[fir] Add fir.global_len conversion placeholder

[clementval]

Summary

As for D113662, this patch just add a place holder for
the fir.global_len operation conversion. This operation
is part of F20xx and is not implemented yet.

This patch is part of the upstreaming effort from fir-dev branch.

[awarzynski]

Makes sense, thank you!

flang/lib/Optimizer/CodeGen/CodeGen.cpp

648

DELETEME

[clementval]

flang/lib/Optimizer/CodeGen/CodeGen.cpp

648

Thanks for catching this.

[kiranchandramohan]

flang/lib/Optimizer/CodeGen/CodeGen.cpp

648

I think the select_type has a return failure which needs deletion.

[clementval]

flang/lib/Optimizer/CodeGen/CodeGen.cpp

648

You are right @kiranchandramohan. I'll remove it.

[clementval]

Remove extra return + rebase

[clementval]

Rebase

flang/include/flang/Optimizer/Dialect/FIROps.td

def fir_GlobalLenOp : fir_Op<"global_len", []> {
   let description = [{
     A global entity (that is not an automatic data object) can have extra LEN
     parameter (compile-time) constants associated with the instance's type.
     These values can be bound to the global instance used `fir.global_len`.
 
     ```mlir
       global @g : !fir.type<t(len1:i32)> {
         fir.global_len len1, 10 : i32
-        %1 = fir.undefined : !fir.type<t(len1:i32)>
-        return %1 : !fir.type<t(len1:i32)>
+        %1 = fir.undefined !fir.type<t(len1:i32)>
+        fir.has_value %1 : !fir.type<t(len1:i32)>
       }
     ```
   }];
 
   let arguments = (ins StrAttr:$lenparam, APIntAttr:$intval);
 
   let parser = "return parseGlobalLenOp(parser, result);";
 

flang/lib/Optimizer/CodeGen/CodeGen.cpp

struct DTEntryOpConversion : public FIROpConversion<fir::DTEntryOp> {
   mlir::LogicalResult
   matchAndRewrite(fir::DTEntryOp dtEnt, OpAdaptor adaptor,
                   mlir::ConversionPatternRewriter &rewriter) const override {
     return rewriter.notifyMatchFailure(
         dtEnt, "fir.dt_entry codegen is not implemented yet");
   }
 };
 
+/// Lower `fir.global_len` operation.
+struct GlobalLenOpConversion : public FIROpConversion<fir::GlobalLenOp> {
+  using FIROpConversion::FIROpConversion;
+
+  mlir::LogicalResult
+  matchAndRewrite(fir::GlobalLenOp globalLen, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+    return rewriter.notifyMatchFailure(
+        globalLen, "fir.global_len codegen is not implemented yet");
+  }
+};
+
 /// Lower `fir.has_value` operation to `llvm.return` operation.
 struct HasValueOpConversion : public FIROpConversion<fir::HasValueOp> {
   using FIROpConversion::FIROpConversion;
 
   mlir::LogicalResult
   matchAndRewrite(fir::HasValueOp op, OpAdaptor adaptor,
                   mlir::ConversionPatternRewriter &rewriter) const override {
     rewriter.replaceOpWithNewOp<LLVM::ReturnOp>(op, adaptor.getOperands());
void runOnOperation() override final {
     mlir::OwningRewritePatternList pattern(context);
     pattern.insert<
         AbsentOpConversion, AddcOpConversion, AddrOfOpConversion,
         AllocaOpConversion, BoxAddrOpConversion, BoxDimsOpConversion,
         BoxEleSizeOpConversion, BoxIsAllocOpConversion, BoxIsArrayOpConversion,
         BoxIsPtrOpConversion, BoxRankOpConversion, CallOpConversion,
         ConvertOpConversion, DispatchOpConversion, DispatchTableOpConversion,
         DTEntryOpConversion, DivcOpConversion, EmboxCharOpConversion,
-        ExtractValueOpConversion, HasValueOpConversion, GlobalOpConversion,
-        InsertOnRangeOpConversion, InsertValueOpConversion,
+        ExtractValueOpConversion, HasValueOpConversion, GlobalLenOpConversion,
+        GlobalOpConversion, InsertOnRangeOpConversion, InsertValueOpConversion,
         IsPresentOpConversion, LoadOpConversion, NegcOpConversion,
         MulcOpConversion, SelectCaseOpConversion, SelectOpConversion,
         SelectRankOpConversion, SelectTypeOpConversion, StoreOpConversion,
         SubcOpConversion, UnboxCharOpConversion, UndefOpConversion,
         UnreachableOpConversion, ZeroOpConversion>(typeConverter);
     mlir::populateStdToLLVMConversionPatterns(typeConverter, pattern);
     mlir::arith::populateArithmeticToLLVMConversionPatterns(typeConverter,
                                                             pattern);

flang/test/Fir/convert-to-llvm-invalid.fir

 ^bb1(%a : i32) :
   return %a : i32
 ^bb2(%b : i32) :
   return %b : i32
 ^bb5 :
   %zero = arith.constant 0 : i32
   return %zero : i32
 }
+
+// -----
+
+// Test `fir.global_len` conversion failure. Not implemented yet.
+
+fir.global @global_derived : !fir.type<minez(f:i32)> {
+  // expected-error@+1{{failed to legalize operation 'fir.global_len'}}
+  fir.global_len f, 1 : i32
+  %0 = fir.undefined !fir.type<minez>
+  fir.has_value %0 : !fir.type<minez>
+}