Vulkan: Add test for Pixel bug with passthrough GLSL function

src/tests/gl_tests/GLSLTest.cpp

@@ -5081,6 +5081,92 @@ TEST_P(GLSLTest_ES3, VaryingStructUsedInFragmentShader)
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
 }
 
+// This test demonstrates an issue with shaders on the Pixel device's vulkan backend.
+// This test should render a red quad without issues but on a Pixel4XL this test causes
+// vkCreateGraphicPipelines to return VK_INCOMPLETE. logcat shows these messages:
+//   > Adreno  : Failed to link shaders.
+//   > Internal Vulkan error: A return array was too small for the result
+TEST_P(GLSLTest_ES31, SamplerPassthroughFailedLink)
+{
+    // TODO: (anglebug.com/5457)
+    ANGLE_SKIP_TEST_IF(IsAndroid() && (IsPixel2() || IsPixel2XL()) && IsVulkan());
+    constexpr char kVS[] =
+        "precision mediump float;\n"
+        "attribute vec4 inputAttribute;\n"
+        "varying mediump vec2 texCoord;\n"
+        "void main() {\n"
+        "    texCoord = inputAttribute.xy;\n"
+        "    gl_Position = vec4(inputAttribute.x, inputAttribute.y, 0.0, 1.0);\n"
+        "}\n";
+
+    constexpr char kFS[] =
+        "precision mediump float;\n"
+        "varying mediump vec2 texCoord;\n"
+        "uniform sampler2D testSampler;\n"
+        "vec3 passthrough(vec3 c) {\n"
+        "    return c;\n"
+        "}\n"
+        "void main() {\n"
+        "    gl_FragColor = vec4(passthrough(texture2D(testSampler, texCoord).rgb), 1.0);\n"
+        "}\n";
+    ANGLE_GL_PROGRAM(program, kVS, kFS);
+
+    // Initialize basic red texture.
+    GLTexture texture;
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                 GLColor::red.data());
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    ASSERT_GL_NO_ERROR();
+
+    drawQuad(program.get(), "inputAttribute", 0.5f);
+    ASSERT_GL_NO_ERROR();
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
+}
+
+// This test demonstrates issues with shaders on the Pixel device's vulkan backend.
+// This test should render a red quad without issues but on a Pixel4XL it renders
+// a black quad
+TEST_P(GLSLTest_ES31, SamplerPassthroughIncorrectColor)
+{
+    // TODO: (anglebug.com/5457)
+    ANGLE_SKIP_TEST_IF(IsAndroid() && (IsPixel2() || IsPixel2XL()) && IsVulkan());
+    constexpr char kVS[] =
+        "precision mediump float;\n"
+        "attribute vec4 inputAttribute;\n"
+        "varying mediump vec2 texCoord;\n"
+        "void main() {\n"
+        "    texCoord = inputAttribute.xy;\n"
+        "    gl_Position = vec4(inputAttribute.x, inputAttribute.y, 0.0, 1.0);\n"
+        "}\n";
+
+    constexpr char kFS[] =
+        "precision mediump float;\n"
+        "varying mediump vec2 texCoord;\n"
+        "uniform sampler2D testSampler;\n"
+        "vec4 passthrough(vec4 c) {\n"
+        "    return c;\n"
+        "}\n"
+        "void main() {\n"
+        "    gl_FragColor = vec4(passthrough(texture2D(testSampler, texCoord)));\n"
+        "}\n";
+    ANGLE_GL_PROGRAM(program, kVS, kFS);
+
+    // Initialize basic red texture.
+    GLTexture texture;
+    glBindTexture(GL_TEXTURE_2D, texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE,
+                 GLColor::red.data());
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    ASSERT_GL_NO_ERROR();
+
+    drawQuad(program.get(), "inputAttribute", 0.5f);
+    ASSERT_GL_NO_ERROR();
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::red);
+}
+
 // Test that multiple multi-field varying structs that get used in the fragment shader work.
 TEST_P(GLSLTest_ES3, ComplexVaryingStructsUsedInFragmentShader)
 {