Cache library deps on Windows

Besides the immediate performance improvement, reducing
the frequency of downloads should make spurious
failures (network, rate-limiting...) less bothersome.

.github/scripts/get_win_deps.ps1

@@ -1,18 +0,0 @@
-function getlibrary ([string] $URI, [string] $filename, [string] $hash, [string] $destdir) {
-	$wc = New-Object Net.WebClient
-	[string] $downloadhash = $null
-	try {
-		$wc.DownloadFile($URI, $filename)
-		$downloadhash = $(Get-FileHash $filename -Algorithm SHA256).Hash
-	} catch {
-		Write-Host "${filename}: failed to download"
-		exit 1
-	}
-	if ($hash -ne $downloadhash) {
-		Write-Host "${filename}: SHA256 mismatch ($downloadhash)"
-		exit 1
-	}
-	Expand-Archive -DestinationPath $destdir $filename
-}
-
-getlibrary 'https://github.com/lexxmark/winflexbison/releases/download/v2.5.25/win_flex_bison-2.5.25.zip' 'winflexbison.zip' '8d324b62be33604b2c45ad1dd34ab93d722534448f55a16ca7292de32b6ac135' bison

.github/scripts/install_deps.sh

@@ -7,7 +7,7 @@ case "${1%-*}" in
 		sudo apt-get -qq update
 		sudo apt-get install -yq bison libpng-dev pkg-config
 		;;
-		macos)
+	macos)
 		# macOS bundles GNU Make 3.81, which doesn't support synced output.
 		# We leave it as the default in `PATH`, to test that our Makefile works with it.
 		# However, CMake automatically uses Homebrew's `gmake`, so our CI has synced output.
@@ -20,11 +20,17 @@ case "${1%-*}" in
 	freebsd)
 		pkg install -y bash bison cmake git png
 		;;
+	windows)
+		choco install -y winflexbison3
+		# The below expects the base name, not the Windows-specific name.
+		bison() { win_bison "$@"; } # An alias doesn't work, so we use a function instead.
+		;;
 	*)
 		echo "WARNING: Cannot install deps for OS '$1'"
 		;;
 esac
 
+echo "PATH=($PATH)" | sed 's/:/\n      /g'
 bison --version
 make --version
 cmake --version

.github/workflows/create-release-artifacts.yml

@@ -14,6 +14,10 @@ env:
   CMAKE_BUILD_TYPE: Release # `cmake -S` now implies `-DCMAKE_BUILD_TYPE=Release`.
   CMAKE_CONFIG_TYPE: Release # `cmake --build` now implies `--config Release`.
 
+  # We instruct CMake to download and build third-party projects in the same place as in `testing.yml`
+  # for the sources cache to remain valid.
+  DEPS_ROOT_DIR: ~/_deps # Note that this needs to be used in a position where Bash will trigger tilde expansion!
+
 jobs:
   windows:
     runs-on: windows-2022
@@ -35,17 +39,21 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v4
       - name: Install deps
-        run: .github/scripts/get_win_deps.ps1
+        run: .github/scripts/install_deps.sh windows
+      - name: Cache library deps
+        uses: actions/cache@v5
+        with:
+          path: ${{ env.DEPS_ROOT_DIR }}/*-tmp/
+          key: dep-srcs-${{ hashFiles('cmake/deps.cmake') }}
+          enableCrossOsArchive: true
       - name: Build Windows binaries
         shell: bash
-        # We instruct CMake to download and build third-party projects outside of our source tree,
-        # otherwise they can trigger `-Werror=dev` (from the `develop` preset).
         run: |
-          cmake -S . -B build --preset msvc${{ matrix.bits }} -DFETCHCONTENT_BASE_DIR="$TEMP/cmake-deps" -DBISON_EXECUTABLE=bison/win_bison.exe
+          cmake -S . -B build --preset msvc${{ matrix.bits }} -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}"
           cmake --build build
-          cmake --install build --config Release --prefix install_dir --verbose
       - name: Package binaries
         run: |
+          cmake --install build --config Release --prefix install_dir --verbose
           Compress-Archive -LiteralPath @("install_dir/bin/rgbasm.exe", "install_dir/bin/rgblink.exe", "install_dir/bin/rgbfix.exe", "install_dir/bin/rgbgfx.exe", "install_dir/bin/z.dll", "install_dir/bin/libpng16.dll") "rgbds-win${{ matrix.bits }}.zip"
       - name: Upload Windows binaries
         uses: actions/upload-artifact@v4

.github/workflows/testing.yml

@@ -12,6 +12,10 @@ env:
   CMAKE_INSTALL_PARALLEL_LEVEL: 4 # `cmake --install` now implies `--parallel 4`.
   CMAKE_CONFIG_TYPE: Debug # `cmake --build` now implies `--config Debug`.
 
