is a note.
+class DiagnosticFilter : public ScopedDiagnosticHandler {
+public:
+  DiagnosticFilter(MLIRContext *ctx, VerbosityLevel verbosityLevel,
+                   bool showNotes = true)
+      : ScopedDiagnosticHandler(ctx) {
+    setHandler([verbosityLevel, showNotes](Diagnostic &diag) {
+      auto severity = diag.getSeverity();
+      switch (severity) {
+      case DiagnosticSeverity::Error:
+        // failure indicates that the error is not handled by the filter and
+        // goes through to the default handler. Therefore, the error can be
+        // successfully printed.
+        return failure();
+      case DiagnosticSeverity::Warning:
+        if (verbosityLevel == VerbosityLevel::ErrorsOnly)
+          return success();
+        else
+          return failure();
+      case DiagnosticSeverity::Remark:
+        if (verbosityLevel == VerbosityLevel::ErrorsOnly ||
+            verbosityLevel == VerbosityLevel::ErrorsAndWarnings)
+          return success();
+        else
+          return failure();
+      case DiagnosticSeverity::Note:
+        if (showNotes)
+          return failure();
+        else
+          return success();
+      default:
+        llvm_unreachable("Unknown diagnostic severity");
+      }
+    });
+  }
+};
 } // namespace
 
 ManagedStatic<MlirOptMainConfigCLOptions> clOptionsConfig;
@@ -479,6 +537,9 @@ static LogicalResult processBuffer(raw_ostream &os,
   // otherwise just perform the actions without worrying about it.
   if (!config.shouldVerifyDiagnostics()) {
     SourceMgrDiagnosticHandler sourceMgrHandler(*sourceMgr, &context);
+    DiagnosticFilter diagnosticFilter(&context,
+                                      config.getDiagnosticVerbosityLevel(),
+                                      config.shouldShowNotes());
     return performActions(os, sourceMgr, &context, config);
   }