Check libpng directly into third_party/

third_party/libpng/CMakeLists.txt

+# CMakeLists.txt

[msarett, 2016/06/02 16:35:33]

Just noticing that this file exists...not sure it is at all useful to us, but I
guess it's an example of how to build libpng with CMake.

+
+# Copyright (C) 2007,2009-2016 Glenn Randers-Pehrson
+# Written by Christian Ehrlicher, 2007
+# Revised by Roger Lowman, 2009-2010
+# Revised by Clifford Yapp, 2011-2012
+# Revised by Roger Leigh, 2016
+
+# This code is released under the libpng license.
+# For conditions of distribution and use, see the disclaimer
+# and license in png.h
+
+cmake_minimum_required(VERSION 2.8.3)
+cmake_policy(VERSION 2.8.3)
+
+# Set MacOSX @rpath usage globally.
+if (POLICY CMP0020)
+  cmake_policy(SET CMP0020 NEW)
+endif(POLICY CMP0020)
+if (POLICY CMP0042)
+  cmake_policy(SET CMP0042 NEW)
+endif(POLICY CMP0042)
+# Use new variable expansion policy.
+if (POLICY CMP0053)
+  cmake_policy(SET CMP0053 NEW)
+endif(POLICY CMP0053)
+if (POLICY CMP0054)
+  cmake_policy(SET CMP0054 NEW)
+endif(POLICY CMP0054)
+
+set(CMAKE_CONFIGURATION_TYPES "Release;Debug;MinSizeRel;RelWithDebInfo")
+
+project(libpng C)
+enable_testing()
+
+set(PNGLIB_MAJOR 1)
+set(PNGLIB_MINOR 6)
+set(PNGLIB_RELEASE 22)
+set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
+set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
+
+# needed packages
+find_package(ZLIB REQUIRED)
+include_directories(${ZLIB_INCLUDE_DIR})
+
+if(NOT WIN32)
+  find_library(M_LIBRARY
+    NAMES m
+    PATHS /usr/lib /usr/local/lib
+  )
+  if(NOT M_LIBRARY)
+    message(STATUS "math lib 'libm' not found; floating point support disabled")
+  endif()
+else()
+  # not needed on windows
+  set(M_LIBRARY "")
+endif()
+
+# COMMAND LINE OPTIONS
+option(PNG_SHARED "Build shared lib" ON)
+option(PNG_STATIC "Build static lib" ON)
+option(PNG_TESTS  "Build libpng tests" ON)
+
+# Many more configuration options could be added here
+option(PNG_FRAMEWORK "Build OS X framework" OFF)
+option(PNG_DEBUG     "Build with debug output" OFF)
+option(PNGARG        "Disable ANSI-C prototypes" OFF)
+
+set(PNG_PREFIX "" CACHE STRING "Prefix to add to the API function names")
+set(DFA_XTRA "" CACHE FILEPATH "File containing extra configuration settings")
+
+# SET LIBNAME
+set(PNG_LIB_NAME png${PNGLIB_MAJOR}${PNGLIB_MINOR})
+
+# to distinguish between debug and release lib
+set(CMAKE_DEBUG_POSTFIX "d")
+
+include(CheckCSourceCompiles)
+option(ld-version-script "Enable linker version script" ON)
+if(ld-version-script AND NOT APPLE)
+  # Check if LD supports linker scripts.
+  file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "VERS_1 {
+        global: sym;
+        local: *;
+};
+
+VERS_2 {
+        global: sym2;
+                main;
+} VERS_1;
+")
+  set(CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/conftest.map'")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_LD_VERSION_SCRIPT)
+  if(NOT HAVE_LD_VERSION_SCRIPT)
+    set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE} "-Wl,-M -Wl,${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+  check_c_source_compiles("void sym(void) {}
+void sym2(void) {}
+int main(void) {return 0;}
+" HAVE_SOLARIS_LD_VERSION_SCRIPT)
+  endif()
+  set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
+  file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
+endif()
+
+# Find symbol prefix.  Likely obsolete and unnecessary with recent
+# toolchains (it's not done in many other projects).
