Don't read lowering options from hidden global options (#4038)

Add a pass to overwrite lowering options on a module. This lets us get rid of the in-library cmdline option and move it to the two tools which need it. With this, prepare and export never change the lowering options.

Also make prepare a nested pass.

include/circt/Conversion/ExportVerilog.h

@@ -18,7 +18,11 @@
 
 namespace circt {
 
-std::unique_ptr<mlir::Pass> createTestPrepareForEmissionPass();
+std::unique_ptr<mlir::Pass>
+createTestApplyLoweringOptionPass(llvm::StringRef options);
+std::unique_ptr<mlir::Pass> createTestApplyLoweringOptionPass();
+
+std::unique_ptr<mlir::Pass> createPrepareForEmissionPass();
 
 std::unique_ptr<mlir::Pass> createExportVerilogPass(llvm::raw_ostream &os);
 std::unique_ptr<mlir::Pass> createExportVerilogPass();

include/circt/Conversion/Passes.td

@@ -75,16 +75,33 @@ def ExportSplitChiselInterface : Pass<"export-split-chisel-interface", "firrtl::
 // ExportVerilog and ExportSplitVerilog
 //===----------------------------------------------------------------------===//
 
-def TestPrepareForEmission : Pass<"test-prepare-for-emission",
-                                  "hw::HWModuleOp"> {
+def TestApplyLoweringOption : Pass<"test-apply-lowering-options",
+                                   "mlir::ModuleOp"> {
+  let summary = "Apply lowering options";
+  let description = [{
+    This pass allows overriding lowering options.  It is intended for test
+    construction.
+  }];
+
+  let constructor = "createTestApplyLoweringOptionPass()";
+  let dependentDialects = [
+    "circt::sv::SVDialect", "circt::comb::CombDialect", "circt::hw::HWDialect"
+  ];
+  let options = [
+    Option<"options", "options", "std::string", "", "Lowering Options">
+  ];
+}
+
+def PrepareForEmission : Pass<"prepare-for-emission",
+                              "hw::HWModuleOp"> {
   let summary = "Prepare IR for ExportVerilog";
   let description = [{
-    This pass runs only PrepareForEmission logic for testing purpose.
+    This pass runs only PrepareForEmission.
     It is not necessary for users to run this pass explicitly since
     ExportVerilog internally runs PrepareForEmission.
   }];
 
-  let constructor = "createTestPrepareForEmissionPass()";
+  let constructor = "createPrepareForEmissionPass()";
   let dependentDialects = [
     "circt::sv::SVDialect", "circt::comb::CombDialect", "circt::hw::HWDialect"
   ];

include/circt/Support/LoweringOptions.h

@@ -13,8 +13,9 @@
 #ifndef CIRCT_SUPPORT_LOWERINGOPTIONS_H
 #define CIRCT_SUPPORT_LOWERINGOPTIONS_H
 
-#include "circt/Support/LLVM.h"
+#include "mlir/IR/BuiltinAttributes.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
 
 namespace mlir {
 class ModuleOp;
@@ -25,14 +26,14 @@ namespace circt {
 /// Options which control the emission from CIRCT to Verilog.
 struct LoweringOptions {
   /// Error callback type used to indicate errors parsing the options string.
-  using ErrorHandlerT = function_ref<void(llvm::Twine)>;
+  using ErrorHandlerT = llvm::function_ref<void(llvm::Twine)>;
 
   /// Create a LoweringOptions with the default values.
   LoweringOptions() = default;
 
   /// Create a LoweringOptions and read in options from a string,
   /// overriding only the set options in the string.
-  LoweringOptions(StringRef options, ErrorHandlerT errorHandler);
+  LoweringOptions(llvm::StringRef options, ErrorHandlerT errorHandler);
 
   /// Create a LoweringOptions with values loaded from an MLIR ModuleOp. This
   /// loads a string attribute with the key `circt.loweringOptions`. If there is
@@ -42,11 +43,11 @@ struct LoweringOptions {
 
   /// Return the value of the `circt.loweringOptions` in the specified module
   /// if present, or a null attribute if not.
-  static StringAttr getAttributeFrom(ModuleOp module);
+  static mlir::StringAttr getAttributeFrom(mlir::ModuleOp module);
 
