[mlir] implement -verify-diagnostics=only-expected (#135131)

This PR implements `verify-diagnostics=only-expected` which is a "best
effort" verification - i.e., `unexpected`s and `near-misses` will not be
considered failures. The purpose is to enable narrowly scoped checking
of verification remarks (just as we have for lit where only a subset of
lines get `CHECK`ed).

mlir/examples/transform-opt/mlir-transform-opt.cpp

@@ -38,11 +38,22 @@ struct MlirTransformOptCLOptions {
       cl::desc("Allow operations coming from an unregistered dialect"),
       cl::init(false)};
 
-  cl::opt<bool> verifyDiagnostics{
-      "verify-diagnostics",
-      cl::desc("Check that emitted diagnostics match expected-* lines "
-               "on the corresponding line"),
-      cl::init(false)};
+  cl::opt<mlir::SourceMgrDiagnosticVerifierHandler::Level> verifyDiagnostics{
+      "verify-diagnostics", llvm::cl::ValueOptional,
+      cl::desc("Check that emitted diagnostics match expected-* lines on the "
+               "corresponding line"),
+      cl::values(
+          clEnumValN(
+              mlir::SourceMgrDiagnosticVerifierHandler::Level::All, "all",
+              "Check all diagnostics (expected, unexpected, near-misses)"),
+          // Implicit value: when passed with no arguments, e.g.
+          // `--verify-diagnostics` or `--verify-diagnostics=`.
+          clEnumValN(
+              mlir::SourceMgrDiagnosticVerifierHandler::Level::All, "",
+              "Check all diagnostics (expected, unexpected, near-misses)"),
+          clEnumValN(
+              mlir::SourceMgrDiagnosticVerifierHandler::Level::OnlyExpected,
+              "only-expected", "Check only expected diagnostics"))};
 
   cl::opt<std::string> payloadFilename{cl::Positional, cl::desc("<input file>"),
                                        cl::init("-")};
@@ -102,12 +113,17 @@ public:
 
   /// Constructs the diagnostic handler of the specified kind of the given
   /// source manager and context.
-  DiagnosticHandlerWrapper(Kind kind, llvm::SourceMgr &mgr,
-                           mlir::MLIRContext *context) {
-    if (kind == Kind::EmitDiagnostics)
+  DiagnosticHandlerWrapper(
+      Kind kind, llvm::SourceMgr &mgr, mlir::MLIRContext *context,
+      std::optional<mlir::SourceMgrDiagnosticVerifierHandler::Level> level =
+          {}) {
+    if (kind == Kind::EmitDiagnostics) {
       handler = new mlir::SourceMgrDiagnosticHandler(mgr, context);
-    else
-      handler = new mlir::SourceMgrDiagnosticVerifierHandler(mgr, context);
+    } else {
+      assert(level.has_value() && "expected level");
+      handler =
+          new mlir::SourceMgrDiagnosticVerifierHandler(mgr, context, *level);
+    }
   }
 
   /// This object is non-copyable but movable.
@@ -150,7 +166,9 @@ class TransformSourceMgr {
 public:
   /// Constructs the source manager indicating whether diagnostic messages will
   /// be verified later on.
-  explicit TransformSourceMgr(bool verifyDiagnostics)
+  explicit TransformSourceMgr(
+      std::optional<mlir::SourceMgrDiagnosticVerifierHandler::Level>
+          verifyDiagnostics)
       : verifyDiagnostics(verifyDiagnostics) {}
 