+function(symbol_prefix)
+  set(SYMBOL_PREFIX)
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E" "-"
+                  INPUT_FILE /dev/null
+                  OUTPUT_VARIABLE OUT
+                  RESULT_VARIABLE STATUS)
+
+  if(CPP_FAIL)
+    message(WARNING "Failed to run the C preprocessor")
+  endif()
+
+  string(REPLACE "\n" ";" OUT "${OUT}")
+  foreach(line ${OUT})
+    string(REGEX MATCH "^PREFIX=" found_match "${line}")
+    if(found_match)
+      STRING(REGEX REPLACE "^PREFIX=(.*\)" "\\1" prefix "${line}")
+      string(REGEX MATCH "__USER_LABEL_PREFIX__" found_match "${prefix}")
+      if(found_match)
+        STRING(REGEX REPLACE "(.*)__USER_LABEL_PREFIX__(.*)" "\\1\\2" prefix "${prefix}")
+      endif()
+      set(SYMBOL_PREFIX "${prefix}")
+    endif()
+  endforeach()
+
+    message(STATUS "Symbol prefix: ${SYMBOL_PREFIX}")
+    set(SYMBOL_PREFIX "${SYMBOL_PREFIX}" PARENT_SCOPE)
+endfunction()
+
+if(UNIX)
+  symbol_prefix()
+endif()
+
+find_program(AWK NAMES gawk awk)
+
+include_directories(${CMAKE_CURRENT_BINARY_DIR})
+
+if(NOT AWK)
+  # No awk available to generate sources; use pre-built pnglibconf.h
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
+                 ${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
+  add_custom_target(genfiles) # Dummy
+else()
+  include(CMakeParseArguments)
+  # Generate .chk from .out with awk
+  # generate_chk(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_chk)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GC "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GC_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GC_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GC_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GC_INPUT}"
+                               "-DOUTPUT=${_GC_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake"
+                       DEPENDS "${_GC_INPUT}" ${_GC_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate .out from .c with awk
+  # generate_out(INPUT inputfile OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_out)
+    set(options)
+    set(oneValueArgs INPUT OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GO_INPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires input.")
+    endif()
+    if (NOT _GO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_out requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${_GO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DINPUT=${_GO_INPUT}"
+                               "-DOUTPUT=${_GO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake"
+                       DEPENDS "${_GO_INPUT}" ${_GO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Generate specific source file with awk
+  # generate_source(OUTPUT outputfile [DEPENDS dep1 [dep2...]])
+  function(generate_source)
+    set(options)
+    set(oneValueArgs OUTPUT)
+    set(multiValueArgs DEPENDS)
+    cmake_parse_arguments(_GSO "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+    if (NOT _GSO_OUTPUT)
+      message(FATAL_ERROR "Invalid arguments.  generate_source requires output.")
+    endif()
+
+    add_custom_command(OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${_GSO_OUTPUT}"
+                       COMMAND "${CMAKE_COMMAND}"
+                               "-DOUTPUT=${_GSO_OUTPUT}"
+                               -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                       DEPENDS ${_GSO_DEPENDS}
+                       WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+  endfunction()
+
+  # Copy file
+  function(generate_copy source destination)
+    add_custom_command(OUTPUT "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E remove "${destination}"
+                       COMMAND "${CMAKE_COMMAND}" -E copy "${source}"
+                                                          "${destination}"
+                       DEPENDS "${source}")
+  endfunction()
+
+  # Generate scripts/pnglibconf.h
+  generate_source(OUTPUT "scripts/pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  # Generate pnglibconf.c
+  generate_source(OUTPUT "pnglibconf.c"
+                  DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.dfa"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/scripts/options.awk"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h")
+
+  if(PNG_PREFIX)
+    set(PNGLIBCONF_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+        "${CMAKE_CURRENT_SOURCE_DIR}/scripts/macro.lst")
+    set(PNGPREFIX_H_EXTRA_DEPENDS
+        "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out")
+  endif()
+
+  generate_out(INPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pnglibconf.h
+  generate_source(OUTPUT "pnglibconf.h"
+                  DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+                          ${PNGLIBCONF_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/intprefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/prefix.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out")
+
+  # Generate pngprefix.h
+  generate_source(OUTPUT "pngprefix.h"
+                  DEPENDS ${PNGPREFIX_H_EXTRA_DEPENDS})
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/sym.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+               DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt")
+
+  generate_out(INPUT "${CMAKE_CURRENT_SOURCE_DIR}/scripts/vers.c"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/png.h"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/pngconf.h"
+                       "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h")
+
+  generate_chk(INPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+               OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+               DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/scripts/checksym.awk"
+                       "${CMAKE_CURRENT_SOURCE_DIR}/scripts/symbols.def")
+
+  add_custom_target(symbol-check DEPENDS
+                    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk")
+
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+  generate_copy("${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out"
+                "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+
+  add_custom_target(genvers DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers")
+  add_custom_target(gensym DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym")
+
+  add_custom_target("genprebuilt"
+                    COMMAND "${CMAKE_COMMAND}"
+                            "-DOUTPUT=scripts/pnglibconf.h.prebuilt"
+                            -P "${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake"
+                    WORKING_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}")
+
+  # A single target handles generation of all generated files.  If
+  # they are dependend upon separately by multiple targets, this
+  # confuses parallel make (it would require a separate top-level
+  # target for each file to track the dependencies properly).
