Fix deprecation warnings and add more deprecation attributes.

I should really at least commpile before pushing.

src/Magnum/Buffer.cpp

@@ -676,6 +676,10 @@ Debug& operator<<(Debug& debug, Buffer::Target value) {
         #endif
 
         #ifdef MAGNUM_BUILD_DEPRECATED
+        #ifdef __GNUC__
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+        #endif
         case Buffer::Target::Array:
         #ifndef MAGNUM_TARGET_GLES2
         case Buffer::Target::CopyRead:
@@ -695,6 +699,9 @@ Debug& operator<<(Debug& debug, Buffer::Target value) {
         #endif
         #ifndef MAGNUM_TARGET_GLES2
         case Buffer::Target::TransformFeedback:
+        #ifdef __GNUC__
+        #pragma GCC diagnostic pop
+        #endif
         #endif
             return debug << static_cast<Buffer::TargetHint>(value);
         #endif

src/Magnum/Buffer.h

@@ -370,7 +370,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::Array instead.
              */
-            Array = GL_ARRAY_BUFFER,
+            Array CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::Array instead") = GL_ARRAY_BUFFER,
             #endif
 
             #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
@@ -391,14 +391,14 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::CopyRead instead.
              */
-            CopyRead = GL_COPY_READ_BUFFER,
+            CopyRead CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::CopyRead instead") = GL_COPY_READ_BUFFER,
 
             /**
              * @copydoc TargetHint::CopyWrite
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::CopyWrite instead.
              */
-            CopyWrite = GL_COPY_WRITE_BUFFER,
+            CopyWrite CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::CopyWrite instead") = GL_COPY_WRITE_BUFFER,
             #endif
 
             #if !defined(MAGNUM_TARGET_GLES2) && !defined(MAGNUM_TARGET_WEBGL)
@@ -407,14 +407,14 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::DispatchIndirect instead.
              */
-            DispatchIndirect = GL_DISPATCH_INDIRECT_BUFFER,
+            DispatchIndirect CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::DispatchIndirect instead") = GL_DISPATCH_INDIRECT_BUFFER,
 
             /**
              * @copydoc TargetHint::DrawIndirect
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::DrawIndirect instead.
              */
-            DrawIndirect = GL_DRAW_INDIRECT_BUFFER,
+            DrawIndirect CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::DrawIndirect instead") = GL_DRAW_INDIRECT_BUFFER,
             #endif
 
             /**
@@ -422,7 +422,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::ElementArray instead.
              */
-            ElementArray = GL_ELEMENT_ARRAY_BUFFER,
+            ElementArray CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::ElementArray instead") = GL_ELEMENT_ARRAY_BUFFER,
 
             #ifndef MAGNUM_TARGET_GLES2
             /**
@@ -430,14 +430,14 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::PixelPack instead.
              */
-            PixelPack = GL_PIXEL_PACK_BUFFER,
+            PixelPack CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::PixelPack instead") = GL_PIXEL_PACK_BUFFER,
 
             /**
              * @copydoc TargetHint::PixelUnpack
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::PixelUnpack instead.
              */
-            PixelUnpack = GL_PIXEL_UNPACK_BUFFER,
+            PixelUnpack CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::PixelUnpack instead") = GL_PIXEL_UNPACK_BUFFER,
             #endif
             #endif
 
@@ -458,7 +458,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::Texture instead.
              */
-            Texture = GL_TEXTURE_BUFFER,
+            Texture CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::Texture instead") = GL_TEXTURE_BUFFER,
             #endif
 
             #if defined(MAGNUM_BUILD_DEPRECATED) && !defined(MAGNUM_TARGET_GLES2)
@@ -467,7 +467,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
              * @deprecated For @ref setTargetHint() only, use
              *      @ref TargetHint::TransformFeedback instead.
              */
-            TransformFeedback = GL_TRANSFORM_FEEDBACK_BUFFER,
+            TransformFeedback CORRADE_DEPRECATED_ENUM("use Buffer::TargetHint::TransformFeedback instead") = GL_TRANSFORM_FEEDBACK_BUFFER,
             #endif
 
             #ifndef MAGNUM_TARGET_GLES2

src/Magnum/DebugOutput.cpp

@@ -324,11 +324,18 @@ Debug& operator<<(Debug& debug, const DebugMessage::Source value) {
         _c(Application)
         #undef _c
         #ifdef MAGNUM_BUILD_DEPRECATED
+        #ifdef __GNUC__
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+        #endif
         case DebugMessage::Source::Api:
         case DebugMessage::Source::WindowSystem:
         case DebugMessage::Source::ShaderCompiler:
         case DebugMessage::Source::Other:
             return debug << DebugOutput::Source(value);
+        #ifdef __GNUC__
+        #pragma GCC diagnostic pop
+        #endif
         #endif
         /* LCOV_EXCL_STOP */
     }

src/Magnum/DebugOutput.h

@@ -635,7 +635,7 @@ class MAGNUM_EXPORT DebugMessage {
         /** @copybrief DebugOutput::setCallback()
          * @deprecated Use @ref DebugOutput::setCallback() instead.
          */
-        CORRADE_DEPRECATED("use DebugOutput::setCallback() instead") static void setCallback(Callback callback, const void* userParam = nullptr) {
+        CORRADE_DEPRECATED("use DebugOutput::setCallback() instead") static void setCallback(DebugOutput::Callback callback, const void* userParam = nullptr) {
             DebugOutput::setCallback(reinterpret_cast<DebugOutput::Callback>(callback), userParam);
         }