target_link_libraries: Allow use with targets in other directories

Previously the command did not allow naming targets on the LHS that
were not created in the calling directory.  Lift this restriction to
enable more flexible use by projects.

Targets named on the RHS will need to be looked up during generation in
the scope of the call site rather than the scope of the LHS target.
Introduce an internal syntax in `[INTERFACE_]LINK_LIBRARIES` properties
to specify target names that need to be looked up in a directory other
than that containing the target on which the property is set.  Add
minimal documentation of the syntax to help users that encounter it.

Unfortunately CMake previously did allow such calls in the case that
only `INTERFACE` libraries are specified, but those libraries would be
looked up in the target's directory rather than the caller's.  Add
policy `CMP0079` to enable the new behavior with new lookup scope in a
compatible way.

Fixes: #17943

40 files changed, 227 insertions, 11 deletions

diff --git a/Tests/CMakeCommands/target_link_libraries/CMakeLists.txt b/Tests/CMakeCommands/target_link_libraries/CMakeLists.txt
index e11f980..85ce1f7 100644
--- a/Tests/CMakeCommands/target_link_libraries/CMakeLists.txt
+++ b/Tests/CMakeCommands/target_link_libraries/CMakeLists.txt
@@ -130,3 +130,15 @@ target_link_libraries(newsignature1 PRIVATE depC INTERFACE depD PUBLIC depB PRIV
 
 assert_property(newsignature1 INTERFACE_LINK_LIBRARIES "depD;depB")
 assert_property(newsignature1 LINK_LIBRARIES "depC;depB;subdirlib")
+
+#----------------------------------------------------------------------------
+# Test cross-directory linking.
+cmake_policy(PUSH)
+cmake_policy(SET CMP0079 NEW)
+add_executable(TopDir TopDir.c)
+add_subdirectory(SubDirA)
+add_subdirectory(SubDirB)
+target_link_libraries(SubDirB TopDirImported)
+add_library(TopDirImported IMPORTED INTERFACE)
+target_compile_definitions(TopDirImported INTERFACE DEF_TopDirImported)
+cmake_policy(POP)
diff --git a/Tests/CMakeCommands/target_link_libraries/SubDirA/CMakeLists.txt b/Tests/CMakeCommands/target_link_libraries/SubDirA/CMakeLists.txt
new file mode 100644
index 0000000..4dae103
--- /dev/null
+++ b/Tests/CMakeCommands/target_link_libraries/SubDirA/CMakeLists.txt
@@ -0,0 +1,15 @@
+add_executable(SubDirA SubDirA.c)
+
+# Link to a target imported in this directory that would not normally
+# be visible to the directory in which TopDir is defined.
+target_link_libraries(TopDir PUBLIC SameNameImported)
+
+# Link SubDirA to a target imported in this directory that has the same
+# name as a target imported in SubDirB's directory.  SubDirB will also
+# tell us to link its copy.  At compile time we verify both are linked.
+target_link_libraries(SubDirA PRIVATE SameNameImported)
+
+# Import a target with the same name as a target imported in SubDirB.
+# Distinguish this copy by having a unique usage requirement.
+add_library(SameNameImported IMPORTED INTERFACE)
+target_compile_definitions(SameNameImported INTERFACE DEF_SameNameImportedSubDirA)
diff --git a/Tests/CMakeCommands/target_link_libraries/SubDirA/SubDirA.c b/Tests/CMakeCommands/target_link_libraries/SubDirA/SubDirA.c
new file mode 100644
index 0000000..4706bb9
--- /dev/null
+++ b/Tests/CMakeCommands/target_link_libraries/SubDirA/SubDirA.c
@@ -0,0 +1,14 @@
+#ifndef DEF_SameNameImportedSubDirA
+#  error "DEF_SameNameImportedSubDirA is not defined but should be!"
+#endif
+#ifndef DEF_SameNameImportedSubDirB
+#  error "DEF_SameNameImportedSubDirB is not defined but should be!"
