Fix linking failure on EFL and GTK for the jsCStack branch merge

• Component: JavaScriptCore
• Status: RESOLVED FIXED

[Csaba Osztrogonác]

After adding the missing files to the cmake buildsystem and removed
the dead code I managed to build EFLWebKit. But I got linking failure
with SHARED_CORE=ON build. Unfortunately it is necessary to be able
run layout tests. (https://bugs.webkit.org/show_bug.cgi?id=80683)

Additionally I got the same linking failure with WebKitGTK build.


GTK build failure:
-------------------
/usr/bin/ld: Source/JavaScriptCore/llint/.libs/libjavascriptcoregtk_3_0_la-LowLevelInterpreter.o: relocation R_X86_64_PC32 against symbol `llint_throw_stack_overflow_error' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value


EFL build failure with SHARED_CORE=ON:
---------------------------------------
Linking CXX shared library ../../lib/libjavascriptcore_efl.so
/usr/bin/ld: CMakeFiles/JavaScriptCore.dir/llint/LowLevelInterpreter.cpp.o: relocation R_X86_64_PC32 against symbol `llint_throw_stack_overflow_error' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Bad value

[Csaba Osztrogonác]

Additional info: The build fails on GTK always and fails on EFL bots, 
because ENABLE_DRT=1 environment variable forces the SHARED_CORE=ON build.

[Mark Hahnenberg]

After reading a little bit about this error, it seems that gcc requires that code linked into a shared library should, by default, be compiled with -fpic due to the constraints of the small code model and the size of the address space on 64-bit platforms. I can see two obvious solutions:

(1) Use -fpic to enable position independent code when building shared libraries.
(2) Use -mcmodel=large to enable the large code model when building shared libraries.

Either one of these should work.

[Mark Hahnenberg]

(In reply to comment #2)
> After reading a little bit about this error, it seems that gcc requires that code linked into a shared library should, by default, be compiled with -fpic due to the constraints of the small code model and the size of the address space on 64-bit platforms. I can see two obvious solutions:
> 
> (1) Use -fpic to enable position independent code when building shared libraries.
> (2) Use -mcmodel=large to enable the large code model when building shared libraries.
> 
> Either one of these should work.

This also might be the result of a lack of proper extern-ing for these symbols. Let me try that first.

[Csaba Osztrogonác]

It seems https://bugs.webkit.org/show_bug.cgi?id=127782 solved the linking problem. Thanks for the quick fix.