Add lock-files script

Add a script to create and update the minimal and recent lock files. On
the way create a `stdlib.sh` script to reduce code duplication and also
a `template.sh` to make writing the next script easier.

Note I could not get `flag_verbose` to work with sourcing the `stdlib`
script without exporting a global variable which I didn't do so as not
to pollute the environment.

If this merges we can remove the `update-lock-files.sh` script from
other repos and use this new script.

lock-files.sh

@@ -0,0 +1,203 @@
+#!/usr/bin/env bash
+#
+# Create and manipulate the lock files.
+#
+# We use lock files `Cargo-recent.lock` and `Cargo-minimal.lock` to pin
+# dependencies and check specific versions in CI.
+#
+# Shellcheck can't search dynamic paths
+# shellcheck source=/dev/null
+
+set -u
+
+main() {
+    set_globals
+    assert_cmds
+    handle_command_line_args "$@"
+}
+
+set_globals() {
+    # The directory of this script.
+    script_dir=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+
+    # Used below by `say`.
+    script=${0##*/}
+
+    # Used below by `verbose_say`.
+    flag_verbose=false
+
+    # Sourcing this file requires `flag_verbose` to be set.
+    . "$script_dir/stdlib.sh"
+
+    # Environment sanity checks
+    assert_nz "$HOME" "\$HOME is undefined"
+    assert_nz "$0" "\$0 is undefined"
+
+    # Make all cargo invocations verbose.
+    export CARGO_TERM_VERBOSE=true
+
+    recent="Cargo-recent.lock"
+    minimal="Cargo-minimal.lock"
+
+    msrv="1.63.0"
+}
+
+handle_command_line_args() {
+    local _no_args=false
+    local _help=false
+    local _create=false
+    local _msrv=""
+    local _update=false
+
+    if [ $# -eq 0 ]; then
+        _no_args=true
+    fi
+
+    local _arg
+    for _arg in "$@"; do
+        case "${_arg%%=*}" in
+            create )
+                _create=true
+                ;;
+
+            update )
+                _update=true
+                ;;
+
+            --msrv )
+                if is_value_arg "$_arg" "--msrv"; then
+                    _msrv="$(get_value_arg "$_arg")"
+                else
+                    say_err "the --msrv option requires a toolchain version argument"
+                    print_help
+                    exit 1
+                fi
+
+                ;;
+
+            -h | --help )
+                _help=true
+                ;;
+
+            --verbose)
+                # verbose is a global flag
+                flag_verbose=true
+                ;;
+
+            *)
+                echo "Unknown argument '$_arg', displaying usage:"
+                echo "${_arg%%=*}"
+                _help=true
+                ;;
+
+        esac
+
+    done
+
+    if [ "$_create" = true ]; then
+        if [ -z "$_msrv" ]; then
+            msrv="$_msrv"
+        fi
+
+        verbose_say "Creating lock files, MSRV: $msrv"
+        create
+    fi
+
+    if [ "$_update" = true ]; then
+        update
+        verbose_say "Your git index will now be dirty if lock file update is required"
+    fi
+
+    if [ "$_help" = true ]; then
+        print_help
+        exit 0
+    fi
+
+    if [ "$_no_args" = true ]; then
+        verbose_say "no option supplied, defaulting to update"
+        update
+    fi
+}
+
+is_value_arg() {
+    local _arg="$1"
+    local _name="$2"
+
+    echo "$_arg" | grep -q -- "$_name="
+    return $?
+}
+
+get_value_arg() {
+    local _arg="$1"
+
+    echo "$_arg" | cut -f2 -d=
+}
+
+# Creates the minimal and recent lock files.
+#
+# If this function fails you may want to be lazy and just duplicate `Cargo.lock`
+# as the minimal and recent lock files.
+create() {
+    # Attempt to create a minimal lock file.
+    rm --force Cargo.lock > /dev/null
+    cargo +nightly check --all-features -Z minimal-versions
+    need_ok "failed to build with -Z minimial-versions, you might have to use a recent lock file for minimal"
+
+    # We only want to create the minimal lock file if we can build with current MSRV.
+    cargo "+$msrv" --locked check --all-features
+    need_ok "failed to build with minimal lock file and MSRV $_msrv"
+    cp Cargo.lock "$minimal"
+
+    # If that worked we can create a recent lock file.
+    cargo update
+    cp Cargo.lock "$recent"
+}
+
+# Updates the minimal and recent lock files.
+update() {
+    for file in "$minimal" "$recent"; do
+        cp --force "$file" Cargo.lock
+        cargo check
+        cp --force Cargo.lock "$file"
+    done
+}
+
+assert_cmds() {
+    need_cmd cat
+    need_cmd cp
+    need_cmd cargo
+}
+
+say() {
+    echo "$script: $1"
+}
+
+say_err() {
+    say "$1" >&2
+}
+
+verbose_say() {
+    if [ "$flag_verbose" = true ]; then
+	say "$1"
+    fi
+}
+
+print_help() {
+    cat <<EOF
+Usage: $script [OPITON] [COMMAND]
+
+COMMAND:
+
+        create                      Create new minimal and recent lock files.
+        update                      Update the minimal and recent lock files (default).
+
+OPTION:
+
+        --msrv=version              The Rust toolchain version to use as MSRV. 
+        --verbose                   Enable verbose output.
+        --help, -h                  Display this help information.
+EOF
+}
+
+# Main script
+main "$@"

