First-class WebGL support, part 2: no debug output.

src/Magnum/AbstractObject.cpp

@@ -32,11 +32,14 @@
 #include "Magnum/Extensions.h"
 
 #include "Implementation/State.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 
 namespace Magnum {
 
-#if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+#ifndef MAGNUM_TARGET_WEBGL
+#ifndef CORRADE_TARGET_NACL
 namespace {
     inline GLenum extTypeFromKhrIdentifier(GLenum khrIdentifier) {
         switch(khrIdentifier) {
@@ -131,7 +134,7 @@ void AbstractObject::labelImplementationNoOp(GLenum, GLuint, Containers::ArrayRe
 void AbstractObject::labelImplementationKhr(const GLenum identifier, const GLuint name, const Containers::ArrayReference<const char> label) {
     #ifndef MAGNUM_TARGET_GLES
     glObjectLabel(identifier, name, label.size(), label);
-    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #elif !defined(CORRADE_TARGET_NACL)
     glObjectLabelKHR(identifier, name, label.size(), label);
     #else
     static_cast<void>(identifier);
@@ -142,7 +145,7 @@ void AbstractObject::labelImplementationKhr(const GLenum identifier, const GLuin
 }
 
 void AbstractObject::labelImplementationExt(const GLenum identifier, const GLuint name, const Containers::ArrayReference<const char> label) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     const GLenum type = extTypeFromKhrIdentifier(identifier);
     glLabelObjectEXT(type, name, label.size(), label);
     #else
@@ -160,7 +163,7 @@ std::string AbstractObject::getLabelImplementationKhr(const GLenum identifier, c
     GLsizei size;
     #ifndef MAGNUM_TARGET_GLES
     glGetObjectLabel(identifier, name, 0, &size, nullptr);
-    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #elif !defined(CORRADE_TARGET_NACL)
     glGetObjectLabelKHR(identifier, name, 0, &size, nullptr);
     #else
     static_cast<void>(identifier);
@@ -173,7 +176,7 @@ std::string AbstractObject::getLabelImplementationKhr(const GLenum identifier, c
     label.resize(size+1);
     #ifndef MAGNUM_TARGET_GLES
     glGetObjectLabel(identifier, name, size+1, nullptr, &label[0]);
-    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #elif !defined(CORRADE_TARGET_NACL)
     glGetObjectLabelKHR(identifier, name, size+1, nullptr, &label[0]);
     #else
     CORRADE_ASSERT_UNREACHABLE();
@@ -188,7 +191,7 @@ std::string AbstractObject::getLabelImplementationExt(const GLenum identifier, c
     GLsizei size;
 
     /* Get label size (w/o null terminator) */
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     const GLenum type = extTypeFromKhrIdentifier(identifier);
     glGetObjectLabelEXT(type, name, 0, &size, nullptr);
     #else
@@ -200,7 +203,7 @@ std::string AbstractObject::getLabelImplementationExt(const GLenum identifier, c
     /* Make place also for the null terminator */
     std::string label;
     label.resize(size+1);
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     glGetObjectLabelEXT(identifier, name, size+1, nullptr, &label[0]);
     #else
     CORRADE_ASSERT_UNREACHABLE();
@@ -210,5 +213,6 @@ std::string AbstractObject::getLabelImplementationExt(const GLenum identifier, c
     label.resize(size);
     return label;
 }
+#endif
 
 }

src/Magnum/AbstractObject.h

@@ -47,6 +47,7 @@ class MAGNUM_EXPORT AbstractObject {
     friend Implementation::DebugState;
 
     public:
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Max object label length
          *
@@ -59,20 +60,24 @@ class MAGNUM_EXPORT AbstractObject {
          *      @ref BufferTexture::setLabel(), @ref Framebuffer::setLabel(),
          *      @ref Mesh::setLabel(), @ref Renderbuffer::setLabel(),
          *      @ref Shader::setLabel(), @fn_gl{Get} with @def_gl{MAX_LABEL_LENGTH}
+         * @requires_gles Debug output is not available in WebGL.
          */
         static Int maxLabelLength();
+        #endif
 
     protected:
         MAGNUM_LOCAL AbstractObject() = default;
         MAGNUM_LOCAL ~AbstractObject() = default;
 
     private:
+        #ifndef MAGNUM_TARGET_WEBGL
         static MAGNUM_LOCAL void labelImplementationNoOp(GLenum, GLuint, Containers::ArrayReference<const char> label);
         static MAGNUM_LOCAL void labelImplementationExt(GLenum identifier, GLuint name, Containers::ArrayReference<const char> label);
         static MAGNUM_LOCAL void labelImplementationKhr(GLenum identifier, GLuint name, Containers::ArrayReference<const char> label);
         static MAGNUM_LOCAL std::string getLabelImplementationNoOp(GLenum, GLuint);
         static MAGNUM_LOCAL std::string getLabelImplementationExt(GLenum identifier, GLuint name);
         static MAGNUM_LOCAL std::string getLabelImplementationKhr(GLenum identifier, GLuint name);
+        #endif
 };
 