+#endif
+#ifdef DEF_TopDirImported
+#  error "DEF_TopDirImported is defined but should not be!"
+#endif
+
+int main(void)
+{
+  return 0;
+}
diff --git a/Tests/CMakeCommands/target_link_libraries/SubDirB/CMakeLists.txt b/Tests/CMakeCommands/target_link_libraries/SubDirB/CMakeLists.txt
new file mode 100644
index 0000000..7c918e6
--- /dev/null
+++ b/Tests/CMakeCommands/target_link_libraries/SubDirB/CMakeLists.txt
@@ -0,0 +1,15 @@
+add_executable(SubDirB SubDirB.c)
+
+# Link to a target imported in this directory that would not normally
+# be visible to the directory in which TopDir is defined.
+target_link_libraries(TopDir PUBLIC SameNameImported)
+
+# Link SubDirA to a target imported in this directory that has the same
+# name as a target imported in SubDirA's directory.  We verify when
+# compiling SubDirA that it sees our target and its own.
+target_link_libraries(SubDirA PRIVATE SameNameImported)
+
+# Import a target with the same name as a target imported in SubDirA.
+# Distinguish this copy by having a unique usage requirement.
+add_library(SameNameImported IMPORTED INTERFACE)
+target_compile_definitions(SameNameImported INTERFACE DEF_SameNameImportedSubDirB)
diff --git a/Tests/CMakeCommands/target_link_libraries/SubDirB/SubDirB.c b/Tests/CMakeCommands/target_link_libraries/SubDirB/SubDirB.c
new file mode 100644
index 0000000..6e56729
--- /dev/null
+++ b/Tests/CMakeCommands/target_link_libraries/SubDirB/SubDirB.c
@@ -0,0 +1,14 @@
+#ifdef DEF_SameNameImportedSubDirA
+#  error "DEF_SameNameImportedSubDirA is defined but should not be!"
+#endif
+#ifdef DEF_SameNameImportedSubDirB
+#  error "DEF_SameNameImportedSubDirB is defined but should not be!"
+#endif
+#ifndef DEF_TopDirImported
+#  error "DEF_TopDirImported is not defined but should be!"
+#endif
+
+int main(void)
+{
+  return 0;
+}
diff --git a/Tests/CMakeCommands/target_link_libraries/TopDir.c b/Tests/CMakeCommands/target_link_libraries/TopDir.c
new file mode 100644
index 0000000..4706bb9
--- /dev/null
+++ b/Tests/CMakeCommands/target_link_libraries/TopDir.c
@@ -0,0 +1,14 @@
+#ifndef DEF_SameNameImportedSubDirA
+#  error "DEF_SameNameImportedSubDirA is not defined but should be!"
+#endif
+#ifndef DEF_SameNameImportedSubDirB
+#  error "DEF_SameNameImportedSubDirB is not defined but should be!"
+#endif
+#ifdef DEF_TopDirImported
+#  error "DEF_TopDirImported is defined but should not be!"
