From dc26841b9ea1e65dedbc916257f70e7f768f724b Mon Sep 17 00:00:00 2001
From: Marvin W <git@larma.de>
Date: Thu, 31 Aug 2017 23:53:40 +0200
Subject: [PATCH] cmake: set _FILE_OFFSET_BITS=64 if required for platform

---
 CMakeLists.txt           | 22 ++++++++++++++++++++--
 cmake/LargeFileOffsets.c | 11 +++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 cmake/LargeFileOffsets.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 15a66f99..929834ca 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -44,10 +44,11 @@ set(TARGET_INSTALL LIBRARY DESTINATION ${LIB_INSTALL_DIR} RUNTIME DESTINATION ${
 set(PLUGIN_INSTALL LIBRARY DESTINATION ${PLUGIN_INSTALL_DIR} RUNTIME DESTINATION ${PLUGIN_INSTALL_DIR})
 
 include(CheckCCompilerFlag)
+include(CheckCSourceCompiles)
 
 macro(AddCFlagIfSupported flag)
     string(REGEX REPLACE "[^a-z^A-Z^_^0-9]+" "_" flag_name ${flag})
-    CHECK_C_COMPILER_FLAG(${flag} COMPILER_SUPPORTS${flag_name})
+    check_c_compiler_flag(${flag} COMPILER_SUPPORTS${flag_name})
     if(${COMPILER_SUPPORTS${flag_name}})
         set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${flag}")
     endif()
@@ -55,7 +56,7 @@ endmacro()
 
 macro(AddValaCFlagIfSupported flag)
     string(REGEX REPLACE "[^a-z^A-Z^_^0-9]+" "_" flag_name ${flag})
-    CHECK_C_COMPILER_FLAG(${flag} COMPILER_SUPPORTS${flag_name})
+    check_c_compiler_flag(${flag} COMPILER_SUPPORTS${flag_name})
     if(${COMPILER_SUPPORTS${flag_name}})
         set(VALA_CFLAGS "${VALA_CFLAGS} ${flag}")
     endif()
@@ -78,6 +79,21 @@ AddValaCFlagIfSupported(-Wno-unused-variable)
 AddValaCFlagIfSupported(-Wno-unused-function)
 AddValaCFlagIfSupported(-Wno-unused-label)
 
+try_compile(__WITHOUT_FILE_OFFSET_BITS_64 ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_SOURCE_DIR}/cmake/LargeFileOffsets.c COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS})
+if(NOT __WITHOUT_FILE_OFFSET_BITS_64)
+    try_compile(__WITH_FILE_OFFSET_BITS_64 ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_SOURCE_DIR}/cmake/LargeFileOffsets.c COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} -D_FILE_OFFSET_BITS=64)
+
+    if(__WITH_FILE_OFFSET_BITS_64)
+        AddCFlagIfSupported(-D_FILE_OFFSET_BITS=64)
+        AddValaCFlagIfSupported(-D_FILE_OFFSET_BITS=64)
+        message(STATUS "Enabled large file support using _FILE_OFFSET_BITS=64")
+    else(__WITH_FILE_OFFSET_BITS_64)
+        message(STATUS "Large file support not available")
+    endif(__WITH_FILE_OFFSET_BITS_64)
+    unset(__WITH_FILE_OFFSET_BITS_64)
+endif(NOT __WITHOUT_FILE_OFFSET_BITS_64)
+unset(__WITHOUT_FILE_OFFSET_BITS_64)
+
 if($ENV{USE_CCACHE})
     # Configure CCache if available
     find_program(CCACHE_FOUND ccache)
@@ -85,6 +101,8 @@ if($ENV{USE_CCACHE})
         message(STATUS "Using ccache")
         set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ccache)
         set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK ccache)
+    else(CCACHE_FOUND)
+        message(STATUS "USE_CCACHE was set but ccache was not found")
     endif(CCACHE_FOUND)
 endif($ENV{USE_CCACHE})
 
diff --git a/cmake/LargeFileOffsets.c b/cmake/LargeFileOffsets.c
new file mode 100644
index 00000000..cbc20f0d
--- /dev/null
+++ b/cmake/LargeFileOffsets.c
@@ -0,0 +1,11 @@
+#include <sys/types.h>
+#define _K ((off_t)1024)
+#define _M ((off_t)1024 * _K)
+#define _G ((off_t)1024 * _M)
+#define _T ((off_t)1024 * _G)
+
+int test[(((64 * _G -1) % 671088649) == 268434537) && (((_T - (64 * _G -1) + 255) % 1792151290) == 305159546)? 1: -1];
+
+int main() {
+    return 0;
+}
\ No newline at end of file