 }

src/Magnum/AbstractQuery.cpp

@@ -28,7 +28,9 @@
 #include <Corrade/Utility/Assert.h>
 
 #include "Magnum/Context.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Magnum/Implementation/DebugState.h"
+#endif
 #include "Magnum/Implementation/QueryState.h"
 #include "Magnum/Implementation/State.h"
 
@@ -73,6 +75,7 @@ void AbstractQuery::createImplementationDSA() {
 }
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string AbstractQuery::label() const {
     #ifndef MAGNUM_TARGET_GLES
     return Context::current()->state().debug->getLabelImplementation(GL_QUERY, _id);
@@ -89,6 +92,7 @@ AbstractQuery& AbstractQuery::setLabelInternal(const Containers::ArrayReference<
     #endif
     return *this;
 }
+#endif
 
 bool AbstractQuery::resultAvailable() {
     GLuint result;

src/Magnum/AbstractQuery.h

@@ -65,6 +65,7 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
         /** @brief OpenGL query ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Query label
          *
@@ -75,6 +76,7 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} with @def_gl{QUERY} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{QUERY_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label() const;
 
@@ -88,6 +90,7 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} with
          *      @def_gl{QUERY} or @fn_gl_extension2{LabelObject,EXT,debug_label}
          *      with @def_gl{QUERY_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         AbstractQuery& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -97,6 +100,7 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
         template<std::size_t size> AbstractQuery& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /**
          * @brief Whether the result is available
@@ -160,7 +164,9 @@ class MAGNUM_EXPORT AbstractQuery: public AbstractObject {
         #endif
 
     private:
+        #ifndef MAGNUM_TARGET_WEBGL
         AbstractQuery& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         void MAGNUM_LOCAL createImplementationDefault();
         #ifndef MAGNUM_TARGET_GLES

src/Magnum/AbstractShaderProgram.cpp

@@ -30,7 +30,9 @@
 #include "Magnum/Shader.h"
 #include "Magnum/Math/RectangularMatrix.h"
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/ShaderProgramState.h"
 #include "Implementation/State.h"
 
@@ -250,6 +252,7 @@ AbstractShaderProgram& AbstractShaderProgram::operator=(AbstractShaderProgram&&
     return *this;
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string AbstractShaderProgram::label() const {
     #ifndef MAGNUM_TARGET_GLES
     return Context::current()->state().debug->getLabelImplementation(GL_PROGRAM, _id);
@@ -266,6 +269,7 @@ AbstractShaderProgram& AbstractShaderProgram::setLabelInternal(const Containers:
     #endif
     return *this;
 }
+#endif
 
 std::pair<bool, std::string> AbstractShaderProgram::validate() {
     glValidateProgram(_id);

src/Magnum/AbstractShaderProgram.h

@@ -574,6 +574,7 @@ class MAGNUM_EXPORT AbstractShaderProgram: public AbstractObject {
         /** @brief OpenGL program ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Shader program label
          *
@@ -584,6 +585,7 @@ class MAGNUM_EXPORT AbstractShaderProgram: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} with @def_gl{PROGRAM} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{PROGRAM_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label() const;
 
@@ -597,6 +599,7 @@ class MAGNUM_EXPORT AbstractShaderProgram: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} with
          *      @def_gl{PROGRAM} or @fn_gl_extension2{LabelObject,EXT,debug_label}
          *      with @def_gl{PROGRAM_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         AbstractShaderProgram& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -606,6 +609,7 @@ class MAGNUM_EXPORT AbstractShaderProgram: public AbstractObject {
         template<std::size_t size> AbstractShaderProgram& setLabel(const char (&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /**
          * @brief Validate program
@@ -949,7 +953,10 @@ class MAGNUM_EXPORT AbstractShaderProgram: public AbstractObject {
         #endif
 
     private:
+        #ifndef MAGNUM_TARGET_WEBGL
         AbstractShaderProgram& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
+
         void bindAttributeLocationInternal(UnsignedInt location, Containers::ArrayReference<const char> name);
         void bindFragmentDataLocationIndexedInternal(UnsignedInt location, UnsignedInt index, Containers::ArrayReference<const char> name);
         void bindFragmentDataLocationInternal(UnsignedInt location, Containers::ArrayReference<const char> name);

src/Magnum/AbstractTexture.cpp

@@ -41,7 +41,9 @@
 #include "Magnum/Shader.h"
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/State.h"
 #include "Implementation/TextureState.h"
 