   /// Deconstructs the source manager. Note that `checkResults` must have been
@@ -179,7 +197,8 @@ public:
     // verification needs to happen and store it.
     if (verifyDiagnostics) {
       diagHandlers.emplace_back(
-          DiagnosticHandlerWrapper::Kind::VerifyDiagnostics, mgr, &context);
+          DiagnosticHandlerWrapper::Kind::VerifyDiagnostics, mgr, &context,
+          verifyDiagnostics);
     } else {
       diagHandlers.emplace_back(DiagnosticHandlerWrapper::Kind::EmitDiagnostics,
                                 mgr, &context);
@@ -204,7 +223,8 @@ public:
 
 private:
   /// Indicates whether diagnostic message verification is requested.
-  const bool verifyDiagnostics;
+  const std::optional<mlir::SourceMgrDiagnosticVerifierHandler::Level>
+      verifyDiagnostics;
 
   /// Indicates that diagnostic message verification has taken place, and the
   /// deconstruction is therefore safe.
@@ -248,7 +268,9 @@ static llvm::LogicalResult processPayloadBuffer(
   context.allowUnregisteredDialects(clOptions->allowUnregisteredDialects);
   mlir::ParserConfig config(&context);
   TransformSourceMgr sourceMgr(
-      /*verifyDiagnostics=*/clOptions->verifyDiagnostics);
+      /*verifyDiagnostics=*/clOptions->verifyDiagnostics.getNumOccurrences()
+          ? std::optional{clOptions->verifyDiagnostics.getValue()}
+          : std::nullopt);
 
   // Parse the input buffer that will be used as transform payload.
   mlir::OwningOpRef<mlir::Operation *> payloadRoot =

mlir/include/mlir/IR/Diagnostics.h

@@ -626,9 +626,12 @@ struct SourceMgrDiagnosticVerifierHandlerImpl;
 /// corresponding line of the source file.
 class SourceMgrDiagnosticVerifierHandler : public SourceMgrDiagnosticHandler {
 public:
+  enum class Level { None = 0, All, OnlyExpected };
   SourceMgrDiagnosticVerifierHandler(llvm::SourceMgr &srcMgr, MLIRContext *ctx,
-                                     raw_ostream &out);
-  SourceMgrDiagnosticVerifierHandler(llvm::SourceMgr &srcMgr, MLIRContext *ctx);
+                                     raw_ostream &out,
+                                     Level level = Level::All);
+  SourceMgrDiagnosticVerifierHandler(llvm::SourceMgr &srcMgr, MLIRContext *ctx,
+                                     Level level = Level::All);
   ~SourceMgrDiagnosticVerifierHandler();
 
   /// Returns the status of the handler and verifies that all expected

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

@@ -185,11 +185,20 @@ public:
 
   /// Set whether to check that emitted diagnostics match `expected-*` lines on
   /// the corresponding line. This is meant for implementing diagnostic tests.
-  MlirOptMainConfig &verifyDiagnostics(bool verify) {
+  MlirOptMainConfig &
+  verifyDiagnostics(SourceMgrDiagnosticVerifierHandler::Level verify) {
     verifyDiagnosticsFlag = verify;
     return *this;
   }
-  bool shouldVerifyDiagnostics() const { return verifyDiagnosticsFlag; }
+
+  bool shouldVerifyDiagnostics() const {
+    return verifyDiagnosticsFlag !=
+           SourceMgrDiagnosticVerifierHandler::Level::None;
+  }
+
+  SourceMgrDiagnosticVerifierHandler::Level verifyDiagnosticsLevel() const {
+    return verifyDiagnosticsFlag;
+  }
 
   /// Set whether to run the verifier after each transformation pass.
   MlirOptMainConfig &verifyPasses(bool verify) {
@@ -276,7 +285,8 @@ protected:
 
   /// Set whether to check that emitted diagnostics match `expected-*` lines on
   /// the corresponding line. This is meant for implementing diagnostic tests.
-  bool verifyDiagnosticsFlag = false;
+  SourceMgrDiagnosticVerifierHandler::Level verifyDiagnosticsFlag =
+      SourceMgrDiagnosticVerifierHandler::Level::None;
 
