Fix paths in pkg-config file

[jamiesnape]

pkg-config should be giving absolute paths rather than relative paths.

Broken by dc9c750 and in 0.6.0. If it would be possible to cut a 0.6.1 release with this fix in it, it would be very much appreciated.

Before:

$ cat yaml-cpp.pc
libdir=lib
includedir=include

Name: Yaml-cpp
Description: A YAML parser and emitter for C++
Version: 0.6.0
Requires:
Libs: -L${libdir} -lyaml-cpp
Cflags: -I${includedir}
$ pkg-config --cflags yaml-cpp 
-Iinclude
$pkg-config --libs yaml-cpp 
-Llib -lyaml-cpp

After (for example with install prefix /usr/local):

$ cat yaml-cpp.pc 
prefix=/usr/local
exec_prefix=${prefix}
includedir=${prefix}/include
libdir=${exec_prefix}/lib

Name: Yaml-cpp
Description: A YAML parser and emitter for C++
Version: 0.6.0
Requires:
Libs: -L${libdir} -lyaml-cpp
Cflags: -I${includedir}
$ pkg-config --cflags yaml-cpp 
-I/usr/local/include
$ pkg-config --libs yaml-cpp 
-L/usr/local/lib -lyaml-cpp

PTAL @jbeder.

[jbeder]

Is there a way to automatically test stuff like this? It would be nice to avoid having these CMake changes breaking things.

[jamiesnape]

Something like:

make install
mkdir /tmp/hello_world
cd /tmp/hello_world
cat << 'EOF' > hello_world.cpp
#include <yaml-cpp/yaml.h>
int main() {
  YAML::Node node = YAML::Node("Hello, World!");
  return 0;
}
EOF
$CXX hello_world.cpp -Wall -std=c++11 $(pkg-config --cflags yaml-cpp) $(pkg-config --libs yaml-cpp) -o hello_world_pkg_config
./hello_world_pkg_config

Though possibly that would still compile (with a warning from ld) if the install prefix were /usr/ or /usr/local.

To test cmake you could add something like:

make install
mkdir /tmp/hello_world
cd /tmp/hello_world
cat << 'EOF' > hello_world.cpp
#include <yaml-cpp/yaml.h>
int main() {
  YAML::Node node = YAML::Node("Hello, World!");
  return 0;
}
EOF
cat << 'EOF' > CMakeLists.txt
cmake_minimum_required(VERSION 2.6)
project(hello_world)
find_package(yaml-cpp REQUIRED)
add_executable(hello_world_cmake hello_world.cpp)
target_link_libraries(hello_world_cmake yaml-cpp)
EOF
cmake .
make
./hello_world_cmake

[jbeder]

I mean automatically; how do I write that test?

[jamiesnape]

The quick way would be paste the above into a file my_bash_script, make it executable, and modify .travis.yml:

script:
  - make
  - test/run-tests
  - make install
  - ./my_bash_script