Commit 328c0f65 (Simplify cmVisualStudio10TargetGenerator source
classification, 2012-03-19) introduced the first use of source
classification from cmGeneratorTarget (which originated as Makefile
generator logic) in a Visual Studio generator for handling of header
files. Fix classification of header files to match known header
extensions instead of only the HEADER_FILE_ONLY property. Make it
consistent with the "Header Files" source group.
Refactoring by commit 11d9b211 (Add cmGeneratorTarget to represent a
target during generation, 2012-03-07) and commit 45c2f932 (Simplify
cmMakefileTargetGenerator using cmGeneratorTarget, 2012-03-07) preserved
behavior introduced by commit 7740ccd1 (some cleanup of the makefile
generator, 2006-02-14) that favored the IgnoreFile extension test over
the availability of a known compilation language associated with a
source file. If a source is not marked as HEADER_FILE_ONLY and has a
known language extension or an explicit LANGUAGE property it should be
treated as that language. The LANGUAGE source file property
documentation says so.
Combine WriteCLSources and WriteObjSources into a single method. Use
the cmGeneratorTarget source classification to simplify tool selection
for each source file. Extend the classification to handle .idl files.
Necessary for the Xcode generator, in which the CMakeLists.txt
files are added as sources merely for convenient access, without
any associated custom command.
For now do not allow an OBJECT library to reference other object
libraries. Teach cmTarget::ComputeLinkImplementation to include the
languages of object libraries used by a target.
This library type can compile sources to object files but does not link
or archive them. It will be useful to reference from executable and
normal library targets for direct inclusion of object files in them.
Diagnose and reject the following as errors:
* An OBJECT library may not be referenced in target_link_libraries.
* An OBJECT library may contain only compiling sources and supporting
headers and custom commands. Other source types that are not normally
ignored are not allowed.
* An OBJECT library may not have PRE_BUILD, PRE_LINK, or POST_BUILD
commands.
* An OBJECT library may not be installed, exported, or imported.
Some of these cases may be supported in the future but are not for now.
Teach the VS generator that OBJECT_LIBRARY targets are "linkable" just
like STATIC_LIBRARY targets for the LinkLibraryDependencies behavior.
Some per-target information and logic is common to all generators.
Some of that information is currently stored in cmTarget but that
should be reserved for the configure step. Create a class to hold
per-target information for generators. On construction classify
sources from the target and store them in separate members. This
classification is already implemented separately in each generator.
Brad King
David Cole