Bazel compilation database generation testing

Pre-requisites

1. Need a linux machine. Mine is Ubuntu 22.04
2. clang compiler toolchain. I am using version clang-16. Verified that this is an issue with clang-14 as well.
3. bazel. You can install bazel using following

• sudo wget -O /usr/local/bin/bazel https://github.com/bazelbuild/bazelisk/releases/latest/download/bazelisk-linux-$([ $(uname -m) = "aarch64" ] && echo "arm64" || echo "amd64")

• sudo chmod +x /usr/local/bin/bazel

Steps to reproduce the problem

1. Clone this repsitory

git clone https://github.com/stonebrakert6/echo_bazel && cd echo_bazel

2. Setup clang toolchain for bazel. This would generate file clang.bazelrc

./setup_clang.sh <PATH_TO_CLANG_LLVM_DIRECTORY>

e.g ./setup_clang.sh /home/stonebrakert6/build/llvm

3. Build the project

bazel build --verbose_failures --subcommands //main/...

Optional - Verify that we have an exe generated. Run it

./bazel-bin/main/a.out

4. Generate compilation database

bazel run :refresh_compile_commands

5. Copy compile_commands.json to output_base. This remove spurious compilation errors

cp compile_commands.json `bazel info output_base`

6. Run clangd in 'check' mode. This should cause clangd to crash with stacktrace

clangd --log=verbose --check=external/com_google_tcmalloc/tcmalloc/tcmalloc.cc