build: extract package dependencies and prefer local libraries

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

1 files changed, 86 insertions, 0 deletions

diff --git a/cmake/ExtractPackages.cmake b/cmake/ExtractPackages.cmake
new file mode 100644
index 0000000..7b525d7
--- /dev/null
+++ b/cmake/ExtractPackages.cmake
@@ -0,0 +1,86 @@
+# Use CMake's libarchive support, including on hosts without dpkg or pacman.
+function(cpsc_extract_archive archive destination)
+    file(MAKE_DIRECTORY "${destination}")
+    execute_process(
+        COMMAND "${CMAKE_COMMAND}" -E tar xf "${archive}"
+        WORKING_DIRECTORY "${destination}"
+        RESULT_VARIABLE result ERROR_VARIABLE error
+    )
+    if(NOT result EQUAL 0)
+        message(FATAL_ERROR "Cannot extract dependency package ${archive}: ${error}")
+    endif()
+endfunction()
+
+function(cpsc_extract_packages)
+    file(GLOB_RECURSE packages CONFIGURE_DEPENDS
+        "${CPSC_DEPS_DIR}/packages/*.deb"
+        "${CPSC_DEPS_DIR}/packages/*.pkg.tar.*"
+        "${CPSC_DEPS_DIR}/packages/*.bottle*.tar.gz"
+    )
+    list(FILTER packages EXCLUDE REGEX "\\.sig$")
+    # Homebrew exposes both a cache symlink and its downloads/ target.
+    set(archives)
+    foreach(package IN LISTS packages)
+        get_filename_component(package "${package}" REALPATH)
+        list(APPEND archives "${package}")
+    endforeach()
+    list(REMOVE_DUPLICATES archives)
+    list(SORT archives)
+
+    set(stamp "${CPSC_DEPS_DIR}/packages.sha256")
+    if(NOT archives)
+        if(EXISTS "${stamp}")
+            file(REMOVE_RECURSE "${CPSC_DEPS_ROOT}")
+            file(REMOVE "${stamp}")
+        endif()
+        return()
+    endif()
+
+    set(signature "${CPSC_DEPS_ROOT}\n")
+    foreach(archive IN LISTS archives)
+        file(SHA256 "${archive}" hash)
+        string(APPEND signature "${archive}:${hash}\n")
+    endforeach()
+    foreach(module ExtractPackages LinuxPackages WindowsPackages HomebrewPackages)
+        file(SHA256 "${CPSC_DEPS_MODULE_DIR}/${module}.cmake" hash)
+        string(APPEND signature "${module}:${hash}\n")
+    endforeach()
+    if(EXISTS "${stamp}" AND IS_DIRECTORY "${CPSC_DEPS_ROOT}")
+        file(READ "${stamp}" previous_signature)
+        if(signature STREQUAL previous_signature)
+            return()
+        endif()
+    endif()
+
+    # Rebuild the managed extraction directory when the package set changes.
+    file(REMOVE "${stamp}")
+    file(REMOVE_RECURSE "${CPSC_DEPS_ROOT}")
+    file(MAKE_DIRECTORY "${CPSC_DEPS_ROOT}")
+    foreach(archive IN LISTS archives)
+        message(STATUS "Extracting dependency package: ${archive}")
+        if(archive MATCHES "\\.deb$")
+            set(unpack "${CPSC_DEPS_DIR}/unpack")
+            file(REMOVE_RECURSE "${unpack}")
+            cpsc_extract_archive("${archive}" "${unpack}")
+            file(GLOB data "${unpack}/data.tar.*" "${unpack}/data.tar")
+            list(LENGTH data data_count)
+            if(NOT data_count EQUAL 1)
+                message(FATAL_ERROR "Dependency package ${archive} must contain one data.tar archive")
+            endif()
+            cpsc_extract_archive("${data}" "${CPSC_DEPS_ROOT}")
+            file(REMOVE_RECURSE "${unpack}")
+        elseif(archive MATCHES "\\.bottle[^/]*\\.tar\\.gz$")
+            cpsc_extract_archive("${archive}" "${CPSC_DEPS_ROOT}/Cellar")
+        else()
+            cpsc_extract_archive("${archive}" "${CPSC_DEPS_ROOT}")
+        endif()
+    endforeach()
+    if(CMAKE_HOST_APPLE)
+        cpsc_prepare_homebrew_packages()
+    elseif(CMAKE_HOST_WIN32)
+        cpsc_prepare_windows_packages()
+    else()
+        cpsc_prepare_linux_packages()
+    endif()
+    file(WRITE "${stamp}" "${signature}")
+endfunction()