   /// Read in options from a string, overriding only the set options in the
   /// string.
-  void parse(StringRef options, ErrorHandlerT callback);
+  void parse(llvm::StringRef options, ErrorHandlerT callback);
 
   /// Returns a string representation of the options.
   std::string toString() const;
@@ -149,21 +150,7 @@ struct LoweringOptions {
   /// Some lint tools dislike expressions being inlined into input ports so this
   /// option avoids such warnings.
   bool disallowExpressionInliningInPorts = false;
-}; // namespace circt
-
-/// Register commandline options for the verilog emitter.
-void registerLoweringCLOptions();
-
-/// Apply any command line specified style options to the mlir module.
-void applyLoweringCLOptions(ModuleOp module);
-
-/// Get a lowering option from CLI option or module op. This function first
-/// tries constructing a lowering option from cli, and if it failed, lowering
-/// option associated with `module` is used. This function doesn't change an
-/// attribute of `module` so that it can be used by child operations of
-/// mlir::ModuleOp in multi-threading environment.
-LoweringOptions getLoweringCLIOption(ModuleOp module,
-                                     LoweringOptions::ErrorHandlerT);
+};
 } // namespace circt
 
 #endif // CIRCT_SUPPORT_LOWERINGOPTIONS_H

include/circt/Support/LoweringOptionsParser.h

@@ -0,0 +1,58 @@
+//===- LoweringOptionsParser.h - CIRCT Lowering Option Parser ---*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Parser for lowering options.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CIRCT_SUPPORT_LOWERINGOPTIONSPARSER_H
+#define CIRCT_SUPPORT_LOWERINGOPTIONSPARSER_H
+
+#include "circt/Support/LLVM.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/CommandLine.h"
+
+namespace circt {
+
+/// Commandline parser for LoweringOptions.  Delegates to the parser
+/// defined by LoweringOptions.
+struct LoweringOptionsParser : public llvm::cl::parser<LoweringOptions> {
+
+  LoweringOptionsParser(llvm::cl::Option &option)
+      : llvm::cl::parser<LoweringOptions>(option) {}
+
+  bool parse(llvm::cl::Option &option, StringRef argName, StringRef argValue,
+             LoweringOptions &value) {
+    bool failed = false;
+    value.parse(argValue, [&](Twine error) { failed = option.error(error); });
+    return failed;
+  }
+};
+
+struct LoweringOptionsOption
+    : llvm::cl::opt<LoweringOptions, false, LoweringOptionsParser> {
+  LoweringOptionsOption(llvm::cl::OptionCategory &cat)
+      : llvm::cl::opt<LoweringOptions, false, LoweringOptionsParser>{
+            "lowering-options",
+            llvm::cl::desc(
+                "Style options.  Valid flags include: "
+                "noAlwaysComb, exprInEventControl, disallowPackedArrays, "
+                "disallowLocalVariables, verifLabels, emittedLineLength=<n>, "
+                "maximumNumberOfTermsPerExpression=<n>, "
+                "maximumNumberOfTermsInConcat=<n>, explicitBitcast, "
+                "maximumNumberOfVariadicOperands=<n>, "
+                "emitReplicatedOpsToHeader, "
+                "locationInfoStyle={plain,wrapInAtSquareBracket,none}, "
+                "disallowPortDeclSharing, printDebugInfo, useOldEmissionMode, "
+                "disallowExpressionInliningInPorts"),
+            llvm::cl::cat(cat), llvm::cl::value_desc("option")} {}
+};
+
+} // namespace circt
+
+#endif // CIRCT_SUPPORT_LOWERINGOPTIONSPARSER_H

lib/Conversion/ExportVerilog/ApplyLoweringOptions.cpp

@@ -0,0 +1,43 @@
+//===- ApplyLoweringOptions.cpp - Test pass for adding lowering options ---===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Pass for testing purposes to apply lowering options ot a module.
+//
+//===----------------------------------------------------------------------===//
+
+#include "../PassDetail.h"
+#include "circt/Conversion/ExportVerilog.h"
+#include "circt/Dialect/Comb/CombDialect.h"
+#include "circt/Dialect/HW/HWDialect.h"
+#include "circt/Dialect/SV/SVDialect.h"
+#include "circt/Support/LoweringOptions.h"
+
+using namespace circt;
+
+namespace {
+
+struct TestApplyLoweringOptionPass
+    : public TestApplyLoweringOptionBase<TestApplyLoweringOptionPass> {
+  TestApplyLoweringOptionPass() = default;
+  void runOnOperation() override {
+    if (!options.hasValue()) {
+      markAllAnalysesPreserved();
+      return;
+    }
+    LoweringOptions opts(options, [this](llvm::Twine tw) {
+      getOperation().emitError(tw);
+      signalPassFailure();
+    });
+    opts.setAsAttribute(getOperation());
+  }
+};
+} // namespace
+
+std::unique_ptr<mlir::Pass> circt::createTestApplyLoweringOptionPass() {
+  return std::make_unique<TestApplyLoweringOptionPass>();
+}

