[llvm] llvm-mc: Error on MCSubtargetInfo construction failure (PR #159226)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/159226

None

>From 0b87f5b0facead42f8e73a0b6c8a6e3acbc1d7c7 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Wed, 17 Sep 2025 10:44:42 +0900
Subject: [PATCH] llvm-mc: Error on MCSubtargetInfo construction failure

---
 llvm/tools/llvm-mc/llvm-mc.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index 136cd69526a3c..224fd80f6a6d3 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -469,7 +469,10 @@ int main(int argc, char **argv) {
 
   std::unique_ptr<MCSubtargetInfo> STI(
       TheTarget->createMCSubtargetInfo(TheTriple, MCPU, FeaturesStr));
-  assert(STI && "Unable to create subtarget info!");
+  if (!STI) {
+    WithColor::error(errs(), ProgName) << "unable to create subtarget info\n";
+    return 1;
+  }
 
   // FIXME: This is not pretty. MCContext has a ptr to MCObjectFileInfo and
   // MCObjectFileInfo needs a MCContext reference in order to initialize itself.