Report an error on IMPORTED targets with a faulty INTERFACE

It is considered an error if the INTERFACE_INCLUDE_DIRECTORIES contains
a directory which does not exist, which indicates a programmer error
by the upstream, or a packaging error.

One of the RunCMake.CompatibleInterface tests also needs to be updated
due to this change. Non-existant includes were used in the test, but
are not needed.

Source/cmTarget.cxx

@@ -131,11 +131,13 @@ public:
   SourceEntriesType SourceEntries;
 
   struct IncludeDirectoriesEntry {
-    IncludeDirectoriesEntry(cmsys::auto_ptr<cmCompiledGeneratorExpression> cge)
-      : ge(cge)
+    IncludeDirectoriesEntry(cmsys::auto_ptr<cmCompiledGeneratorExpression> cge,
+      const std::string &targetName = std::string())
+      : ge(cge), TargetName(targetName)
     {}
     const cmsys::auto_ptr<cmCompiledGeneratorExpression> ge;
     std::vector<std::string> CachedIncludes;
+    const std::string TargetName;
   };
   std::vector<IncludeDirectoriesEntry*> IncludeDirectoriesEntries;
   std::vector<cmValueWithOrigin> LinkInterfaceIncludeDirectoriesEntries;
@@ -2818,6 +2820,28 @@ static void processIncludeDirectories(cmTarget *tgt,
     for(std::vector<std::string>::iterator
           li = entryIncludes.begin(); li != entryIncludes.end(); ++li)
       {
+      cmTarget *dependentTarget =
+                              mf->FindTargetToUse((*it)->TargetName.c_str());
+
+      const bool fromImported = dependentTarget
+                             && dependentTarget->IsImported();
+
+      if (fromImported && !cmSystemTools::FileExists(li->c_str()))
+        {
+        cmOStringStream e;
+        e << "Imported target \"" << (*it)->TargetName << "\" includes "
+             "non-existent path\n  \"" << *li << "\"\nin its "
+             "INTERFACE_INCLUDE_DIRECTORIES. Possible reasons include:\n"
+             "* The path was deleted, renamed, or moved to another "
+             "location.\n"
+             "* An install or uninstall procedure did not complete "
+             "successfully.\n"
+             "* The installation package was faulty and references files it "
+             "does not provide.\n";
+        tgt->GetMakefile()->IssueMessage(cmake::FATAL_ERROR, e.str().c_str());
+        return;
+        }
+
       if (testIsOff && !cmSystemTools::IsOff(li->c_str()))
         {
         cmSystemTools::ConvertToUnixSlashes(*li);
@@ -2913,7 +2937,8 @@ std::vector<std::string> cmTarget::GetIncludeDirectories(const char *config)
                               it->Value + ",INTERFACE_INCLUDE_DIRECTORIES>");
 
       this->Internal->CachedLinkInterfaceIncludeDirectoriesEntries.push_back(
-                        new cmTargetInternals::IncludeDirectoriesEntry(cge));
+                        new cmTargetInternals::IncludeDirectoriesEntry(cge,
+                                                              it->Value));
       }
     }
 

Tests/RunCMake/CompatibleInterface/InterfaceString-builtin-prop.cmake

@@ -3,8 +3,6 @@ add_library(foo UNKNOWN IMPORTED)
 add_library(bar UNKNOWN IMPORTED)
 
 set_property(TARGET foo APPEND PROPERTY COMPATIBLE_INTERFACE_STRING INCLUDE_DIRECTORIES)
-set_property(TARGET foo PROPERTY INTERFACE_INCLUDE_DIRECTORIES foo_inc)
-set_property(TARGET bar PROPERTY INTERFACE_INCLUDE_DIRECTORIES bar_inc)
 
 add_executable(user main.cpp)
 set_property(TARGET user PROPERTY INCLUDE_DIRECTORIES bar_inc)

Tests/RunCMake/include_directories/ImportedTarget-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/include_directories/ImportedTarget-stderr.txt

@@ -0,0 +1,13 @@
+CMake Error in CMakeLists.txt:
+  Imported target "imported" includes non-existent path
+
+    "/does/not/exist"
+
+  in its INTERFACE_INCLUDE_DIRECTORIES.  Possible reasons include:
+
+  \* The path was deleted, renamed, or moved to another location.
+
+  \* An install or uninstall procedure did not complete successfully.
+
+  \* The installation package was faulty and references files it does not
+  provide.

Tests/RunCMake/include_directories/ImportedTarget.cmake

@@ -0,0 +1,9 @@
+
+project(ImportedTarget)
+
+add_library(testTarget "${CMAKE_CURRENT_SOURCE_DIR}/empty.cpp")
+
+add_library(imported UNKNOWN IMPORTED)
+set_property(TARGET imported PROPERTY INTERFACE_INCLUDE_DIRECTORIES "/does/not/exist")
+
+target_link_libraries(testTarget imported)

Tests/RunCMake/include_directories/RunCMakeTest.cmake

@@ -6,3 +6,4 @@ run_cmake(TID-bad-target)
 run_cmake(SourceDirectoryInInterface)
 run_cmake(BinaryDirectoryInInterface)
 run_cmake(RelativePathInInterface)
+run_cmake(ImportedTarget)