Merge topic 'link-libs-config-case'

2af18704fd Merge branch 'backport-3.16-link-libs-config-case'
3f976bf201 target_link_libraries: Fix regression in case of $<CONFIG> genex
5a95b5e091 target_link_libraries: Fix regression in case of $<CONFIG> genex

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4544
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 8484c58..0a78af6 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2432,11 +2432,9 @@
   }
 
   for (std::string const& config : configsList) {
-    const std::string buildType = cmSystemTools::UpperCase(config);
-
     // FIXME: Refactor collection of sources to not evaluate object libraries.
     std::vector<cmSourceFile*> sources;
-    target->GetSourceFiles(sources, buildType);
+    target->GetSourceFiles(sources, config);
 
     for (const std::string& lang : { "C", "CXX", "OBJC", "OBJCXX" }) {
       auto langSources = std::count_if(
@@ -2605,15 +2603,13 @@
     config = this->Makefile->GetSafeDefinition("CMAKE_BUILD_TYPE");
   }
 
-  const std::string buildType = cmSystemTools::UpperCase(config);
-
   std::string filename_base =
     cmStrCat(this->GetCurrentBinaryDirectory(), "/CMakeFiles/",
              target->GetName(), ".dir/Unity/");
 
   // FIXME: Refactor collection of sources to not evaluate object libraries.
   std::vector<cmSourceFile*> sources;
-  target->GetSourceFiles(sources, buildType);
+  target->GetSourceFiles(sources, config);
 
   auto batchSizeString = target->GetProperty("UNITY_BUILD_BATCH_SIZE");
   const size_t unityBatchSize =
diff --git a/Tests/RunCMake/target_link_libraries/ConfigCase-result.txt b/Tests/RunCMake/target_link_libraries/ConfigCase-result.txt
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ConfigCase-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/target_link_libraries/ConfigCase-stderr.txt b/Tests/RunCMake/target_link_libraries/ConfigCase-stderr.txt
new file mode 100644
index 0000000..953c972
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ConfigCase-stderr.txt
@@ -0,0 +1,13 @@
+^CMake Error at ConfigCase.cmake:[0-9]+ \(add_library\):
+  Target "impl" links to target "config::impl-Debug" 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:[0-9]+ \(include\)
++
+CMake Error at ConfigCase.cmake:[0-9]+ \(add_library\):
+  Target "impl" links to target "config::iface-Debug" 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:[0-9]+ \(include\)
diff --git a/Tests/RunCMake/target_link_libraries/ConfigCase.cmake b/Tests/RunCMake/target_link_libraries/ConfigCase.cmake
new file mode 100644
index 0000000..fc39478
--- /dev/null
+++ b/Tests/RunCMake/target_link_libraries/ConfigCase.cmake
@@ -0,0 +1,6 @@
+cmake_policy(VERSION 3.15)
+enable_language(C)
+add_library(iface INTERFACE)
+target_link_libraries(iface INTERFACE "config::iface-$<CONFIG>")
+add_library(impl empty.c)
+target_link_libraries(impl PRIVATE "config::impl-$<CONFIG>" iface)
diff --git a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
index c7feb5f..fb223ab 100644
--- a/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
+++ b/Tests/RunCMake/target_link_libraries/RunCMakeTest.cmake
@@ -1,5 +1,13 @@
 include(RunCMake)
 
+if(RunCMake_GENERATOR_IS_MULTI_CONFIG)
+  set(RunCMake_TEST_OPTIONS -DCMAKE_CONFIGURATION_TYPES=Debug)
+else()
+  set(RunCMake_TEST_OPTIONS -DCMAKE_BUILD_TYPE=Debug)
+endif()
+run_cmake(ConfigCase)
+unset(RunCMake_TEST_OPTIONS)
+
 run_cmake(CMP0023-WARN)
 run_cmake(CMP0023-NEW)
 run_cmake(CMP0023-WARN-2)