stdlib.sh

@@ -0,0 +1,56 @@
+# rust-bitcoin stdlib for Bash (of sorts).
+#
+# Much of the code here was originally stolen from the old `rustup.sh` script
+# https://github.com/rust-lang-deprecated/rustup.sh/blob/master/rustup.sh
+#
+# If you have never read the comments at the top of that file, consider it, they are gold.
+#
+# No shebang, this file should not be executed.
+# shellcheck disable=SC2148
+#
+# Disable because `flag_verbose` is referenced but not assigned, however we check it is non-zero.
+# shellcheck disable=SC2154
+
+set -u
+
+err() {
+    echo "$1" >&2
+    exit 1
+}
+
+need_cmd() {
+    if ! command -v "$1" > /dev/null 2>&1
+    then err "need '$1' (command not found)"
+    fi
+}
+
+need_ok() {
+    if [ $? != 0 ]; then err "$1"; fi
+}
+
+assert_nz() {
+    if [ -z "$1" ]; then err "assert_nz $2"; fi
+}
+
+# Run a command that should never fail. If the command fails execution
+# will immediately terminate with an error showing the failing
+# command.
+ensure() {
+    "$@"
+    need_ok "command failed: $*"
+}
+
+# This is just for indicating that commands' results are being
+# intentionally ignored. Usually, because it's being executed
+# as part of error handling.
+ignore() {
+    run "$@"
+}
+
+# Assert that we have a nightly Rust toolchain installed.
+need_nightly() {
+    cargo_ver=$(cargo --version)
+    if echo "$cargo_ver" | grep -q -v nightly; then
+        err "Need a nightly compiler; have $(cargo --version) (use RUSTUP_TOOLCHAIN=+nightly cmd)"
+    fi
+}

template.sh

@@ -0,0 +1,105 @@
+#!/usr/bin/env bash
+#
+# Bash shell script template.
+#
+# Shellcheck can't search dynamic paths
+# shellcheck source=/dev/null
+
+# Note we don't use `set -x` because error handling is done manually.
+# If you use pipes you may want to use `set -euxo pipefail` instead.
+set -u
+
+main() {
+    set_globals
+    assert_cmds
+    handle_command_line_args "$@"
+}
+
+set_globals() {
+    # The git repository where script is run from.
+    # repo_dir=$(git rev-parse --show-toplevel)
+
+    # The directory of this script.
+    script_dir=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+
+    # Used below by `say`.
+    script=${0##*/}
+
+    # Used below by `verbose_say`.
+    flag_verbose=false
+
+    # Sourcing this file requires `flag_verbose` to be set.
+    . "$script_dir/stdlib.sh"
+
+    # Environment sanity checks
+    assert_nz "$HOME" "\$HOME is undefined"
+    assert_nz "$0" "\$0 is undefined"
+
+    # Make all cargo invocations verbose.
+    export CARGO_TERM_VERBOSE=true
+}
+
+handle_command_line_args() {
+    local _help=false
+
+    local _arg
+    for _arg in "$@"; do
+        case "${_arg%%=*}" in
+            -h | --help )
+                _help=true
+                ;;
+
+            --verbose)
+                # verbose is a global flag
+                flag_verbose=true
+                ;;
+
+            *)
+                echo "Unknown argument '$_arg', displaying usage:"
+                echo "${_arg%%=*}"
+                _help=true
+                ;;
+
+        esac
+
+    done
+
+    if [ "$_help" = true ]; then
+        print_help
+        exit 0
+    fi
+
+    verbose_say "Enabled verbose output"
+}
+
+assert_cmds() {
+    need_cmd cat
+}
+
+say() {
+    echo "$script: $1"
+}
+
+say_err() {
+    say "$1" >&2
+}
+
+verbose_say() {
+    if [ "$flag_verbose" = true ]; then
+	say "$1"
+    fi
+}
+
+print_help() {
+    cat <<EOF
+Usage: $script [--verbose]
+
+Options:
+
+        --verbose,                        Enable verbose output
+        --help, -h                        Display usage information
+EOF
+}
+
+# Main script
+main "$@"