[compiler-rt] [compiler-rt][MSVC][CMake] Wrap Linker flags for ICX (PR #118496)

[Mészáros Gergely via llvm-commits]

https://github.com/Maetveis created https://github.com/llvm/llvm-project/pull/118496

RFC: https://discourse.llvm.org/t/rfc-cmake-linker-flags-need-wl-equivalent-for-intel-c-icx-on-windows/82446

My previous pass missed some flags because I used `-Werror=unknown-argument``, but `/D``, `/I` and `/O` are accepted by clang (even when only linking), but mean different things than intended for `link.exe``. Wrapping the linker with a script revealed these flags.

The approach I used to find these is documented as github gist here: https://gist.github.com/Maetveis/00567488f0d6ff74095d91ed306fafc5

>From 7db600392c6a7a233d355373f8b60a0aca334a52 Mon Sep 17 00:00:00 2001
From: Gergely Meszaros <gergely.meszaros at intel.com>
Date: Tue, 3 Dec 2024 06:59:37 -0800
Subject: [PATCH] [compiler-rt][MSVC][CMake] Wrap Linker flags for ICX

RFC: https://discourse.llvm.org/t/rfc-cmake-linker-flags-need-wl-equivalent-for-intel-c-icx-on-windows/82446

My previous pass missed some flags because I used `-Werror=unknown-argument``,
but `/D``, `/I` and `/O` are accepted by clang (even when only linking),
but mean different things than intended for `link.exe``.
Wrapping the linker with a script revealed these flags.
---
 compiler-rt/CMakeLists.txt          | 2 +-
 compiler-rt/lib/asan/CMakeLists.txt | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
index 20054c6e85a407..80d5aaabfd8c3f 100644
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -768,7 +768,7 @@ if (CMAKE_LINKER MATCHES "link.exe$")
   # it, but CMake doesn't seem to have a way to set linker flags for
   # individual static libraries, so we enable the suppression flag for
   # the whole compiler-rt project.
-  set(CMAKE_STATIC_LINKER_FLAGS "${CMAKE_STATIC_LINKER_FLAGS} /IGNORE:4221")
+  set(CMAKE_STATIC_LINKER_FLAGS "${CMAKE_STATIC_LINKER_FLAGS} ${CMAKE_CXX_LINKER_WRAPPER_FLAG}/IGNORE:4221")
 endif()
 
 add_subdirectory(include)
diff --git a/compiler-rt/lib/asan/CMakeLists.txt b/compiler-rt/lib/asan/CMakeLists.txt
index fb3d74283a61e0..5ec995ae159b73 100644
--- a/compiler-rt/lib/asan/CMakeLists.txt
+++ b/compiler-rt/lib/asan/CMakeLists.txt
@@ -141,7 +141,7 @@ append_list_if(COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC
 # LLVM turns /OPT:ICF back on when LLVM_ENABLE_PDBs is set
 # we _REALLY_ need to turn it back off for ASAN, because the way
 # asan emulates weak functions from DLLs requires NOICF
-append_list_if(MSVC "/DEBUG;/OPT:NOICF" ASAN_DYNAMIC_LINK_FLAGS)
+append_list_if(MSVC "LINKER:/DEBUG;LINKER:/OPT:NOICF" ASAN_DYNAMIC_LINK_FLAGS)
 
 set(ASAN_DYNAMIC_LIBS
   ${COMPILER_RT_UNWINDER_LINK_LIBS}