[CMake] Bug in cmake 2.8.4/5 when using IMPORTED static targets?

[Marco Corvo]

Hi all,

I'm trying to use a new feature of releases 2.8.4/5, that is the 
possibility to define dependencies for IMPORTED targets and when I run 
cmake I get a SIGSEV signal. Trying to get some more info with Valgrind 
I found that:

-- Configuring done
==5659== Invalid read of size 1
==5659==    at 0x82001B0: cmTarget::IsImported() const (cmTarget.h:235)
==5659==    by 0x83CA8BB: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:272)
==5659==    by 0x83CA93E: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:281)
==5659==    by 0x83CA93E: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:281)
==5659==    by 0x83CAB3D: cmComputeTargetDepends::AddTargetDepend(int, 
char const*, bool) (cmComputeTargetDepends.cxx:263)
==5659==    by 0x83CAC5F: 
cmComputeTargetDepends::CollectTargetDepends(int) 
(cmComputeTargetDepends.cxx:216)
==5659==    by 0x83CAEFB: cmComputeTargetDepends::CollectDepends() 
(cmComputeTargetDepends.cxx:193)
==5659==    by 0x83CB055: cmComputeTargetDepends::Compute() 
(cmComputeTargetDepends.cxx:114)
==5659==    by 0x8346B4E: cmGlobalGenerator::ComputeTargetDepends() 
(cmGlobalGenerator.cxx:912)
==5659==    by 0x8346ECB: cmGlobalGenerator::Generate() 
(cmGlobalGenerator.cxx:873)
==5659==    by 0x835C9AE: cmGlobalUnixMakefileGenerator3::Generate() 
(cmGlobalUnixMakefileGenerator3.cxx:156)
==5659==    by 0x8260986: cmake::Generate() (cmake.cxx:2390)
==5659==  Address 0xdd is not stack'd, malloc'd or (recently) free'd
==5659==
==5659==
==5659== Process terminating with default action of signal 11 (SIGSEGV): 
dumping core
==5659==  Access not within mapped region at address 0xDD
==5659==    at 0x82001B0: cmTarget::IsImported() const (cmTarget.h:235)
==5659==    by 0x83CA8BB: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:272)
==5659==    by 0x83CA93E: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:281)
==5659==    by 0x83CA93E: cmComputeTargetDepends::AddTargetDepend(int, 
cmTarget*, bool) (cmComputeTargetDepends.cxx:281)
==5659==    by 0x83CAB3D: cmComputeTargetDepends::AddTargetDepend(int, 
char const*, bool) (cmComputeTargetDepends.cxx:263)
==5659==    by 0x83CAC5F: 
cmComputeTargetDepends::CollectTargetDepends(int) 
(cmComputeTargetDepends.cxx:216)
==5659==    by 0x83CAEFB: cmComputeTargetDepends::CollectDepends() 
(cmComputeTargetDepends.cxx:193)
==5659==    by 0x83CB055: cmComputeTargetDepends::Compute() 
(cmComputeTargetDepends.cxx:114)
==5659==    by 0x8346B4E: cmGlobalGenerator::ComputeTargetDepends() 
(cmGlobalGenerator.cxx:912)
==5659==    by 0x8346ECB: cmGlobalGenerator::Generate() 
(cmGlobalGenerator.cxx:873)
==5659==    by 0x835C9AE: cmGlobalUnixMakefileGenerator3::Generate() 
(cmGlobalUnixMakefileGenerator3.cxx:156)
==5659==    by 0x8260986: cmake::Generate() (cmake.cxx:2390)

So it looks like cmake is trying to access (dereference) a NULL pointer. 
In particular, digging in the source code, the issue arises (apparently) 
in cmComputeTargetDepends.cxx(AddTargetDepend) at line 279

cmTarget* transitive_dependee =
         dependee->GetMakefile()->FindTargetToUse(i->c_str());

when cmake recursively calculates the dependency of my target, which 
relies on all IMPORTED targets, and hits an IMPORTED target (a library) 
with NO dependencies, that is the last leaf of my deps tree. The 
"transitive_dependee" returned by FindTargetToTuse turns out to be a 
NULL pointer and when IsImported() is called on it, it makes the program 
crash.

Have anyone else tried to use this feature of cmake 2.8.4 and eventually 
discovered this issue?

Cheers,

Marco


-- 
Marco Corvo
SuperB experiment
CNRS - Orsay
c/o INFN - Padova