Add 64 bit file offset flag

Author: LawrenceHunter

cmake/modules/CompilerOptions.cmake

@@ -54,6 +54,9 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 # continue to check with modern compiler versions.
 set(STDC_HEADERS 1)
 
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_FILE_OFFSET_BITS=64")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_FILE_OFFSET_BITS=64")
+
 # acx_strict.m4
 if(ENABLE_STRICT)
     enable_cxx_compiler_flag_if_supported(-Wall)

configure.ac

@@ -47,6 +47,8 @@ AC_PROG_CXX
 PKG_PROG_PKG_CONFIG
 
 # Compiler flags
+CFLAGS="${CFLAGS} -D_FILE_OFFSET_BITS=64"
+CXXFLAGS="${CXXFLAGS} -D_FILE_OFFSET_BITS=64"
 ACX_PEDANTIC
 ACX_STRICT
 ACX_64BIT