Using full paths is more versatile. The current solution
breaks when specifying an absolute path for CMAKE_INSTALL_INCLUDEDIR
which is an otherwise supported option by CMake's GNUInstallDirs.
CMake does not support Autoconf-style ${prefix}-pseudo variables,
hence trying to emulate the behaviour gains us nothing and breaks
providing absolute paths to CMAKE_INSTALL_LIBDIR.
* The GNUInstallDirs module is more idiomatic and supported by
Kitware upstream, whereas the current directories are not
standardised across CMake-using packages. Using CMake native
mechanisms is better than reinventing the wheel, as it makes
using the build system more uniform across the ecosystem
* Use CMAKE_CXX_STANDARD to force C++11
* Require CMake 3.1.0 at a minimum
* Fixed lower/UPPERcase format for function/macro calls
* Fixed indents by replacing tabs with 4 spaces
Recent commit 911e2b0fea ("By default use <prefix> relative paths when
installing") introduced relative install paths in CMake. But this
interacts badly with commit e6f1cffdd3 from a year ago: now, the paths in
`pkgconfig/jsoncpp.pc` are relative, which is incorrect.
Before 911e2b0fea (1.7.2 on Archlinux), this was correct:
$ head -4 /usr/lib/pkgconfig/jsoncpp.pc
prefix=/usr
exec_prefix=${prefix}
libdir=/usr/lib
includedir=/usr/include
After 911e2b0fea (1.7.3 on Archlinux), this is now incorrect:
$ head -4 /usr/lib/pkgconfig/jsoncpp.pc
prefix=/usr
exec_prefix=${prefix}
libdir=lib
includedir=include
This change causes hard-to-debug compilation errors for projects that
depend on jsoncpp, for instance:
CXXLD libring.la
/tmp/ring-daemon/src/ring-daemon/src/../libtool: line 7486: cd: lib: No such file or directory
libtool: error: cannot determine absolute directory name of 'lib'
make[3]: *** [Makefile:679: libring.la] Error 1
This is because jsoncpp contributes `-Llib -ljsoncpp` to the LDFLAGS, via
the pkg-config machinery. Notice the relative path in `-Llib`.
To fix this, simply revert commit e6f1cffdd3 ("Fix custom includedir &
libdir substitution in pkg-config"). The change in 911e2b0fea should have
the same effect.
See #279, #470 for references.
Do not prepend ${prefix} to substituted includedir & libdir
in the pkg-config file -- if the paths are overriden by user, CMake puts
absolute paths there (even if user specifies a relative path). Instead,
use the absolute path provided by CMake and appropriately default
LIBRARY_INSTALL_DIR & INCLUDE_INSTALL_DIR to absolute paths with
${CMAKE_INSTALL_PREFIX} prepended.
Fixes: https://github.com/open-source-parsers/jsoncpp/issues/279
Signed-off-by: Michał Górny <mgorny@gentoo.org>
RPM-based distros such as Fedora or Mageia put 64bit libraries in /usr/lib64
while 32bit libraries go to /usr/lib. This is usually taken into account
in CMake projects using a LIB_SUFFIX parameter that can be set to "" or "64".