+  add_custom_target(genfiles DEPENDS
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.sym"
+    "${CMAKE_CURRENT_BINARY_DIR}/libpng.vers"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/intprefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/pnglibconf.c"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/prefix.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/sym.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
+    "${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
+endif(NOT AWK)
+
+# OUR SOURCES
+set(libpng_public_hdrs
+  png.h
+  pngconf.h
+  "${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h"
+)
+set(libpng_private_hdrs
+  pngpriv.h
+  pngdebug.h
+  pnginfo.h
+  pngstruct.h
+)
+if(AWK)
+  list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
+endif()
+set(libpng_sources
+  ${libpng_public_hdrs}
+  ${libpng_private_hdrs}
+  png.c
+  pngerror.c
+  pngget.c
+  pngmem.c
+  pngpread.c
+  pngread.c
+  pngrio.c
+  pngrtran.c
+  pngrutil.c
+  pngset.c
+  pngtrans.c
+  pngwio.c
+  pngwrite.c
+  pngwtran.c
+  pngwutil.c
+)
+set(pngtest_sources
+  pngtest.c
+)
+set(pngvalid_sources
+  contrib/libtests/pngvalid.c
+)
+set(pngstest_sources
+  contrib/libtests/pngstest.c
+)
+set(pngunknown_sources
+  contrib/libtests/pngunknown.c
+)
+set(pngimage_sources
+  contrib/libtests/pngimage.c
+)
+set(pngfix_sources
+  contrib/tools/pngfix.c
+)
+set(png_fix_itxt_sources
+  contrib/tools/png-fix-itxt.c
+)
+
+if(MSVC)
+  add_definitions(-D_CRT_SECURE_NO_DEPRECATE)
+endif(MSVC)
+
+if(PNG_DEBUG)
+  add_definitions(-DPNG_DEBUG)
+endif()
+
+# NOW BUILD OUR TARGET
+include_directories(${CMAKE_CURRENT_SOURCE_DIR} ${ZLIB_INCLUDE_DIR})
+
+unset(PNG_LIB_TARGETS)
+
+if(PNG_SHARED)
+  add_library(png SHARED ${libpng_sources})
+  set(PNG_LIB_TARGETS png)
+  set_target_properties(png PROPERTIES OUTPUT_NAME ${PNG_LIB_NAME})
+  add_dependencies(png genfiles)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png PROPERTIES PREFIX "lib")
+    set_target_properties(png PROPERTIES IMPORT_PREFIX "lib")
+  endif()
+  target_link_libraries(png ${ZLIB_LIBRARY} ${M_LIBRARY})
+
+  if(UNIX AND AWK)
+    if(HAVE_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,--version-script='${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    elseif(HAVE_SOLARIS_LD_VERSION_SCRIPT)
+      set_target_properties(png PROPERTIES LINK_FLAGS
+        "-Wl,-M -Wl,'${CMAKE_CURRENT_BINARY_DIR}/libpng.vers'")
+    endif()
+  endif()
+endif()
+
+if(PNG_STATIC)
+  # does not work without changing name
+  set(PNG_LIB_NAME_STATIC png_static)
+  add_library(png_static STATIC ${libpng_sources})
+  add_dependencies(png_static genfiles)
+  # MSVC doesn't use a different file extension for shared vs. static
+  # libs.  We are able to change OUTPUT_NAME to remove the _static
+  # for all other platforms.