@@ -242,6 +244,7 @@ inline void AbstractTexture::createIfNotAlready() {
     CORRADE_INTERNAL_ASSERT(_created);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string AbstractTexture::label() {
     createIfNotAlready();
     return Context::current()->state().debug->getLabelImplementation(GL_TEXTURE, _id);
@@ -252,6 +255,7 @@ AbstractTexture& AbstractTexture::setLabelInternal(const Containers::ArrayRefere
     Context::current()->state().debug->labelImplementation(GL_TEXTURE, _id, label);
     return *this;
 }
+#endif
 
 void AbstractTexture::bind(Int textureUnit) {
     Implementation::TextureState& textureState = *Context::current()->state().texture;

src/Magnum/AbstractTexture.h

@@ -263,6 +263,7 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
         /** @brief Move assignment */
         AbstractTexture& operator=(AbstractTexture&& other) noexcept;
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Texture label
          *
@@ -273,6 +274,7 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{TEXTURE}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -286,6 +288,7 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} or
          *      @fn_gl_extension2{LabelObject,EXT,debug_label} with
          *      @def_gl{TEXTURE}
+         * @requires_gles Debug output is not available in WebGL.
          */
         AbstractTexture& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -295,6 +298,7 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
         template<std::size_t size> AbstractTexture& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /** @brief OpenGL texture ID */
         GLuint id() const { return _id; }
@@ -326,7 +330,9 @@ class MAGNUM_EXPORT AbstractTexture: public AbstractObject {
 
         explicit AbstractTexture(GLenum target);
 
+        #ifndef MAGNUM_TARGET_WEBGL
         AbstractTexture& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         /* Unlike bind() this also sets the texture binding unit as active */
         void MAGNUM_LOCAL bindInternal();

src/Magnum/Buffer.cpp

@@ -32,7 +32,9 @@
 
 #include "Implementation/State.h"
 #include "Implementation/BufferState.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 
 namespace Magnum {
 
@@ -208,6 +210,7 @@ inline void Buffer::createIfNotAlready() {
     CORRADE_INTERNAL_ASSERT(_created);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string Buffer::label() {
     createIfNotAlready();
     #ifndef MAGNUM_TARGET_GLES
@@ -226,6 +229,7 @@ Buffer& Buffer::setLabelInternal(const Containers::ArrayReference<const char> la
     #endif
     return *this;
 }
+#endif
 
 void Buffer::bindInternal(const TargetHint target, Buffer* const buffer) {
     const GLuint id = buffer ? buffer->_id : 0;

src/Magnum/Buffer.h

@@ -798,6 +798,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
         /** @brief OpenGL buffer ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Buffer label
          *
@@ -808,6 +809,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} with @def_gl{BUFFER} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{BUFFER_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -821,6 +823,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} with @def_gl{BUFFER}
          *      or @fn_gl_extension2{LabelObject,EXT,debug_label} with
          *      @def_gl{BUFFER_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         Buffer& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -830,6 +833,7 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
         template<std::size_t size> Buffer& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /** @brief Target hint */
         TargetHint targetHint() const { return _targetHint; }
@@ -1217,7 +1221,9 @@ class MAGNUM_EXPORT Buffer: public AbstractObject {
 
         void MAGNUM_LOCAL createIfNotAlready();
 
+        #ifndef MAGNUM_TARGET_WEBGL
         Buffer& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         #ifndef MAGNUM_TARGET_GLES
         void subDataInternal(GLintptr offset, GLsizeiptr size, GLvoid* data);

src/Magnum/CMakeLists.txt

@@ -39,7 +39,6 @@ set(Magnum_SRCS
     ColorFormat.cpp
     CubeMapTexture.cpp
     Context.cpp
-    DebugOutput.cpp
     DefaultFramebuffer.cpp
     Framebuffer.cpp
     Image.cpp
@@ -56,7 +55,6 @@ set(Magnum_SRCS
     Version.cpp
 
     Implementation/BufferState.cpp
-    Implementation/DebugState.cpp
     Implementation/FramebufferState.cpp
     Implementation/MeshState.cpp
     Implementation/QueryState.cpp
@@ -96,7 +94,6 @@ set(Magnum_HEADERS
     ColorFormat.h
     Context.h
     CubeMapTexture.h
-    DebugOutput.h
     DefaultFramebuffer.h
     DimensionTraits.h
     Extensions.h
@@ -128,7 +125,6 @@ set(Magnum_HEADERS
 # Header files to display in project view of IDEs only
 set(Magnum_PRIVATE_HEADERS
     Implementation/BufferState.h
-    Implementation/DebugState.h
     Implementation/FramebufferState.h
     Implementation/maxTextureSize.h
     Implementation/MeshState.h
@@ -142,8 +138,6 @@ set(Magnum_PRIVATE_HEADERS
 # Deprecated headers
 if(BUILD_DEPRECATED)
     set(Magnum_HEADERS ${Magnum_HEADERS}
-        DebugMarker.h
-        DebugMessage.h
         Query.h)
 endif()
 
@@ -182,6 +176,26 @@ if(NOT TARGET_GLES2)
 
 endif()
 
+# Non-WebGL stuff
+if(NOT TARGET_WEBGL)
+    list(APPEND Magnum_SRCS
+        DebugOutput.cpp
+
+        Implementation/DebugState.cpp)
+
+    list(APPEND Magnum_HEADERS
+        DebugOutput.h)
+
+    list(APPEND Magnum_PRIVATE_HEADERS
+        Implementation/DebugState.h)
+
+    if(BUILD_DEPRECATED)
+        list(APPEND Magnum_HEADERS
+            DebugMarker.h
+            DebugMessage.h)
+    endif()
+endif()
+
 # Link in GL function pointer variables on platforms that support it
 if(NOT CORRADE_TARGET_EMSCRIPTEN AND NOT CORRADE_TARGET_NACL)
     list(APPEND Magnum_SRCS $<TARGET_OBJECTS:MagnumFlextGLObjects>)

src/Magnum/CubeMapTexture.h

@@ -648,7 +648,7 @@ class MAGNUM_EXPORT CubeMapTexture: public AbstractTexture {
         }
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         CubeMapTexture& setLabel(const std::string& label) {
             AbstractTexture::setLabel(label);
             return *this;

src/Magnum/DebugOutput.cpp

@@ -25,6 +25,7 @@
 
 #include "DebugOutput.h"
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include <Corrade/Utility/Assert.h>
 
