[llvm] [orc-rt] Ensure EH/RTTI=On overrides LLVM opts, applies to unit tests. (PR #172155)

[Lang Hames via llvm-commits]

https://github.com/lhames created https://github.com/llvm/llvm-project/pull/172155

When -DORC_RT_ENABLE_EXCEPTIONS=On and -DORC_RT_ENABLE_RTTI=On are passed we need to ensure that the resulting compiler flags (e.g. -fexceptions, -frtti for clang/GCC) are appended so that we override any inherited options (e.g. -fno-exceptions, -fno-rtti) from LLVM.

Updates unit tests to ensure that these compiler options are applied to them too.

>From 3631ded602dfaa7418b3187d3066d535736ba0c5 Mon Sep 17 00:00:00 2001
From: Lang Hames <lhames at gmail.com>
Date: Sat, 13 Dec 2025 22:43:02 +1100
Subject: [PATCH] [orc-rt] Ensure EH/RTTI=On overrides LLVM opts, applies to
 unit tests.

When -DORC_RT_ENABLE_EXCEPTIONS=On and -DORC_RT_ENABLE_RTTI=On are passed we
need to ensure that the resulting compiler flags (e.g. -fexceptions, -frtti
for clang/GCC) are appended so that we override any inherited options (e.g.
-fno-exceptions, -fno-rtti) from LLVM.

Updates unit tests to ensure that these compiler options are applied to them
too.
---
 orc-rt/CMakeLists.txt           | 8 ++++++--
 orc-rt/unittests/CMakeLists.txt | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/orc-rt/CMakeLists.txt b/orc-rt/CMakeLists.txt
index 5da7cc7fbe299..95b7b852138e7 100644
--- a/orc-rt/CMakeLists.txt
+++ b/orc-rt/CMakeLists.txt
@@ -44,11 +44,15 @@ set(ORC_RT_BINARY_DIR ${CMAKE_CURRENT_BINARY_DIR})
 
 # Configure RTTI and exceptions compile flags
 set(ORC_RT_COMPILE_FLAGS)
-if(NOT ORC_RT_ENABLE_RTTI)
+if(ORC_RT_ENABLE_RTTI)
+  list(APPEND ORC_RT_COMPILE_FLAGS -frtti)
+else()
   list(APPEND ORC_RT_COMPILE_FLAGS -fno-rtti)
 endif()
 
-if(NOT ORC_RT_ENABLE_EXCEPTIONS)
+if(ORC_RT_ENABLE_EXCEPTIONS)
+  list(APPEND ORC_RT_COMPILE_FLAGS -fexceptions)
+else()
   list(APPEND ORC_RT_COMPILE_FLAGS -fno-exceptions)
 endif()
 
diff --git a/orc-rt/unittests/CMakeLists.txt b/orc-rt/unittests/CMakeLists.txt
index c43ec17b54de3..ea2611c1ec9e9 100644
--- a/orc-rt/unittests/CMakeLists.txt
+++ b/orc-rt/unittests/CMakeLists.txt
@@ -9,6 +9,9 @@ endif ()
 
 function(add_orc_rt_unittest test_dirname)
   add_unittest(OrcRTUnitTests ${test_dirname} ${ARGN})
+
+  # Apply ORC_RT_COMPILE_FLAGS to the unittest target
+  target_compile_options(${test_dirname} PRIVATE ${ORC_RT_COMPILE_FLAGS})
 endfunction()
 
 add_orc_rt_unittest(CoreTests