Add CMAKE_BUILD_INTERFACE_INCLUDES build-variable.

This makes

 set(CMAKE_BUILD_INTERFACE_INCLUDES ON)

add the equivalent of

 set_property(TARGET tgt APPEND PROPERTY
   INTERFACE_INCLUDE_DIRECTORIES
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR};${CMAKE_CURRENT_BINARY_DIR}>
 )

to every target.

If the headers are in CMAKE_CURRENT_SOURCE_DIR, and the generated headers
are in CMAKE_CURRENT_BINARY_DIR, this is a convenient way to build a target
bar, which depends on foo, just by using target_link_libraries() and adding
the INTERFACE_INCLUDE_DIRECTORIES to the INCLUDE_DIRECTORIES of the target
being linked. There will be more-convenient porcelain API to consume the
property in the future.

1 files changed, 17 insertions, 0 deletions

diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 0f439e9..d030aa7 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -938,6 +938,23 @@ void cmGlobalGenerator::Generate()
       (*targets)[tit->first] = tit->second;
       (*targets)[tit->first].SetMakefile(mf);
       }
+
+    for ( tit = targets->begin(); tit != targets->end(); ++ tit )
+      {
+      if (mf->IsOn("CMAKE_BUILD_INTERFACE_INCLUDES"))
+        {
+        const char *binDir = mf->GetStartOutputDirectory();
+        const char *srcDir = mf->GetStartDirectory();
+        const std::string dirs = std::string(binDir ? binDir : "")
+                                + std::string(binDir ? ";" : "")
+                                + std::string(srcDir ? srcDir : "");
+        if (!dirs.empty())
+          {
+          tit->second.AppendProperty("INTERFACE_INCLUDE_DIRECTORIES",
+                                ("$<BUILD_INTERFACE:" + dirs + ">").c_str());
+          }
+        }
+      }
     }
 
   // Add generator specific helper commands