cmake: Fix a build error on iOS
Avoid the awk-based configuration when cross-compiling from macOS
to iOS.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 874387c..c85aa74 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,7 @@
# Revised by Cosmin Truta, 2018
# Revised by Kyle Bentley, 2018
# Revised by David Callu, 2020
+# Revised by Steve Robinson, 2020
# This code is released under the libpng license.
# For conditions of distribution and use, see the disclaimer
@@ -273,7 +274,7 @@
include_directories(${CMAKE_CURRENT_BINARY_DIR})
-if(NOT AWK OR ANDROID)
+if(NOT AWK OR ANDROID OR IOS)
# No awk available to generate sources; use pre-built pnglibconf.h
configure_file(${CMAKE_CURRENT_SOURCE_DIR}/scripts/pnglibconf.h.prebuilt
${CMAKE_CURRENT_BINARY_DIR}/pnglibconf.h)
@@ -452,7 +453,7 @@
"${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.chk"
"${CMAKE_CURRENT_BINARY_DIR}/scripts/symbols.out"
"${CMAKE_CURRENT_BINARY_DIR}/scripts/vers.out")
-endif(NOT AWK OR ANDROID)
+endif(NOT AWK OR ANDROID OR IOS)
# OUR SOURCES
set(libpng_public_hdrs
@@ -466,7 +467,7 @@
pnginfo.h
pngstruct.h
)
-if(AWK AND NOT ANDROID)
+if(AWK AND NOT ANDROID AND NOT IOS)
list(APPEND libpng_private_hdrs "${CMAKE_CURRENT_BINARY_DIR}/pngprefix.h")
endif()
set(libpng_sources
