Validate precision in uniform blocks for WebGL.

src/libANGLE/Program.cpp

@@ -666,7 +666,7 @@ Error Program::link(const gl::Context *context)
             return NoError();
         }
 
-        if (!linkUniformBlocks(mInfoLog, caps))
+        if (!linkUniformBlocks(mInfoLog, caps, context->getExtensions().webglCompatibility))
         {
             return NoError();
         }
@@ -713,7 +713,7 @@ Error Program::link(const gl::Context *context)
             return NoError();
         }
 
-        if (!linkUniformBlocks(mInfoLog, caps))
+        if (!linkUniformBlocks(mInfoLog, caps, context->getExtensions().webglCompatibility))
         {
             return NoError();
         }
@@ -2069,10 +2069,12 @@ void Program::linkSamplerBindings()
 bool Program::linkValidateInterfaceBlockFields(InfoLog &infoLog,
                                                const std::string &uniformName,
                                                const sh::InterfaceBlockField &vertexUniform,
-                                               const sh::InterfaceBlockField &fragmentUniform)
+                                               const sh::InterfaceBlockField &fragmentUniform,
+                                               bool webglCompatibility)
 {
-    // We don't validate precision on UBO fields. See resolution of Khronos bug 10287.
-    if (!linkValidateVariablesBase(infoLog, uniformName, vertexUniform, fragmentUniform, false))
+    // If webgl, validate precision of UBO fields, otherwise don't.  See Khronos bug 10287.
+    if (!linkValidateVariablesBase(infoLog, uniformName, vertexUniform, fragmentUniform,
+                                   webglCompatibility))
     {
         return false;
     }
@@ -2209,7 +2211,8 @@ bool Program::validateUniformBlocksCount(GLuint maxUniformBlocks,
 bool Program::validateVertexAndFragmentInterfaceBlocks(
     const std::vector<sh::InterfaceBlock> &vertexInterfaceBlocks,
     const std::vector<sh::InterfaceBlock> &fragmentInterfaceBlocks,
-    InfoLog &infoLog) const
+    InfoLog &infoLog,
+    bool webglCompatibility) const
 {
     // Check that interface blocks defined in the vertex and fragment shaders are identical
     typedef std::map<std::string, const sh::InterfaceBlock *> UniformBlockMap;
@@ -2226,7 +2229,8 @@ bool Program::validateVertexAndFragmentInterfaceBlocks(
         if (entry != linkedUniformBlocks.end())
         {
             const sh::InterfaceBlock &vertexInterfaceBlock = *entry->second;
-            if (!areMatchingInterfaceBlocks(infoLog, vertexInterfaceBlock, fragmentInterfaceBlock))
+            if (!areMatchingInterfaceBlocks(infoLog, vertexInterfaceBlock, fragmentInterfaceBlock,
+                                            webglCompatibility))
             {
                 return false;
             }
@@ -2235,7 +2239,7 @@ bool Program::validateVertexAndFragmentInterfaceBlocks(
     return true;
 }
 
-bool Program::linkUniformBlocks(InfoLog &infoLog, const Caps &caps)
+bool Program::linkUniformBlocks(InfoLog &infoLog, const Caps &caps, bool webglCompatibility)
 {
     if (mState.mAttachedComputeShader)
     {
@@ -2273,7 +2277,7 @@ bool Program::linkUniformBlocks(InfoLog &infoLog, const Caps &caps)
         return false;
     }
     if (!validateVertexAndFragmentInterfaceBlocks(vertexInterfaceBlocks, fragmentInterfaceBlocks,
-                                                  infoLog))
+                                                  infoLog, webglCompatibility))
     {
         return false;
     }
@@ -2283,7 +2287,8 @@ bool Program::linkUniformBlocks(InfoLog &infoLog, const Caps &caps)
 
 bool Program::areMatchingInterfaceBlocks(InfoLog &infoLog,
                                          const sh::InterfaceBlock &vertexInterfaceBlock,
-                                         const sh::InterfaceBlock &fragmentInterfaceBlock) const
+                                         const sh::InterfaceBlock &fragmentInterfaceBlock,
+                                         bool webglCompatibility) const
 {
     const char* blockName = vertexInterfaceBlock.name.c_str();
     // validate blocks for the same member types
@@ -2322,7 +2327,8 @@ bool Program::areMatchingInterfaceBlocks(InfoLog &infoLog,
             return false;
         }
         std::string memberName = "interface block '" + vertexInterfaceBlock.name + "' member '" + vertexMember.name + "'";
-        if (!linkValidateInterfaceBlockFields(infoLog, memberName, vertexMember, fragmentMember))
+        if (!linkValidateInterfaceBlockFields(infoLog, memberName, vertexMember, fragmentMember,
+                                              webglCompatibility))
         {
             return false;
         }

