[mlir] Fix bug that prevents application of PrintingFlags in Location

[jungmair]

The current implementation of LocationSnapshotPass takes an OpPrintingFlags argument and stores it as member, but does not use it for printing.
Small fix: use already stored flags for printing (as originally intended)

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[llvmbot]

@llvm/pr-subscribers-mlir-core

Author: Michael Jungmair (jungmair)

Changes

The current implementation of LocationSnapshotPass takes an OpPrintingFlags argument and stores it as member, but does not use it for printing.
Small fix: use already stored flags for printing (as originally intended)

---

Full diff: https://github.com/llvm/llvm-project/pull/119373.diff

1 Files Affected:

• (modified) mlir/lib/Transforms/LocationSnapshot.cpp (+1-1)

diff --git a/mlir/lib/Transforms/LocationSnapshot.cpp b/mlir/lib/Transforms/LocationSnapshot.cpp
index b85850acda91bd..b8f3817db9db6e 100644
--- a/mlir/lib/Transforms/LocationSnapshot.cpp
+++ b/mlir/lib/Transforms/LocationSnapshot.cpp
@@ -140,7 +140,7 @@ struct LocationSnapshotPass
 
   void runOnOperation() override {
     Operation *op = getOperation();
-    if (failed(generateLocationsFromIR(fileName, op, OpPrintingFlags(), tag)))
+    if (failed(generateLocationsFromIR(fileName, op, flags, tag)))
       return signalPassFailure();
   }
 

[llvmbot]

@llvm/pr-subscribers-mlir

Author: Michael Jungmair (jungmair)

Changes

The current implementation of LocationSnapshotPass takes an OpPrintingFlags argument and stores it as member, but does not use it for printing.
Small fix: use already stored flags for printing (as originally intended)

---

Full diff: https://github.com/llvm/llvm-project/pull/119373.diff

1 Files Affected:

• (modified) mlir/lib/Transforms/LocationSnapshot.cpp (+1-1)

diff --git a/mlir/lib/Transforms/LocationSnapshot.cpp b/mlir/lib/Transforms/LocationSnapshot.cpp
index b85850acda91bd..b8f3817db9db6e 100644
--- a/mlir/lib/Transforms/LocationSnapshot.cpp
+++ b/mlir/lib/Transforms/LocationSnapshot.cpp
@@ -140,7 +140,7 @@ struct LocationSnapshotPass
 
   void runOnOperation() override {
     Operation *op = getOperation();
-    if (failed(generateLocationsFromIR(fileName, op, OpPrintingFlags(), tag)))
+    if (failed(generateLocationsFromIR(fileName, op, flags, tag)))
       return signalPassFailure();
   }
 

[jungmair]

@River707 Maybe you could have a look on this?

[joker-eph]

Thanks for the fix!
Is this something that we can exercise with a test?

[jungmair]

Thanks for the fix! Is this something that we can exercise with a test?

In theory yes, but IMO it is 1) highly unlikely that there will be a regression 2) requires a bit more effort because the flags are not exposed with mlir-opt and thus would require writing a C++ application that uses it with flags.

[joker-eph]

OK that's a problem though: the flags should be made a proper pass option, can you moves these to the .td file?

[jungmair]

I just looked into it, but it is not that easy. As far as I see, there is no previous usage of OpPrintingFlags as pass option/no existing option parser. Also OpPrintingFlags has ~9 settings, so this is not really trivial. What do you propose?

[joker-eph]

It is a strong concern to me that pass-options must roundtrip.

It does not seem really difficult though, very mechanical, see: joker-eph@ceb4834

More importantly, most of these are irrelevant, so I believe we can prune this down to: joker-eph@94a5496

Does this achieve what you're after?

[jungmair]

Yes, thanks for your help on this.
I fixed a small typo/bug in your changes and added a test that verifies that the generated snapshot file fits the printing flags (i.e., is printed with debug info)

[joker-eph]

Just a nit, but better avoid $$ and split over multiple line: lit will treat it the same.

Suggested change

	// RUN: mlir-opt -allow-unregistered-dialect -snapshot-op-locations='filename=%/t print-debuginfo' -mlir-print-local-scope -mlir-print-debuginfo %s | FileCheck %s --check-prefix=DBG -DFILE=%/t && cat %/t | FileCheck %s --check-prefix=DBGFILE
	// RUN: mlir-opt -allow-unregistered-dialect -snapshot-op-locations='filename=%/t print-debuginfo' -mlir-print-local-scope -mlir-print-debuginfo %s | FileCheck %s --check-prefix=DBG -DFILE=%/t
	// RUN: cat %/t | FileCheck %s --check-prefix=DBGFILE

[jungmair]

Could you also merge it :)