Add a convenient way to add the includes install dir to the INTERFACE.

Export the INCLUDES DESTINATION without appending to the
INTERFACE_INCLUDE_DIRECTORIES of the target itself. That way, a target
can be exported multiple times with different INCLUDES DESTINATION
without unintended cross-pollution of export sets.

1 files changed, 8 insertions, 4 deletions

diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index b4e6e81..cff539f 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -277,27 +277,31 @@ static bool checkInterfaceDirs(const std::string &prepro,
 
 //----------------------------------------------------------------------------
 void cmExportFileGenerator::PopulateIncludeDirectoriesInterface(
-                      cmTarget *target,
+                      cmTargetExport *tei,
                       cmGeneratorExpression::PreprocessContext preprocessRule,
                       ImportPropertyMap &properties,
                       std::vector<std::string> &missingTargets)
 {
+  cmTarget *target = tei->Target;
   assert(preprocessRule == cmGeneratorExpression::InstallInterface);
 
   const char *propName = "INTERFACE_INCLUDE_DIRECTORIES";
   const char *input = target->GetProperty(propName);
-  if (!input)
+  if (!input && tei->InterfaceIncludeDirectories.empty())
     {
     return;
     }
-  if (!*input)
+  if (!*input && tei->InterfaceIncludeDirectories.empty())
     {
     // Set to empty
     properties[propName] = "";
     return;
     }
 
-  std::string prepro = cmGeneratorExpression::Preprocess(input,
+  std::string includes = (input?input:"");
+  const char* sep = input ? ";" : "";
+  includes += sep + tei->InterfaceIncludeDirectories;
+  std::string prepro = cmGeneratorExpression::Preprocess(includes,
                                                           preprocessRule);
   if (!prepro.empty())
     {