 #include "Magnum/Context.h"
@@ -40,7 +41,7 @@ namespace Magnum {
 
 namespace {
 
-#if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+#ifndef CORRADE_TARGET_NACL
 void
 #ifdef CORRADE_TARGET_WINDOWS
 APIENTRY
@@ -169,7 +170,7 @@ void DebugOutput::setEnabledInternal(const GLenum source, const GLenum type, con
 void DebugOutput::controlImplementationNoOp(GLenum, GLenum, GLenum, std::initializer_list<UnsignedInt>, bool) {}
 
 void DebugOutput::controlImplementationKhr(const GLenum source, const GLenum type, const GLenum severity, const std::initializer_list<UnsignedInt> ids, const bool enabled) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     #ifndef MAGNUM_TARGET_GLES
     glDebugMessageControl
     #else
@@ -195,7 +196,7 @@ void DebugOutput::callbackImplementationKhr(const Callback callback, const void*
 
     /* Adding callback */
     if(!original && callback) {
-        #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+        #ifndef CORRADE_TARGET_NACL
         #ifndef MAGNUM_TARGET_GLES
         glDebugMessageCallback
         #else
@@ -209,7 +210,7 @@ void DebugOutput::callbackImplementationKhr(const Callback callback, const void*
 
     /* Deleting callback */
     } else if(original && !callback) {
-        #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+        #ifndef CORRADE_TARGET_NACL
         #ifndef MAGNUM_TARGET_GLES
         glDebugMessageCallback
         #else
@@ -277,7 +278,7 @@ void DebugMessage::insertInternal(const Source source, const Type type, const Un
 void DebugMessage::insertImplementationNoOp(Source, Type, UnsignedInt, DebugOutput::Severity, const Containers::ArrayReference<const char>) {}
 
 void DebugMessage::insertImplementationKhr(const Source source, const Type type, const UnsignedInt id, const DebugOutput::Severity severity, const Containers::ArrayReference<const char> string) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     #ifndef MAGNUM_TARGET_GLES
     glDebugMessageInsert
     #else
@@ -295,7 +296,7 @@ void DebugMessage::insertImplementationKhr(const Source source, const Type type,
 }
 
 void DebugMessage::insertImplementationExt(Source, Type, UnsignedInt, DebugOutput::Severity, const Containers::ArrayReference<const char> string) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     glInsertEventMarkerEXT(string.size(), string.data());
     #else
     static_cast<void>(string);
@@ -377,7 +378,7 @@ void DebugGroup::pop() {
 void DebugGroup::pushImplementationNoOp(Source, UnsignedInt, Containers::ArrayReference<const char>) {}
 
 void DebugGroup::pushImplementationKhr(const Source source, const UnsignedInt id, const Containers::ArrayReference<const char> message) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     #ifndef MAGNUM_TARGET_GLES
     glPushDebugGroup
     #else
@@ -393,7 +394,7 @@ void DebugGroup::pushImplementationKhr(const Source source, const UnsignedInt id
 }
 
 void DebugGroup::pushImplementationExt(Source, UnsignedInt, const Containers::ArrayReference<const char> message) {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     glPushGroupMarkerEXT(message.size(), message.data());
     #else
     static_cast<void>(message);
@@ -406,7 +407,7 @@ void DebugGroup::popImplementationNoOp() {}
 void DebugGroup::popImplementationKhr() {
     #ifndef MAGNUM_TARGET_GLES
     glPopDebugGroup();
-    #elif !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #elif !defined(CORRADE_TARGET_NACL)
     glPopDebugGroupKHR();
     #else
     CORRADE_ASSERT_UNREACHABLE();
@@ -414,7 +415,7 @@ void DebugGroup::popImplementationKhr() {
 }
 
 void DebugGroup::popImplementationExt() {
-    #if !defined(CORRADE_TARGET_EMSCRIPTEN) && !defined(CORRADE_TARGET_NACL)
+    #ifndef CORRADE_TARGET_NACL
     glPopGroupMarkerEXT();
     #else
     CORRADE_ASSERT_UNREACHABLE();
@@ -435,3 +436,4 @@ Debug operator<<(Debug debug, const DebugGroup::Source value) {
 #endif
 
 }
+#endif

src/Magnum/DebugOutput.h

@@ -25,21 +25,24 @@
     DEALINGS IN THE SOFTWARE.
 */
 
+#ifndef MAGNUM_TARGET_WEBGL
 /** @file
  * @brief Class @ref Magnum::DebugOutput, @ref Magnum::DebugMessage, @ref Magnum::DebugGroup
  */
+#endif
 
