[llvm] Escape LLVM_TARGETS_TO_BUILD while checking against LLVM_ALL_TARGETS and LLVM_EXPERIMENTAL_TARGETS_TO_BUILD (PR #70885)

[via llvm-commits]

https://github.com/natschz created https://github.com/llvm/llvm-project/pull/70885

Targeting X86 while building LLVM with the Android NDK, currently fails with "The target `X86' is not a core tier target. It may be experimental, if so it must be passed via LLVM_EXPERIMENTAL_TARGETS_TO_BUILD."

This is happening because the Android NDK defines a variable named X86, which will lead to a "fun" CMake feature. For further details reference [this post](https://discourse.llvm.org/t/the-target-x86-is-not-a-core-tier-target/73784).

To fix this, the LLVM_TARGETS_TO_BUILD need to be escaped while checking agains LLVM_ALL_TARGETS and LLVM_EXPERIMENTAL_TARGETS_TO_BUILD.


>From 31a06749b6f4312ac91b4bfea99abf010a052d27 Mon Sep 17 00:00:00 2001
From: Natschz <>
Date: Wed, 1 Nov 2023 02:56:53 +0100
Subject: [PATCH] Escape LLVM_TARGETS_TO_BUILD while checking against
 LLVM_ALL_TARGETS and LLVM_EXPERIMENTAL_TARGETS_TO_BUILD

---
 llvm/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 82d4beea91e346e..f96704beddc7721 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -942,7 +942,7 @@ foreach(t ${LLVM_TARGETS_TO_BUILD})
   # LLVM_EXPERIMENTAL_TARGETS_TO_BUILD, not LLVM_TARGETS_TO_BUILD.
   # We allow experimental targets that are not in LLVM_ALL_EXPERIMENTAL_TARGETS,
   # as long as they are passed via LLVM_EXPERIMENTAL_TARGETS_TO_BUILD.
-  if ( NOT ${t} IN_LIST LLVM_ALL_TARGETS AND NOT ${t} IN_LIST LLVM_EXPERIMENTAL_TARGETS_TO_BUILD )
+  if ( NOT "${t}" IN_LIST LLVM_ALL_TARGETS AND NOT "${t}" IN_LIST LLVM_EXPERIMENTAL_TARGETS_TO_BUILD )
     if( ${t} IN_LIST LLVM_ALL_EXPERIMENTAL_TARGETS )
       message(FATAL_ERROR "The target `${t}' is experimental and must be passed "
         "via LLVM_EXPERIMENTAL_TARGETS_TO_BUILD.")