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Colin Patrick McCabe resolved HADOOP-11997. ------------------------------------------- Resolution: Duplicate > CMake CMAKE_C_FLAGS are non-portable > ------------------------------------ > > Key: HADOOP-11997 > URL: https://issues.apache.org/jira/browse/HADOOP-11997 > Project: Hadoop Common > Issue Type: Sub-task > Components: build > Affects Versions: 2.7.0 > Environment: All > Reporter: Alan Burlison > Assignee: Alan Burlison > Priority: Critical > > hadoop-common-project/hadoop-common/src/CMakeLists.txt > (https://github.com/apache/hadoop/blob/trunk/hadoop-common-project/hadoop-common/src/CMakeLists.txt#L110) > contains the following unconditional assignments to CMAKE_C_FLAGS: > set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -g -Wall -O2") > set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_REENTRANT -D_GNU_SOURCE") > set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_LARGEFILE_SOURCE > -D_FILE_OFFSET_BITS=64") > There are several issues here: > 1. "-D_GNU_SOURCE" globally enables the use of all Linux-only extensions in > hadoop-common native source. This is probably a major contributor to the poor > cross-platform portability of Hadoop native code to non-Linux platforms as it > makes it easy for developers to use non-portable Linux features without > realising. Use of Linux-specific features should be correctly bracketed with > conditional macro blocks that provide an alternative for non-Linux platforms. > 2. "-g -Wall -O2" turns on debugging for all builds, I believe the correct > mechanism is to set the CMAKE_BUILD_TYPE CMake variable. If it is still > necessary to override CFLAGS it should probably be done conditionally > dependent on the value of CMAKE_BUILD_TYPE. > 3. "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64" On Solaris these flags are > only needed for largefile support in ILP32 applications, LP64 applications > are largefile by default. I believe the same is true on Linux, so these flags > are harmless but redundant for 64-bit compilation. -- This message was sent by Atlassian JIRA (v6.3.4#6332)