+  # We instruct CMake to download and build third-party projects outside of our source tree,
+  # otherwise they can trigger `-Werror=dev` (from the `develop` preset).
+  DEPS_ROOT_DIR: ~/_deps # Note that this needs to be used in a position where Bash will trigger tilde expansion!
+
 jobs:
   unix:
     strategy:
@@ -20,9 +24,7 @@ jobs:
         cxx: [g++, clang++]
         buildsys: [make, cmake]
         exclude:
-          # Don't use `g++` on macOS; it's just an alias to `clang++`.
+          - { os: macos-14, cxx: g++ } # Don't use `g++` on macOS; it's just an alias to `clang++`.
-          - os: macos-14
-            cxx: g++
       fail-fast: false
     runs-on: ${{ matrix.os }}
     steps:
@@ -67,7 +69,7 @@ jobs:
           tee -a <<<"hash=${hash%-}" $GITHUB_OUTPUT
       - name: Check test dependency repositories cache
         id: test-deps-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ fromJSON(steps.test-deps-cache-params.outputs.paths) }}
           key: ${{ matrix.os }}-${{ steps.test-deps-cache-params.outputs.hash }}
@@ -124,7 +126,7 @@ jobs:
           tee -a <<<"hash=${hash%-}" $GITHUB_OUTPUT
       - name: Check test dependency repositories cache
         id: test-deps-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ fromJSON(steps.test-deps-cache-params.outputs.paths) }}
           key: ${{ matrix.os }}-${{ steps.test-deps-cache-params.outputs.hash }}
@@ -158,18 +160,23 @@ jobs:
       - name: Checkout repo
         uses: actions/checkout@v4
       - name: Install deps
-        run: .github/scripts/get_win_deps.ps1
+        run: |
+          bash .github/scripts/install_deps.sh ${{ matrix.os }}
+      - name: Cache library deps
+        uses: actions/cache@v5
+        with:
+          path: ${{ env.DEPS_ROOT_DIR }}/*-tmp/
+          key: dep-srcs-${{ hashFiles('cmake/deps.cmake') }}
+          enableCrossOsArchive: true
       - name: Build Windows binaries
         shell: bash
-        # We instruct CMake to download and build third-party projects outside of our source tree,
-        # otherwise they can trigger `-Werror=dev` (from the `develop` preset).
         run: | # ASan seems to be broken on Windows, so we disable it.
-          cmake -S . -B build --preset develop-msvc${{ matrix.bits }} -DFETCHCONTENT_BASE_DIR="$TEMP/cmake-deps" -DBISON_EXECUTABLE=bison/win_bison.exe -DSANITIZERS=OFF
+          cmake -S . -B build --preset develop-msvc${{ matrix.bits }} -DFETCHCONTENT_BASE_DIR="${{ env.DEPS_ROOT_DIR }}" -DSANITIZERS=OFF
           cmake --build build
-          cmake --install build --config Debug --prefix install_dir --verbose
       - name: Package binaries
         shell: bash
         run: |
+          cmake --install build --config Debug --prefix install_dir --verbose
           mkdir bins
           cp -v install_dir/bin/{rgb*.exe,*.dll} bins
       - name: Upload Windows binaries
@@ -187,7 +194,7 @@ jobs:
           tee -a <<<"hash=${hash%-}" $GITHUB_OUTPUT
       - name: Check test dependency repositories cache
         id: test-deps-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ fromJSON(steps.test-deps-cache-params.outputs.paths) }}
           key: ${{ matrix.os }}-${{ matrix.bits }}-${{ steps.test-deps-cache-params.outputs.hash }}
@@ -296,7 +303,7 @@ jobs:
           tee -a <<<"hash=${hash%-}" $GITHUB_OUTPUT
       - name: Check test dependency repositories cache
         id: test-deps-cache
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: ${{ fromJSON(steps.test-deps-cache-params.outputs.paths) }}
           key: mingw-${{ matrix.bits }}-${{ steps.test-deps-cache-params.outputs.hash }}