lib/Conversion/ExportVerilog/CMakeLists.txt

@@ -1,5 +1,6 @@
 
 add_circt_translation_library(CIRCTExportVerilog
+  ApplyLoweringOptions.cpp
   ExportVerilog.cpp
   LegalizeNames.cpp
   PrepareForEmission.cpp

lib/Conversion/ExportVerilog/ExportVerilog.cpp

@@ -34,6 +34,7 @@
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/ImplicitLocOpBuilder.h"
 #include "mlir/IR/Threading.h"
+#include "mlir/Pass/PassManager.h"
 #include "mlir/Support/FileUtilities.h"
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/STLExtras.h"
@@ -4969,26 +4970,14 @@ void SharedEmitterState::emitOps(EmissionList &thingsToEmit, raw_ostream &os,
   }
 }
 
-/// Prepare the given MLIR module for emission.
-static void prepareForEmission(ModuleOp module,
-                               const LoweringOptions &options) {
-  SmallVector<HWModuleOp> modulesToPrepare;
-  module.walk([&](HWModuleOp op) { modulesToPrepare.push_back(op); });
-  parallelForEach(module->getContext(), modulesToPrepare,
-                  [&](auto op) { prepareHWModule(op, options); });
-}
-
 //===----------------------------------------------------------------------===//
 // Unified Emitter
 //===----------------------------------------------------------------------===//
 
-LogicalResult circt::exportVerilog(ModuleOp module, llvm::raw_ostream &os) {
-  // Prepare the ops in the module for emission and legalize the names that will
-  // end up in the output.
-  LoweringOptions options(module);
-  prepareForEmission(module, options);
+static LogicalResult exportVerilogImpl(ModuleOp module, llvm::raw_ostream &os) {
   GlobalNameTable globalNames = legalizeGlobalNames(module);
 
+  LoweringOptions options(module);
   SharedEmitterState emitter(module, options, std::move(globalNames));
   emitter.gatherFiles(false);
 
@@ -5024,18 +5013,29 @@ LogicalResult circt::exportVerilog(ModuleOp module, llvm::raw_ostream &os) {
   return failure(emitter.encounteredError);
 }
 
+LogicalResult circt::exportVerilog(ModuleOp module, llvm::raw_ostream &os) {
+  LoweringOptions options(module);
+  SmallVector<HWModuleOp> modulesToPrepare;
+  module.walk([&](HWModuleOp op) { modulesToPrepare.push_back(op); });
+  parallelForEach(module->getContext(), modulesToPrepare,
+                  [&](auto op) { prepareHWModule(op, options); });
+  return exportVerilogImpl(module, os);
+}
+
 namespace {
 
 struct ExportVerilogPass : public ExportVerilogBase<ExportVerilogPass> {
   ExportVerilogPass(raw_ostream &os) : os(os) {}
   void runOnOperation() override {
-    // Make sure LoweringOptions are applied to the module if it was overridden
-    // on the command line.
-    // TODO: This should be moved up to circt-opt and circt-translate.
-    applyLoweringCLOptions(getOperation());
+    // Prepare the ops in the module for emission.
+    mlir::OpPassManager preparePM("builtin.module");
+    auto &modulePM = preparePM.nest<hw::HWModuleOp>();
+    modulePM.addPass(createPrepareForEmissionPass());
+    if (failed(runPipeline(preparePM, getOperation())))
+      return signalPassFailure();
 
-    if (failed(exportVerilog(getOperation(), os)))
-      signalPassFailure();
+    if (failed(exportVerilogImpl(getOperation(), os)))
+      return signalPassFailure();
   }
 
 private:
@@ -5102,11 +5102,11 @@ static void createSplitOutputFile(StringAttr fileName, FileInfo &file,
   output->keep();
 }
 
