Fix support for a static build of Epoxy. Add support building and running tests with CMake. Add support for linking with the static run-time library with MSVC.

1 files changed, 75 insertions, 0 deletions

diff --git a/src/dispatch_wgl.c b/src/dispatch_wgl.c
index 3ce4406..bbb5528 100644
--- a/src/dispatch_wgl.c
+++ b/src/dispatch_wgl.c
@@ -89,6 +89,81 @@ epoxy_handle_external_wglMakeCurrent(void)
     }
 }
 
+/**
+ * This global symbol is apparently looked up by Windows when loading
+ * a DLL, but it doesn't declare the prototype.
+ */
+BOOL WINAPI
+DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved);
+
+BOOL WINAPI
+DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved)
+{
+    void *data;
+
+    (void)dll; // Prevent "unused parameter" warning.
+    (void)reserved; // Prevent "unused parameter" warning.
+    switch (reason) {
+    case DLL_PROCESS_ATTACH:
+        gl_tls_index = TlsAlloc();
+        if (gl_tls_index == TLS_OUT_OF_INDEXES)
+            return FALSE;
+        wgl_tls_index = TlsAlloc();
+        if (wgl_tls_index == TLS_OUT_OF_INDEXES)
+            return FALSE;
+
+        epoxy_first_context_current = false;
+
+        /* FALLTHROUGH */
+
+    case DLL_THREAD_ATTACH:
+        data = LocalAlloc(LPTR, gl_tls_size);
+        TlsSetValue(gl_tls_index, data);
+
+        data = LocalAlloc(LPTR, wgl_tls_size);
+        TlsSetValue(wgl_tls_index, data);
+
+        break;
+
+    case DLL_THREAD_DETACH:
+    case DLL_PROCESS_DETACH:
+        data = TlsGetValue(gl_tls_index);
+        LocalFree(data);
+
+        data = TlsGetValue(wgl_tls_index);
+        LocalFree(data);
+
+        if (reason == DLL_PROCESS_DETACH) {
+            TlsFree(gl_tls_index);
+            TlsFree(wgl_tls_index);
+        }
+        break;
+    }
+
+    return TRUE;
+}
+
+#ifdef EPOXY_STATIC_LIB
+#ifdef __GNUC__
+	PIMAGE_TLS_CALLBACK dllmain_callback __attribute__((section(".CRT$XLB"))) = (PIMAGE_TLS_CALLBACK)DllMain;
+#else
+#	ifdef _WIN64
+#		pragma comment(linker, "/INCLUDE:_tls_used")
+#		pragma comment(linker, "/INCLUDE:dllmain_callback")
+#		pragma const_seg(".CRT$XLB")
+		extern const PIMAGE_TLS_CALLBACK dllmain_callback;
+		const PIMAGE_TLS_CALLBACK dllmain_callback = DllMain;
+#		pragma const_seg()
+#	else
+#		pragma comment(linker, "/INCLUDE:__tls_used")
+#		pragma comment(linker, "/INCLUDE:_dllmain_callback")
+#		pragma data_seg(".CRT$XLB")
+		PIMAGE_TLS_CALLBACK dllmain_callback = DllMain;
+#		pragma data_seg()
+#	endif
+#endif
+#endif
+
 WRAPPER_VISIBILITY (BOOL)
 WRAPPER(epoxy_wglMakeCurrent)(HDC hdc, HGLRC hglrc)
 {