Changeset 367853f


Ignore:
Timestamp:
03/30/2019 10:51:46 PM (3 years ago)
Author:
Bruce Dubbs <bdubbs@…>
Branches:
10.0, 10.1, 11.0, 9.0, 9.1, ken/refactor-virt, lazarus, qt5new, trunk, xry111/git-date, xry111/git-date-for-trunk, xry111/git-date-test
Children:
178639f
Parents:
ba31c2b
Message:

Minor wording changes in sw notes

git-svn-id: svn://svn.linuxfromscratch.org/BLFS/trunk/BOOK@21417 af4574ff-66df-0310-9fd7-8a98e5e911e0

File:
1 edited

Legend:

Unmodified
Added
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  • introduction/important/building-notes.xml

    rba31c2b r367853f  
    460460      There are now three different build systems in common use for
    461461      converting C or C++ source code into compiled programs or
    462       libraries, and their details (particularly, finding out about available
     462      libraries and their details (particularly, finding out about available
    463463      options and their default values) differ. It may be easiest to understand
    464       the issues caused by some choices (typically, slow execution, or
    465       unexpected use of, or omission of, optimizatons) by starting with the item
    466       which drew attention to this, the CFLAGS and CXXFLAGS.
     464      the issues caused by some choices (typically slow execution or
     465      unexpected use of, or omission of, optimizatons) by starting with
     466      the CFLAGS and CXXFLAGS environment variables.
    467467    </para>
    468468
     
    470470      Most LFS and BLFS builders are probably aware of the basics of CFLAGS
    471471      and CXXFLAGS for altering how a program is compiled. Typically, some
    472       form of optimization is used for a released program (-O2 or -O3),
    473       sometimes with the creation of debug symbols (-g) when using -O2.
     472      form of optimization is used by upstream developers (-O2 or -O3),
     473      sometimes with the creation of debug symbols (-g), as defaults.
    474474    </para>
    475475
     
    477477      If there are contradictory flags (e.g. multiple different -O values),
    478478      the <emphasis>last</emphasis> value will be used. Sometimes this means
    479       that flags specifiedi in environment variables will be picked up before
     479      that flags specified in environment variables will be picked up before
    480480      values hardcoded in the Makefile, and therefore ignored.  For example,
    481481      where a user specifies '-O2' and that is followed by '-O3' the build will
     
    495495    </para>
    496496
    497     <bridgehead renderas="sect3">Autotools with Make</bridgehead>
     497    <bridgehead renderas="sect3" id="autotools-info">Autotools with Make</bridgehead>
    498498
    499499      <para>
     
    504504
    505505      <para>
    506         Sometimes, running <command>./configure --help</command> will produce
     506        Sometimes running <command>./configure --help</command> will produce
    507507        useful options about switches which might be used.  At other times,
    508         after looking at the output from a run of configure you may need to look
     508        after looking at the output from configure you may need to look
    509509        at the details of the script to find out what it was actually searching
    510510        for.
     
    516516       any flags which would otherwise be used (<emphasis>variously</emphasis>:
    517517       ignored, used to replace the programmer's suggestion, used before the
    518        programmer's suggestion, used after the programmer's suggestion).
     518       programmer's suggestion, or used after the programmer's suggestion).
    519519      </para>
    520520
     
    528528     </para>
    529529
    530     <bridgehead renderas="sect3">CMake</bridgehead>
     530    <bridgehead renderas="sect3" id="cmake-info">CMake</bridgehead>
    531531
    532532      <para>
     
    548548        of CMAKE_BUILD_TYPE values, and these affect the flags. The default
    549549        is that this is not set and no flags are generated. Any CFLAGS or
    550         CXXFLAGS in the environment will be used. If  the programmer has coded
     550        CXXFLAGS in the environment will be used. If the programmer has coded
    551551        any debug assertions, those will be enabled unless -DNDEBUG is used.
    552552        The following CMAKE_BUILD_TYPE values will generate the flags shown,
     
    575575      </para>
    576576
    577     <bridgehead renderas="sect3">Meson</bridgehead>
     577    <bridgehead renderas="sect3" id="meson-info">Meson</bridgehead>
    578578
    579579      <para>
    580580        Meson has some similarities to CMake, but many differences. To get
    581         details of the definesthat you may wish to change is slightly involved
    582         using meson-0.49.2:
    583       </para>
    584 
    585 <screen><userinput>meson ..
     581        details of the defines that you may wish to change ypu need to do:
     582      </para>
     583
     584<screen><userinput>mkdir build
     585cd    build
     586meson ..
    586587meson configure | less</userinput></screen>
    587588
    588589      <para>
    589         After identifying what to set, meson then needs to be reconfigured:
    590       </para>
    591 
    592 <screen><userinput>meson --prefix=/usr -Dsome_option=true -Dother_option=false --reconfigure</userinput></screen>
     590        After identifying what to set, meson then needs to be reconfigured.
     591        For example:
     592      </para>
     593
     594<screen><userinput>meson --prefix=/usr -Dbuildtype=&lt;type&gt; -Dother_option=false --reconfigure</userinput></screen>
    593595
    594596      <para>
    595597        Alternatively, you could remove the build directory where you did this,
    596         recreate it, and then run meson with the desired switches.
     598        recreate it, and then run meson with the desired options.
    597599      </para>
    598600
     
    622624
    623625      <para>
    624         Although the release buildtype is described as enabling -DNDEBUG, and all
     626        Although the 'release' buildtype is described as enabling -DNDEBUG, and all
    625627        CMake Release builds pass that, it has so far only been observed (in
    626628        verbose builds) for <xref linkend="mesa"/>. That suggests that it might
     
    635637      <para>
    636638        To see the details of the commands which are being run in a package using
    637         meson, again use 'ninja -v'.
     639        meson, use 'ninja -v'.
    638640      </para>
    639641
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