[CMake] Avoiding a relink

[Jed Brown]

On Fri 2009-02-27 11:09, Bill O'Hara wrote:
> Lets say I have a CMakeLists.txt like this:
> 
> add_library(foo STATIC foo.c bar.c)
> add_executable(test test.c)
> target_link_libraries(test foo)
> 
> where test.c uses only functions defined in foo.c but not bar.c (assume some
> other target will use foo as well and use functions from both foo.c and bar.c).
> 
> Is it possible to avoid the relink of test when foo is changed because of a
> change in bar.c? Just as an optimization to avoid unnecessary relinks to speed
> up the user experience?

I'm guessing this won't work because it requires very deep knowledge to
determine that nothing in bar.c is called, even transitively, through
foo.c.

What I'd like though is to not relink targets when a shared library
changes.  That is, suppose libfoo is a shared library in the example
above.  If relinking is required then a header must have changed so
'test.c' would need to be recompiled.  If no headers have changed, then
libfoo can be rebuilt and the executable 'test' does not need to be
rebuilt.  Presumably there is a reason this isn't the default, what is
it?

Jed
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 197 bytes
Desc: not available
URL: <http://www.cmake.org/pipermail/cmake/attachments/20090227/258ef875/attachment.pgp>