+#endif
+
+int main(void)
+{
+  return 0;
+}
diff --git a/Tests/ExportImport/Export/CMakeLists.txt b/Tests/ExportImport/Export/CMakeLists.txt
index fdb2fa1..cb048be 100644
--- a/Tests/ExportImport/Export/CMakeLists.txt
+++ b/Tests/ExportImport/Export/CMakeLists.txt
@@ -155,6 +155,13 @@ add_library(testStaticLibRequiredPrivate testStaticLibRequiredPrivate.c)
 target_link_libraries(testLibDepends PRIVATE testStaticLibRequiredPrivate)
 cmake_policy(POP)
 
+cmake_policy(PUSH)
+cmake_policy(SET CMP0079 NEW)
+add_library(TopDirLib STATIC testTopDirLib.c)
+add_subdirectory(SubDirLinkA)
+add_subdirectory(SubDirLinkB)
+cmake_policy(POP)
+
 macro(add_include_lib _libName)
   file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/${_libName}.c" "/* no content */\n")
   add_library(${_libName} "${CMAKE_CURRENT_BINARY_DIR}/${_libName}.c")
@@ -508,6 +515,7 @@ install(
   testLibCycleA testLibCycleB
   testLibNoSONAME
   cmp0022NEW cmp0022OLD
+  TopDirLib SubDirLinkA
   systemlib
   EXPORT exp
   RUNTIME DESTINATION $<1:bin>$<0:/wrong>
@@ -566,6 +574,7 @@ export(TARGETS testExe1 testLib1 testLib2 testLib3
   testSharedLibRequired testSharedLibRequiredUser testSharedLibRequiredUser2
   testSharedLibDepends renamed_on_export
   cmp0022NEW cmp0022OLD
+  TopDirLib SubDirLinkA
   systemlib
   NAMESPACE bld_
   FILE ExportBuildTree.cmake
diff --git a/Tests/ExportImport/Export/SubDirLinkA/CMakeLists.txt b/Tests/ExportImport/Export/SubDirLinkA/CMakeLists.txt
new file mode 100644
index 0000000..1c3c9dc
--- /dev/null
+++ b/Tests/ExportImport/Export/SubDirLinkA/CMakeLists.txt
@@ -0,0 +1,6 @@
+add_library(SubDirLinkAImported IMPORTED INTERFACE)
+target_compile_definitions(SubDirLinkAImported INTERFACE DEF_SubDirLinkAImportedForExport)
+
+target_link_libraries(TopDirLib PUBLIC SubDirLinkAImported)
+
+add_library(SubDirLinkA STATIC SubDirLinkA.c)
diff --git a/Tests/ExportImport/Export/SubDirLinkA/SubDirLinkA.c b/Tests/ExportImport/Export/SubDirLinkA/SubDirLinkA.c
new file mode 100644
index 0000000..abf76f5
--- /dev/null
+++ b/Tests/ExportImport/Export/SubDirLinkA/SubDirLinkA.c
@@ -0,0 +1,11 @@
+#ifdef DEF_SubDirLinkAImportedForExport
+#  error "DEF_SubDirLinkAImportedForExport is defined but should not be!"
+#endif
+#ifndef DEF_SubDirLinkBImportedForExport
+#  error "DEF_SubDirLinkBImportedForExport is not defined but should be!"
+#endif
+
+int testSubDirLinkA(void)
+{
+  return 0;
+}
diff --git a/Tests/ExportImport/Export/SubDirLinkB/CMakeLists.txt b/Tests/ExportImport/Export/SubDirLinkB/CMakeLists.txt
new file mode 100644
index 0000000..22e168f
--- /dev/null
+++ b/Tests/ExportImport/Export/SubDirLinkB/CMakeLists.txt
@@ -0,0 +1,4 @@
+add_library(SubDirLinkBImported IMPORTED INTERFACE)
+target_compile_definitions(SubDirLinkBImported INTERFACE DEF_SubDirLinkBImportedForExport)
+
+target_link_libraries(SubDirLinkA PUBLIC SubDirLinkBImported)
diff --git a/Tests/ExportImport/Export/testTopDirLib.c b/Tests/ExportImport/Export/testTopDirLib.c
new file mode 100644
index 0000000..1ec68de
--- /dev/null
+++ b/Tests/ExportImport/Export/testTopDirLib.c
@@ -0,0 +1,11 @@
+#ifndef DEF_SubDirLinkAImportedForExport
+#  error "DEF_SubDirLinkAImportedForExport is not defined but should be!"
+#endif
+#ifdef DEF_SubDirLinkBImportedForExport
+#  error "DEF_SubDirLinkBImportedForExport is defined but should not be!"
+#endif
+
+int testTopDirLib(void)
+{
+  return 0;
+}
diff --git a/Tests/ExportImport/Import/A/CMakeLists.txt b/Tests/ExportImport/Import/A/CMakeLists.txt
index 7510d7e..8791a19 100644
--- a/Tests/ExportImport/Import/A/CMakeLists.txt
+++ b/Tests/ExportImport/Import/A/CMakeLists.txt
@@ -1,3 +1,9 @@
+# Prepare imported targets that the exported project itself imported.