src/libANGLE/Program.h

@@ -424,7 +424,11 @@ class Program final : angle::NonCopyable, public LabeledObject
     GLsizei getTransformFeedbackVaryingMaxLength() const;
     GLenum getTransformFeedbackBufferMode() const;
 
-    static bool linkValidateInterfaceBlockFields(InfoLog &infoLog, const std::string &uniformName, const sh::InterfaceBlockField &vertexUniform, const sh::InterfaceBlockField &fragmentUniform);
+    static bool linkValidateInterfaceBlockFields(InfoLog &infoLog,
+                                                 const std::string &uniformName,
+                                                 const sh::InterfaceBlockField &vertexUniform,
+                                                 const sh::InterfaceBlockField &fragmentUniform,
+                                                 bool webglCompatibility);
 
     void addRef();
     void release(const Context *context);
@@ -495,8 +499,9 @@ class Program final : angle::NonCopyable, public LabeledObject
     bool validateVertexAndFragmentInterfaceBlocks(
         const std::vector<sh::InterfaceBlock> &vertexInterfaceBlocks,
         const std::vector<sh::InterfaceBlock> &fragmentInterfaceBlocks,
-        InfoLog &infoLog) const;
-    bool linkUniformBlocks(InfoLog &infoLog, const Caps &caps);
+        InfoLog &infoLog,
+        bool webglCompatibility) const;
+    bool linkUniformBlocks(InfoLog &infoLog, const Caps &caps, bool webglCompatibility);
     bool linkVaryings(InfoLog &infoLog) const;
 
     bool linkUniforms(InfoLog &infoLog, const Caps &caps, const Bindings &uniformLocationBindings);
@@ -504,7 +509,8 @@ class Program final : angle::NonCopyable, public LabeledObject
 
     bool areMatchingInterfaceBlocks(InfoLog &infoLog,
                                     const sh::InterfaceBlock &vertexInterfaceBlock,
-                                    const sh::InterfaceBlock &fragmentInterfaceBlock) const;
+                                    const sh::InterfaceBlock &fragmentInterfaceBlock,
+                                    bool webglCompatibility) const;
 
     static bool linkValidateVaryings(InfoLog &infoLog,
                                      const std::string &varyingName,

src/tests/gl_tests/WebGLCompatibilityTest.cpp

@@ -2824,6 +2824,40 @@ TEST_P(WebGLCompatibilityTest, DrawBuffers)
     }
 }
 
+// Linking should fail when corresponding vertex/fragment uniform blocks have different precision
+// qualifiers.
+TEST_P(WebGL2CompatibilityTest, UniformBlockPrecisionMismatch)
+{
+    const std::string vertexShader =
+        "#version 300 es\n"
+        "uniform Block { mediump vec4 val; };\n"
+        "void main() { gl_Position = val; }\n";
+    const std::string fragmentShader =
+        "#version 300 es\n"
+        "uniform Block { highp vec4 val; };\n"
+        "out highp vec4 out_FragColor;\n"
+        "void main() { out_FragColor = val; }\n";
+
+    GLuint vs = CompileShader(GL_VERTEX_SHADER, vertexShader);
+    ASSERT_NE(0u, vs);
+    GLuint fs = CompileShader(GL_FRAGMENT_SHADER, fragmentShader);
+    ASSERT_NE(0u, fs);
+
+    GLuint program = glCreateProgram();
+
+    glAttachShader(program, vs);
+    glDeleteShader(vs);
+    glAttachShader(program, fs);
+    glDeleteShader(fs);
+
+    glLinkProgram(program);
+    GLint linkStatus;
+    glGetProgramiv(program, GL_LINK_STATUS, &linkStatus);
+    ASSERT_EQ(0, linkStatus);
+
+    glDeleteProgram(program);
+}
+
 // Use this to select which configurations (e.g. which renderer, which GLES major version) these
 // tests should be run against.
 ANGLE_INSTANTIATE_TEST(WebGLCompatibilityTest,