   /// Run the verifier after each transformation pass.
   bool verifyPassesFlag = true;

mlir/lib/IR/Diagnostics.cpp

@@ -661,7 +661,9 @@ struct ExpectedDiag {
 };
 
 struct SourceMgrDiagnosticVerifierHandlerImpl {
-  SourceMgrDiagnosticVerifierHandlerImpl() : status(success()) {}
+  SourceMgrDiagnosticVerifierHandlerImpl(
+      SourceMgrDiagnosticVerifierHandler::Level level)
+      : status(success()), level(level) {}
 
   /// Returns the expected diagnostics for the given source file.
   std::optional<MutableArrayRef<ExpectedDiag>>
@@ -672,6 +674,10 @@ struct SourceMgrDiagnosticVerifierHandlerImpl {
   computeExpectedDiags(raw_ostream &os, llvm::SourceMgr &mgr,
                        const llvm::MemoryBuffer *buf);
 
+  SourceMgrDiagnosticVerifierHandler::Level getVerifyLevel() const {
+    return level;
+  }
+
   /// The current status of the verifier.
   LogicalResult status;
 
@@ -685,6 +691,10 @@ struct SourceMgrDiagnosticVerifierHandlerImpl {
   llvm::Regex expected =
       llvm::Regex("expected-(error|note|remark|warning)(-re)? "
                   "*(@([+-][0-9]+|above|below|unknown))? *{{(.*)}}$");
+
+  /// Verification level.
+  SourceMgrDiagnosticVerifierHandler::Level level =
+      SourceMgrDiagnosticVerifierHandler::Level::All;
 };
 } // namespace detail
 } // namespace mlir
@@ -803,9 +813,9 @@ SourceMgrDiagnosticVerifierHandlerImpl::computeExpectedDiags(
 }
 
 SourceMgrDiagnosticVerifierHandler::SourceMgrDiagnosticVerifierHandler(
-    llvm::SourceMgr &srcMgr, MLIRContext *ctx, raw_ostream &out)
+    llvm::SourceMgr &srcMgr, MLIRContext *ctx, raw_ostream &out, Level level)
     : SourceMgrDiagnosticHandler(srcMgr, ctx, out),
-      impl(new SourceMgrDiagnosticVerifierHandlerImpl()) {
+      impl(new SourceMgrDiagnosticVerifierHandlerImpl(level)) {
   // Compute the expected diagnostics for each of the current files in the
   // source manager.
   for (unsigned i = 0, e = mgr.getNumBuffers(); i != e; ++i)
@@ -823,8 +833,8 @@ SourceMgrDiagnosticVerifierHandler::SourceMgrDiagnosticVerifierHandler(
 }
 
 SourceMgrDiagnosticVerifierHandler::SourceMgrDiagnosticVerifierHandler(
-    llvm::SourceMgr &srcMgr, MLIRContext *ctx)
-    : SourceMgrDiagnosticVerifierHandler(srcMgr, ctx, llvm::errs()) {}
+    llvm::SourceMgr &srcMgr, MLIRContext *ctx, Level level)
+    : SourceMgrDiagnosticVerifierHandler(srcMgr, ctx, llvm::errs(), level) {}
 
 SourceMgrDiagnosticVerifierHandler::~SourceMgrDiagnosticVerifierHandler() {
   // Ensure that all expected diagnostics were handled.
@@ -898,6 +908,9 @@ void SourceMgrDiagnosticVerifierHandler::process(LocationAttr loc,
     }
   }
 
+  if (impl->getVerifyLevel() == Level::OnlyExpected)
+    return;
+
   // Otherwise, emit an error for the near miss.
   if (nearMiss)
     mgr.PrintMessage(os, nearMiss->fileLoc, llvm::SourceMgr::DK_Error,

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

@@ -163,11 +163,26 @@ struct MlirOptMainConfigCLOptions : public MlirOptMainConfig {
         cl::desc("Split marker to use for merging the ouput"),
         cl::location(outputSplitMarkerFlag), cl::init(kDefaultSplitMarker));
 
