[flang] automatically load FIR dialect with hlfir

[tblah]

Summary

MLIR loads dialects lazily so if a hlfir type (or operation) is found
before any fir type (or operation), the fir dialect will not have been
loaded when the hlfir thing is verified. Verification of some hlfir
operations does depend on fir types (e.g. hlfir.sum needs
fir::SequenceType).

[jeanPerier]

Makes sense. Would adding let dependentDialects = ["fir::FIROpsDialect"]; in hlfir_Dialect declaration in [1] also work ?
If so, that is probably more in line with the tablegen dialect definition approach.

[1]: https://github.com/llvm/llvm-project/blob/3ad26060e4bceb2cf9f4959d659cbb29d88344cf/flang/include/flang/Optimizer/HLFIR/HLFIROpBase.td#L39.

[tblah]

Updated to make the change in tablegen

[tblah]

In D143930#4125273, @jeanPerier wrote:

Makes sense. Would adding let dependentDialects = ["fir::FIROpsDialect"]; in hlfir_Dialect declaration in [1] also work ?
If so, that is probably more in line with the tablegen dialect definition approach.

[1]: https://github.com/llvm/llvm-project/blob/3ad26060e4bceb2cf9f4959d659cbb29d88344cf/flang/include/flang/Optimizer/HLFIR/HLFIROpBase.td#L39.

Thanks for suggesting this - that's much cleaner

[jeanPerier]

Thanks, LGTM

flang/include/flang/Optimizer/HLFIR/HLFIROpBase.td

let description = [{
 
     A bufferization pass transforms hlfir.expr values into FIR temporary in
     memory, and its translation pass to FIR translates high level operations
     into sequence of lower level FIR operations operating on memory.
   }];
 
   let useDefaultTypePrinterParser = 1;
   let cppNamespace = "hlfir";
+  let dependentDialects = ["fir::FIROpsDialect"];
 }
 
 
 def hlfir_ExprType : TypeDef<hlfir_Dialect, "Expr"> {
   let mnemonic = "expr";
   let summary = "The type of an array, character, or derived type Fortran expression";
 
   let description = [{

flang/include/flang/Optimizer/HLFIR/HLFIROps.h

 //===-- HLFIROps.h - FIR operations -----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef FORTRAN_OPTIMIZER_HLFIR_HLFIROPS_H
 #define FORTRAN_OPTIMIZER_HLFIR_HLFIROPS_H
 
 #include "flang/Optimizer/Dialect/FIRAttr.h"
+#include "flang/Optimizer/Dialect/FIRDialect.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
 #include "flang/Optimizer/Dialect/FortranVariableInterface.h"
 #include "flang/Optimizer/HLFIR/HLFIRDialect.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Interfaces/InferTypeOpInterface.h"
 #include "mlir/Interfaces/SideEffectInterfaces.h"
 
 #define GET_OP_CLASSES
 #include "flang/Optimizer/HLFIR/HLFIROps.h.inc"
 
 #endif // FORTRAN_OPTIMIZER_HLFIR_HLFIROPS_H