Fix FindEGL compile check when using Emscripten

Carsten Hartenfels · Carsten Hartenfels · commit 64cf14a83af2 · 2025-02-05T14:51:48.000+01:00
Under Emscripten, EGL does not require any libraries to be linked in. The FindEGL module already has a partial concession of this since 3b0bf71, but it still searches for the library and, crucially, tries to link it when performing the compile check if found. If the system you're on has a libEGL.so installed, this will end up trying to link that into the build, which will obviously fail because you can't like a native shared object into a WebAssembly build. This commit removes the library part entirely under Emscripten, making the find module no longer go searching for it pointlessly and not attempt to link anything when performing the compile check.
diff --git a/find-modules/FindEGL.cmake b/find-modules/FindEGL.cmake
@@ -57,13 +57,15 @@ find_path(EGL_INCLUDE_DIR
     HINTS
         ${PKG_EGL_INCLUDE_DIRS}
 )
-find_library(EGL_LIBRARY
-    NAMES
-        EGL
-        libEGL
-    HINTS
-        ${PKG_EGL_LIBRARY_DIRS}
-)
+if(NOT EMSCRIPTEN)
+    find_library(EGL_LIBRARY
+        NAMES
+            EGL
+            libEGL
+        HINTS
+            ${PKG_EGL_LIBRARY_DIRS}
+    )
+endif()
 
 # NB: We do *not* use the version information from pkg-config, as that
 #     is the implementation version (eg: the Mesa version)
@@ -95,7 +97,9 @@ if(EGL_INCLUDE_DIR)
 endif()
 
 cmake_push_check_state(RESET)
-list(APPEND CMAKE_REQUIRED_LIBRARIES "${EGL_LIBRARY}")
+if(NOT EMSCRIPTEN)
+    list(APPEND CMAKE_REQUIRED_LIBRARIES "${EGL_LIBRARY}")
+endif()
 list(APPEND CMAKE_REQUIRED_INCLUDES "${EGL_INCLUDE_DIR}")
 
 check_cxx_source_compiles("