+  if(NOT MSVC)
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}"
+      CLEAN_DIRECT_OUTPUT 1)
+  else()
+    set_target_properties(png_static PROPERTIES
+      OUTPUT_NAME "${PNG_LIB_NAME}_static"
+      CLEAN_DIRECT_OUTPUT 1)
+  endif()
+  list(APPEND PNG_LIB_TARGETS png_static)
+  if(MSVC)
+    # msvc does not append 'lib' - do it here to have consistent name
+    set_target_properties(png_static PROPERTIES PREFIX "lib")
+  endif()
+  target_link_libraries(png_static ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(PNG_FRAMEWORK)
+  set(PNG_LIB_NAME_FRAMEWORK png_framework)
+  add_library(png_framework SHARED ${libpng_sources})
+  add_dependencies(png_framework genfiles)
+  list(APPEND PNG_LIB_TARGETS png_framework)
+  set_target_properties(png_framework PROPERTIES
+    FRAMEWORK TRUE
+    FRAMEWORK_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_SHORT_VERSION_STRING ${PNGLIB_MAJOR}.${PNGLIB_MINOR}
+    MACOSX_FRAMEWORK_BUNDLE_VERSION ${PNGLIB_VERSION}
+    MACOSX_FRAMEWORK_IDENTIFIER org.libpng.libpng
+    XCODE_ATTRIBUTE_INSTALL_PATH "@rpath"
+    PUBLIC_HEADER "${libpng_public_hdrs}"
+    OUTPUT_NAME png)
+  target_link_libraries(png_framework ${ZLIB_LIBRARY} ${M_LIBRARY})
+endif()
+
+if(NOT PNG_LIB_TARGETS)
+  message(SEND_ERROR
+    "No library variant selected to build. "
+    "Please enable at least one of the following options: "
+    " PNG_STATIC, PNG_SHARED, PNG_FRAMEWORK")
+endif()
+
+if(PNG_SHARED AND WIN32)
+  set_target_properties(png PROPERTIES DEFINE_SYMBOL PNG_BUILD_DLL)
+endif()
+
+function(png_add_test)
+  set(options)
+  set(oneValueArgs NAME COMMAND)
+  set(multiValueArgs OPTIONS FILES)
+  cmake_parse_arguments(_PAT "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
+
+  if (NOT _PAT_NAME)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires name.")
+  endif()
+  if (NOT _PAT_COMMAND)
+    message(FATAL_ERROR "Invalid arguments.  png_add_test requires command.")
+  endif()
+
+  set(TEST_OPTIONS "${_PAT_OPTIONS}")
+  set(TEST_FILES "${_PAT_FILES}")
+
+  configure_file("${CMAKE_CURRENT_SOURCE_DIR}/scripts/test.cmake.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake" @ONLY)
+  if(CMAKE_MAJOR_VERSION GREATER 2) # have generator expressions
+    add_test(NAME "${_PAT_NAME}"
+             COMMAND "${CMAKE_COMMAND}"
+             "-DLIBPNG=$<TARGET_FILE:png>"
+             "-DTEST_COMMAND=$<TARGET_FILE:${_PAT_COMMAND}>"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  else() # old 2.x add_test; limited and won't work well on Windows
+    # Note LIBPNG is a dummy value as there are no generator expressions
+    add_test("${_PAT_NAME}" "${CMAKE_COMMAND}"
+             "-DLIBPNG=${CMAKE_CURRENT_BINARY_DIR}/libpng.so"
+             "-DTEST_COMMAND=./${_PAT_COMMAND}"
+             -P "${CMAKE_CURRENT_BINARY_DIR}/tests/${_PAT_NAME}.cmake")
+  endif()
+endfunction()
+
+if(PNG_TESTS AND PNG_SHARED)
+  # Find test PNG files by globbing, but sort lists to ensure
+  # consistency between different filesystems.