 #include <string>
 #include <Corrade/Containers/Array.h>
 
-#include "Magnum/Magnum.h"
 #include "Magnum/OpenGL.h"
+#include "Magnum/Magnum.h"
 #include "Magnum/visibility.h"
 
 #ifdef MAGNUM_BUILD_DEPRECATED
 #include <Corrade/Utility/Macros.h>
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
 namespace Magnum {
 
 namespace Implementation { struct DebugState; }
@@ -118,6 +121,8 @@ objects with labels. See @ref AbstractQuery::setLabel(),
 @ref Buffer::setLabel(), @ref Framebuffer::setLabel(), @ref Mesh::setLabel(),
 @ref Renderbuffer::setLabel(), @ref Shader::setLabel() and
 @ref TransformFeedback::setLabel() for more information.
+
+@requires_gles Debug output is not available in WebGL.
 */
 class MAGNUM_EXPORT DebugOutput {
     friend Implementation::DebugState;
@@ -453,6 +458,8 @@ and the debug output is either not supported or turned off, the calls will not
 result in any allocations and thus won't have any negative performance effects.
 
 @see @ref DebugGroup
+
+@requires_gles Debug output is not available in WebGL.
 */
 class MAGNUM_EXPORT DebugMessage {
     friend Implementation::DebugState;
@@ -760,6 +767,8 @@ and the debug output is either not supported or turned off, the calls will not
 result in any allocations and thus won't have any negative performance effects.
 
 @see @ref DebugMessage
+
+@requires_gles Debug output is not available in WebGL.
 */
 class MAGNUM_EXPORT DebugGroup {
     friend Implementation::DebugState;
@@ -888,5 +897,8 @@ class MAGNUM_EXPORT DebugGroup {
 Debug MAGNUM_EXPORT operator<<(Debug debug, DebugGroup::Source value);
 
 }
+#else
+#error this header is not available in WebGL build
+#endif
 
 #endif

src/Magnum/Framebuffer.cpp

@@ -45,7 +45,9 @@
 #include "Magnum/RectangleTexture.h"
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/State.h"
 #include "Implementation/FramebufferState.h"
 
@@ -121,6 +123,7 @@ Framebuffer::~Framebuffer() {
     glDeleteFramebuffers(1, &_id);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string Framebuffer::label() {
     createIfNotAlready();
     return Context::current()->state().debug->getLabelImplementation(GL_FRAMEBUFFER, _id);
@@ -131,6 +134,7 @@ Framebuffer& Framebuffer::setLabelInternal(const Containers::ArrayReference<cons
     Context::current()->state().debug->labelImplementation(GL_FRAMEBUFFER, _id, label);
     return *this;
 }
+#endif
 
 Framebuffer::Status Framebuffer::checkStatus(const FramebufferTarget target) {
     return Status((this->*Context::current()->state().framebuffer->checkStatusImplementation)(target));

src/Magnum/Framebuffer.h

@@ -338,6 +338,7 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
         /** @brief OpenGL framebuffer ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Framebuffer label
          *
@@ -348,6 +349,7 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
          * @see @fn_gl{GetObjectLabel} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{FRAMEBUFFER}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -361,6 +363,7 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} or
          *      @fn_gl_extension2{LabelObject,EXT,debug_label} with
          *      @def_gl{FRAMEBUFFER}
+         * @requires_gles Debug output is not available in WebGL.
          */
         Framebuffer& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -370,6 +373,7 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
         template<std::size_t size> Framebuffer& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /**
          * @brief Check framebuffer status
@@ -669,7 +673,9 @@ class MAGNUM_EXPORT Framebuffer: public AbstractFramebuffer, public AbstractObje
         void MAGNUM_LOCAL createImplementationDSA();
         #endif
 
+        #ifndef MAGNUM_TARGET_WEBGL
         Framebuffer& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         void MAGNUM_LOCAL renderbufferImplementationDefault(BufferAttachment attachment, Renderbuffer& renderbuffer);
         #ifndef MAGNUM_TARGET_GLES

src/Magnum/Implementation/DebugState.h

@@ -30,6 +30,10 @@
 
 #include "Magnum/DebugOutput.h"
 
+#ifdef MAGNUM_TARGET_WEBGL
+#error this header is not available in WebGL build
+#endif
+
 namespace Magnum { namespace Implementation {
 
 struct DebugState {

src/Magnum/Implementation/State.cpp

@@ -31,7 +31,9 @@
 #include "Magnum/Extensions.h"
 
