[ATfL] Enable sanitizers for testing (#566)

[ATfL] Enable sanitizers for testing ATfL.

Scripts implements 2-stage pipeline: first clang is built using
arm-toolchain sources.
Then this clang is used to compile ATfL sanitizer build.

The script creates a build of the toolchain in the
'build_clang_with_sanitizer'
directory, inside the repository tree and tests it.

---------

Co-authored-by: Kiran Chandramohan <[email protected]>

Author: vrukesh

arm-software/linux/scripts/build_atfl_sanitizer.sh

@@ -0,0 +1,87 @@
+#!/bin/bash
+
+# Copyright (c) 2025, Arm Limited and affiliates.
+# Part of the Arm Toolchain project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# A bash script to build the Arm Toolchain for Linux, with Address (ASan) and Undefined Behaviour Sanitizer (UBSan) enabled.
+
+# Script implements 2-stage pipeline: first clang is built using arm-toolchain sources.
+# Then this clang is used to compile ATfL sanitizer build.
+#
+# The script creates a build of the toolchain in the 'build_clang_with_sanitizer' directory, inside
+# the repository tree.
+
+set -vex
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+REPO_ROOT=$( git -C "${SCRIPT_DIR}" rev-parse --show-toplevel )
+
+echo "==> Stage 1: Building clang (unsanitized)"
+
+mkdir -p "${REPO_ROOT}"/build_llvm
+cd "${REPO_ROOT}"/build_llvm
+
+cmake -G Ninja ../llvm \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ \
+    -DLLVM_LIT_ARGS="-v" \
+    -DCMAKE_INSTALL_PREFIX=../stage1.install \
+    -DCMAKE_C_COMPILER=clang \
+    -DCMAKE_CXX_COMPILER=clang++ \
+    -DLLVM_TARGETS_TO_BUILD=AArch64 \
+    -DLLVM_ENABLE_PROJECTS="clang;llvm" \
+    -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind;compiler-rt"
+
+ninja
+
+echo "==> Stage 2: Building libraries (sanitized)"
+
+mkdir -p "${REPO_ROOT}"/build_libcxx
+cd "${REPO_ROOT}"/build_libcxx
+
+cmake -G Ninja ../runtimes \
+    -DLLVM_TARGETS_TO_BUILD=AArch64 \
+    -DLLVM_USE_SANITIZER="Address;Undefined" \
+    -DLLVM_ENABLE_ASSERTIONS=True \
+    -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind;compiler-rt" \
+    -DCMAKE_C_COMPILER="${REPO_ROOT}/build_llvm/bin/clang" \
+    -DCMAKE_CXX_COMPILER="${REPO_ROOT}/build_llvm/bin/clang++" \
+    -DLIBCXX_ENABLE_TIME_ZONE_DATABASE=off
+
+ninja
+
+echo "==> Stage 3: Building clang (sanitized)"
+
+mkdir -p "${REPO_ROOT}"/build_clang_with_sanitizer
+cd "${REPO_ROOT}"/build_clang_with_sanitizer
+
+export LD_LIBRARY_PATH="${REPO_ROOT}"/build_libcxx/lib:$LD_LIBRARY_PATH
+
+# Flag to disable LeakSanitizer (memory leaks detection) in AddressSanitizer.
+export ASAN_OPTIONS=detect_leaks=0
+
+# Have chosen Address Sanitizer and Undefined Sanitizer to build and test.
+# These sanitizers are most commonly used and relatively easy to set-up.
+# These sanitizers will help to detect runtime issues related to use after free, 
+# overflow (Heap buffer, stack buffer) etc.
+# We have explicitly disabled memory leak detection, since the observed issues are
+# unrelated to product under test.
+cmake -G Ninja ../llvm \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DLLVM_USE_SANITIZER="Address;Undefined" \
+  -DLLVM_ENABLE_ASSERTIONS=True \
+  -DCMAKE_C_COMPILER="${REPO_ROOT}/build_llvm/bin/clang" \
+  -DCMAKE_CXX_COMPILER="${REPO_ROOT}/build_llvm/bin/clang++" \
+  -DLLVM_LIT_ARGS="--ignore-fail --xunit-xml-output=lit_results.junit.xml \
+  --param=env='ASAN_OPTIONS=detect_leaks=0' \
+  --filter-out='(time\.zone|tzdb|time\.clock|orc|activation-options|quarantine_size|mmap_write_exec|assert\.cpp|asan_preload_test|thread_local_quarantine_size|leak|tzdb|assert\.cpp|use_globals|closed-fds)'" \
+  -DCMAKE_INSTALL_PREFIX=../stage3.install \
+  -DLLVM_TARGETS_TO_BUILD=AArch64 \
+  -DLLVM_ENABLE_PROJECTS="clang;llvm" \
+  -DLLVM_ENABLE_RUNTIMES="libcxx;libcxxabi;libunwind;compiler-rt" \
+  -DLIBCXX_ENABLE_TIME_ZONE_DATABASE=off
+
+ninja
+echo "==> Stage 3: Completed building clang (sanitized)"

arm-software/linux/scripts/test_atfl_sanitizer.sh

@@ -0,0 +1,54 @@
+#!/bin/bash
+
+# Copyright (c) 2025, Arm Limited and affiliates.
+# Part of the Arm Toolchain project, under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# A bash script to run the tests from the Arm Toolchain for Linux, when sanitizers
+# are enabled.
+
+# The script assumes a successful build of the toolchain exists in the 'build_clang_with_sanitizer'
+# directory inside the repository tree.
+
+# Script does not exit, when the command in the script exits with a non-zero status.
+# Also, print the line of the script being executed.
+set -vx
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+REPO_ROOT=$( git -C "${SCRIPT_DIR}" rev-parse --show-toplevel )
+
+cd "${REPO_ROOT}"/build_clang_with_sanitizer || exit
+
+# Flag to disable memory leaks detection of LeakSanitizer.
+export ASAN_OPTIONS=detect_leaks=0
+
+# If a test fails, lit will ordinarily return a non-zero result,
+# which prevents further testing. Setting the --ignore-fail option
+# will cause testing to continue, so that CI systems can get a
+# full set of results.
+# Upstream clang and LLVM tests do not generate the junit xml results file by default.
+# Additionally setting the --xunit-xml-output option store the
+# results.
+export LIT_ARGS="--ignore-fail --xunit-xml-output=lit_results.junit.xml --param=env='ASAN_OPTIONS=detect_leaks=0'"
+
+# Skip the flaky tests
+export LIT_ARGS="${LIT_ARGS} --filter-out 'time.zone|tzdb|time.clock|orc|activation-options|quarantine_size|mmap_write_exec|log-path_test|assert.cpp|initialization-nobug|use_globals|closed-fds'"
+
+ninja -v check-llvm
+echo "check-llvm exit code: $?"
+
+ninja -v check-clang
+echo "check-clang exit code: $?"
+
+ninja -v check-cxx
+echo "check-cxx exit code: $?"
+
+ninja -v check-cxxabi
+echo "check-cxxabi exit code: $?"
+
+ninja -v check-compiler-rt
+echo "check-compiler-rt exit code: $?"
+
+ninja -v check-unwind
+echo "check-unwind exit code: $?"