+  file(GLOB PNGSUITE_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/pngsuite/*.png")
+  list(SORT PNGSUITE_PNGS)
+  file(GLOB TEST_PNGS "${CMAKE_CURRENT_SOURCE_DIR}/contrib/testpngs/*.png")
+  list(SORT TEST_PNGS)
+
+  set(PNGTEST_PNG "${CMAKE_CURRENT_SOURCE_DIR}/pngtest.png")
+
+  add_executable(pngtest ${pngtest_sources})
+  target_link_libraries(pngtest png)
+
+  png_add_test(NAME pngtest COMMAND pngtest FILES "${PNGTEST_PNG}")
+
+  add_executable(pngvalid ${pngvalid_sources})
+  target_link_libraries(pngvalid png)
+
+  png_add_test(NAME pngvalid-gamma-16-to-8
+               COMMAND pngvalid OPTIONS --gamma-16-to-8)
+  png_add_test(NAME pngvalid-gamma-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode)
+  png_add_test(NAME pngvalid-gamma-background
+               COMMAND pngvalid OPTIONS --gamma-background)
+  png_add_test(NAME pngvalid-gamma-expand16-alpha-mode
+               COMMAND pngvalid OPTIONS --gamma-alpha-mode --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-background
+               COMMAND pngvalid OPTIONS --gamma-background --expand16)
+  png_add_test(NAME pngvalid-gamma-expand16-transform
+               COMMAND pngvalid OPTIONS --gamma-transform --expand16)
+  png_add_test(NAME pngvalid-gamma-sbit
+               COMMAND pngvalid OPTIONS --gamma-sbit)
+  png_add_test(NAME pngvalid-gamma-threshold
+               COMMAND pngvalid OPTIONS --gamma-threshold)
+  png_add_test(NAME pngvalid-gamma-transform
+               COMMAND pngvalid OPTIONS --gamma-transform)
+  png_add_test(NAME pngvalid-progressive-interlace-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read --interlace)
+  png_add_test(NAME pngvalid-progressive-size
+               COMMAND pngvalid OPTIONS --size --progressive-read)
+  png_add_test(NAME pngvalid-progressive-standard
+               COMMAND pngvalid OPTIONS --standard --progressive-read)
+  png_add_test(NAME pngvalid-standard
+               COMMAND pngvalid OPTIONS --standard)
+  png_add_test(NAME pngvalid-transform
+               COMMAND pngvalid OPTIONS --transform)
+
+  add_executable(pngstest ${pngstest_sources})
+  target_link_libraries(pngstest png)
+
+  foreach(gamma_type 1.8 linear none sRGB)
+    foreach(alpha_type none alpha)
+      set(PNGSTEST_FILES)
+      foreach(test_png ${TEST_PNGS})
+        string(REGEX MATCH ".*-linear[-.].*" TEST_PNG_LINEAR "${test_png}")
+        string(REGEX MATCH ".*-sRGB[-.].*" TEST_PNG_SRGB "${test_png}")
+        string(REGEX MATCH ".*-1.8[-.].*" TEST_PNG_G18 "${test_png}")
+        string(REGEX MATCH ".*-alpha-.*" TEST_PNG_ALPHA "${test_png}")
+
+        set(TEST_PNG_VALID TRUE)
+
+        if(TEST_PNG_ALPHA)
+          if (NOT "${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if ("${alpha_type}" STREQUAL "alpha")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_LINEAR)
+          if(NOT "${gamma_type}" STREQUAL "linear")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_SRGB)
+          if(NOT "${gamma_type}" STREQUAL "sRGB")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        elseif(TEST_PNG_G18)
+          if(NOT "${gamma_type}" STREQUAL "1.8")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        else()
+          if(NOT "${gamma_type}" STREQUAL "none")
+            set(TEST_PNG_VALID FALSE)
+          endif()
+        endif()
+
+        if(TEST_PNG_VALID)
+          list(APPEND PNGSTEST_FILES "${test_png}")
+        endif()
+      endforeach()
+      # Should already be sorted, but sort anyway to be certain.
