Translator: Fix zero-init of I/O block arrays

Bug: angleproject:6609
Change-Id: I8245e868fe6bc4798e74088916e1d8cdd0727b6b
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3260325
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

src/compiler/translator/tree_ops/InitializeVariables.cpp

@@ -59,18 +59,16 @@ void AddZeroInitSequence(const TIntermTyped *initializedNode,
     }
     else if (initializedNode->getType().isInterfaceBlock())
     {
-        const ImmutableString &name =
-            static_cast<const TIntermSymbol *>(initializedNode)->getName();
         const TType &type                     = initializedNode->getType();
         const TInterfaceBlock &interfaceBlock = *type.getInterfaceBlock();
         const TFieldList &fieldList           = interfaceBlock.fields();
         for (size_t fieldIndex = 0; fieldIndex < fieldList.size(); ++fieldIndex)
         {
-            const TField &field          = *fieldList[fieldIndex];
-            TIntermTyped *blockReference = ReferenceGlobalVariable(name, *symbolTable);
-            TIntermTyped *fieldIndexRef  = CreateIndexNode(static_cast<int>(fieldIndex));
-            TIntermTyped *fieldReference = new TIntermBinary(
-                TOperator::EOpIndexDirectInterfaceBlock, blockReference, fieldIndexRef);
+            const TField &field         = *fieldList[fieldIndex];
+            TIntermTyped *fieldIndexRef = CreateIndexNode(static_cast<int>(fieldIndex));
+            TIntermTyped *fieldReference =
+                new TIntermBinary(TOperator::EOpIndexDirectInterfaceBlock,
+                                  initializedNode->deepCopy(), fieldIndexRef);
             TIntermTyped *fieldZero = CreateZeroNode(*field.type());
             TIntermTyped *assignment =
                 new TIntermBinary(TOperator::EOpAssign, fieldReference, fieldZero);

src/tests/gl_tests/GLSLTest.cpp

@@ -14028,6 +14028,47 @@ void main()
     EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
 }
 
+// Tests initializing a shader IO block array using the shader translator option.
+TEST_P(GLSLTest_ES31_InitShaderVariables, InitIOBlockArray)
+{
+    ANGLE_SKIP_TEST_IF(!IsGLExtensionEnabled("GL_EXT_shader_io_blocks"));
+
+    const char kVS[] = R"(#version 310 es
+#extension GL_EXT_shader_io_blocks : require
+in vec4 position;
+out BlockType {
+    vec4 blockMember;
+} BlockTypeOut[2];
+
+void main()
+{
+    gl_Position = position;
+})";
+
+    const char kFS[] = R"(#version 310 es
+#extension GL_EXT_shader_io_blocks : require
+precision mediump float;
+out vec4 colorOut;
+in BlockType {
+    vec4 blockMember;
+} BlockTypeOut[2];
+
+void main()
+{
+    if (BlockTypeOut[0].blockMember == vec4(0) &&
+        BlockTypeOut[1].blockMember == vec4(0)) {
+        colorOut = vec4(0, 1, 0, 1);
+    } else {
+        colorOut = vec4(1, 0, 0, 1);
+    }
+})";
+
+    ANGLE_GL_PROGRAM(testProgram, kVS, kFS);
+    drawQuad(testProgram, "position", 0.5f, 1.0f, true);
+    ASSERT_GL_NO_ERROR();
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::green);
+}
+
 // Tests initializing a shader IO block with a struct using the shader translator option.
 TEST_P(GLSLTest_ES31_InitShaderVariables, InitIOBlockWithStruct)
 {