[Scons-users] Dependency on $CC tool tripped up by subdir

[William Deegan]

Marc,

On Oct 4, 2012, at 1:57 PM, Marc Branchaud <marcnarc at xiplink.com> wrote:


> Hi all,

> 

> I think I've found a bug, but I might be missing something.  I'm trying to

> use a custom toolchain for my builds.  The following SConstruct doesn't work

> in SCons 2.2.0 (nor even in SCons 1.2.0):

> 

> -- 8< --

> e = DefaultEnvironment()

> 

> mycc = e.Command(target="tools/mycc",

>                 source="/usr/bin/gcc",

>                 action="cp $SOURCE $TARGET")

> 

> e.Replace(CC = mycc[0].abspath)

> 

> e.Program(target='testapp', source='test.c')

> -- >8 --

> 

> This fails with "/path/to/tools/mycc: not found".  SCons fails to notice that

> it needs to build mycc before testapp.  In fact, --tree=prune shows that

> testapp and test.o have no dependency on tools/mycc:

> 

> +-.

>  +-SConstruct

>  +-test.c

>  +-test.o

>  | +-test.c

>  +-testapp

>  | +-[test.o]

>  +-tools

>    +-tools/mycc

>      +-/usr/bin/gcc

>      +-/bin/cp

> 

> However, it works if I take the "tools/" part out of the mycc target, i.e.:

> 	mycc = e.Command(target="mycc", ...

> Moving mycc out of the subdirectory fixes the dependencies:

> 

> +-.

>  +-SConstruct

>  +-mycc

>  | +-/usr/bin/gcc

>  | +-/bin/cp

>  +-test.c

>  +-test.o

>  | +-test.c

>  | +-[mycc]

>  +-testapp

>    +-[test.o]

>    +-[mycc]

> 

> So my question is:  Is this a bug, or can someone show me how to get SCons to

> automatically build and use tools/mycc for the test app?



What happens if you change it to this:

> e = DefaultEnvironment()

> 

> mycc = e.Command(target="tools/mycc",

>                 source="/usr/bin/gcc",

>                 action="cp $SOURCE $TARGET")

> 

> e.Replace(CC = 'tools/mycc')

> 

> e.Program(target='testapp', source='test.c')


-Bill