[clang] [Fuchsia] Set no RT lib for baremetal (PR #173825)

[Prabhu Rajasekaran via cfe-commits]

https://github.com/Prabhuk created https://github.com/llvm/llvm-project/pull/173825

Setting LIBCXX_HAS_RT_LIB to OFF to prevent RT lib dependencies being
generated for non POSIX baremetal targets.


>From fa373aea4874fa4b257f7efbe28f4bcdf0d5f1d7 Mon Sep 17 00:00:00 2001
From: prabhukr <prabhukr at google.com>
Date: Mon, 29 Dec 2025 05:34:17 +0000
Subject: [PATCH] [Fuchsia] Set no RT lib for baremetal

Setting LIBCXX_HAS_RT_LIB to OFF to prevent RT lib dependencies being
generated for non POSIX baremetal targets.
---
 clang/cmake/caches/Fuchsia-stage2.cmake | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/clang/cmake/caches/Fuchsia-stage2.cmake b/clang/cmake/caches/Fuchsia-stage2.cmake
index be41a6db7dff3..ed285ceeb34dc 100644
--- a/clang/cmake/caches/Fuchsia-stage2.cmake
+++ b/clang/cmake/caches/Fuchsia-stage2.cmake
@@ -373,6 +373,7 @@ foreach(target armv6m-none-eabi;armv7m-none-eabi;armv7em-none-eabi;armv8m.main-n
   set(RUNTIMES_${target}_LIBCXX_ENABLE_THREADS OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_MONOTONIC_CLOCK OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_HAS_TERMINAL_AVAILABLE OFF CACHE BOOL "")
+  set(RUNTIMES_${target}_LIBCXX_HAS_RT_LIB OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
   set(RUNTIMES_${target}_LLVM_INCLUDE_TESTS OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
@@ -429,6 +430,7 @@ foreach(target riscv32-unknown-elf)
   set(RUNTIMES_${target}_LIBCXX_ENABLE_THREADS OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_ENABLE_MONOTONIC_CLOCK OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_HAS_TERMINAL_AVAILABLE OFF CACHE BOOL "")
+  set(RUNTIMES_${target}_LIBCXX_HAS_RT_LIB OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
   set(RUNTIMES_${target}_LLVM_INCLUDE_TESTS OFF CACHE BOOL "")
   set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")