deps: Add build recipe for GIF

src/cmake/build_gif.cmake

@@ -0,0 +1,140 @@
+# Copyright Contributors to the OpenImageIO project.
+# SPDX-License-Identifier: Apache-2.0
+# https://github.com/AcademySoftwareFoundation/OpenImageIO
+
+###########################################################################
+# Build GIF library locally
+#
+# This script downloads and builds the GIF library from source since GIF
+# doesn't provide a CMake-based build system like other dependencies.
+###########################################################################
+
+# Set version and source information
+set_cache(GIF_BUILD_VERSION 5.2.1 "GIFLIB version for local builds")
+set(GIF_URL "https://downloads.sourceforge.net/project/giflib/giflib-${GIF_BUILD_VERSION}.tar.gz")
+set(GIF_URL_HASH SHA256=31da5562f44c5f15d63340a09a4fd62b48c45620cd302f77a6d9acf0077879bd)
+
+# Configuration options
+set_cache(GIF_BUILD_SHARED_LIBS ${LOCAL_BUILD_SHARED_LIBS_DEFAULT}
+          DOC "Should execute a local GIF build, if necessary, build shared libraries" ADVANCED)
+
+string(MAKE_C_IDENTIFIER ${GIF_BUILD_VERSION} GIF_VERSION_IDENT)
+
+# Set up  variables 
+set(GIF_LOCAL_SOURCE_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/GIF")
+set(GIF_LOCAL_BUILD_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/GIF-build")
+set(GIF_LOCAL_INSTALL_DIR "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/dist")
+
+# Ensure necessary directories exist
+file(MAKE_DIRECTORY ${GIF_LOCAL_INSTALL_DIR}/include)
+file(MAKE_DIRECTORY ${GIF_LOCAL_INSTALL_DIR}/lib)
+
+# Download and build using ExternalProject
+# GIF uses a simple Makefile-based build system, so we skip the configure step
+include(ExternalProject)
+ExternalProject_Add(GIF_ext
+    # Source location and verification
+    URL             ${GIF_URL}
+    URL_HASH        ${GIF_URL_HASH}
+    DOWNLOAD_DIR    "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/downloads"
+    DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+
+    # Build directories
+    PREFIX          "${GIF_LOCAL_BUILD_DIR}"
+    SOURCE_DIR      "${GIF_LOCAL_SOURCE_DIR}"
+
+    # Build in source since GIF doesn't support out-of-source builds
+    BUILD_IN_SOURCE 1
+
+    # Build steps
+    CONFIGURE_COMMAND ""  # Skip configure step (no configure script)
+    BUILD_COMMAND   make -j${CMAKE_BUILD_PARALLEL_LEVEL} PREFIX=${GIF_LOCAL_INSTALL_DIR}
+    INSTALL_COMMAND make PREFIX=${GIF_LOCAL_INSTALL_DIR} install
+
+    # Apply a patch to fix the Makefile - with hash verification
+    PATCH_COMMAND   ${CMAKE_COMMAND} -E echo "Downloading patch file..." &&
+                curl -L https://sourceforge.net/p/giflib/bugs/_discuss/thread/4e811ad29b/c323/attachment/Makefile.patch -o Makefile.patch &&
+                ${CMAKE_COMMAND} -E echo "Computing patch file hash..." &&
+                ${CMAKE_COMMAND} -E md5sum Makefile.patch > patch_hash.txt &&
+                ${CMAKE_COMMAND} -E compare_files patch_hash.txt ${PROJECT_SOURCE_DIR}/cmake/patches/giflib-5.2.1-expected-hash.txt &&
+                ${CMAKE_COMMAND} -E echo "Patch file verified, applying..." &&
+                patch -p0 < Makefile.patch
+
+    # Enable logging
+    LOG_DOWNLOAD ON
+    LOG_BUILD ON
+    LOG_INSTALL ON
+)
+
+# Add custom commands to ensure header file and library are properly installed
+# This is needed because the GIF Makefile installation might be unreliable
+add_custom_command(
+    TARGET GIF_ext
+    POST_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different
+        ${GIF_LOCAL_SOURCE_DIR}/gif_lib.h
+        ${GIF_LOCAL_INSTALL_DIR}/include/
+    COMMAND ${CMAKE_COMMAND} -E copy_if_different
+        ${GIF_LOCAL_SOURCE_DIR}/libgif.a
+        ${GIF_LOCAL_INSTALL_DIR}/lib/
+)
+
+#############################################################################
+# Create a custom FindGIF.cmake module
+# 
+# The standard FindGIF.cmake module may have trouble locating the locally 
+# built library, so we provide our own module that points directly to our
+# build outputs.
+#############################################################################
+
+file(MAKE_DIRECTORY "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/cmake/modules")
+file(WRITE "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/cmake/modules/FindGIF.cmake"
+"# Custom FindGIF module for locally-built GIF
+set(GIF_FOUND TRUE)
+set(GIF_VERSION ${GIF_BUILD_VERSION})
+set(GIF_INCLUDE_DIR \"${GIF_LOCAL_INSTALL_DIR}/include\")
+set(GIF_LIBRARY \"${GIF_LOCAL_INSTALL_DIR}/lib/libgif.a\")
+set(GIF_LIBRARIES \${GIF_LIBRARY})
+set(GIF_INCLUDE_DIRS \${GIF_INCLUDE_DIR})
+
+# Create imported target for use with modern CMake
+if(NOT TARGET GIF::GIF)
+  add_library(GIF::GIF UNKNOWN IMPORTED)
+  set_target_properties(GIF::GIF PROPERTIES
+    IMPORTED_LOCATION \"\${GIF_LIBRARY}\"
+    INTERFACE_INCLUDE_DIRECTORIES \"\${GIF_INCLUDE_DIR}\"
+  )
+endif()
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(GIF
+  REQUIRED_VARS GIF_LIBRARY GIF_INCLUDE_DIR
+  VERSION_VAR GIF_VERSION
+)
+")
+
+# Add our modules directory to the CMAKE_MODULE_PATH
+list(APPEND CMAKE_MODULE_PATH "${${PROJECT_NAME}_LOCAL_DEPS_ROOT}/cmake/modules")
+
+# Create the GIF::GIF imported target in the current scope
+if(NOT TARGET GIF::GIF)
+    add_library(GIF::GIF UNKNOWN IMPORTED GLOBAL)
+    set_target_properties(GIF::GIF PROPERTIES
+        IMPORTED_LOCATION "${GIF_LOCAL_INSTALL_DIR}/lib/libgif.a"
+        INTERFACE_INCLUDE_DIRECTORIES "${GIF_LOCAL_INSTALL_DIR}/include"
+    )
+    add_dependencies(GIF::GIF GIF_ext)
+endif()
+
+# Set up variables for the find_package system
+set(GIF_ROOT ${GIF_LOCAL_INSTALL_DIR})
+
+# Signal to caller that we need to find again at the installed location
+set(GIF_REFIND TRUE)
+set(GIF_REFIND_VERSION ${GIF_BUILD_VERSION})
+set(GIF_REFIND_ARGS MODULE REQUIRED)
+
+# Handle shared library installation if requested
+if(GIF_BUILD_SHARED_LIBS)
+    install_local_dependency_libs(GIF gif)
+endif()