Handle missing execution modes for limitation check (#4594)

Fixes https://crbug.com/40216

* Handle entry points with no execution modes when checking implicit
  derivative execution model checks

2 files changed, 43 insertions, 5 deletions

diff --git a/source/val/validate_image.cpp b/source/val/validate_image.cpp
index 3baff820..64f6ba7b 100644
--- a/source/val/validate_image.cpp
+++ b/source/val/validate_image.cpp
@@ -2068,11 +2068,13 @@ spv_result_t ImagePass(ValidationState_t& _, const Instruction* inst) {
                                       std::string* message) {
           const auto* models = state.GetExecutionModels(entry_point->id());
           const auto* modes = state.GetExecutionModes(entry_point->id());
-          if (models->find(SpvExecutionModelGLCompute) != models->end() &&
-              modes->find(SpvExecutionModeDerivativeGroupLinearNV) ==
-                  modes->end() &&
-              modes->find(SpvExecutionModeDerivativeGroupQuadsNV) ==
-                  modes->end()) {
+          if (models &&
+              models->find(SpvExecutionModelGLCompute) != models->end() &&
+              (!modes ||
+               (modes->find(SpvExecutionModeDerivativeGroupLinearNV) ==
+                    modes->end() &&
+                modes->find(SpvExecutionModeDerivativeGroupQuadsNV) ==
+                    modes->end()))) {
             if (message) {
               *message =
                   std::string(
diff --git a/test/val/val_image_test.cpp b/test/val/val_image_test.cpp
index f49c81a5..11b14fb0 100644
--- a/test/val/val_image_test.cpp
+++ b/test/val/val_image_test.cpp
@@ -6063,6 +6063,42 @@ TEST_F(ValidateImage, ImageTexelPointerRgba16fVulkan) {
                         "R32f, R32i, or R32ui for Vulkan environment"));
 }
 
+TEST_F(ValidateImage, ImageExecutionModeLimitationNoMode) {
+  const std::string text = R"(
+OpCapability Shader
+OpMemoryModel Logical GLSL450
+OpEntryPoint GLCompute %2 " " %4
+%void = OpTypeVoid
+%8 = OpTypeFunction %void
+%float = OpTypeFloat 32
+%v4float = OpTypeVector %float 4
+%12 = OpTypeImage %float 2D 0 0 0 1 Rgba8ui
+%13 = OpTypeSampledImage %12
+%_ptr_UniformConstant_13 = OpTypePointer UniformConstant %13
+%5 = OpVariable %_ptr_UniformConstant_13 UniformConstant
+%_ptr_Input_v4float = OpTypePointer Input %v4float
+%4 = OpVariable %_ptr_Input_v4float Input
+%v2float = OpTypeVector %float 2
+%float_1_35631564en19 = OpConstant %float 1.35631564e-19
+%2 = OpFunction %void None %8
+%8224 = OpLabel
+%6 = OpLoad %13 %5
+%19 = OpLoad %v4float %4
+%20 = OpVectorShuffle %v2float %19 %19 0 1
+%21 = OpVectorTimesScalar %v2float %20 %float_1_35631564en19
+%65312 = OpImageSampleImplicitLod %v4float %6 %21
+OpUnreachable
+OpFunctionEnd
+)";
+
+  CompileSuccessfully(text);
+  EXPECT_EQ(SPV_ERROR_INVALID_ID, ValidateInstructions());
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("ImplicitLod instructions require "
+                        "DerivativeGroupQuadsNV or DerivativeGroupLinearNV "
+                        "execution mode for GLCompute execution model"));
+}
+
 }  // namespace
 }  // namespace val
 }  // namespace spvtools