Bug#900440: clang-6.0: clang cmake config files are installed to the wrong folder and have invalid path

[Norbert Lange]

Package: clang-6.0
Version: 1:6.0-3+b1
Severity: important

Dear Maintainer,

I was trying to compile doxygen doxygen-1.8.14 with libclang support,
the clang config for cmake is unusable.

First issue:
the paths in are relative to the cmake files and thus not correct if
placed in a differnt directory

copying/moving the files to the correct directory fixes this:
cp /usr/share/llvm-6.0/cmake/. /usr/lib/llvm-6.0/lib/cmake/clang -r

Second issue:
The file ClangTargets-relwithdebinfo.cmake paints the clang binary
at /usr/lib/llvm-6.0/bin/clang-6.0, this file does not exist.

editing the path to /usr/lib/llvm-6.0/bin/clang fixes this

A minimal CMakeLists.txt is following to reproduce this issue,
maybe a good idea to add such a test to the package

--------------------
cmake_minimum_required(VERSION 2.8.12)
project(testllvm)

find_package(LLVM CONFIG REQUIRED)
find_package(Clang CONFIG REQUIRED)

if(NOT LLVM_VERSION STREQUAL Clang_VERSION)
    #message(FATAL_ERROR "LLVM ${LLVM_VERSION} not matching to Clang ${Clang_VERSION}")
endif()

# rconfigure me with `cmake -DClang_DIR=/usr/lib/llvm-6.0/lib/cmake/clang` PATHTOTHISDIR
--------------------


-- System Information:
Debian Release: buster/sid
  APT prefers testing-debug
  APT policy: (500, 'testing-debug'), (200, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.16.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages clang-6.0 depends on:
ii  binutils                 2.30-20
ii  libc6                    2.27-3
ii  libc6-dev                2.27-3
ii  libclang-common-6.0-dev  1:6.0-3+b1
ii  libclang1-6.0            1:6.0-3+b1
ii  libgcc-7-dev             7.3.0-19
ii  libgcc1                  1:8.1.0-3
ii  libjsoncpp1              1.7.4-3
ii  libllvm6.0               1:6.0-3+b1
ii  libobjc-7-dev            7.3.0-19
ii  libstdc++-7-dev          7.3.0-19
ii  libstdc++6               8.1.0-3

Versions of packages clang-6.0 recommends:
pn  libomp-dev    <none>
ii  llvm-6.0-dev  1:6.0-3+b1
ii  python        2.7.15~rc1-1

Versions of packages clang-6.0 suggests:
pn  clang-6.0-doc  <none>
pn  gnustep        <none>
pn  gnustep-devel  <none>

-- no debconf information