#!/usr/bin/env bash
# brintcc — the C compiler driver for wasm32-hwjs-linux.
#
# The front door. It resolves configuration (libexec/config.sh), decides which
# libc this line is for, and execs the implementation in libexec/. It is an
# exec, not a call: this toolchain compiles entire distributions, and a second
# process per translation unit is a cost paid a million times.
#
# LIBC SELECTION. Default musl; `-mlibc=glibc` or a target triple naming a gnu
# environment selects the glibc implementation. The selector is STRIPPED before
# the exec — clang has no -mlibc flag and refuses the line if it sees one.
# Autotools does not ask for a libc by flag; it looks for a program named after
# the target triple, which is what the wasm32-hwjs-linux-*-gcc symlinks beside
# this file are for. Invoked through one of those, the name decides the default.
set -euo pipefail
# PATH PROBES
#
# dirname and basename in the shell. path_dirname_v and path_basename_v answer
# in $PATH_DIRNAME and $PATH_BASENAME what "$(dirname -- "$1")" and
# "$(basename -- "$1")" hold, the trailing newlines the substitution strips
# included, and start no process. The same block is in bin/brintcc,
# libexec/config.sh, libexec/brintcc-glibc and libexec/brintld.
path_dirname_v() {
  local _pd="$1"
  _pd="${_pd%"${_pd##*[!/]}"}"
  if [[ -z "$_pd" ]]; then
    if [[ -n "$1" ]]; then PATH_DIRNAME=/; else PATH_DIRNAME=.; fi
  elif [[ "$_pd" != */* ]]; then
    PATH_DIRNAME=.
  else
    _pd="${_pd%/*}"
    _pd="${_pd%"${_pd##*[!/]}"}"
    PATH_DIRNAME="${_pd:-/}"
  fi
  PATH_DIRNAME="${PATH_DIRNAME%"${PATH_DIRNAME##*[!$'\n']}"}"
}
path_basename_v() {
  local _pb="$1"
  _pb="${_pb%"${_pb##*[!/]}"}"
  if [[ -n "$_pb" ]]; then
    PATH_BASENAME="${_pb##*/}"
  elif [[ -n "$1" ]]; then
    PATH_BASENAME=/
  else
    PATH_BASENAME=
  fi
  PATH_BASENAME="${PATH_BASENAME%"${PATH_BASENAME##*[!$'\n']}"}"
}
# End of the path probes.

# readlink -f, not dirname alone: these front doors are meant to be symlinked
# into a prefix on PATH, and a symlink's dirname is the prefix, not this repo.
path_dirname_v "$(readlink -f "${BASH_SOURCE[0]}")"
source "$PATH_DIRNAME/../libexec/config.sh"

brintium_require llvm sysroot
brintium_select_libc "$@"

case "$BRINTIUM_LIBC" in
  glibc)
    # The glibc arm compiles against the kernel UAPI headers unconditionally
    # (-isystem, on every line), so an absent pointer is a refusal here rather
    # than an -isystem of a directory that does not exist and a header error
    # a thousand lines into a build.
    brintium_require kernel-headers
    exec "$BRINTIUM/libexec/brintcc-glibc" "${BRINTIUM_ARGV[@]}" ;;
  musl)
    exec "$BRINTIUM/libexec/brintcc-musl" "${BRINTIUM_ARGV[@]}" ;;
esac