spirv-val: accept graphs with no inputs and/or no body (KhronosGroup#6291)

Also add a couple of missing layout tests

- Graphs with disallowed body instructions should be ejected
- Instructions that must be used within a graph body after a first
  graph should be rejected.

Change-Id: I4c48f933fa130733b151c7f10d43b7d843bab70c

Signed-off-by: Kevin Petit <kevin.petit@arm.com>

Author: kpet

source/val/validate_layout.cpp

@@ -372,7 +372,8 @@ spv_result_t GraphScopedInstructions(ValidationState_t& _,
         _.SetGraphDefinitionRegion(kGraphDefinitionInputs);
       } break;
       case spv::Op::OpGraphSetOutputARM: {
-        if ((_.graph_definition_region() != kGraphDefinitionInputs) &&
+        if ((_.graph_definition_region() != kGraphDefinitionBegin) &&
+            (_.graph_definition_region() != kGraphDefinitionInputs) &&
             (_.graph_definition_region() != kGraphDefinitionBody) &&
             (_.graph_definition_region() != kGraphDefinitionOutputs)) {
           return _.diag(SPV_ERROR_INVALID_LAYOUT, inst)
@@ -399,9 +400,10 @@ spv_result_t GraphScopedInstructions(ValidationState_t& _,
         }
         break;
       default:
-        if (_.graph_definition_region() < kGraphDefinitionInputs) {
+        if (_.graph_definition_region() == kGraphDefinitionOutside) {
           return _.diag(SPV_ERROR_INVALID_LAYOUT, inst)
-                 << spvOpcodeString(opcode) << " must appear in a graph body";
+                 << "Op" << spvOpcodeString(opcode)
+                 << " must appear in a graph body";
         }
         if (_.graph_definition_region() == kGraphDefinitionOutputs) {
           return _.diag(SPV_ERROR_INVALID_LAYOUT, inst)
@@ -413,7 +415,7 @@ spv_result_t GraphScopedInstructions(ValidationState_t& _,
     }
   } else {
     return _.diag(SPV_ERROR_INVALID_LAYOUT, inst)
-           << spvOpcodeString(opcode)
+           << "Op" << spvOpcodeString(opcode)
            << " cannot appear in the graph definitions section";
   }
   return SPV_SUCCESS;

test/val/val_graph_test.cpp

@@ -60,6 +60,7 @@ std::string GenerateModule(const std::string& src) {
            %uint_4 = OpConstant %uint 4
           %float_1 = OpConstant %float 1.0
        %int8tensor = OpTypeTensorARM %int8 %uint_4
+     %int8r3tensor = OpTypeTensorARM %int8 %uint_3
       %int32tensor = OpTypeTensorARM %int32 %uint_4
 %int8tensor_array3 = OpTypeArray %int8tensor %uint_3
 %int32tensor_array3 = OpTypeArray %int32tensor %uint_3
@@ -209,6 +210,61 @@ TEST_F(ValidateGraph, ValidGraphConstantOusideGraph) {
   EXPECT_EQ(SPV_SUCCESS, ValidateInstructions(SPVENV));
 }
 
+TEST_F(ValidateGraph, ValidGraphWithNoInputsNoBody) {
+  const std::string src = R"(
+              %cst = OpGraphConstantARM %int8tensor 1
+       %graph_type = OpTypeGraphARM 0 %int8tensor
+                     OpGraphEntryPointARM %graph "longname" %var_int8tensor
+            %graph = OpGraphARM %graph_type
+                     OpGraphSetOutputARM %cst %uint_0
+                     OpGraphEndARM
+)";
+  std::string spvasm = GenerateModule(src);
+
+  CompileSuccessfully(spvasm, SPVENV);
+  EXPECT_EQ(SPV_SUCCESS, ValidateInstructions(SPVENV));
+}
+
+TEST_F(ValidateGraph, InvalidGraphWithDisallowedBodyInstructions) {
+  const std::string src = R"(
+       %graph_type = OpTypeGraphARM 1 %int8tensor %int8tensor
+                     OpGraphEntryPointARM %graph "longname" %var_int8tensor %var_int8tensor
+            %graph = OpGraphARM %graph_type
+               %in = OpGraphInputARM %int8tensor %uint_0
+              %val = OpCompositeExtract %int8r3tensor %in 0
+              %out = OpCompositeInsert %int8tensor %val %in 0
+                     OpGraphSetOutputARM %out %uint_0
+                     OpGraphEndARM
+)";
+  std::string spvasm = GenerateModule(src);
+
+  CompileSuccessfully(spvasm, SPVENV);
+  EXPECT_EQ(SPV_ERROR_INVALID_LAYOUT, ValidateInstructions(SPVENV));
+  EXPECT_THAT(
+      getDiagnosticString(),
+      HasSubstr(
+          "OpCompositeInsert cannot appear in the graph definitions section"));
+}
+
+TEST_F(ValidateGraph, InvalidInstructionOutsideGraphAfterGraph) {
+  const std::string src = R"(
+%graph_type = OpTypeGraphARM 1 %int8tensor %int8tensor
+       %cst = OpGraphConstantARM %int8tensor 1
+              OpGraphEntryPointARM %graph "longname" %var_int8tensor %var_int8tensor
+     %graph = OpGraphARM %graph_type
+        %in = OpGraphInputARM %int8tensor %uint_0
+              OpGraphSetOutputARM %in %uint_0
+              OpGraphEndARM
+       %val = OpCompositeExtract %int8r3tensor %cst 0
+)";
+  std::string spvasm = GenerateModule(src);
+
+  CompileSuccessfully(spvasm, SPVENV);
+  EXPECT_EQ(SPV_ERROR_INVALID_LAYOUT, ValidateInstructions(SPVENV));
+  EXPECT_THAT(getDiagnosticString(),
+              HasSubstr("OpCompositeExtract must appear in a graph body"));
+}
+
 //
 // Type tests
 //