+add_library(SubDirLinkAImported IMPORTED INTERFACE)
+target_compile_definitions(SubDirLinkAImported INTERFACE DEF_SubDirLinkAImportedForImport)
+add_library(SubDirLinkBImported IMPORTED INTERFACE)
+target_compile_definitions(SubDirLinkBImported INTERFACE DEF_SubDirLinkBImportedForImport)
+
 # Import targets from the exported build tree.
 include(${Import_BINARY_DIR}/../Export/ExportBuildTree.cmake)
 
@@ -158,6 +164,11 @@ target_link_libraries(cmp0022OLD_exp_test exp_cmp0022OLD)
 add_executable(cmp0022NEW_exp_test cmp0022NEW_test_vs6_2.cpp)
 target_link_libraries(cmp0022NEW_exp_test exp_cmp0022NEW)
 
+add_executable(SubDirLink_bld SubDirLink.c)
+target_link_libraries(SubDirLink_bld PRIVATE bld_TopDirLib bld_SubDirLinkA)
+add_executable(SubDirLink_exp SubDirLink.c)
+target_link_libraries(SubDirLink_exp PRIVATE exp_TopDirLib exp_SubDirLinkA)
+
 # Try building a plugin to an executable imported from the build tree.
 add_library(imp_mod1b MODULE imp_mod1.c)
 target_link_libraries(imp_mod1b bld_testExe2)
diff --git a/Tests/ExportImport/Import/A/SubDirLink.c b/Tests/ExportImport/Import/A/SubDirLink.c
new file mode 100644
index 0000000..eb4b860
--- /dev/null
+++ b/Tests/ExportImport/Import/A/SubDirLink.c
@@ -0,0 +1,14 @@
+#ifndef DEF_SubDirLinkAImportedForImport
+#  error "DEF_SubDirLinkAImportedForImport is not defined but should be!"
+#endif
+#ifndef DEF_SubDirLinkBImportedForImport
+#  error "DEF_SubDirLinkBImportedForImport is not defined but should be!"
+#endif
+
+extern int testTopDirLib(void);
+extern int testSubDirLinkA(void);
+
+int main(void)
+{
+  return (testTopDirLib() + testSubDirLinkA() + 0);
+}
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW-stdout.txt b/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW-stdout.txt
new file mode 100644
index 0000000..89cd806
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW-stdout.txt
@@ -0,0 +1 @@
+-- INTERFACE_LINK_LIBRARIES='foo::@<[Xx0-9A-Fa-f]+>'
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW.cmake
new file mode 100644
index 0000000..82486c4
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-NEW.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0079 NEW)
+include(CMP0079-iface-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD-stdout.txt b/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD-stdout.txt
new file mode 100644
index 0000000..e575e16
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD-stdout.txt
@@ -0,0 +1 @@
+-- INTERFACE_LINK_LIBRARIES='foo'
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD.cmake
new file mode 100644
index 0000000..e04a2bb
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-OLD.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0079 OLD)
+include(CMP0079-iface-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stderr.txt b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stderr.txt
new file mode 100644
index 0000000..6dd7d30
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stderr.txt
@@ -0,0 +1,17 @@
+^CMake Warning \(dev\) at CMP0079-iface/CMakeLists.txt:[0-9]+ \(target_link_libraries\):
+  Policy CMP0079 is not set: target_link_libraries allows use with targets in
+  other directories.  Run "cmake --help-policy CMP0079" for policy details.
+  Use the cmake_policy command to set the policy and suppress this warning.
+
+  Target
+
+    top
+
+  is not created in this directory.  For compatibility with older versions of
+  CMake, link library
+
+    foo
+
+  will be looked up in the directory in which the target was created rather
+  than in this calling directory.