-    static cl::opt<bool, /*ExternalStorage=*/true> verifyDiagnostics(
-        "verify-diagnostics",
-        cl::desc("Check that emitted diagnostics match "
-                 "expected-* lines on the corresponding line"),
-        cl::location(verifyDiagnosticsFlag), cl::init(false));
+    static cl::opt<SourceMgrDiagnosticVerifierHandler::Level,
+                   /*ExternalStorage=*/true>
+        verifyDiagnostics{
+            "verify-diagnostics", llvm::cl::ValueOptional,
+            cl::desc("Check that emitted diagnostics match expected-* lines on "
+                     "the corresponding line"),
+            cl::location(verifyDiagnosticsFlag),
+            cl::values(
+                clEnumValN(SourceMgrDiagnosticVerifierHandler::Level::All,
+                           "all",
+                           "Check all diagnostics (expected, unexpected, "
+                           "near-misses)"),
+                // Implicit value: when passed with no arguments, e.g.
+                // `--verify-diagnostics` or `--verify-diagnostics=`.
+                clEnumValN(SourceMgrDiagnosticVerifierHandler::Level::All, "",
+                           "Check all diagnostics (expected, unexpected, "
+                           "near-misses)"),
+                clEnumValN(
+                    SourceMgrDiagnosticVerifierHandler::Level::OnlyExpected,
+                    "only-expected", "Check only expected diagnostics"))};
 
     static cl::opt<bool, /*ExternalStorage=*/true> verifyPasses(
         "verify-each",
@@ -537,7 +552,8 @@ static LogicalResult processBuffer(raw_ostream &os,
     return performActions(os, sourceMgr, &context, config);
   }
 
-  SourceMgrDiagnosticVerifierHandler sourceMgrHandler(*sourceMgr, &context);
+  SourceMgrDiagnosticVerifierHandler sourceMgrHandler(
+      *sourceMgr, &context, config.verifyDiagnosticsLevel());
 
   // Do any processing requested by command line flags.  We don't care whether
   // these actions succeed or fail, we only care what diagnostics they produce

mlir/lib/Tools/mlir-translate/MlirTranslateMain.cpp

@@ -72,11 +72,23 @@ LogicalResult mlir::mlirTranslateMain(int argc, char **argv,
                      "default marker and process each chunk independently"),
       llvm::cl::init("")};
 
-  static llvm::cl::opt<bool> verifyDiagnostics(
-      "verify-diagnostics",
-      llvm::cl::desc("Check that emitted diagnostics match "
-                     "expected-* lines on the corresponding line"),
-      llvm::cl::init(false));
+  static llvm::cl::opt<SourceMgrDiagnosticVerifierHandler::Level>
+      verifyDiagnostics{
+          "verify-diagnostics", llvm::cl::ValueOptional,
+          llvm::cl::desc("Check that emitted diagnostics match expected-* "
+                         "lines on the corresponding line"),
+          llvm::cl::values(
+              clEnumValN(
+                  SourceMgrDiagnosticVerifierHandler::Level::All, "all",
+                  "Check all diagnostics (expected, unexpected, near-misses)"),
+              // Implicit value: when passed with no arguments, e.g.
+              // `--verify-diagnostics` or `--verify-diagnostics=`.
+              clEnumValN(
+                  SourceMgrDiagnosticVerifierHandler::Level::All, "",
+                  "Check all diagnostics (expected, unexpected, near-misses)"),
+              clEnumValN(
+                  SourceMgrDiagnosticVerifierHandler::Level::OnlyExpected,
+                  "only-expected", "Check only expected diagnostics"))};
 
   static llvm::cl::opt<bool> errorDiagnosticsOnly(
       "error-diagnostics-only",
@@ -149,17 +161,17 @@ LogicalResult mlir::mlirTranslateMain(int argc, char **argv,
 
