From a896e0371cf8af315fb74e55bba7aeff1dbeffa9 Mon Sep 17 00:00:00 2001
From: Paul Osmialowski <pawel.osmialowski@arm.com>
Date: Fri, 28 Feb 2025 09:55:59 +0000
Subject: [PATCH] [ATfL] Introduce the ability to set the default target triple

Amazon Linux uses different target triple than other distributions.
An attempt to accomodate it in Clang's frontend driver has been
rejected already [1], so the only way to handle it is to set the
default target triple explicitly when building LLVM. This will affect
the name of the runtimes library which LLVM creates.

[1] https://github.com/llvm/llvm-project/pull/109263
---
 arm-software/linux/build.sh          | 18 +++++++++++-------
 arm-software/linux/build.sh-HOWTO.md |  2 ++
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/arm-software/linux/build.sh b/arm-software/linux/build.sh
index 8aee2f7fec3b..b3288b18f09a 100755
--- a/arm-software/linux/build.sh
+++ b/arm-software/linux/build.sh
@@ -35,6 +35,7 @@ ATFL_VERSION=${ATFL_VERSION:-"0.0"}
 OS_NAME=${OS_NAME:-"linux"}
 TAR_NAME=${TAR_NAME:-"atfl-${ATFL_VERSION}-${OS_NAME}-aarch64.tar.gz"}
 ATFL_ASSERTIONS=${ATFL_ASSERTIONS:-"ON"}
+ATFL_TARGET_TRIPLE=${ATFL_TARGET_TRIPLE:-"aarch64-unknown-linux-gnu"}
 PROCESSOR_COUNT=$(getconf _NPROCESSORS_ONLN)
 PARALLEL_JOBS=${PARALLEL_JOBS:-"${PROCESSOR_COUNT}"}
 # " <-- this is to help syntax highlighters to find a matching double quote
@@ -58,6 +59,7 @@ COMMON_CMAKE_FLAGS=(
     -DLLVM_ENABLE_PLUGINS=ON
     -DLLVM_TOOL_LIBUNWIND_BUILD=ON
     -DLLVM_TARGETS_TO_BUILD=AArch64
+    -DLLVM_DEFAULT_TARGET_TRIPLE=${ATFL_TARGET_TRIPLE}
     -DZLIB_LIBRARY_RELEASE=${ZLIB_STATIC_PATH}
 )
 PRODUCT_CMAKE_FLAGS=(
@@ -94,7 +96,7 @@ COMPILER_CMAKE_FLAGS=(
     -DCOMPILER_RT_BUILD_STANDALONE_LIBATOMIC=OFF
     -DCOMPILER_RT_USE_ATOMIC_LIBRARY=ON
     -DCOMPILER_RT_USE_LLVM_UNWINDER=OFF
-    -DCOMPILER_RT_LIBRARY_atomic_aarch64-unknown-linux-gnu="-rtlib=compiler-rt"
+    -DCOMPILER_RT_LIBRARY_atomic_${ATFL_TARGET_TRIPLE}="-rtlib=compiler-rt"
     -DLIBOMP_COPY_EXPORTS=False
     -DLIBOMP_USE_HWLOC=False
     -DLIBOMP_OMPT_SUPPORT=ON
@@ -191,6 +193,8 @@ Environment Variables:
                         (default: $ATFL_ASSERTIONS)
     ATFL_VERSION        Specify the version string
                         (default: $ATFL_VERSION)
+    ATFL_TARGET_TRIPLE  Specify the default target triple
+                        (default: $ATFL_TARGET_TRIPLE)
     OS_NAME             Specify the OS name
                         (default: $OS_NAME)
     TAR_NAME            The name of the tarball to be created
@@ -358,10 +362,10 @@ shared_lib_build() {
     run_command cmake --install . 2>&1 | tee -a "${LOGS_DIR}/shared_lib.txt"
     mv "${ATFL_DIR}" "${ATFL_DIR}.libs"
     mv "${ATFL_DIR}.keep" "${ATFL_DIR}"
-    cp "${ATFL_DIR}.libs/lib/aarch64-unknown-linux-gnu/libomp.a" \
-        "${ATFL_DIR}/lib/aarch64-unknown-linux-gnu"
+    cp "${ATFL_DIR}.libs/lib/${ATFL_TARGET_TRIPLE}/libomp.a" \
+        "${ATFL_DIR}/lib/${ATFL_TARGET_TRIPLE}"
     cp -d ${ATFL_DIR}.libs/lib/libflang_rt* \
-        "${ATFL_DIR}/lib/aarch64-unknown-linux-gnu"
+        "${ATFL_DIR}/lib/${ATFL_TARGET_TRIPLE}"
     rm -r "${ATFL_DIR}.libs"
     echo '-L<CFGDIR>/../runtimes/runtimes-bins/openmp/runtime/src $-Wl,--push-state $-Wl,--as-needed $-lomp $-ldl $-Wl,--pop-state' >bin/clang.cfg
     echo '-L<CFGDIR>/../runtimes/runtimes-bins/openmp/runtime/src $-Wl,--push-state $-Wl,--as-needed $-lomp $-ldl $-Wl,--pop-state' >bin/clang++.cfg
@@ -380,12 +384,12 @@ package() {
       echo "The Amath libraries will not be packaged."
     else
       cp "${LIBRARIES_DIR}/libamath.a" \
-          "${ATFL_DIR}/lib/aarch64-unknown-linux-gnu"
+          "${ATFL_DIR}/lib/${ATFL_TARGET_TRIPLE}"
       cp "${LIBRARIES_DIR}/libamath.so" \
-          "${ATFL_DIR}/lib/aarch64-unknown-linux-gnu"
+          "${ATFL_DIR}/lib/${ATFL_TARGET_TRIPLE}"
     fi
     cp "${ATFL_DIR}/lib/libflang_rt.runtime.a" \
-      "${ATFL_DIR}/lib/aarch64-unknown-linux-gnu"
+      "${ATFL_DIR}/lib/${ATFL_TARGET_TRIPLE}"
     cp ${ATFL_DIR}/include/flang/omp* "${ATFL_DIR}/include"
     echo 'export PATH="$(dirname `realpath $BASH_SOURCE`)/bin:$PATH"' >"${ATFL_DIR}/env.bash"
     echo "export PS1=\"(ATfL ${ATFL_VERSION}) \$PS1\"" >>"${ATFL_DIR}/env.bash"
diff --git a/arm-software/linux/build.sh-HOWTO.md b/arm-software/linux/build.sh-HOWTO.md
index bea5468abad3..cd743e380dc1 100644
--- a/arm-software/linux/build.sh-HOWTO.md
+++ b/arm-software/linux/build.sh-HOWTO.md
@@ -152,6 +152,8 @@ The `build.sh` script reads the following environment variables:
   (default: number of the available CPU cores)
 - `ATFL_ASSERTIONS` - Enable assertions in the build ON/OFF
   (default: ON), set this to `OFF` when doing a proper release (not nightly) build
+- `ATFL_TARGET_TRIPLE` - Specify the default target triple
+  (default: aarch64-unknown-linux-gnu), Set it to aarch64-amazon-linux when building for Amazon Linux
 - `TAR_NAME` - The name of the tarball to be created
   (default: atfl-0.0-linux-aarch64.tar.gz)
 - `ZLIB_STATIC_PATH` - Specifies the location of the static zlib library (libz.a)