Check libpng directly into third_party/

third_party/libpng/scripts/genout.cmake.in

Index: third_party/libpng/scripts/genout.cmake.in
diff --git a/third_party/libpng/scripts/genout.cmake.in b/third_party/libpng/scripts/genout.cmake.in
new file mode 100644
index 0000000000000000000000000000000000000000..01f12de2fc434b450b73c77a4998fef4f2b6f37c
--- /dev/null
+++ b/third_party/libpng/scripts/genout.cmake.in
@@ -0,0 +1,93 @@
+# genout.cmake.in
+# Generate .out from .c with awk (generic), based upon the automake logic.
+
+# Copyright (C) 2016 Glenn Randers-Pehrson
+# Written 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
+
+# Variables substituted from CMakeLists.txt
+set(SRCDIR "@CMAKE_CURRENT_SOURCE_DIR@")
+set(BINDIR "@CMAKE_CURRENT_BINARY_DIR@")
+
+set(AWK "@AWK@")
+set(CMAKE_C_COMPILER "@CMAKE_C_COMPILER@")
+set(CMAKE_C_FLAGS @CMAKE_C_FLAGS@)
+set(INCDIR "@CMAKE_CURRENT_BINARY_DIR@")
+set(PNG_PREFIX "@PNG_PREFIX@")
+set(PNGLIB_MAJOR "@PNGLIB_MAJOR@")
+set(PNGLIB_MINOR "@PNGLIB_MINOR@")
+set(PNGLIB_VERSION "@PNGLIB_VERSION@")
+set(ZLIBINCDIR "@ZLIB_INCLUDE_DIR@")
+
+set(PLATFORM_C_FLAGS)
+if(APPLE)
+  set(CMAKE_OSX_ARCHITECTURES "@CMAKE_OSX_ARCHITECTURES@")
+  set(CMAKE_OSX_SYSROOT "@CMAKE_OSX_SYSROOT@")
+  if(CMAKE_OSX_ARCHITECTURES)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -arch ${CMAKE_OSX_ARCHITECTURES})
+  endif()
+  if(CMAKE_OSX_SYSROOT)
+    set(PLATFORM_C_FLAGS ${PLATFORM_C_FLAGS} -isysroot ${CMAKE_OSX_SYSROOT})
+  endif()
+endif()
+
+get_filename_component(INPUTEXT "${INPUT}" EXT)
+get_filename_component(OUTPUTEXT "${OUTPUT}" EXT)
+get_filename_component(INPUTBASE "${INPUT}" NAME_WE)
+get_filename_component(OUTPUTBASE "${OUTPUT}" NAME_WE)
+get_filename_component(INPUTDIR "${INPUT}" PATH)
+get_filename_component(OUTPUTDIR "${OUTPUT}" PATH)
+
+if ("${INPUTEXT}" STREQUAL ".c" AND "${OUTPUTEXT}" STREQUAL ".out")
+  get_filename_component(GENDIR "${OUTPUT}" PATH)
+  file(MAKE_DIRECTORY "${GENDIR}")
+
+  file(REMOVE "${OUTPUT}.tf1" "${OUTPUT}.tf2")
+
+  set(INCLUDES "-I${INCDIR}")
+  if(ZLIBINCDIR)
+    foreach(dir ${ZLIBINCDIR})
+      list(APPEND INCLUDES "-I${dir}")
+    endforeach()
+  endif()
+
+  if(PNG_PREFIX)
+    set(PNG_PREFIX_DEF "-DPNG_PREFIX=${PNG_PREFIX}")
+  endif()
+
+  execute_process(COMMAND "${CMAKE_C_COMPILER}" "-E"
+                          ${CMAKE_C_FLAGS}
+                          ${PLATFORM_C_FLAGS}
+                          "-I${SRCDIR}"
+                          "-I${BINDIR}"
+                          ${INCLUDES}
+                          "-DPNGLIB_LIBNAME=PNG${PNGLIB_MAJOR}${PNGLIB_MINOR}_0"
+                          "-DPNGLIB_VERSION=${PNGLIB_VERSION}"
+                          "-DSYMBOL_PREFIX=${SYMBOL_PREFIX}"
+                          "-DPNG_NO_USE_READ_MACROS"
+                          "-DPNG_BUILDING_SYMBOL_TABLE"
+                          ${PNG_PREFIX_DEF}
+                          "${INPUT}"
+                  OUTPUT_FILE "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE CPP_FAIL)
+  if(CPP_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf1")
+  endif()
+
+  execute_process(COMMAND "${AWK}" -f "${SRCDIR}/scripts/dfn.awk"
+                          "out=${OUTPUT}.tf2" "${OUTPUT}.tf1"
+                  WORKING_DIRECTORY "${BINDIR}"
+                  RESULT_VARIABLE AWK_FAIL)
+  if(AWK_FAIL)
+    message(FATAL_ERROR "Failed to generate ${OUTPUT}.tf2")
+  endif()
+
+  file(REMOVE "${OUTPUT}.tf1")
+  file(RENAME "${OUTPUT}.tf2" "${OUTPUT}")
+else()
+  message(FATAL_ERROR "Unsupported conversion: ${INPUTEXT} to ${OUTPUTEXT}")
+endif()