Create make rules for INTERFACE_LIBRARY targets.

The result is that the depends of the target are created.

So,

 add_library(somelib foo.cpp)
 add_library(anotherlib EXCLUDE_FROM_ALL foo.cpp)
 add_library(extra EXCLUDE_FROM_ALL foo.cpp)
 target_link_libraries(anotherlib extra)

 add_library(iface INTERFACE)
 target_link_libraries(iface INTERFACE anotherlib)

Executing 'make iface' will result in the anotherlib and extra targets
being made.

Adding a regular executable to the INTERFACE of an INTERFACE_LIBRARY
will not result in the executable being built with 'make iface' because
of the logic in cmComputeTargetDepends::AddTargetDepend.

So far, this is implemented only for the Makefile generator. Other
generators will follow if this feature is possible for them.

Make INTERFACE_LIBRARY targets part of the all target by default.
Test this by building the all target and making the expected library
EXCLUDE_FROM_ALL.

1 files changed, 23 insertions, 0 deletions

diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 5e10e25..bd37a54 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -1112,6 +1112,29 @@ void cmTarget::GetDirectLinkLibraries(const char *config,
 }
 
 //----------------------------------------------------------------------------
+void cmTarget::GetInterfaceLinkLibraries(const char *config,
+                            std::vector<std::string> &libs, cmTarget *head)
+{
+  const char *prop = this->GetProperty("INTERFACE_LINK_LIBRARIES");
+  if (prop)
+    {
+    cmListFileBacktrace lfbt;
+    cmGeneratorExpression ge(lfbt);
+    const cmsys::auto_ptr<cmCompiledGeneratorExpression> cge = ge.Parse(prop);
+
+    cmGeneratorExpressionDAGChecker dagChecker(lfbt,
+                                        this->GetName(),
+                                        "INTERFACE_LINK_LIBRARIES", 0, 0);
+    cmSystemTools::ExpandListArgument(cge->Evaluate(this->Makefile,
+                                        config,
+                                        false,
+                                        head,
+                                        &dagChecker),
+                                      libs);
+    }
+}
+
+//----------------------------------------------------------------------------
 std::string cmTarget::GetDebugGeneratorExpressions(const std::string &value,
                                   cmTarget::LinkLibraryType llt)
 {