View Issue Details Jump to Notes ] Print ]
IDProjectCategoryView StatusDate SubmittedLast Update
0015970CMakeCMakepublic2016-02-11 13:442016-06-10 14:31
Assigned ToKitware Robot 
PlatformLinuxOSUbuntuOS Version14.04
Product VersionCMake 
Target VersionFixed in Version 
Summary0015970: CMake changes order of include directories when a directory is specified both as a SYSTEM and non-SYSTEM include
DescriptionI ran into a problem recently where a package I was building set a SYSTEM include directory which was already a non-SYSTEM include directory imported from a dependency. When this happened, CMake dropped the non-SYSTEM directory in favor of the SYSTEM one, causing my build to fail.

According to GCC [1], it gives precedence to non-SYSTEM include directories, and specifying both for the same path produces a warning.

[1] [^]
> All directories named by -isystem are searched after all directories named by -I, no matter what their order was on the command line. If the same directory is named by both -I and -isystem, the -I option is ignored. GCC provides an informative message when this occurs if -v is used.

With CMake, if both are specified, it drops the non-SYSTEM include and fails silently. For example, when building this project with any recent version of CMake on Linux, the build command is:

/usr/bin/c++ -isystem /path/to/overlay/devel/include -I/opt/ros/indigo/include -o CMakeFiles/foo.dir/foo.cpp.o -c /home/jbohren/scratch/isystem/foo.cpp

But with the three `incude_directory` options given in `CMakeLists.txt`, I would expect it to read:

/usr/bin/c++ -I/path/to/overlay/devel/include -I/opt/ros/indigo/include -isystem /path/to/overlay/devel/include -o CMakeFiles/foo.dir/foo.cpp.o -c /home/jbohren/scratch/isystem/foo.cpp

Even the following would maintain the order of the search paths, since the non-SYSTEM directories are all scanned before the SYSTEM ones:

/usr/bin/c++ -I/path/to/overlay/devel/include -I/opt/ros/indigo/include -o CMakeFiles/foo.dir/foo.cpp.o -c /home/jbohren/scratch/isystem/foo.cpp
Steps To ReproduceBuild this trivial CMake project to observe the effect: [^]
TagsNo tags attached.
Attached Files


Kitware Robot (administrator)
2016-06-10 14:29

Resolving issue as `moved`.

This issue tracker is no longer used. Further discussion of this issue may take place in the current CMake Issues page linked in the banner at the top of this page.

 Issue History
Date Modified Username Field Change
2016-02-11 13:44 jbohren New Issue
2016-06-10 14:29 Kitware Robot Note Added: 0042938
2016-06-10 14:29 Kitware Robot Status new => resolved
2016-06-10 14:29 Kitware Robot Resolution open => moved
2016-06-10 14:29 Kitware Robot Assigned To => Kitware Robot
2016-06-10 14:31 Kitware Robot Status resolved => closed

Copyright © 2000 - 2018 MantisBT Team