Rename install_deps.sh to install-deps.sh for consistency

.github/scripts/install-deps.sh

@@ -0,0 +1,101 @@
+#!/bin/sh
+# This script requires `sh` instead of `bash` because the latter is not always installed on FreeBSD.
+set -eu
+
+# Python and the Pillow library are dependencies for libbet, a repo built by our external tests.
+# Other dependencies are for building rgbds itself.
+
+case $# in
+	1) OS="$1"; TOOLSET=     ;;
+	2) OS="$1"; TOOLSET="$2" ;;
+	*) echo >&2 "Usage: $0 <os> [<toolset>]" && exit 1 ;;
+esac
+
+case "${OS%%-*}" in
+	ubuntu|debian)
+		pkgs=bison
+		case "$TOOLSET" in
+			mingw32)
+				pkgs="$pkgs libz-mingw-w64-dev g++-mingw-w64-i686-win32"
+				TOOLSET=
+			;;
+			mingw64)
+				pkgs="$pkgs libz-mingw-w64-dev g++-mingw-w64-x86-64-win32"
+				TOOLSET=
+			;;
+			g++-10 | lcov)
+				pkgs="$pkgs libpng-dev pkgconf python3-pil $TOOLSET"
+				TOOLSET=
+			;;
+			'' | g++ | clang++)
+				pkgs="$pkgs libpng-dev pkgconf python3-pil"
+				TOOLSET=
+			;;
+		esac
+		sudo apt-get update -qq
+		# shellcheck disable=SC2086 # (This word splitting is intentional.)
+		sudo apt-get install -yq $pkgs
+		;;
+	macos)
+		pkgs="bison make pillow"
+		case "$TOOLSET" in
+			lld)
+				pkgs="$pkgs $TOOLSET"
+				TOOLSET=
+			;;
+			clang++)
+				TOOLSET=
+			;;
+		esac
+		# macOS bundles GNU Make 3.81, which doesn't support synced output.
+		# We leave it as the default in `PATH`, to test that our Makefile works with it.
+		# However, CMake automatically uses Homebrew's `gmake`, so our CI has synced output.
+		# shellcheck disable=SC2086 # (This word splitting is intentional.)
+		brew install $pkgs
+		# Export `bison` to allow using the version we install from Homebrew,
+		# instead of the outdated one preinstalled on macOS (which doesn't even support `-Wall`...).
+		export PATH="$(brew --prefix)/opt/bison/bin:$PATH"
+		printf 'PATH=%s\n' "$PATH" >>"$GITHUB_ENV" # Make it available to later CI steps too.
+		;;
+	freebsd)
+		pkg install -y bash bison cmake git png
+		;;
+	windows)
+		# GitHub Actions' hosted runners ship CMake 3.x, but versions prior to 4.0.0 ignore `CPACK_PACKAGE_FILE_NAME`.
+		choco install -y winflexbison3 cmake
+		# The version-printing code below will invoke `bison`, not the Windows-specific name `win_bison`.
+		bison() { win_bison "$@"; } # An alias doesn't work, so we use a function instead.
+		py -3 -m pip install pillow
+		;;
+	windowsmingw)
+		py -3 -m pip install pillow
+		;;
+	*)
+		echo "Cannot install deps for OS '$1'"
+		exit 1
+		;;
+esac
+
+if [ -n "$TOOLSET" ]; then
+	printf >&2 'Unknown toolset `%s` for OS `%s`\n' "$TOOLSET" "$OS"
+	exit 1
+fi
+
+# We do not build RGBDS *in* MinGW on Windows, so skip printing build tool info.
+if [ "$OS" = "windowsmingw" ]; then
+	exit 0
+fi
+
+# Print some system info, for easier debugging.
+# https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-commands#grouping-log-lines
+
+echo ::group::PATH
+echo "PATH=($PATH)" | sed 's/:/\n      /g'
+echo ::endgroup::
+
+for prog in bison make cmake; do
+	printf '::group::' # No line terminator, the next command's first line becomes the group's title.
+	$prog --version
+	type $prog
+	echo ::endgroup::
+done