Return the correct location count for matrices in structs

src/compiler/translator/ValidateVaryingLocations.cpp

@@ -37,7 +37,8 @@ int GetLocationCount(const TIntermSymbol *varying, bool ignoreVaryingArraySize)
             const auto *fieldType = field->type();
             ASSERT(fieldType->getStruct() == nullptr && !fieldType->isArray());
 
-            totalLocation += fieldType->getSecondarySize();
+            totalLocation +=
+                fieldType->isMatrix() ? fieldType->getNominalSize() : fieldType->getSecondarySize();
         }
         return totalLocation;
     }

src/tests/gl_tests/MatrixTest.cpp

@@ -183,10 +183,6 @@ layout(location=6) in vec3 vector;
 
 out vec4 oColor;
 
-bool isZero(vec4 value) {
-    return value == vec4(0,0,0,0);
-}
-
 void main()
 {
     oColor = vec4(matrix[0][0]);
@@ -227,6 +223,82 @@ void main()
     EXPECT_GL_FALSE(compileResult);
 }
 
+TEST_P(MatrixTest31, Mat3x4StructVarying)
+{
+    constexpr char kVS[] = R"(#version 310 es
+precision mediump float;
+
+in vec4 a_position;
+
+struct S
+{
+    mat3x4 m;
+};
+layout(location=0) out S matrix;
+layout(location=3) out vec3 vector;
+
+void main()
+{
+    matrix.m = mat3x4(1.0);
+    vector = vec3(1.0);
+    gl_Position = a_position;
+})";
+
+    constexpr char kFS[] = R"(#version 310 es
+precision mediump float;
+
+struct S
+{
+    mat3x4 m;
+};
+layout(location=0) in S matrix;
+layout(location=3) in vec3 vector;
+
+out vec4 oColor;
+
+void main()
+{
+    oColor = vec4(matrix.m[0]);
+})";
+
+    ANGLE_GL_PROGRAM(program, kVS, kFS);
+    glUseProgram(program);
+    drawQuad(program, "a_position", 0.5f);
+    EXPECT_GL_NO_ERROR();
+}
+
+TEST_P(MatrixTest31, Mat3x4StructVaryingBadLocation)
+{
+    constexpr char kVS[] = R"(#version 310 es
+precision mediump float;
+
+in vec4 a_position;
+
+struct S
+{
+    mat3x4 m;
+};
+layout(location=0) out S matrix;
+layout(location=2) out vec3 vector;
+
+void main()
+{
+    matrix.m = mat3x4(1.0);
+    vector = vec3(1.0);
+    gl_Position = a_position;
+})";
+
+    GLProgram program;
+
+    GLuint vs                    = glCreateShader(GL_VERTEX_SHADER);
+    const char *sourceVsArray[1] = {kVS};
+    glShaderSource(vs, 1, sourceVsArray, nullptr);
+    glCompileShader(vs);
+    GLint compileResult;
+    glGetShaderiv(vs, GL_COMPILE_STATUS, &compileResult);
+    EXPECT_GL_FALSE(compileResult);
+}
+
 ANGLE_INSTANTIATE_TEST_ES31(MatrixTest31);
 
 }  // namespace