GL: new "angle-chatty-shader-compiler" workaround.

doc/changelog.dox

@@ -81,6 +81,9 @@ See also:
     happening during EGL initialization in recent NVidia drivers.  See
     @ref opengl-workarounds and [mosra/magnum#491](https://github.com/mosra/magnum/pull/491)
     for more information.
+-   A new @cpp "angle-chatty-shader-compiler" @ce workarounds for silencing
+    useless linker output on ANGLE. See @ref opengl-workarounds for more
+    information.
 
 @subsubsection changelog-latest-new-math Math library
 

src/Magnum/GL/AbstractShaderProgram.cpp

@@ -544,6 +544,12 @@ void AbstractShaderProgram::cleanLogImplementationIntelWindows(std::string& mess
 }
 #endif
 
+#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+void AbstractShaderProgram::cleanLogImplementationAngle(std::string& message) {
+    if(message == "\n") message = {};
+}
+#endif
+
 Int AbstractShaderProgram::uniformLocationInternal(const Containers::ArrayView<const char> name) {
     const GLint location = glGetUniformLocation(_id, name);
     if(location == -1)

src/Magnum/GL/AbstractShaderProgram.h

@@ -1351,6 +1351,9 @@ class MAGNUM_GL_EXPORT AbstractShaderProgram: public AbstractObject {
         #if defined(CORRADE_TARGET_WINDOWS) && !defined(MAGNUM_TARGET_GLES)
         static MAGNUM_GL_LOCAL void cleanLogImplementationIntelWindows(std::string& message);
         #endif
+        #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+        static MAGNUM_GL_LOCAL void cleanLogImplementationAngle(std::string& message);
+        #endif
 
         void use();
 

src/Magnum/GL/Implementation/ShaderProgramState.cpp

@@ -65,6 +65,11 @@ ShaderProgramState::ShaderProgramState(Context& context, std::vector<std::string
         cleanLogImplementation = &AbstractShaderProgram::cleanLogImplementationIntelWindows;
     } else
     #endif
+    #if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+    if((context.detectedDriver() & Context::DetectedDriver::Angle) && !context.isDriverWorkaroundDisabled("angle-chatty-shader-compiler")) {
+        cleanLogImplementation = &AbstractShaderProgram::cleanLogImplementationAngle;
+    } else
+    #endif
     {
         cleanLogImplementation = &AbstractShaderProgram::cleanLogImplementationNoOp;
     }

src/Magnum/GL/Implementation/driverSpecific.cpp

@@ -40,6 +40,13 @@ namespace {
 /* Search the code for the following strings to see where they are implemented. */
 const char* KnownWorkarounds[]{
 /* [workarounds] */
+#if defined(MAGNUM_TARGET_GLES) && !defined(MAGNUM_TARGET_WEBGL)
+/* ANGLE's shader linker insists on returning a message consisting of a
+   single newline on success, causing annoying noise in the console. Similar to
+   "intel-windows-chatty-shader-compiler". */
+"angle-chatty-shader-compiler",
+#endif
+
 #if defined(CORRADE_TARGET_APPLE) && !defined(MAGNUM_TARGET_GLES)
 /* Calling glBufferData(), glMapBuffer(), glMapBufferRange() or glUnmapBuffer()
    on ANY buffer when ANY buffer is attached to a currently bound
@@ -337,7 +344,7 @@ const char* KnownWorkarounds[]{
 "intel-windows-broken-dsa-integer-vertex-attributes",
 
 /* Shader compiler on Intel Windows drivers insists on telling me "No errors."
-   when it should just stay silent. */
+   when it should just stay silent. See also "angle-chatty-shader-compiler". */
 "intel-windows-chatty-shader-compiler",
 
 /* When using more than just a vertex and fragment shader (geometry shader,