#!/usr/bin/env bash
# brintconfigure — run a package's configure script against this toolchain.
#
# WHY THIS EXISTS. A configure run needs WASMLD_HWJS_CONFTEST=1 and the build
# that follows it must NOT have it. That knob fast-links autoconf's probes with
# plain wasm-ld, skipping the whole-program merge and the pass: behaviour-
# equivalent for a probe whose only question is "did this link", and the
# difference between a configure that finishes and one that spends ~30 seconds
# per probe running LTO over every pulled bitcode member of a static archive.
# Left set through `make`, the same knob builds every real object in the package
# on the arm that skips the pass.
#
# Until now that was a variable a human set by hand and had to remember to
# unset. Here it is scoped to the process this script execs, which is the only
# scope in which it is ever correct — and bin/brintmake refuses outright if it
# finds the knob still set, so forgetting is loud instead of silent.
#
# Usage:
#   brintconfigure [--libc=musl|glibc] [path/to/configure] [configure args...]
#
# With no path, ./configure in the current directory.
set -euo pipefail
# 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.
source "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")/../libexec/config.sh"

LIBC=''
if [ $# -gt 0 ]; then
  case "$1" in
    --libc=*) LIBC="$(brintium_parse_libc_opt "$1")"; shift ;;
  esac
fi

# A leading argument that names an existing file is the configure script
# (out-of-tree builds run ../src/configure); anything else is configure's own.
CONFIGURE='./configure'
if [ $# -gt 0 ] && [ -f "$1" ]; then
  CONFIGURE="$1"; shift
fi

[ -f "$CONFIGURE" ] || brintium_fatal \
  "no configure script at '$CONFIGURE' (from $PWD). Run this from the package's build directory, or pass the script's path as the first argument. Refusing rather than running make or guessing at autogen.sh: which one a package wants is the package's decision, not this script's."
[ -x "$CONFIGURE" ] || brintium_fatal \
  "'$CONFIGURE' is not executable. A configure script arrives executable; one that is not has been copied or checked out wrong, and running it through a shell would paper over that. chmod +x it if you know it is intact."

brintium_require llvm sysroot
if [ "$LIBC" = glibc ]; then brintium_require kernel-headers; fi
brintium_export_build_tools "$LIBC"

# Scoped by the exec: this assignment reaches the configure process and dies
# with it. No caller has to remember to unset it.
export WASMLD_HWJS_CONFTEST=1

echo "brintium: configuring with CC=$CC (conftest fast-link ON for this run only)" >&2
exec "$CONFIGURE" "$@"