Do not skip searching for X11 and Wayland on Windows

While the search is unlikely to succeed on Windows, having different
behaviour between the platforms (eg: find_package(Wayland REQUIRED) was
not fatal on Windows, even though Wayland_FOUND would always be FALSE)
is not ideal, and if someone did port them to Windows for some reason,
the find modules should support that.

If applications actually want different behaviour between platforms
(like requiring a module on Unix, but not on Windows), they should
implement that logic themselves (since they will have to deal with
targets not being defined, etc, anyway).

REVIEW: 120481

1 files changed, 70 insertions, 76 deletions

diff --git a/find-modules/FindEGL.cmake b/find-modules/FindEGL.cmake
index f1962b9a..99d268df 100644
--- a/find-modules/FindEGL.cmake
+++ b/find-modules/FindEGL.cmake
@@ -2,7 +2,7 @@
 # FindEGL
 # -------
 #
-# Try to find EGL on a Unix system.
+# Try to find EGL.
 #
 # This will define the following variables:
 #
@@ -65,90 +65,84 @@ if(CMAKE_MINIMUM_REQUIRED_VERSION VERSION_LESS 2.8.12)
     message(AUTHOR_WARNING "Your project should require at least CMake 2.8.12 to use FindEGL.cmake")
 endif()
 
-if(NOT WIN32)
-    # Use pkg-config to get the directories and then use these values
-    # in the FIND_PATH() and FIND_LIBRARY() calls
-    find_package(PkgConfig)
-    pkg_check_modules(PKG_EGL QUIET egl)
+# Use pkg-config to get the directories and then use these values
+# in the FIND_PATH() and FIND_LIBRARY() calls
+find_package(PkgConfig)
+pkg_check_modules(PKG_EGL QUIET egl)
 
-    set(EGL_DEFINITIONS ${PKG_EGL_CFLAGS_OTHER})
+set(EGL_DEFINITIONS ${PKG_EGL_CFLAGS_OTHER})
 
-    find_path(EGL_INCLUDE_DIR
-        NAMES
-            egl.h
-        HINTS
-            ${PKG_EGL_INCLUDE_DIRS}
-        PATH_SUFFIXES
-            EGL
-    )
-    find_library(EGL_LIBRARY
-        NAMES
-            EGL
-        HINTS
-            ${PKG_EGL_LIBRARY_DIRS}
-    )
-
-    # NB: We do *not* use the version information from pkg-config, as that
-    #     is the implementation version (eg: the Mesa version)
-    if(EGL_INCLUDE_DIR)
-        # egl.h has defines of the form EGL_VERSION_x_y for each supported
-        # version; so the header for EGL 1.1 will define EGL_VERSION_1_0 and
-        # EGL_VERSION_1_1.  Finding the highest supported version involves
-        # finding all these defines and selecting the highest numbered.
-        file(READ "${EGL_INCLUDE_DIR}/egl.h" _EGL_header_contents)
-        string(REGEX MATCHALL
-            "[ \\t]EGL_VERSION_[0-9_]+"
-            _EGL_version_lines
-            "${_EGL_header_contents}"
-        )
-        unset(_EGL_header_contents)
-        foreach(_EGL_version_line ${_EGL_version_lines})
-            string(REGEX REPLACE
-                "[ \\t]EGL_VERSION_([0-9_]+)"
-                "\\1"
-                _version_candidate
-                "${_EGL_version_line}"
-            )
-            string(REPLACE "_" "." _version_candidate "${_version_candidate}")
-            if(NOT DEFINED EGL_VERSION OR EGL_VERSION VERSION_LESS _version_candidate)
-                set(EGL_VERSION "${_version_candidate}")
-            endif()
-        endforeach()
-        unset(_EGL_version_lines)
-    endif()
+find_path(EGL_INCLUDE_DIR
+    NAMES
+        egl.h
+    HINTS
+        ${PKG_EGL_INCLUDE_DIRS}
+    PATH_SUFFIXES
+        EGL
+)
+find_library(EGL_LIBRARY
+    NAMES
+        EGL
+    HINTS
+        ${PKG_EGL_LIBRARY_DIRS}
+)
 
