Interconnect: add /OPT:NOICF for clang-cl as well.

It uses the MSVC linker by default, thus the same optimization is used
by default. The breakage happens only in a Release build.

doc/corrade-changelog.dox

@@ -516,6 +516,8 @@ namespace Corrade {
     crash on Emscripten 3.1.27+, which reduced the default stack size from
     5 MB to 64 kB.
 -   New @cpp #pragma ACME forget @ce option in the @ref acme utility
+-   `/OPT:NOICF` is now added for the @ref Interconnect library for clang-cl
+    as well (see [mosra/corrade#178](https://github.com/mosra/corrade/issues/178))
 
 @subsection corrade-changelog-latest-bugfixes Bug fixes
 

modules/FindCorrade.cmake

@@ -474,8 +474,9 @@ foreach(_component ${Corrade_FIND_COMPONENTS})
         # Interconnect library
         if(_component STREQUAL Interconnect)
             # Disable /OPT:ICF on MSVC, which merges functions with identical
-            # contents and thus breaks signal comparison
-            if(CORRADE_TARGET_WINDOWS AND CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+            # contents and thus breaks signal comparison. Same case is for
+            # clang-cl which uses the MSVC linker by default.
+            if(CORRADE_TARGET_WINDOWS AND (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC"))
                 if(CMAKE_VERSION VERSION_LESS 3.13)
                     set_property(TARGET Corrade::${_component} PROPERTY
                         INTERFACE_LINK_LIBRARIES "-OPT:NOICF,REF")

src/Corrade/Interconnect/CMakeLists.txt

@@ -58,8 +58,9 @@ endif()
 
 target_link_libraries(CorradeInterconnect PUBLIC CorradeUtility)
 # Disable /OPT:ICF on MSVC, which merges functions with identical contents and
-# thus breaks signal comparison
-if(CORRADE_TARGET_WINDOWS AND CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+# thus breaks signal comparison. Same case is for clang-cl which uses the MSVC
+# linker by default.
+if(CORRADE_TARGET_WINDOWS AND (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" OR CMAKE_CXX_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC"))
     if(CMAKE_VERSION VERSION_LESS 3.13)
         target_link_libraries(CorradeInterconnect INTERFACE "-OPT:NOICF,REF")
     else()