command_buffer: Use GLSL core version that matches the OpenGL version

gpu/command_buffer/service/shader_translator_unittest.cc

Index: gpu/command_buffer/service/shader_translator_unittest.cc
diff --git a/gpu/command_buffer/service/shader_translator_unittest.cc b/gpu/command_buffer/service/shader_translator_unittest.cc
index 5f6173818f922b1fccf54e31bf338e68873c5ec4..0c60b44c5a63853badb359d0a7f8618be4249c97 100644
--- a/gpu/command_buffer/service/shader_translator_unittest.cc
+++ b/gpu/command_buffer/service/shader_translator_unittest.cc
@@ -6,6 +6,7 @@
 
 #include "gpu/command_buffer/service/shader_translator.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gl/gl_version_info.h"
 
 namespace gpu {
 namespace gles2 {
@@ -13,6 +14,9 @@ namespace gles2 {
 class ShaderTranslatorTest : public testing::Test {
  public:
   ShaderTranslatorTest() {
+    shader_output_language_ =
+        ShaderTranslator::GetShaderOutputLanguageForContext(
+            gfx::GLVersionInfo("2.0", "", ""));
   }
 
   ~ShaderTranslatorTest() override {}
@@ -27,14 +31,12 @@ class ShaderTranslatorTest : public testing::Test {
     vertex_translator_ = new ShaderTranslator();
     fragment_translator_ = new ShaderTranslator();
 
-    ASSERT_TRUE(vertex_translator_->Init(
-        GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
-        ShaderTranslatorInterface::kGlsl,
-        SH_EMULATE_BUILT_IN_FUNCTIONS));
-    ASSERT_TRUE(fragment_translator_->Init(
-        GL_FRAGMENT_SHADER, SH_GLES2_SPEC, &resources,
-        ShaderTranslatorInterface::kGlsl,
-        static_cast<ShCompileOptions>(0)));
+    ASSERT_TRUE(vertex_translator_->Init(GL_VERTEX_SHADER, SH_GLES2_SPEC,
+                                         &resources, shader_output_language_,
+                                         SH_EMULATE_BUILT_IN_FUNCTIONS));
+    ASSERT_TRUE(fragment_translator_->Init(GL_FRAGMENT_SHADER, SH_GLES2_SPEC,
+                                           &resources, shader_output_language_,
+                                           static_cast<ShCompileOptions>(0)));
   }
   void TearDown() override {
     vertex_translator_ = NULL;
@@ -43,6 +45,7 @@ class ShaderTranslatorTest : public testing::Test {
 
   scoped_refptr<ShaderTranslator> vertex_translator_;
   scoped_refptr<ShaderTranslator> fragment_translator_;
+  ShShaderOutput shader_output_language_;
 };
 
 TEST_F(ShaderTranslatorTest, ValidVertexShader) {
@@ -290,19 +293,16 @@ TEST_F(ShaderTranslatorTest, OptionsString) {
   ShBuiltInResources resources;
   ShInitBuiltInResources(&resources);
 
-  ASSERT_TRUE(translator_1->Init(
-      GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
-      ShaderTranslatorInterface::kGlsl,
-      SH_EMULATE_BUILT_IN_FUNCTIONS));
-  ASSERT_TRUE(translator_2->Init(
-      GL_FRAGMENT_SHADER, SH_GLES2_SPEC, &resources,
-      ShaderTranslatorInterface::kGlsl,
-      static_cast<ShCompileOptions>(0)));
+  ASSERT_TRUE(translator_1->Init(GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
+                                 SH_GLSL_150_CORE_OUTPUT,
+                                 SH_EMULATE_BUILT_IN_FUNCTIONS));
+  ASSERT_TRUE(translator_2->Init(GL_FRAGMENT_SHADER, SH_GLES2_SPEC, &resources,
+                                 SH_GLSL_150_CORE_OUTPUT,
+                                 static_cast<ShCompileOptions>(0)));
   resources.EXT_draw_buffers = 1;
-  ASSERT_TRUE(translator_3->Init(
-      GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
-      ShaderTranslatorInterface::kGlsl,
-      SH_EMULATE_BUILT_IN_FUNCTIONS));
+  ASSERT_TRUE(translator_3->Init(GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
+                                 SH_GLSL_150_CORE_OUTPUT,
+                                 SH_EMULATE_BUILT_IN_FUNCTIONS));
 
   std::string options_1(
       translator_1->GetStringForOptionsThatWouldAffectCompilation());
@@ -319,6 +319,113 @@ TEST_F(ShaderTranslatorTest, OptionsString) {
   EXPECT_NE(options_3, options_4);
 }
 