+      list(SORT PNGSTEST_FILES)
+      png_add_test(NAME pngstest-${gamma_type}-${alpha_type}
+                   COMMAND pngstest
+                   OPTIONS --tmpfile "${gamma_type}-${alpha_type}-" --log
+                   FILES ${PNGSTEST_FILES})
+    endforeach()
+  endforeach()
+
+  add_executable(pngunknown ${pngunknown_sources})
+  target_link_libraries(pngunknown png)
+
+  png_add_test(NAME pngunknown-discard COMMAND pngunknown OPTIONS --strict default=discard FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-IDAT COMMAND pngunknown OPTIONS --strict default=discard IDAT=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-if-safe COMMAND pngunknown OPTIONS --strict default=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sAPI COMMAND pngunknown OPTIONS --strict bKGD=save cHRM=save gAMA=save all=discard iCCP=save sBIT=save sRGB=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-save COMMAND pngunknown OPTIONS --strict default=save FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-sTER COMMAND pngunknown OPTIONS --strict sTER=if-safe FILES "${PNGTEST_PNG}")
+  png_add_test(NAME pngunknown-vpAg COMMAND pngunknown OPTIONS --strict vpAg=if-safe FILES "${PNGTEST_PNG}")
+
+  add_executable(pngimage ${pngimage_sources})
+  target_link_libraries(pngimage png)
+
+  png_add_test(NAME pngimage-quick COMMAND pngimage OPTIONS --list-combos --log FILES ${PNGSUITE_PNGS})
+  png_add_test(NAME pngimage-full COMMAND pngimage OPTIONS --exhaustive --list-combos --log FILES ${PNGSUITE_PNGS})
+endif()
+
+if(PNG_SHARED)
+  add_executable(pngfix ${pngfix_sources})
+  target_link_libraries(pngfix png)
+  set(PNG_BIN_TARGETS pngfix)
+
+  add_executable(png-fix-itxt ${png_fix_itxt_sources})
+  target_link_libraries(png-fix-itxt ${ZLIB_LIBRARY} ${M_LIBRARY})
+  list(APPEND PNG_BIN_TARGETS png-fix-itxt)
+endif()
+
+# Ensure the CMAKE_LIBRARY_OUTPUT_DIRECTORY is set
+IF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+  SET(CMAKE_LIBRARY_OUTPUT_DIRECTORY "lib")
+ENDIF(NOT CMAKE_LIBRARY_OUTPUT_DIRECTORY)
+
+# Set a variable with CMake code which:
+# Creates a symlink from src to dest (if possible) or alternatively
+# copies if different.
+macro(CREATE_SYMLINK SRC_FILE DEST_FILE)
+  FILE(REMOVE ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  if(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    ADD_CUSTOM_COMMAND(
+        OUTPUT ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}   ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE}
+        COMMAND ${CMAKE_COMMAND} -E copy_if_different  "${SRC_FILE}" ${CMAKE_CURRENT_BINARY_DIR}/${DEST_FILE}
+        DEPENDS ${PNG_LIB_TARGETS}
+        )
+    ADD_CUSTOM_TARGET(${DEST_FILE}_COPY ALL DEPENDS ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE})
+  else(WIN32 AND NOT CYGWIN AND NOT MSYS)
+    get_filename_component(LINK_TARGET "${SRC_FILE}" NAME)
+    execute_process(COMMAND ${CMAKE_COMMAND} -E make_directory ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+    execute_process(COMMAND ${CMAKE_COMMAND} -E create_symlink "${LINK_TARGET}" ${DEST_FILE} WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
+  endif(WIN32 AND NOT CYGWIN AND NOT MSYS)
+endmacro()
+
+# Create source generation scripts.
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genchk.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genchk.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/genout.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/genout.cmake @ONLY)
+configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/gensrc.cmake.in
+               ${CMAKE_CURRENT_BINARY_DIR}/scripts/gensrc.cmake @ONLY)
+
+
+# libpng is a library so default to 'lib'
+if(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+  set(CMAKE_INSTALL_LIBDIR lib)
+endif(NOT DEFINED CMAKE_INSTALL_LIBDIR)
+
+# CREATE PKGCONFIG FILES
+# we use the same files like ./configure, so we have to set its vars
+# Only do this on Windows for Cygwin - the files don't make much sense outside
+# a UNIX look alike
+if(NOT WIN32 OR CYGWIN OR MINGW)
+  set(prefix      ${CMAKE_INSTALL_PREFIX})
+  set(exec_prefix ${CMAKE_INSTALL_PREFIX})
+  set(libdir      ${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_LIBDIR})
+  set(includedir  ${CMAKE_INSTALL_PREFIX}/include)
+  set(LIBS        "-lz -lm")
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng.pc.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc @ONLY)
+  CREATE_SYMLINK(${PNGLIB_NAME}.pc libpng.pc)
+
+  configure_file(${CMAKE_CURRENT_SOURCE_DIR}/libpng-config.in
+    ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config @ONLY)
+  CREATE_SYMLINK(${PNGLIB_NAME}-config libpng-config)
+endif(NOT WIN32 OR CYGWIN OR MINGW)
+
+# SET UP LINKS
+if(PNG_SHARED)
+  set_target_properties(png PROPERTIES
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.22rc01
+    VERSION 16.${PNGLIB_RELEASE}.0
+    SOVERSION 16
+    CLEAN_DIRECT_OUTPUT 1)
+endif()
+
+# If CMake > 2.4.x, we set a variable used below to export
+# targets to an export file.
