On free pascal static dynamic linker
lazarus / 1-Linux

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benohb · 2018-04-02 08:41

I am really confused about FPC static/dynamic linker in linux .Maybe
I'm wrong in understanding But I see it as illogical
According to the wiki, Free Pascal comes by default "statically
linked" with libraries this makes the program no longer needs external
requirements..It is understandable



http://wiki.freepascal.org/Size_Matters
QuoteFPC compiles and links a static executable by default. That means
it tells the linker to put all .o files of the project and all
packages into one big executable.
But why when you use the command "objdump"


Example with fpgui


Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i objdump
./customstyles_test | grep NEEDED    NEEDED               libX11.so.6 
NEEDED               libXft.so.2  NEEDED              
libfontconfig.so.1  NEEDED               libc.so.6 

Note that still need external libraries and must be in the operating
system



What's going on ??

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Thaddy · 2018-04-02 09:20

The libc I can understand but the X* stuff (that YOU wrote yourself)
should not be there....
Happy Easter.

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benohb · 2018-04-02 09:29

The strange thing is here.. with fpgui library comes a file
fpg_xft_x11.pas  it is static linkerd with libxft and libfontconfig
I turned it dynamically
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
xfthlib:=LoadLibrary('/usr/lib/XXX-linux-gnu/libXft.so.2');pointer(Xft
DrawCreate):=GetProcAddress(xfthlib,'XftDrawCreate');.................
pointer(FcFontSetDestroy):=GetProcAddress(xfthlib,'FcFontSetDestroy');
//<------Note here The program runs without errors ..This is proof
that libxft load libfontconfig Automatically
I think the executable in Linux has become static/dynamic at the same
time it makes the static linker without its Advantages

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Thaddy · 2018-04-02 09:42

That Is strange... Nice Easter puzzle...

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taazz · 2018-04-02 09:43

You misunderstood the range of linking. all code that is compiled by
the FPC compiler is statically linked there is no dynamic link (yet?).
FPGUI and lcl do not provide obj files for system libraries and choose
to bind with them directly either statically or dynamically. A static
bind is one that uses the extern type of linking and a dynamic binding
is the one that use loadlibrary, getprocaddress etc procedures to bind
to the libraries at runtime. Both are referred to as static/dynamic
linking but they are different processes that is why I prefer to call
the process of attaching to external libraries as binding instead of
linking although the linker is responsible on both cases.

So in short if the code is not compile by fpc then its probably a bind
usually a static bind becoming.

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Thaddy · 2018-04-02 10:02

taazz: he wrote the bindings... you are probably using them every day.
It is a puzzle...

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benohb · 2018-04-02 10:07

taazz ..Thank you