ENH: Allow IMPORTED_IMPLIB w/o IMPORTED_LOCATION

Linking to a Windows shared library (.dll) requires only its import
library (.lib).  This teaches CMake to recognize SHARED IMPORTED library
targets that set only IMPORTED_IMPLIB and not IMPORTED_LOCATION.

4 files changed, 36 insertions, 3 deletions

diff --git a/Tests/ExportImport/Export/CMakeLists.txt b/Tests/ExportImport/Export/CMakeLists.txt
index 26687b1..19cd22f 100644
--- a/Tests/ExportImport/Export/CMakeLists.txt
+++ b/Tests/ExportImport/Export/CMakeLists.txt
@@ -39,6 +39,8 @@ set_property(TARGET testLib3 PROPERTY SOVERSION 3)
 add_library(testLib4 SHARED testLib4.c)
 set_property(TARGET testLib4 PROPERTY FRAMEWORK 1)
 
+add_library(testLib5 SHARED testLib5.c)
+
 # Work-around: Visual Studio 6 does not support per-target object files.
 set(VS6)
 if("${CMAKE_GENERATOR}" MATCHES "Visual Studio 6")
@@ -85,15 +87,27 @@ install(
   LIBRARY DESTINATION lib/impl
   ARCHIVE DESTINATION lib/impl
   )
+install(
+  TARGETS testLib5
+  EXPORT exp
+  # Leave out RUNTIME DESTINATION to test implib-only export.
+  LIBRARY DESTINATION lib
+  ARCHIVE DESTINATION lib
+  )
 install(EXPORT exp NAMESPACE exp_ DESTINATION lib/exp)
 
+# Install testLib5.dll outside the export.
+if(WIN32)
+  install(TARGETS testLib5 RUNTIME DESTINATION bin)
+endif(WIN32)
+
 # Export from build tree.
 export(TARGETS testExe1 testLib1 testLib2 testLib3
   testExe2libImp testLib3Imp
   NAMESPACE bld_
   FILE ExportBuildTree.cmake
   )
-export(TARGETS testExe2 testLib4 testExe3 testExe2lib
+export(TARGETS testExe2 testLib4 testLib5 testExe3 testExe2lib
   testLib4lib testLib4libdbg testLib4libopt
   NAMESPACE bld_
   APPEND FILE ExportBuildTree.cmake
diff --git a/Tests/ExportImport/Export/testLib5.c b/Tests/ExportImport/Export/testLib5.c
new file mode 100644
index 0000000..20a8215
--- /dev/null
+++ b/Tests/ExportImport/Export/testLib5.c
@@ -0,0 +1,7 @@
+#if defined(_WIN32) || defined(__CYGWIN__)
+# define testLib5_EXPORT __declspec(dllexport)
+#else
+# define testLib5_EXPORT
+#endif
+
+testLib5_EXPORT int testLib5(void) { return 0; }
diff --git a/Tests/ExportImport/Import/A/CMakeLists.txt b/Tests/ExportImport/Import/A/CMakeLists.txt
index 16cff2d..e874cdb 100644
--- a/Tests/ExportImport/Import/A/CMakeLists.txt
+++ b/Tests/ExportImport/Import/A/CMakeLists.txt
@@ -23,7 +23,12 @@ add_executable(imp_testExe1
   )
 
 # Try linking to a library imported from the install tree.
-target_link_libraries(imp_testExe1 exp_testLib2 exp_testLib3 exp_testLib4)
+target_link_libraries(imp_testExe1
+  exp_testLib2
+  exp_testLib3
+  exp_testLib4
+  exp_testLib5
+  )
 
 # Try building a plugin to an executable imported from the install tree.
 add_library(imp_mod1 MODULE imp_mod1.c)
@@ -48,7 +53,12 @@ add_executable(imp_testExe1b
   )
 
 # Try linking to a library imported from the build tree.
-target_link_libraries(imp_testExe1b bld_testLib2 bld_testLib3 bld_testLib4)
+target_link_libraries(imp_testExe1b
+  bld_testLib2
+  bld_testLib3
+  bld_testLib4
+  bld_testLib5
+  )
 
 # Try building a plugin to an executable imported from the build tree.
 add_library(imp_mod1b MODULE imp_mod1.c)
diff --git a/Tests/ExportImport/Import/A/imp_testExe1.c b/Tests/ExportImport/Import/A/imp_testExe1.c
index 6424d33..6a6ba0f 100644
--- a/Tests/ExportImport/Import/A/imp_testExe1.c
+++ b/Tests/ExportImport/Import/A/imp_testExe1.c
@@ -4,6 +4,7 @@ extern int testLib2();
 extern int testLib3();
 extern int testLib4();
 extern int testLib4lib();
+extern int testLib5();
 
 /* Switch a symbol between debug and optimized builds to make sure the
    proper library is found from the testLib4 link interface.  */
@@ -17,5 +18,6 @@ extern testLib4libcfg(void);
 int main()
 {
   return (testLib2() + generated_by_testExe1() + testLib3() + testLib4()
+          + testLib5()
           + generated_by_testExe3() + testLib4lib() + testLib4libcfg());
 }