[llvm] [ci] skip clang installation and separate configuration for runtimes. (PR #136162)

[Matheus Izvekov via llvm-commits]

https://github.com/mizvekov updated https://github.com/llvm/llvm-project/pull/136162

>From 0b939e9297a7a2d720ae469fb5af147c823b802a Mon Sep 17 00:00:00 2001
From: Matheus Izvekov <mizvekov at gmail.com>
Date: Thu, 17 Apr 2025 13:45:09 -0300
Subject: [PATCH] [ci] skip clang installation and separate configuration for
 runtimes.

They will be built with the just built clang either way.
This avoids building the runtimes twice when LLDB is also tested.
---
 .ci/monolithic-linux.sh | 53 +++++++++++------------------------------
 1 file changed, 14 insertions(+), 39 deletions(-)

diff --git a/.ci/monolithic-linux.sh b/.ci/monolithic-linux.sh
index a56a8bcbffecb..694629c34c777 100755
--- a/.ci/monolithic-linux.sh
+++ b/.ci/monolithic-linux.sh
@@ -18,7 +18,6 @@ set -o pipefail
 
 MONOREPO_ROOT="${MONOREPO_ROOT:="$(git rev-parse --show-toplevel)"}"
 BUILD_DIR="${BUILD_DIR:=${MONOREPO_ROOT}/build}"
-INSTALL_DIR="${BUILD_DIR}/install"
 rm -rf "${BUILD_DIR}"
 
 ccache --zero-stats
@@ -85,69 +84,45 @@ cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -D LIBCXX_CXX_ABI=libcxxabi \
       -D MLIR_ENABLE_BINDINGS_PYTHON=ON \
       -D LLDB_ENABLE_PYTHON=ON \
-      -D LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS=ON \
-      -D CMAKE_INSTALL_PREFIX="${INSTALL_DIR}"
+      -D LLDB_ENFORCE_STRICT_TEST_REQUIREMENTS=ON
 
 echo "--- ninja"
+
 # Targets are not escaped as they are passed as separate arguments.
 ninja -C "${BUILD_DIR}" -k 0 ${targets}
 
 runtimes="${3}"
 runtime_targets="${4}"
 
-# Compiling runtimes with just-built Clang and running their tests
-# as an additional testing for Clang.
+# Run runtimes tests.
+# We don't need to do a clean separate build of runtimes, because runtimes
+# will be built against just built clang, and because LIBCXX_TEST_PARAMS
+# and LIBCXXABI_TEST_PARAMS only affect lit configuration, which successfully
+# propagates without a clean build. Other that those two variables, builds
+# are supposed to be the same.
 if [[ "${runtimes}" != "" ]]; then
   if [[ "${runtime_targets}" == "" ]]; then
     echo "Runtimes to build are specified, but targets are not."
     exit 1
   fi
 
-  echo "--- ninja install-clang"
-
-  ninja -C ${BUILD_DIR} install-clang install-clang-resource-headers
-
-  RUNTIMES_BUILD_DIR="${MONOREPO_ROOT}/build-runtimes"
-  INSTALL_DIR="${BUILD_DIR}/install"
-  mkdir -p ${RUNTIMES_BUILD_DIR}
-
   echo "--- cmake runtimes C++26"
 
-  rm -rf "${RUNTIMES_BUILD_DIR}"
-  cmake -S "${MONOREPO_ROOT}/runtimes" -B "${RUNTIMES_BUILD_DIR}" -GNinja \
-      -D CMAKE_C_COMPILER="${INSTALL_DIR}/bin/clang" \
-      -D CMAKE_CXX_COMPILER="${INSTALL_DIR}/bin/clang++" \
-      -D LLVM_ENABLE_RUNTIMES="${runtimes}" \
-      -D LIBCXX_CXX_ABI=libcxxabi \
-      -D CMAKE_BUILD_TYPE=RelWithDebInfo \
-      -D CMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
+  cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -D LIBCXX_TEST_PARAMS="std=c++26" \
-      -D LIBCXXABI_TEST_PARAMS="std=c++26" \
-      -D LLVM_LIT_ARGS="${lit_args}"
+      -D LIBCXXABI_TEST_PARAMS="std=c++26"
 
   echo "--- ninja runtimes C++26"
 
-  ninja -vC "${RUNTIMES_BUILD_DIR}" ${runtime_targets}
+  ninja -vC "${BUILD_DIR}" ${runtime_targets}
 
   echo "--- cmake runtimes clang modules"
 
-  # We don't need to do a clean build of runtimes, because LIBCXX_TEST_PARAMS
-  # and LIBCXXABI_TEST_PARAMS only affect lit configuration, which successfully
-  # propagates without a clean build. Other that those two variables, builds
-  # are supposed to be the same.
-
-  cmake -S "${MONOREPO_ROOT}/runtimes" -B "${RUNTIMES_BUILD_DIR}" -GNinja \
-      -D CMAKE_C_COMPILER="${INSTALL_DIR}/bin/clang" \
-      -D CMAKE_CXX_COMPILER="${INSTALL_DIR}/bin/clang++" \
-      -D LLVM_ENABLE_RUNTIMES="${runtimes}" \
-      -D LIBCXX_CXX_ABI=libcxxabi \
-      -D CMAKE_BUILD_TYPE=RelWithDebInfo \
-      -D CMAKE_INSTALL_PREFIX="${INSTALL_DIR}" \
+  cmake -S "${MONOREPO_ROOT}"/llvm -B "${BUILD_DIR}" \
       -D LIBCXX_TEST_PARAMS="enable_modules=clang" \
-      -D LIBCXXABI_TEST_PARAMS="enable_modules=clang" \
-      -D LLVM_LIT_ARGS="${lit_args}"
+      -D LIBCXXABI_TEST_PARAMS="enable_modules=clang"
 
   echo "--- ninja runtimes clang modules"
 
-  ninja -vC "${RUNTIMES_BUILD_DIR}" ${runtime_targets}
+  ninja -vC "${BUILD_DIR}" ${runtime_targets}
 fi