[mlir] Use the process (host) triple in MLIRTargetLLVMTests

[sstamenova]

The test is meant to execute on the native target and only initializes the native target. However, it then gets the default target triple instead of the process (host) triple. This fails in cases where the native target and the default target are not the same.

The test was added here: https://reviews.llvm.org/D154100

[llvmbot]

@llvm/pr-subscribers-mlir

@llvm/pr-subscribers-mlir-llvm

Author: Stella Stamenova (sstamenova)

Changes

The test is meant to execute on the native target and only initializes the native target. However, it then gets the default target triple instead of the process (host) triple. This fails in cases where the native target and the default target are not the same.

The test was added here: https://reviews.llvm.org/D154100

---

Full diff: https://github.com/llvm/llvm-project/pull/69538.diff

1 Files Affected:

• (modified) mlir/unittests/Target/LLVM/SerializeToLLVMBitcode.cpp (+1-1)

diff --git a/mlir/unittests/Target/LLVM/SerializeToLLVMBitcode.cpp b/mlir/unittests/Target/LLVM/SerializeToLLVMBitcode.cpp
index c23ed7efd72fdf4..69c9d9b2f320202 100644
--- a/mlir/unittests/Target/LLVM/SerializeToLLVMBitcode.cpp
+++ b/mlir/unittests/Target/LLVM/SerializeToLLVMBitcode.cpp
@@ -55,7 +55,7 @@ TEST_F(MLIRTargetLLVM, SKIP_WITHOUT_NATIVE(SerializeToLLVMBitcode)) {
   ASSERT_TRUE(!!module);
 
   // Serialize the module.
-  std::string targetTriple = llvm::sys::getDefaultTargetTriple();
+  std::string targetTriple = llvm::sys::getProcessTriple();
   LLVM::ModuleToObject serializer(*(module->getOperation()), targetTriple, "",
                                   "");
   std::optional<SmallVector<char, 0>> serializedModule = serializer.run();

[fabianmcg]

LGTM! Thank you for catching this!

[joker-eph]

Why would the test fail? It seems like just emitting LLVM IR and parsing it back which should not even require a target?

[joker-eph]

@fabianmcg : why is the test decorated with SKIP_WITHOUT_NATIVE ?

(I can't comment above, it's line 41)

[sstamenova]

Why would the test fail? It seems like just emitting LLVM IR and parsing it back which should not even require a target?

It fails because the test code only registers the native target. The error is: loc("-":0:0): error: Failed to lookup target: No available targets are compatible with triple XYZ

[joker-eph]

Thanks @sstamenova, we could likely fix this and make it work without the native target, but that's probably not worth the effort considering what this test is about!

[fabianmcg]

Why would the test fail? It seems like just emitting LLVM IR and parsing it back which should not even require a target?

The reason is that ModuleToObject always sets Target information. Thus, it fails if there's no valid target, that's also the reason the test is skipped when there's is no native target, as it fails with the error pointed by Stella.