[Mlir-commits] [mlir] [MLIR][Linalg] Fix linalg crash during elementwise op fusion (PR #117667)

[Quinn Dawkins]

================
@@ -595,7 +595,10 @@ AffineMap inverseAndBroadcastProjectedPermutation(AffineMap map);
 /// potentially empty maps. Assumes each of the underlying map has 0 symbols.
 /// The resulting map has a number of dims equal to the max of `maps`' dims and
 /// the concatenated results as its results.
-/// Returns an empty map if all input `maps` are empty.
+///
+/// This method asserts when `maps` is empty.
+/// TODO: this should return an empty map when `maps` is empty but there is no
+/// way to get the MLIRContext needed to construct it.
----------------
qedawkins wrote:

For small changes like this (especially when it's fixing a bug), just a note in the PR description explaining how to adapt downstream use cases is good enough. Something like
```
concatAffineMaps now takes an MLIRContext in case the list of maps is empty.
```

https://github.com/llvm/llvm-project/pull/117667