[mlir][spirv] Fix crash in spirv-lower-abi-attributes

[kuhar]

Summary

... when the are no SPIR-V env attributes.

Fixes: https://github.com/llvm/llvm-project/issues/59983

mlir/lib/Dialect/SPIRV/Transforms/LowerABIAttributesPass.cpp

 }
 
 void LowerABIAttributesPass::runOnOperation() {
   // Uses the signature conversion methodology of the dialect conversion
   // framework to implement the conversion.
   spirv::ModuleOp module = getOperation();
   MLIRContext *context = &getContext();
 
-  spirv::TargetEnv targetEnv(spirv::lookupTargetEnv(module));
+  spirv::TargetEnvAttr targetEnvAttr = spirv::lookupTargetEnv(module);
+  if (!targetEnvAttr) {
+    module->emitOpError("missing SPIR-V target env attribute");
+    return signalPassFailure();
+  }
+  spirv::TargetEnv targetEnv(targetEnvAttr);
 
   SPIRVTypeConverter typeConverter(targetEnv);
 
   // Insert a bitcast in the case of a pointer type change.
   typeConverter.addSourceMaterialization([](OpBuilder &builder,
                                             spirv::PointerType type,
                                             ValueRange inputs, Location loc) {
     if (inputs.size() != 1 || !inputs[0].getType().isa<spirv::PointerType>())

mlir/test/Dialect/SPIRV/Transforms/abi-interface.mlir

-// RUN: mlir-opt -split-input-file -spirv-lower-abi-attrs %s | FileCheck %s
+// RUN: mlir-opt --split-input-file --spirv-lower-abi-attrs --verify-diagnostics %s \
+// RUN:   | FileCheck %s
 
 module attributes {
   spirv.target_env = #spirv.target_env<
     #spirv.vce<v1.0, [Shader], [SPV_KHR_storage_buffer_storage_class]>, #spirv.resource_limits<>>
 } {
 
 // CHECK-LABEL: spirv.module
 spirv.module Logical GLSL450 {
attributes {spirv.entry_point_abi = #spirv.entry_point_abi<workgroup_size = [32, 1, 1], subgroup_size = 64>} {
     // CHECK: spirv.Return
     spirv.Return
   }
   // CHECK: spirv.EntryPoint "GLCompute" [[FN]]
   // CHECK: spirv.ExecutionMode [[FN]] "LocalSize", 32, 1, 1
 } // end spirv.module
 
 } // end module
+
+// -----
+
+module {
+// expected-error@+1 {{'spirv.module' op missing SPIR-V target env attribute}}
+spirv.module Logical GLSL450 {}
+} // end module