From 89b8e238eb39d6c8bb637b8d1c6e0fad1f45e77f Mon Sep 17 00:00:00 2001
From: alan-baker <33432579+alan-baker@users.noreply.github.com>
Date: Mon, 22 Oct 2018 08:47:56 -0400
Subject: [PATCH] Better checking of the index operand (#1992)

Fixes https://crbug.com/897069

* Code previously assumed the index instruction had a type
* Added a test to reproduce
---
 source/val/validate_composites.cpp |  4 ++--
 test/val/val_composites_test.cpp   | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/source/val/validate_composites.cpp b/source/val/validate_composites.cpp
index 6be60261e..038873506 100644
--- a/source/val/validate_composites.cpp
+++ b/source/val/validate_composites.cpp
@@ -148,8 +148,8 @@ spv_result_t ValidateVectorExtractDynamic(ValidationState_t& _,
            << "Expected Vector component type to be equal to Result Type";
   }
 
-  const uint32_t index_type = _.GetOperandTypeId(inst, 3);
-  if (!_.IsIntScalarType(index_type)) {
+  const auto index = _.FindDef(inst->GetOperandAs<uint32_t>(3));
+  if (!index || index->type_id() == 0 || !_.IsIntScalarType(index->type_id())) {
     return _.diag(SPV_ERROR_INVALID_DATA, inst)
            << "Expected Index to be int scalar";
   }
diff --git a/test/val/val_composites_test.cpp b/test/val/val_composites_test.cpp
index 5b8381590..24e765745 100644
--- a/test/val/val_composites_test.cpp
+++ b/test/val/val_composites_test.cpp
@@ -1469,6 +1469,30 @@ OpFunctionEnd
   EXPECT_EQ(SPV_SUCCESS, ValidateInstructions());
 }
 
+TEST_F(ValidateComposites, ExtractDynamicLabelIndex) {
+  const std::string spirv = R"(
+OpCapability Shader
+OpCapability Linkage
+OpMemoryModel Logical GLSL450
+%void = OpTypeVoid
+%float = OpTypeFloat 32
+%v4float = OpTypeVector %float 4
+%void_fn = OpTypeFunction %void
+%float_0 = OpConstant %float 0
+%v4float_0 = OpConstantComposite %v4float %float_0 %float_0 %float_0 %float_0
+%func = OpFunction %void None %void_fn
+%1 = OpLabel
+%ex = OpVectorExtractDynamic %float %v4float_0 %1
+OpReturn
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(spirv);
+  EXPECT_EQ(SPV_ERROR_INVALID_DATA, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("Expected Index to be int scalar"));
+}
+
 }  // namespace
 }  // namespace val
 }  // namespace spvtools