Strange include path in Eclipse CDT + GNU ARM

Question

After tinkering with some project settings, namely changing the FPU type, some strange entries appeared in the includes, eg.:

project/#undef __ARM_NEON

These are not shown at any of the usual places where includes can be specified (C/C++ build -> Settings -> tool settings -> compiler xy -> Includes.

This obviously invalid include path creates an annoying warning message at the "problems" tab.

Sometimes tinkering more with the FPU settings will make these entries disappear, or cause more similar entries to appear, but I could not see any logical behavior here. Is this a bug?

Screenshot

Answer 1

Please see: http://blog.bachi.net/?m=201409 for the solution.

workspace.metadata.pluginsorg.eclipse.cdt.coreROME2_P1_A2.language.settings.xml

Remove:

<entry kind="includePath" name="/${ProjName}/#undef __ARM_FP">
    <flag value="BUILTIN|READONLY|VALUE_WORKSPACE_PATH"/>
</entry>
<entry kind="includePath" name="/${ProjName}/#undef __ARM_FEATURE_FMA">
    <flag value="BUILTIN|READONLY|VALUE_WORKSPACE_PATH"/>
</entry>
<entry kind="includePath" name="/${ProjName}/#undef __ARM_NEON__">
    <flag value="BUILTIN|READONLY|VALUE_WORKSPACE_PATH"/>
</entry>
<entry kind="includePath" name="/${ProjName}/#undef __ARM_NEON">
    <flag value="BUILTIN|READONLY|VALUE_WORKSPACE_PATH"/>
</entry>

Add:

<language id="org.eclipse.cdt.core.g++">
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/arm-none-eabi/include/c++/6.3.1">
        <flag value="BUILTIN|READONLY"/>
    </entry>
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/arm-none-eabi/include/c++/6.3.1/arm-none-eabi/thumb/v8-m.main">
        <flag value="BUILTIN|READONLY"/>
    </entry>
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/arm-none-eabi/include/c++/6.3.1/backward">
        <flag value="BUILTIN|READONLY"/>
    </entry>
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/lib/gcc/arm-none-eabi/6.3.1/include">
        <flag value="BUILTIN|READONLY"/>
    </entry>
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/lib/gcc/arm-none-eabi/6.3.1/include-fixed">
        <flag value="BUILTIN|READONLY"/>
    </entry>
    <entry kind="includePath" name="C:/Program Files (x86)/GNU Tools ARM Embedded/6 2017-q1-update/arm-none-eabi/include">
        <flag value="BUILTIN|READONLY"/>
    </entry>
</language>