 #include "BufferState.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "DebugState.h"
+#endif
 #include "FramebufferState.h"
 #include "MeshState.h"
 #include "QueryState.h"
@@ -56,7 +58,9 @@ State::State(Context& context) {
     #endif
 
     buffer.reset(new BufferState{context, extensions});
+    #ifndef MAGNUM_TARGET_WEBGL
     debug.reset(new DebugState{context, extensions});
+    #endif
     framebuffer.reset(new FramebufferState{context, extensions});
     mesh.reset(new MeshState{context, extensions});
     query.reset(new QueryState{context, extensions});

src/Magnum/Implementation/State.h

@@ -33,7 +33,9 @@
 namespace Magnum { namespace Implementation {
 
 struct BufferState;
+#ifndef MAGNUM_TARGET_WEBGL
 struct DebugState;
+#endif
 struct FramebufferState;
 struct MeshState;
 struct QueryState;
@@ -54,7 +56,9 @@ struct State {
     enum: GLuint { DisengagedBinding = ~0u };
 
     std::unique_ptr<BufferState> buffer;
+    #ifndef MAGNUM_TARGET_WEBGL
     std::unique_ptr<DebugState> debug;
+    #endif
     std::unique_ptr<FramebufferState> framebuffer;
     std::unique_ptr<MeshState> mesh;
     std::unique_ptr<QueryState> query;

src/Magnum/Mesh.cpp

@@ -32,7 +32,9 @@
 #include "Magnum/Context.h"
 #include "Magnum/Extensions.h"
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/BufferState.h"
 #include "Implementation/MeshState.h"
 #include "Implementation/State.h"
@@ -172,6 +174,7 @@ inline void Mesh::createIfNotAlready() {
     CORRADE_INTERNAL_ASSERT(_created);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string Mesh::label() {
     createIfNotAlready();
     #ifndef MAGNUM_TARGET_GLES
@@ -190,6 +193,7 @@ Mesh& Mesh::setLabelInternal(const Containers::ArrayReference<const char> label)
     #endif
     return *this;
 }
+#endif
 
 Mesh& Mesh::setIndexBuffer(Buffer& buffer, GLintptr offset, IndexType type, UnsignedInt start, UnsignedInt end) {
     #if defined(CORRADE_TARGET_NACL) || defined(MAGNUM_TARGET_WEBGL)

src/Magnum/Mesh.h

@@ -458,6 +458,7 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
          */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Mesh label
          *
@@ -468,6 +469,7 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} with @def_gl{VERTEX_ARRAY} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{VERTEX_ARRAY_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -481,6 +483,7 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} with
          *      @def_gl{VERTEX_ARRAY} or @fn_gl_extension2{LabelObject,EXT,debug_label}
          *      with @def_gl{VERTEX_ARRAY_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         Mesh& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -490,6 +493,7 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
         template<std::size_t size> Mesh& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /**
          * @brief Whether the mesh is indexed
@@ -862,7 +866,9 @@ class MAGNUM_EXPORT Mesh: public AbstractObject {
 
         void MAGNUM_LOCAL createIfNotAlready();
 
+        #ifndef MAGNUM_TARGET_WEBGL
         Mesh& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         /* Computing stride of interleaved vertex attributes */
         template<UnsignedInt location, class T, class ...U> static GLsizei strideOfInterleaved(const Attribute<location, T>& attribute, const U&... attributes) {

src/Magnum/PrimitiveQuery.h

@@ -115,7 +115,7 @@ class PrimitiveQuery: public AbstractQuery {
         #endif
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         PrimitiveQuery& setLabel(const std::string& label) {
             AbstractQuery::setLabel(label);
             return *this;

src/Magnum/Renderbuffer.cpp

@@ -28,7 +28,9 @@
 #include "Magnum/Context.h"
 #include "Magnum/Extensions.h"
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/FramebufferState.h"
 #include "Implementation/State.h"
 
@@ -102,6 +104,7 @@ inline void Renderbuffer::createIfNotAlready() {
     CORRADE_INTERNAL_ASSERT(_created);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string Renderbuffer::label() {
     createIfNotAlready();
     return Context::current()->state().debug->getLabelImplementation(GL_RENDERBUFFER, _id);
@@ -112,6 +115,7 @@ Renderbuffer& Renderbuffer::setLabelInternal(const Containers::ArrayReference<co
     Context::current()->state().debug->labelImplementation(GL_RENDERBUFFER, _id, label);
     return *this;
 }
+#endif
 
 void Renderbuffer::setStorage(const RenderbufferFormat internalFormat, const Vector2i& size) {
     (this->*Context::current()->state().framebuffer->renderbufferStorageImplementation)(internalFormat, size);

src/Magnum/Renderbuffer.h

@@ -117,6 +117,7 @@ class MAGNUM_EXPORT Renderbuffer: public AbstractObject {
         /** @brief OpenGL internal renderbuffer ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Renderbuffer label
          *
@@ -127,6 +128,7 @@ class MAGNUM_EXPORT Renderbuffer: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{RENDERBUFFER}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -140,6 +142,7 @@ class MAGNUM_EXPORT Renderbuffer: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} or
          *      @fn_gl_extension2{LabelObject,EXT,debug_label} with
          *      @def_gl{RENDERBUFFER}
+         * @requires_gles Debug output is not available in WebGL.
          */
         Renderbuffer& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -149,6 +152,7 @@ class MAGNUM_EXPORT Renderbuffer: public AbstractObject {
         template<std::size_t size> Renderbuffer& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /**
          * @brief Set renderbuffer storage
@@ -192,7 +196,9 @@ class MAGNUM_EXPORT Renderbuffer: public AbstractObject {
 
         void MAGNUM_LOCAL createIfNotAlready();
 