+# TODO: Use VERSION_GREATER after our cmake_minimum_required >= 2.6.2
+if(CMAKE_MAJOR_VERSION GREATER 1 AND CMAKE_MINOR_VERSION GREATER 4)
+  set(PNG_EXPORT_RULE EXPORT libpng)
+elseif(CMAKE_MAJOR_VERSION GREATER 2) # future proof
+  set(PNG_EXPORT_RULE EXPORT libpng)
+endif()
+
+# INSTALL
+if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_LIB_TARGETS}
+      ${PNG_EXPORT_RULE}
+      RUNTIME DESTINATION bin
+      LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
+      FRAMEWORK DESTINATION ${CMAKE_INSTALL_LIBDIR})
+
+  if(PNG_SHARED)
+    # Create a symlink for libpng.dll.a => libpng16.dll.a on Cygwin
+    if(CYGWIN OR MINGW)
+       get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
+       CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_IMPORT_LIBRARY_SUFFIX})
+       install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_IMPORT_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(CYGWIN OR MINGW)
+
+    if(NOT WIN32)
+      get_target_property(BUILD_TARGET_LOCATION png LOCATION_${CMAKE_BUILD_TYPE})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_SHARED_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_SHARED_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32)
+  endif(PNG_SHARED)
+
+  if(PNG_STATIC)
+    if(NOT WIN32 OR CYGWIN OR MINGW)
+      get_target_property(BUILD_TARGET_LOCATION png_static LOCATION_${CMAKE_BUILD_TYPE})
+      CREATE_SYMLINK(${BUILD_TARGET_LOCATION} libpng${CMAKE_STATIC_LIBRARY_SUFFIX})
+      install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng${CMAKE_STATIC_LIBRARY_SUFFIX}
+         DESTINATION ${CMAKE_INSTALL_LIBDIR})
+    endif(NOT WIN32 OR CYGWIN OR MINGW)
+ endif()
+endif()
+
+if(NOT SKIP_INSTALL_HEADERS AND NOT SKIP_INSTALL_ALL )
+  install(FILES ${libpng_public_hdrs}   DESTINATION include)
+  install(FILES ${libpng_public_hdrs}   DESTINATION include/${PNGLIB_NAME})
+endif()
+if(NOT SKIP_INSTALL_EXECUTABLES AND NOT SKIP_INSTALL_ALL )
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config DESTINATION bin)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+
+if(NOT SKIP_INSTALL_PROGRAMS AND NOT SKIP_INSTALL_ALL )
+  install(TARGETS ${PNG_BIN_TARGETS}
+      RUNTIME DESTINATION bin)
+endif()
+
+if(NOT SKIP_INSTALL_FILES AND NOT SKIP_INSTALL_ALL )
+  # Install man pages
+  if(NOT PNG_MAN_DIR)
+    set(PNG_MAN_DIR "share/man")
+  endif()
+  install(FILES libpng.3 libpngpf.3      DESTINATION ${PNG_MAN_DIR}/man3)
+  install(FILES png.5                    DESTINATION ${PNG_MAN_DIR}/man5)
+  # Install pkg-config files
+  if(NOT WIN32 OR CYGWIN OR MINGW)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/libpng.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/libpng-config
+            DESTINATION bin)
+    install(FILES ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}.pc
+            DESTINATION ${CMAKE_INSTALL_LIBDIR}/pkgconfig)
+    install(PROGRAMS ${CMAKE_CURRENT_BINARY_DIR}/${PNGLIB_NAME}-config
+            DESTINATION bin)
+  endif(NOT WIN32 OR CYGWIN OR MINGW)
+endif()
+
+# On versions of CMake that support it, create an export file CMake
+# users can include() to import our targets
+if(PNG_EXPORT_RULE AND NOT SKIP_INSTALL_EXPORT AND NOT SKIP_INSTALL_ALL )
+  install(EXPORT libpng DESTINATION lib/libpng FILE lib${PNG_LIB_NAME}.cmake)
+endif()
+
+# what's with libpng-manual.txt and all the extra files?
+
+# UNINSTALL
+# do we need this?
+
+# DIST
+# do we need this?
+
+# to create msvc import lib for mingw compiled shared lib
+# pexports libpng.dll > libpng.def
+# lib /def:libpng.def /machine:x86
+