Add a way to exclude INTERFACE properties from exported targets.

Projects set interface requirements upstream, and existing
downstreams use of target_link_libraries will consume those interfaces.

This can create a backward compatibility concern as the result may
be changing the order of include directories of downstreams, or another
side-effect of using the INTERFACE properties.

Provide a way for them to emulate the behavior of a version-based
policy in the config file.
This commit is contained in:
Stephen Kelly 2013-01-29 16:32:51 +01:00
parent d4297d5697
commit 2c3654c3de
2 changed files with 25 additions and 3 deletions

View File

@ -264,15 +264,16 @@ void cmExportFileGenerator::GenerateInterfaceProperties(cmTarget *target,
{
if (!properties.empty())
{
os << "if(NOT ${CMAKE_FIND_PACKAGE_NAME}_NO_INTERFACES)\n";
std::string targetName = this->Namespace;
targetName += target->GetName();
os << "set_target_properties(" << targetName << " PROPERTIES\n";
os << " set_target_properties(" << targetName << " PROPERTIES\n";
for(ImportPropertyMap::const_iterator pi = properties.begin();
pi != properties.end(); ++pi)
{
os << " " << pi->first << " \"" << pi->second << "\"\n";
os << " " << pi->first << " \"" << pi->second << "\"\n";
}
os << ")\n\n";
os << " )\nendif()\n\n";
}
}

View File

@ -376,6 +376,27 @@ void cmFindPackageCommand::GenerateDocumentation()
"The package configuration file may set <package>_FOUND to false "
"to tell find_package that component requirements are not satisfied."
"\n"
"Targets exported by the install() command may have additional INTERFACE "
"properties set for include directories, compile definitions etc. As "
"these may create a backward compatibility concern for consumers of "
"existing projects, it is possible to set the <package>_NO_INTERFACES "
"variable to disable populating those interfaces. It is possible to "
"emulate a version-based policy for whether the interfaces should be "
"enabled in the config file before including the imported targets file. "
"This allows consumers to decide when to enable the new interfaces when "
"upgrading. The upstream project is responsible for adding code similar "
"to this in the version which generates the INTERFACE content:\n"
" if(${CMAKE_FIND_PACKAGE_NAME}_FIND_VERSION VERSION_LESS 2.3\n"
" AND NOT ${CMAKE_FIND_PACKAGE_NAME}_INTERFACES)\n"
" set(${CMAKE_FIND_PACKAGE_NAME}_NO_INTERFACES 1)\n"
" endif()\n"
" include(\"${CMAKE_CURRENT_LIST_DIR}/<package>Targets.cmake\")\n"
"\n"
"Downstream users may then choose to use the new interfaces by finding "
"the newer version of upstream. They can also choose to not use the new "
"interfaces by setting <package>_INTERFACES to false before finding the "
"package.\n"
"\n"
"See the cmake_policy() command documentation for discussion of the "
"NO_POLICY_SCOPE option."
;