       MLIRContext context;
       context.allowUnregisteredDialects(allowUnregisteredDialects);
-      context.printOpOnDiagnostic(!verifyDiagnostics);
+      context.printOpOnDiagnostic(verifyDiagnostics.getNumOccurrences() == 0);
       auto sourceMgr = std::make_shared<llvm::SourceMgr>();
       sourceMgr->AddNewSourceBuffer(std::move(ownedBuffer), SMLoc());
 
-      if (verifyDiagnostics) {
+      if (verifyDiagnostics.getNumOccurrences()) {
         // In the diagnostic verification flow, we ignore whether the
         // translation failed (in most cases, it is expected to fail) and we do
         // not filter non-error diagnostics even if `errorDiagnosticsOnly` is
         // set. Instead, we check if the diagnostics were produced as expected.
-        SourceMgrDiagnosticVerifierHandler sourceMgrHandler(*sourceMgr,
-                                                            &context);
+        SourceMgrDiagnosticVerifierHandler sourceMgrHandler(
+            *sourceMgr, &context, verifyDiagnostics);
         (void)(*translationRequested)(sourceMgr, os, &context);
         result = sourceMgrHandler.verify();
       } else if (errorDiagnosticsOnly) {

mlir/test/Pass/full_diagnostics.mlir

@@ -1,4 +1,5 @@
 // RUN: mlir-opt %s -pass-pipeline='builtin.module(func.func(test-pass-failure{gen-diagnostics}))' -verify-diagnostics
+// RUN: mlir-opt %s -pass-pipeline='builtin.module(func.func(test-pass-failure{gen-diagnostics}))' -verify-diagnostics=all
 
 // Test that all errors are reported.
 // expected-error@below {{illegal operation}}

mlir/test/Pass/full_diagnostics_only_expected.mlir

@@ -0,0 +1,17 @@
+// RUN: mlir-opt %s -pass-pipeline='builtin.module(func.func(test-pass-failure{gen-diagnostics}))' -verify-diagnostics=only-expected
+
+// Test that only expected errors are reported.
+// reports {{illegal operation}} but unchecked
+func.func @TestAlwaysIllegalOperationPass1() {
+  return
+}
+
+// expected-error@+1 {{illegal operation}}
+func.func @TestAlwaysIllegalOperationPass2() {
+  return
+}
+
+// reports {{illegal operation}} but unchecked
+func.func @TestAlwaysIllegalOperationPass3() {
+  return
+}

mlir/test/mlir-translate/verify-only-expected.mlir

@@ -0,0 +1,24 @@
+// Check that verify-diagnostics=only-expected passes with only one actual `expected-error`
+// RUN: mlir-translate %s --allow-unregistered-dialect -verify-diagnostics=only-expected -split-input-file -mlir-to-llvmir
+
+// Check that verify-diagnostics=all fails because we're missing two `expected-error`
+// RUN: not mlir-translate %s --allow-unregistered-dialect -verify-diagnostics=all -split-input-file -mlir-to-llvmir 2>&1 | FileCheck %s --check-prefix=CHECK-VERIFY-ALL
+// CHECK-VERIFY-ALL: unexpected error: cannot be converted to LLVM IR: missing `LLVMTranslationDialectInterface` registration for dialect for op: simple.terminator1
+// CHECK-VERIFY-ALL: unexpected error: cannot be converted to LLVM IR: missing `LLVMTranslationDialectInterface` registration for dialect for op: simple.terminator3
+
+llvm.func @trivial() {
+  "simple.terminator1"() : () -> ()
+}
+
+// -----
+
+llvm.func @trivial() {
+  // expected-error @+1 {{cannot be converted to LLVM IR: missing `LLVMTranslationDialectInterface` registration for dialect for op: simple.terminator2}}
+  "simple.terminator2"() : () -> ()
+}
+
+// -----
+
+llvm.func @trivial() {
+  "simple.terminator3"() : () -> ()
+}