[libc-commits] [libc] [llvm] [libc] Remove special full build handling for GPU (PR #128572)

[Joseph Huber via libc-commits]

https://github.com/jhuber6 created https://github.com/llvm/llvm-project/pull/128572

Summary:
Currently we default to non-fullbuild for all targets, but realistically
we should do this depending on the target OS. Some OS's like the GPU or
upcoming UEFI have no existing hosted system, so they cannot be built
with an overlay build. These are already errors so there's no reason to
complicate things and require passing it in through the runtimes build.


>From 21e8166abde65cc01e9a5d7243f4f71bb5082b80 Mon Sep 17 00:00:00 2001
From: Joseph Huber <huberjn at outlook.com>
Date: Mon, 24 Feb 2025 14:48:24 -0600
Subject: [PATCH] [libc] Remove special full build handling for GPU

Summary:
Currently we default to non-fullbuild for all targets, but realistically
we should do this depending on the target OS. Some OS's like the GPU or
upcoming UEFI have no existing hosted system, so they cannot be built
with an overlay build. These are already errors so there's no reason to
complicate things and require passing it in through the runtimes build.
---
 libc/CMakeLists.txt          | 8 +++++++-
 llvm/runtimes/CMakeLists.txt | 2 --
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/libc/CMakeLists.txt b/libc/CMakeLists.txt
index 47708c2267818..a4fbba92c2727 100644
--- a/libc/CMakeLists.txt
+++ b/libc/CMakeLists.txt
@@ -128,7 +128,13 @@ else()
   endif()
 endif()
 
-option(LLVM_LIBC_FULL_BUILD "Build and test LLVM libc as if it is the full libc" OFF)
+# Some targets can only support the full build.
+set(default_to_full_build OFF)
+if(LIBC_TARGET_OS_IS_GPU)
+  set(default_to_full_build ON)
+endif()
+
+option(LLVM_LIBC_FULL_BUILD "Build and test LLVM libc as if it is the full libc" ${default_to_full_build})
 option(LLVM_LIBC_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR "Build LLVM libc tests assuming our implementation-defined behavior" ON)
 option(LLVM_LIBC_ENABLE_LINTING "Enables linting of libc source files" OFF)
 
diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
index 2370b41fb7f0b..77a82ed196cd9 100644
--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
@@ -535,7 +535,6 @@ if(build_runtimes)
              "-DRUNTIMES_amdgcn-amd-amdhsa_LIBC_GPU_LOADER_EXECUTABLE=$<TARGET_FILE:amdhsa-loader>")
         list(APPEND extra_deps amdhsa-loader)
       endif()
-      list(APPEND extra_cmake_args "-DRUNTIMES_amdgcn-amd-amdhsa_LLVM_LIBC_FULL_BUILD=ON")
     endif()
     if("libc" IN_LIST RUNTIMES_nvptx64-nvidia-cuda_LLVM_ENABLE_RUNTIMES)
       if(TARGET nvptx-loader)
@@ -543,7 +542,6 @@ if(build_runtimes)
              "-DRUNTIMES_nvptx64-nvidia-cuda_LIBC_GPU_LOADER_EXECUTABLE=$<TARGET_FILE:nvptx-loader>")
         list(APPEND extra_deps nvptx-loader)
       endif()
-      list(APPEND extra_cmake_args "-DRUNTIMES_nvptx64-nvidia-cuda_LLVM_LIBC_FULL_BUILD=ON")
     endif()
     if(TARGET clang-offload-packager)
       list(APPEND extra_deps clang-offload-packager)