[flang-commits] [flang] [flang] Fix -debug crash from VScaleAttrPass (PR #180234)

[Philipp Rados via flang-commits]

================
@@ -63,16 +66,29 @@ void VScaleAttrPass::runOnOperation() {
 
   LLVM_DEBUG(llvm::dbgs() << "Func-name:" << func.getSymName() << "\n");
 
+  if (!llvm::isPowerOf2_32(vscaleMin)) {
+    LLVM_DEBUG(
+        llvm::dbgs()
+        << "VScaleAttr: vscaleMin has to be a power-of-two greater than 0\n");
+    return;
----------------
prados-oc wrote:

Yes, I agree. However I'm struggling to find a way to properly test this since the tests now error e.g:
```
// RUN: fir-opt --vscale-attr="vscale-min=0 vscale-max=4" --verify-diagnostics %s | FileCheck %s --check-prefix=VSCALE-MIN-0

// VSCALE-MIN-0: expected-error @func {{VScaleAttr: vscaleMin has to be a power-of-two greater than 0}}
func.func @_QPtest(%arg0: !fir.ref<i32> {fir.bindc_name = "x"}) {
  return
}
```
so FileCheck won't receive the input.
I couldn't find any other test that uses `--check-prefix` when testing diagnostics. Do you have an idea how to do this? 

https://github.com/llvm/llvm-project/pull/180234