[Mlir-commits] [mlir] MLIR Rewriters: add new listener to emit match failures to user, enhance docs (PR #94130)

[Matthias Springer]

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@@ -511,6 +512,50 @@ class RewriterBase : public OpBuilder {
     OpBuilder::Listener *listener;
   };
 
+  /// A listener that emits all notifyMatchFailure calls
+  /// with the given DiagnosticSeverity (default is Error).
+  /// This can be used so that any notifyMatchFailure calls will be emitted
+  /// as a message with the given severity (Remark will be used for Note)
+  struct MatchFailureEmittingListener : public RewriterBase::Listener {
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matthias-springer wrote:

If you emit an error/warning/remark every time a pattern fails to match, you will be bombarded with output in many cases (even though the lowering was successful). Just try running `-canonicalize` on a larger piece of IR and see how many pattern fail to match. (Most of them don't report match failures due to laziness though.)


https://github.com/llvm/llvm-project/pull/94130