9 files changed, 47 insertions, 8 deletions
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index b476a27..ad1c83e 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -649,6 +649,8 @@ static bool processSources(cmTarget const* tgt,
   for (std::vector<cmTargetInternals::TargetPropertyEntry*>::const_iterator
       it = entries.begin(), end = entries.end(); it != end; ++it)
     {
+    cmLinkImplItem const& item = (*it)->LinkImplItem;
+    std::string const& targetName = item;
     std::vector<std::string> entrySources;
     cmSystemTools::ExpandListArgument((*it)->ge->Evaluate(mf,
                                               config,
@@ -667,11 +669,10 @@ static bool processSources(cmTarget const* tgt,
         i != entrySources.end(); ++i)
       {
       std::string& src = *i;
-
       cmSourceFile* sf = mf->GetOrCreateSource(src);
       std::string e;
-      src = sf->GetFullPath(&e);
-      if(src.empty())
+      std::string fullPath = sf->GetFullPath(&e);
+      if(fullPath.empty())
         {
         if(!e.empty())
           {
@@ -681,6 +682,25 @@ static bool processSources(cmTarget const* tgt,
           }
         return contextDependent;
         }
+
+      if (!targetName.empty() && !cmSystemTools::FileIsFullPath(src.c_str()))
+        {
+        cmOStringStream err;
+        if (!targetName.empty())
+          {
+          err << "Target \"" << targetName << "\" contains relative "
+            "path in its INTERFACE_SOURCES:\n"
+            "  \"" << src << "\"";
+          }
+        else
+          {
+          err << "Found relative path while evaluating sources of "
+          "\"" << tgt->GetName() << "\":\n  \"" << src << "\"\n";
+          }
+        tgt->GetMakefile()->IssueMessage(cmake::FATAL_ERROR, err.str());
+        return contextDependent;
+        }
+      src = fullPath;
       }
     std::string usedSources;
     for(std::vector<std::string>::iterator
diff --git a/Tests/ConfigSources/CMakeLists.txt b/Tests/ConfigSources/CMakeLists.txt
index c272257..748aad8 100644
--- a/Tests/ConfigSources/CMakeLists.txt
+++ b/Tests/ConfigSources/CMakeLists.txt
@@ -5,9 +5,9 @@ project(ConfigSources)
 
 add_library(iface INTERFACE)
 set_property(TARGET iface PROPERTY INTERFACE_SOURCES
-  iface_src.cpp
-  $<$<CONFIG:Debug>:iface_debug_src.cpp>
-  $<$<CONFIG:Release>:does_not_exist.cpp>
+  "${CMAKE_CURRENT_SOURCE_DIR}/iface_src.cpp"
+  "$<$<CONFIG:Debug>:${CMAKE_CURRENT_SOURCE_DIR}/iface_debug_src.cpp>"
+  "$<$<CONFIG:Release>:${CMAKE_CURRENT_SOURCE_DIR}/does_not_exist.cpp>"
 )
 
 add_executable(ConfigSources
diff --git a/Tests/RunCMake/TargetSources/OriginDebug.cmake b/Tests/RunCMake/TargetSources/OriginDebug.cmake
index 5fe9ba7..d40a1d8 100644
--- a/Tests/RunCMake/TargetSources/OriginDebug.cmake
+++ b/Tests/RunCMake/TargetSources/OriginDebug.cmake
@@ -7,7 +7,7 @@ set(CMAKE_DEBUG_TARGET_PROPERTIES SOURCES)
 
 add_library(iface INTERFACE)
 set_property(TARGET iface PROPERTY INTERFACE_SOURCES
-  empty_1.cpp
+  "${CMAKE_CURRENT_SOURCE_DIR}/empty_1.cpp"
 )
 
 add_library(OriginDebug empty_2.cpp)
diff --git a/Tests/RunCMake/TargetSources/RelativePathInInterface-result.txt b/Tests/RunCMake/TargetSources/RelativePathInInterface-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/TargetSources/RelativePathInInterface-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/TargetSources/RelativePathInInterface-stderr.txt b/Tests/RunCMake/TargetSources/RelativePathInInterface-stderr.txt
new file mode 100644
index 0000000..d47dd4d
--- /dev/null
+++ b/Tests/RunCMake/TargetSources/RelativePathInInterface-stderr.txt
@@ -0,0 +1,4 @@
+CMake Error in CMakeLists.txt:
+  Target "iface" contains relative path in its INTERFACE_SOURCES:
+
+    "empty_1.cpp"
diff --git a/Tests/RunCMake/TargetSources/RelativePathInInterface.cmake b/Tests/RunCMake/TargetSources/RelativePathInInterface.cmake
new file mode 100644
index 0000000..8bb6149
--- /dev/null
+++ b/Tests/RunCMake/TargetSources/RelativePathInInterface.cmake
@@ -0,0 +1,6 @@
+
+add_library(iface INTERFACE)
+target_sources(iface INTERFACE empty_1.cpp)
+
+add_executable(main main.cpp)
+target_link_libraries(main iface)
diff --git a/Tests/RunCMake/TargetSources/RunCMakeTest.cmake b/Tests/RunCMake/TargetSources/RunCMakeTest.cmake
index 1d2eaec..c6d7f43 100644
--- a/Tests/RunCMake/TargetSources/RunCMakeTest.cmake
+++ b/Tests/RunCMake/TargetSources/RunCMakeTest.cmake
@@ -8,3 +8,4 @@ else()
 endif()
 
 run_cmake(CMP0026-LOCATION)
+run_cmake(RelativePathInInterface)
diff --git a/Tests/RunCMake/TargetSources/main.cpp b/Tests/RunCMake/TargetSources/main.cpp
new file mode 100644
index 0000000..766b775
--- /dev/null
+++ b/Tests/RunCMake/TargetSources/main.cpp
@@ -0,0 +1,5 @@
+
+int main()
+{
+  return 0;
+}
diff --git a/Tests/SourcesProperty/CMakeLists.txt b/Tests/SourcesProperty/CMakeLists.txt
index 6c99e00..d1c35d8 100644
--- a/Tests/SourcesProperty/CMakeLists.txt
+++ b/Tests/SourcesProperty/CMakeLists.txt
@@ -4,7 +4,9 @@ cmake_minimum_required(VERSION 3.0)
 project(SourcesProperty)
 
 add_library(iface INTERFACE)
-set_property(TARGET iface PROPERTY INTERFACE_SOURCES iface.cpp)
+set_property(TARGET iface PROPERTY INTERFACE_SOURCES
+  "${CMAKE_CURRENT_SOURCE_DIR}/iface.cpp"
+)
 
 add_executable(SourcesProperty main.cpp)
 target_link_libraries(SourcesProperty iface)