-    include(FindPackageHandleStandardArgs)
-    find_package_handle_standard_args(EGL
-        FOUND_VAR
-            EGL_FOUND
-        REQUIRED_VARS
-            EGL_LIBRARY
-            EGL_INCLUDE_DIR
-        VERSION_VAR
-            EGL_VERSION
+# NB: We do *not* use the version information from pkg-config, as that
+#     is the implementation version (eg: the Mesa version)
+if(EGL_INCLUDE_DIR)
+    # egl.h has defines of the form EGL_VERSION_x_y for each supported
+    # version; so the header for EGL 1.1 will define EGL_VERSION_1_0 and
+    # EGL_VERSION_1_1.  Finding the highest supported version involves
+    # finding all these defines and selecting the highest numbered.
+    file(READ "${EGL_INCLUDE_DIR}/egl.h" _EGL_header_contents)
+    string(REGEX MATCHALL
+        "[ \\t]EGL_VERSION_[0-9_]+"
+        _EGL_version_lines
+        "${_EGL_header_contents}"
     )
-
-    if(EGL_FOUND AND NOT TARGET EGL::EGL)
-        add_library(EGL::EGL UNKNOWN IMPORTED)
-        set_target_properties(EGL::EGL PROPERTIES
-            IMPORTED_LOCATION "${EGL_LIBRARY}"
-            INTERFACE_COMPILE_OPTIONS "${EGL_DEFINITIONS}"
-            INTERFACE_INCLUDE_DIRECTORIES "${EGL_INCLUDE_DIR}"
+    unset(_EGL_header_contents)
+    foreach(_EGL_version_line ${_EGL_version_lines})
+        string(REGEX REPLACE
+            "[ \\t]EGL_VERSION_([0-9_]+)"
+            "\\1"
+            _version_candidate
+            "${_EGL_version_line}"
         )
-    endif()
-
-    mark_as_advanced(EGL_LIBRARY EGL_INCLUDE_DIR)
+        string(REPLACE "_" "." _version_candidate "${_version_candidate}")
+        if(NOT DEFINED EGL_VERSION OR EGL_VERSION VERSION_LESS _version_candidate)
+            set(EGL_VERSION "${_version_candidate}")
+        endif()
+    endforeach()
+    unset(_EGL_version_lines)
+endif()
 
-    # compatibility variables
-    set(EGL_LIBRARIES ${EGL_LIBRARY})
-    set(EGL_INCLUDE_DIRS ${EGL_INCLUDE_DIR})
-    set(EGL_VERSION_STRING ${EGL_VERSION})
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(EGL
+    FOUND_VAR
+        EGL_FOUND
+    REQUIRED_VARS
+        EGL_LIBRARY
+        EGL_INCLUDE_DIR
+    VERSION_VAR
+        EGL_VERSION
+)
 
-else()
-    message(STATUS "FindEGL.cmake cannot find EGL on Windows systems. Try finding WGL instead.")
-    set(EGL_FOUND FALSE)
+if(EGL_FOUND AND NOT TARGET EGL::EGL)
+    add_library(EGL::EGL UNKNOWN IMPORTED)
+    set_target_properties(EGL::EGL PROPERTIES
+        IMPORTED_LOCATION "${EGL_LIBRARY}"
+        INTERFACE_COMPILE_OPTIONS "${EGL_DEFINITIONS}"
+        INTERFACE_INCLUDE_DIRECTORIES "${EGL_INCLUDE_DIR}"
+    )
 endif()
 
+mark_as_advanced(EGL_LIBRARY EGL_INCLUDE_DIR)
+
+# compatibility variables
+set(EGL_LIBRARIES ${EGL_LIBRARY})
+set(EGL_INCLUDE_DIRS ${EGL_INCLUDE_DIR})
+set(EGL_VERSION_STRING ${EGL_VERSION})
+
 include(FeatureSummary)
 set_package_properties(EGL PROPERTIES
     URL "https://www.khronos.org/egl/"