+        #ifndef MAGNUM_TARGET_WEBGL
         Renderbuffer& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         void MAGNUM_LOCAL storageImplementationDefault(RenderbufferFormat internalFormat, const Vector2i& size);
         #ifndef MAGNUM_TARGET_GLES

src/Magnum/Renderer.cpp

@@ -231,8 +231,10 @@ Debug operator<<(Debug debug, const Renderer::Error value) {
         _c(InvalidOperation)
         _c(InvalidFramebufferOperation)
         _c(OutOfMemory)
+        #ifndef MAGNUM_TARGET_WEBGL
         _c(StackUnderflow)
         _c(StackOverflow)
+        #endif
         #undef _c
     }
 

src/Magnum/Renderer.h

@@ -84,13 +84,15 @@ class MAGNUM_EXPORT Renderer {
              */
             Blending = GL_BLEND,
 
+            #ifndef MAGNUM_TARGET_WEBGL
             /**
              * Debug output. Disabled by default unless the GL context was
              * created with debug output enabled.
              * @see @ref DebugOutput, @ref Feature::DebugOutputSynchronous,
              *      @ref Platform::Sdl2Application::Configuration::Flag::Debug "Platform::*Application::Configuration::Flag::Debug"
              * @requires_gl43 Extension @extension{KHR,debug}
-             * @requires_es_extension Extension @es_extension{KHR,debug}
+             * @requires_es_extension Extension @es_extension2{KHR,debug,debug}
+             * @requires_gles Debug output is not available in WebGL.
              */
             #ifndef MAGNUM_TARGET_GLES
             DebugOutput = GL_DEBUG_OUTPUT,
@@ -103,13 +105,15 @@ class MAGNUM_EXPORT Renderer {
              * @ref Feature::DebugOutput is enabled.
              * @see @ref DebugMessage
              * @requires_gl43 Extension @extension{KHR,debug}
-             * @requires_es_extension Extension @es_extension{KHR,debug}
+             * @requires_es_extension Extension @es_extension2{KHR,debug,debug}
+             * @requires_gles Debug output is not available in WebGL.
              */
             #ifndef MAGNUM_TARGET_GLES
             DebugOutputSynchronous = GL_DEBUG_OUTPUT_SYNCHRONOUS,
             #else
             DebugOutputSynchronous = GL_DEBUG_OUTPUT_SYNCHRONOUS_KHR,
             #endif
+            #endif
 
             #ifndef MAGNUM_TARGET_GLES
             /**
@@ -974,11 +978,13 @@ class MAGNUM_EXPORT Renderer {
             /** There is not enough memory left to execute the command. */
             OutOfMemory = GL_OUT_OF_MEMORY,
 
+            #ifndef MAGNUM_TARGET_WEBGL
             /**
              * Given operation would cause an internal stack to underflow.
              * @see @ref DebugGroup
              * @requires_gl43 Extension @extension{KHR,debug}
              * @requires_es_extension Extension @es_extension2{KHR,debug,debug}
+             * @requires_gles Debug output is not available in WebGL.
              */
             #ifndef MAGNUM_TARGET_GLES
             StackUnderflow = GL_STACK_UNDERFLOW,
@@ -991,12 +997,14 @@ class MAGNUM_EXPORT Renderer {
              * @see @ref DebugGroup
              * @requires_gl43 Extension @extension{KHR,debug}
              * @requires_es_extension Extension @es_extension2{KHR,debug,debug}
+             * @requires_gles Debug output is not available in WebGL.
              */
             #ifndef MAGNUM_TARGET_GLES
             StackOverflow = GL_STACK_OVERFLOW
             #else
             StackOverflow = GL_STACK_OVERFLOW_KHR
             #endif
+            #endif
         };
 
         /**

src/Magnum/SampleQuery.h

@@ -232,7 +232,7 @@ class SampleQuery: public AbstractQuery {
         #endif
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         SampleQuery& setLabel(const std::string& label) {
             AbstractQuery::setLabel(label);
             return *this;

src/Magnum/Shader.cpp

@@ -32,7 +32,9 @@
 #include "Magnum/Context.h"
 #include "Magnum/Extensions.h"
 
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Implementation/DebugState.h"
+#endif
 #include "Implementation/State.h"
 #include "Implementation/ShaderState.h"
 
@@ -646,6 +648,7 @@ Shader::~Shader() {
     glDeleteShader(_id);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string Shader::label() const {
     #ifndef MAGNUM_TARGET_GLES
     return Context::current()->state().debug->getLabelImplementation(GL_SHADER, _id);
@@ -662,6 +665,7 @@ Shader& Shader::setLabelInternal(const Containers::ArrayReference<const char> la
     #endif
     return *this;
 }
+#endif
 
 std::vector<std::string> Shader::sources() const { return _sources; }
 

src/Magnum/Shader.h

@@ -488,6 +488,7 @@ class MAGNUM_EXPORT Shader: public AbstractObject {
         /** @brief OpenGL shader ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Shader label
          *
@@ -498,6 +499,7 @@ class MAGNUM_EXPORT Shader: public AbstractObject {
          * @see @fn_gl{GetObjectLabel} with @def_gl{SHADER} or
          *      @fn_gl_extension2{GetObjectLabel,EXT,debug_label} with
          *      @def_gl{SHADER_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label() const;
 