+class ShaderTranslatorOutputVersionTest
+    : public testing::TestWithParam<testing::tuple<const char*, const char*>> {
+};
+
+TEST_P(ShaderTranslatorOutputVersionTest, HasCorrectOutputGLSLVersion) {
+  // Test that translating to a shader targeting certain OpenGL context version
+  // (version string in test param tuple index 0) produces a GLSL shader that
+  // contains correct version string for that context (version directive
+  // in test param tuple index 1).
+
+  const char* kShader =
+      "attribute vec4 vPosition;\n"
+      "void main() {\n"
+      "  gl_Position = vPosition;\n"
+      "}";
+
+  gfx::GLVersionInfo output_context_version(testing::get<0>(GetParam()), "",
+                                            "");
+
+  scoped_refptr<ShaderTranslator> translator = new ShaderTranslator();
+  ShBuiltInResources resources;
+  ShInitBuiltInResources(&resources);
+  ShCompileOptions compile_options = SH_OBJECT_CODE;
+  ShShaderOutput shader_output_language =
+      ShaderTranslator::GetShaderOutputLanguageForContext(
+          output_context_version);
+  ASSERT_TRUE(translator->Init(GL_VERTEX_SHADER, SH_GLES2_SPEC, &resources,
+                               shader_output_language, compile_options));
+
+  std::string translated_source;
+  int shader_version;
+  EXPECT_TRUE(translator->Translate(kShader, nullptr, &translated_source,
+                                    &shader_version, nullptr, nullptr, nullptr,
+                                    nullptr));
+
+  std::string expected_version_directive = testing::get<1>(GetParam());
+  if (expected_version_directive.empty()) {
+    EXPECT_TRUE(translated_source.find("#version") == std::string::npos)
+        << "Translation was:\n" << translated_source;
+  } else {
+    EXPECT_TRUE(translated_source.find(expected_version_directive) !=
+                std::string::npos)
+        << "Translation was:\n" << translated_source;
+  }
+}
+
+// For some compilers, using make_tuple("a", "bb") would end up
+// instantiating make_tuple<char[1], char[2]>. This does not work.
+namespace {
+testing::tuple<const char*, const char*> make_gl_glsl_tuple(
+    const char* gl_version,
+    const char* glsl_version_directive) {
+  return testing::make_tuple(gl_version, glsl_version_directive);
+}
+}
+
+// Test data for the above test. OpenGL specifications specify a
+// certain version of GLSL to be guaranteed to be supported. Test
+// that ShaderTranslator produces a GLSL shader with the exact
+// specified GLSL version for each known OpenGL version.
+INSTANTIATE_TEST_CASE_P(
+    KnownOpenGLContexts,
+    ShaderTranslatorOutputVersionTest,
+    testing::Values(make_gl_glsl_tuple("4.5", "#version 450\n"),
+                    make_gl_glsl_tuple("4.4", "#version 440\n"),
+                    make_gl_glsl_tuple("4.3", "#version 430\n"),
+                    make_gl_glsl_tuple("4.2", "#version 420\n"),
+                    make_gl_glsl_tuple("4.1", "#version 410\n"),
+                    make_gl_glsl_tuple("4.0", "#version 400\n"),
+                    make_gl_glsl_tuple("3.3", "#version 330\n"),
+                    make_gl_glsl_tuple("3.2", "#version 150\n"),
+                    make_gl_glsl_tuple("3.1", "#version 140\n"),
+                    make_gl_glsl_tuple("3.0", "#version 130\n")));
+
+// Test data for the above test. Check that early OpenGL contexts get
+// GLSL compatibility profile shader, e.g. shader has no #version
+// directive. Also check that future version 3.3+ OpenGL contexts get
+// similar shader. We do not expect that future 3.3+ specs contain
+// the "all eariler GLSL versions" clause, since 3.3 did not contain
+// it either.
+INSTANTIATE_TEST_CASE_P(OldOrUnknownOpenGLContexts,
+                        ShaderTranslatorOutputVersionTest,
+                        testing::Values(make_gl_glsl_tuple("3.4", ""),
+                                        make_gl_glsl_tuple("2.0", "")));
+
+// Test data for the above test. Cases for the future OpenGL versions. The
+// code assumes that the future OpenGL specs specify the clause that all
+// earlier GLSL versions are supported. We select the highest GLSL
+// version known at the time of writing.
+INSTANTIATE_TEST_CASE_P(
+    BackwardsCompatibleFutureOpenGLContexts,
+    ShaderTranslatorOutputVersionTest,
+    testing::Values(make_gl_glsl_tuple("5.0", "#version 450\n"),
+                    make_gl_glsl_tuple("4.6", "#version 450\n")));
+
+// Test data for the above test. Check that for the OpenGL ES output
+// contexts, the shader is such that GLSL 1.0 is used. The translator
+// selects GLSL 1.0 by not output any version at the moment, though we
+// do not know if that would be correct for the future OpenGL ES specs.
+INSTANTIATE_TEST_CASE_P(OpenGLESContexts,
+                        ShaderTranslatorOutputVersionTest,
+                        testing::Values(make_gl_glsl_tuple("opengl es 2.0", ""),
+                                        make_gl_glsl_tuple("opengl es 3.0", ""),
+                                        make_gl_glsl_tuple("opengl es 3.1", ""),
+                                        make_gl_glsl_tuple("opengl es 3.2",
+                                                           "")));
+
 }  // namespace gles2
 }  // namespace gpu