+This warning is for project developers.  Use -Wno-dev to suppress it.$
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stdout.txt b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stdout.txt
new file mode 100644
index 0000000..e575e16
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN-stdout.txt
@@ -0,0 +1 @@
+-- INTERFACE_LINK_LIBRARIES='foo'
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN.cmake
new file mode 100644
index 0000000..2041893
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-WARN.cmake
@@ -0,0 +1 @@
+include(CMP0079-iface-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface-common.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-iface-common.cmake
new file mode 100644
index 0000000..3982ff2
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface-common.cmake
@@ -0,0 +1,6 @@
+enable_language(C)
+
+add_executable(top empty.c)
+add_subdirectory(CMP0079-iface)
+get_property(libs TARGET top PROPERTY INTERFACE_LINK_LIBRARIES)
+message(STATUS "INTERFACE_LINK_LIBRARIES='${libs}'")
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-iface/CMakeLists.txt b/Tests/RunCMake/target_link_libraries/CMP0079-iface/CMakeLists.txt
new file mode 100644
index 0000000..4b15b32
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-iface/CMakeLists.txt
@@ -0,0 +1 @@
+target_link_libraries(top INTERFACE foo)
diff --git a/Tests/RunCMake/target_link_libraries/SubDirTarget-result.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus-result.txt
index d00491f..d00491f 100644
--- a/Tests/RunCMake/target_link_libraries/SubDirTarget-result.txt
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus-result.txt
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus-stderr.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus-stderr.txt
new file mode 100644
index 0000000..b9fe3f6
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus-stderr.txt
@@ -0,0 +1,6 @@
+^CMake Error at CMP0079-link-NEW-bogus.cmake:[0-9]+ \(add_executable\):
+  Target "top" links to target "foo::@<0xdeadbeef>" but the target was not
+  found.  Perhaps a find_package\(\) call is missing for an IMPORTED target, or
+  an ALIAS target is missing\?
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus.cmake
new file mode 100644
index 0000000..8622f14
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-bogus.cmake
@@ -0,0 +1,6 @@
+cmake_policy(SET CMP0028 NEW)
+cmake_policy(SET CMP0079 NEW)
+enable_language(C)
+
+add_executable(top empty.c)
+set_property(TARGET top APPEND PROPERTY LINK_LIBRARIES "foo::@<0xdeadbeef>")
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-stdout.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-stdout.txt
new file mode 100644
index 0000000..84b30bd
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW-stdout.txt
@@ -0,0 +1 @@
+-- LINK_LIBRARIES='foo::@<[Xx0-9A-Fa-f]+>'
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW.cmake
new file mode 100644
index 0000000..72e4574
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-NEW.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0079 NEW)
+include(CMP0079-link-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-result.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-stderr.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-stderr.txt
new file mode 100644
index 0000000..0b4c4c6
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD-stderr.txt
@@ -0,0 +1,5 @@
+^CMake Error at CMP0079-link/CMakeLists.txt:[0-9]+ \(target_link_libraries\):
+  Attempt to add link library "foo" to target "top" which is not built in
+  this directory.
+
+  This is allowed only when policy CMP0079 is set to NEW.$
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD.cmake
new file mode 100644
index 0000000..caa7231
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-OLD.cmake
@@ -0,0 +1,2 @@
+cmake_policy(SET CMP0079 OLD)
+include(CMP0079-link-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-result.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-stderr.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-stderr.txt
new file mode 100644
index 0000000..0b4c4c6
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN-stderr.txt
@@ -0,0 +1,5 @@
+^CMake Error at CMP0079-link/CMakeLists.txt:[0-9]+ \(target_link_libraries\):
+  Attempt to add link library "foo" to target "top" which is not built in
+  this directory.