@@ -511,6 +513,7 @@ class MAGNUM_EXPORT Shader: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} with
          *      @def_gl{SHADER} or @fn_gl_extension2{LabelObject,EXT,debug_label}
          *      with @def_gl{SHADER_OBJECT_EXT}
+         * @requires_gles Debug output is not available in WebGL.
          */
         Shader& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
@@ -520,6 +523,7 @@ class MAGNUM_EXPORT Shader: public AbstractObject {
         template<std::size_t size> Shader& setLabel(const char(&label)[size]) {
             return setLabelInternal({label, size - 1});
         }
+        #endif
 
         /** @brief Shader type */
         Type type() const { return _type; }

src/Magnum/Texture.h

@@ -875,7 +875,7 @@ template<UnsignedInt dimensions> class Texture: public AbstractTexture {
         }
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         Texture<dimensions>& setLabel(const std::string& label) {
             AbstractTexture::setLabel(label);
             return *this;

src/Magnum/TextureArray.h

@@ -530,7 +530,7 @@ template<UnsignedInt dimensions> class TextureArray: public AbstractTexture {
         }
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         TextureArray<dimensions>& setLabel(const std::string& label) {
             AbstractTexture::setLabel(label);
             return *this;

src/Magnum/TimeQuery.h

@@ -138,7 +138,7 @@ class TimeQuery: public AbstractQuery {
         #endif
 
         /* Overloads to remove WTF-factor from method chaining order */
-        #ifndef DOXYGEN_GENERATING_OUTPUT
+        #if !defined(DOXYGEN_GENERATING_OUTPUT) && !defined(MAGNUM_TARGET_WEBGL)
         TimeQuery& setLabel(const std::string& label) {
             AbstractQuery::setLabel(label);
             return *this;

src/Magnum/TransformFeedback.cpp

@@ -32,7 +32,9 @@
 #include "Magnum/Buffer.h"
 #include "Magnum/Context.h"
 #include "Magnum/Extensions.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Magnum/Implementation/DebugState.h"
+#endif
 #include "Magnum/Implementation/State.h"
 #include "Magnum/Implementation/TransformFeedbackState.h"
 
@@ -144,6 +146,7 @@ inline void TransformFeedback::createIfNotAlready() {
     CORRADE_INTERNAL_ASSERT(_created);
 }
 
+#ifndef MAGNUM_TARGET_WEBGL
 std::string TransformFeedback::label() {
     createIfNotAlready();
     return Context::current()->state().debug->getLabelImplementation(GL_TRANSFORM_FEEDBACK, _id);
@@ -154,6 +157,7 @@ TransformFeedback& TransformFeedback::setLabelInternal(const Containers::ArrayRe
     Context::current()->state().debug->labelImplementation(GL_TRANSFORM_FEEDBACK, _id, label);
     return *this;
 }
+#endif
 
 TransformFeedback& TransformFeedback::attachBuffer(const UnsignedInt index, Buffer& buffer, const GLintptr offset, const GLsizeiptr size) {
     (this->*Context::current()->state().transformFeedback->attachRangeImplementation)(index, buffer, offset, size);

src/Magnum/TransformFeedback.h

@@ -179,6 +179,7 @@ class MAGNUM_EXPORT TransformFeedback: public AbstractObject {
         /** @brief OpenGL transform feedback ID */
         GLuint id() const { return _id; }
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Buffer label
          *
@@ -188,6 +189,7 @@ class MAGNUM_EXPORT TransformFeedback: public AbstractObject {
          * extension is available, this function returns empty string.
          * @see @fn_gl{GetObjectLabel} or @fn_gl_extension2{GetObjectLabel,EXT,debug_label}
          *      with @def_gl{TRANSFORM_FEEDBACK}
+         * @requires_gles Debug output is not available in WebGL.
          */
         std::string label();
 
@@ -201,10 +203,12 @@ class MAGNUM_EXPORT TransformFeedback: public AbstractObject {
          * @see @ref maxLabelLength(), @fn_gl{ObjectLabel} or
          *      @fn_gl_extension2{LabelObject,EXT,debug_label} with
          *      @def_gl{TRANSFORM_FEEDBACK}
+         * @requires_gles Debug output is not available in WebGL.
          */
         TransformFeedback& setLabel(const std::string& label) {
             return setLabelInternal({label.data(), label.size()});
         }
+        #endif
 
         /** @overload */
         template<std::size_t size> TransformFeedback& setLabel(const char(&label)[size]) {
@@ -364,7 +368,9 @@ class MAGNUM_EXPORT TransformFeedback: public AbstractObject {
         void MAGNUM_LOCAL attachImplementationDSA(GLuint firstIndex, std::initializer_list<Buffer*> buffers);
         #endif
 
+        #ifndef MAGNUM_TARGET_WEBGL
         TransformFeedback& setLabelInternal(Containers::ArrayReference<const char> label);
+        #endif
 
         GLuint _id;
         bool _created; /* see createIfNotAlready() for details */