Re: [Chicken-users] understanding the CMake build

[Thomas Chust]

On Mon, 11 Sep 2006, Brandon J. Van Every wrote:

> [...] But, we'll see if my INCLUDE_DIRECTORIES bulletproofing has any 
> effect on this problem. [...]

Hello,

I just pulled the latest changes using darcs and rebuilt 
{chicken,csi}-static with CMake -- I still get dynamically linked 
executables.

I observed that the command issued by CMake to link e.g. chicken-static 
reads

   /usr/bin/gcc  -Os -DNDEBUG -headerpad_max_install_names -fPIC \
     "CMakeFiles/chicken-static.dir/batch-driver.o" \
     "CMakeFiles/chicken-static.dir/c-backend.o" \
     "CMakeFiles/chicken-static.dir/c-platform.o" \
     "CMakeFiles/chicken-static.dir/chicken.o" \
     "CMakeFiles/chicken-static.dir/compiler.o" \
     "CMakeFiles/chicken-static.dir/optimizer.o" \
     "CMakeFiles/chicken-static.dir/support.o" \
     -o chicken-static \
     -L/Users/murphy/Build/chicken/static -lchicken \
     -ldl -lffi -lm

[linebreaks and backslashes inserted for better readability]

I *know* that this cannot work as desired on MacOS X. The reason is, that 
the MacOS X linker does scan the path in the -L option before all other 
paths all right, but it *always scans the full library path first for a 
shared library* when processing the -l options. As there is a 
libchicken.dylib in /usr/local/lib, this results in dynamic linkage.

The only reliable way to fix this that I can think of is to specify the 
full path to the static library instead of giving an -l option for it. 
The following command would be the correct one for my system:

   /usr/bin/gcc  -Os -DNDEBUG -headerpad_max_install_names -fPIC \
     "CMakeFiles/chicken-static.dir/batch-driver.o" \
     "CMakeFiles/chicken-static.dir/c-backend.o" \
     "CMakeFiles/chicken-static.dir/c-platform.o" \
     "CMakeFiles/chicken-static.dir/chicken.o" \
     "CMakeFiles/chicken-static.dir/compiler.o" \
     "CMakeFiles/chicken-static.dir/optimizer.o" \
     "CMakeFiles/chicken-static.dir/support.o" \
     -o chicken-static \
     /Users/murphy/Build/chicken/static/libchicken.a \
     /usr/local/lib/libffi.a \
     -lm

Note that it's also advisable to link the non-standard libffi statically 
and that it makes no sense to include the dynamic loader library in a 
(partially) statically linked executable because CHICKEN will not allow 
the loading of dynamic code into such an executable anyway and I know that 
it will also break the linked executable on some Linux systems.

Unfortunately I can't check whether making the necessary changes to 
CMakeLists.txt won't break the build on other systems, so I better don't 
touch anything. I vaguely remeber that some Unix dialect I've worked with 
wasn't at all happy with full static library paths on the linker command 
line...

cu,
Thomas