ARCHITECTURE.md

@@ -28,6 +28,8 @@ rgbds/
 │   │   └── ...
 │   └── workflows/
 │       └── ...
+├── cmake/
+│   └── ...
 ├── contrib/
 │   ├── bash_compl/
 │   ├── zsh_compl/
@@ -70,6 +72,8 @@ rgbds/
     Scripts used by GitHub Actions workflow files.
   * **`workflows/`:**  
     GitHub Actions CI workflow description files. Used for automated testing, deployment, etc.
+- **`cmake/`**:  
+  Files relevant to our CMake build system that are not required to be somewhere else (e.g. `CMakePresets.json` *has* to be at the root).
 - **`contrib/`:**  
   Scripts and other resources which may be useful to RGBDS users and developers.
   * **`bash_compl/`:**  
@@ -108,7 +112,7 @@ rgbds/
   Configuration for C++ static analysis with [`clang-tidy`](https://clang.llvm.org/extra/clang-tidy/) (for which we define the shortcut `make tidy`).
 - **`CMakeLists.txt`:**  
   Defines how to build RGBDS with CMake.
-- **`CMakePresets.json`:**
+- **`CMakePresets.json`:**  
   Defines some [presets](https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html) useful for working with our CMake.
 - **`compile_flags.txt`:**  
   Compiler flags for `clang-tidy`.

CMakeLists.txt

@@ -140,26 +140,13 @@ endif()
 ## Dependencies.
 
 include(FetchContent)
-FetchContent_Declare(PNG
+include(cmake/deps.cmake)
-                     URL https://download.sourceforge.net/libpng/libpng-1.6.55.tar.xz
+
-                     URL_HASH SHA256=d925722864837ad5ae2a82070d4b2e0603dc72af44bd457c3962298258b8e82d
-                     FIND_PACKAGE_ARGS 1.5.4)
-FetchContent_Declare(ZLIB
-                     URL https://www.zlib.net/zlib-1.3.2.tar.xz
-                     URL_HASH SHA256=d7a0654783a4da529d1bb793b7ad9c3318020af77667bcae35f95d0e42a792f3
-# libpng documents requiring "zlib 1.0.4 or later (1.2.13 or later recommended for performance and security reasons)".
-# We thus enforce 1.0.4, but note that the libpng source code mentions that "it may work with versions as old as zlib 0.95".
-                     FIND_PACKAGE_ARGS 1.0.4)
-set(ZLIB_BUILD_SHARED ON CACHE INTERNAL "")
-set(ZLIB_BUILD_STATIC OFF CACHE INTERNAL "")
 FetchContent_MakeAvailable(ZLIB)
 if(NOT DEFINED ZLIB_INCLUDE_DIRS)
   set(ZLIB_INCLUDE_DIRS "${zlib_BINARY_DIR};${zlib_SOURCE_DIR}") # libpng's `genout` script relies on this variable to be set.
 endif()
-set(PNG_TESTS OFF CACHE INTERNAL "") # We do not care for these two (and they can even cause compile errors!)
+
-set(PNG_TOOLS OFF CACHE INTERNAL "")
-set(PNG_SHARED ON CACHE INTERNAL "") # Upstream seems to favour the dynamic lib over the static one?
-set(PNG_STATIC OFF CACHE INTERNAL "")
 FetchContent_MakeAvailable(PNG)
 if(NOT TARGET PNG::PNG)
   if(PNG_SHARED)

cmake/deps.cmake

@@ -0,0 +1,23 @@
+# This file declares the dependencies we use, using `FetchContent`.
+# https://cmake.org/cmake.help/latest/guide/using-dependencies/index.html#downloading-and-building-from-source-with-fetchcontent
+# These are kept in a separate file so that it can be hashed as a key for our CI's `actions/cache`.
+
+FetchContent_Declare(PNG
+                     URL https://download.sourceforge.net/libpng/libpng-1.6.55.tar.xz
+                     URL_HASH SHA256=d925722864837ad5ae2a82070d4b2e0603dc72af44bd457c3962298258b8e82d
+                     FIND_PACKAGE_ARGS 1.5.4)
+
+set(PNG_TESTS OFF CACHE INTERNAL "") # We do not care for these two (and they can even cause compile errors!)
+set(PNG_TOOLS OFF CACHE INTERNAL "")
+set(PNG_SHARED ON CACHE INTERNAL "") # Upstream seems to favour the dynamic lib over the static one?
+set(PNG_STATIC OFF CACHE INTERNAL "")
+
+FetchContent_Declare(ZLIB
+                     URL https://www.zlib.net/zlib-1.3.2.tar.xz
+                     URL_HASH SHA256=d7a0654783a4da529d1bb793b7ad9c3318020af77667bcae35f95d0e42a792f3
+# libpng documents requiring "zlib 1.0.4 or later (1.2.13 or later recommended for performance and security reasons)".
+# We thus enforce 1.0.4, but note that the libpng source code mentions that "it may work with versions as old as zlib 0.95".
+                     FIND_PACKAGE_ARGS 1.0.4)
+
+set(ZLIB_BUILD_SHARED ON CACHE INTERNAL "")
+set(ZLIB_BUILD_STATIC OFF CACHE INTERNAL "")