+
+  This is allowed only when policy CMP0079 is set to NEW.$
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN.cmake
new file mode 100644
index 0000000..e83818a
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-WARN.cmake
@@ -0,0 +1 @@
+include(CMP0079-link-common.cmake)
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link-common.cmake b/Tests/RunCMake/target_link_libraries/CMP0079-link-common.cmake
new file mode 100644
index 0000000..4f9454f
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link-common.cmake
@@ -0,0 +1,6 @@
+enable_language(C)
+
+add_executable(top empty.c)
+add_subdirectory(CMP0079-link)
+get_property(libs TARGET top PROPERTY LINK_LIBRARIES)
+message(STATUS "LINK_LIBRARIES='${libs}'")
diff --git a/Tests/RunCMake/target_link_libraries/CMP0079-link/CMakeLists.txt b/Tests/RunCMake/target_link_libraries/CMP0079-link/CMakeLists.txt
new file mode 100644
index 0000000..8b2b3c9
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/CMP0079-link/CMakeLists.txt
@@ -0,0 +1 @@
+target_link_libraries(top PUBLIC foo)
diff --git a/Tests/RunCMake/target_link_libraries/CMakeLists.txt b/Tests/RunCMake/target_link_libraries/CMakeLists.txt
index 12cd3c7..8f85fbf 100644
--- a/Tests/RunCMake/target_link_libraries/CMakeLists.txt
+++ b/Tests/RunCMake/target_link_libraries/CMakeLists.txt
@@ -1,3 +1,3 @@
 cmake_minimum_required(VERSION 2.8.4)
 project(${RunCMake_TEST} NONE)
-include(${RunCMake_TEST}.cmake)
+include(${RunCMake_TEST}.cmake NO_POLICY_SCOPE)
diff --git a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
index 97b0888..a041d6d 100644
--- a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
+++ b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
@@ -4,11 +4,17 @@ run_cmake(CMP0023-WARN)
 run_cmake(CMP0023-NEW)
 run_cmake(CMP0023-WARN-2)
 run_cmake(CMP0023-NEW-2)
+run_cmake(CMP0079-iface-WARN)
+run_cmake(CMP0079-iface-OLD)
+run_cmake(CMP0079-iface-NEW)
+run_cmake(CMP0079-link-WARN)
+run_cmake(CMP0079-link-OLD)
+run_cmake(CMP0079-link-NEW)
+run_cmake(CMP0079-link-NEW-bogus)
 run_cmake(ImportedTarget)
 run_cmake(ImportedTargetFailure)
 run_cmake(MixedSignature)
 run_cmake(Separate-PRIVATE-LINK_PRIVATE-uses)
-run_cmake(SubDirTarget)
 run_cmake(SharedDepNotTarget)
 run_cmake(StaticPrivateDepNotExported)
 run_cmake(StaticPrivateDepNotTarget)
diff --git a/Tests/RunCMake/target_link_libraries/SubDirTarget-stderr.txt b/Tests/RunCMake/target_link_libraries/SubDirTarget-stderr.txt
deleted file mode 100644
index 5cd1f23..0000000
--- a/Tests/RunCMake/target_link_libraries/SubDirTarget-stderr.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-^CMake Error at SubDirTarget.cmake:[0-9]+ \(target_link_libraries\):
-  Attempt to add link library "m" to target "subexe" which is not built in
-  this directory.
-Call Stack \(most recent call first\):
-  CMakeLists.txt:[0-9]+ \(include\)$
diff --git a/Tests/RunCMake/target_link_libraries/SubDirTarget.cmake b/Tests/RunCMake/target_link_libraries/SubDirTarget.cmake
deleted file mode 100644
index 32431ce..0000000
--- a/Tests/RunCMake/target_link_libraries/SubDirTarget.cmake
+++ /dev/null
@@ -1,3 +0,0 @@
-enable_language(C)
-add_subdirectory(SubDirTarget)
-target_link_libraries(subexe m)
diff --git a/Tests/RunCMake/target_link_libraries/SubDirTarget/CMakeLists.txt b/Tests/RunCMake/target_link_libraries/SubDirTarget/CMakeLists.txt
deleted file mode 100644
index b0b2380..0000000
--- a/Tests/RunCMake/target_link_libraries/SubDirTarget/CMakeLists.txt
+++ /dev/null
@@ -1 +0,0 @@
-add_executable(subexe ../empty.c)