-LogicalResult circt::exportSplitVerilog(ModuleOp module, StringRef dirname) {
+static LogicalResult exportSplitVerilogImpl(ModuleOp module,
+                                            StringRef dirname) {
   // Prepare the ops in the module for emission and legalize the names that will
   // end up in the output.
   LoweringOptions options(module);
-  prepareForEmission(module, options);
   GlobalNameTable globalNames = legalizeGlobalNames(module);
 
   SharedEmitterState emitter(module, options, std::move(globalNames));
@@ -5166,6 +5166,15 @@ LogicalResult circt::exportSplitVerilog(ModuleOp module, StringRef dirname) {
   return failure(emitter.encounteredError);
 }
 
+LogicalResult circt::exportSplitVerilog(ModuleOp module, StringRef dirname) {
+  LoweringOptions options(module);
+  SmallVector<HWModuleOp> modulesToPrepare;
+  module.walk([&](HWModuleOp op) { modulesToPrepare.push_back(op); });
+  parallelForEach(module->getContext(), modulesToPrepare,
+                  [&](auto op) { prepareHWModule(op, options); });
+  return exportSplitVerilogImpl(module, dirname);
+}
+
 namespace {
 
 struct ExportSplitVerilogPass
@@ -5174,12 +5183,15 @@ struct ExportSplitVerilogPass
     directoryName = directory.str();
   }
   void runOnOperation() override {
-    // Make sure LoweringOptions are applied to the module if it was overridden
-    // on the command line.
-    // TODO: This should be moved up to circt-opt and circt-translate.
-    applyLoweringCLOptions(getOperation());
-    if (failed(exportSplitVerilog(getOperation(), directoryName)))
-      signalPassFailure();
+    // Prepare the ops in the module for emission.
+    mlir::OpPassManager preparePM("builtin.module");
+    auto &modulePM = preparePM.nest<hw::HWModuleOp>();
+    modulePM.addPass(createPrepareForEmissionPass());
+    if (failed(runPipeline(preparePM, getOperation())))
+      return signalPassFailure();
+
+    if (failed(exportSplitVerilogImpl(getOperation(), directoryName)))
+      return signalPassFailure();
   }
 };
 } // end anonymous namespace

lib/Conversion/ExportVerilog/PrepareForEmission.cpp

@@ -21,11 +21,11 @@
 #include "ExportVerilogInternals.h"
 #include "circt/Conversion/ExportVerilog.h"
 #include "circt/Dialect/Comb/CombOps.h"
-#include "circt/Support/LoweringOptions.h"
 #include "mlir/IR/ImplicitLocOpBuilder.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/TypeSwitch.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 
 #define DEBUG_TYPE "prepare-for-emission"
@@ -1019,19 +1019,17 @@ void ExportVerilog::prepareHWModule(hw::HWModuleOp module,
 
 namespace {
 
-struct TestPrepareForEmissionPass
-    : public TestPrepareForEmissionBase<TestPrepareForEmissionPass> {
-  TestPrepareForEmissionPass() {}
+struct PrepareForEmissionPass
+    : public PrepareForEmissionBase<PrepareForEmissionPass> {
   void runOnOperation() override {
     HWModuleOp module = getOperation();
-    LoweringOptions options = getLoweringCLIOption(
-        cast<mlir::ModuleOp>(module->getParentOp()),
-        [&](llvm::Twine twine) { module.emitError(twine); });
+    LoweringOptions options(cast<mlir::ModuleOp>(module->getParentOp()));
     prepareHWModule(module, options);
   }
 };
+
 } // end anonymous namespace
 
-std::unique_ptr<mlir::Pass> circt::createTestPrepareForEmissionPass() {
-  return std::make_unique<TestPrepareForEmissionPass>();
+std::unique_ptr<mlir::Pass> circt::createPrepareForEmissionPass() {
+  return std::make_unique<PrepareForEmissionPass>();
 }

lib/Conversion/PassDetail.h

@@ -10,6 +10,7 @@
 #ifndef CONVERSION_PASSDETAIL_H
 #define CONVERSION_PASSDETAIL_H
 
+#include "circt/Support/LoweringOptions.h"
 #include "mlir/IR/BuiltinOps.h"
 #include "mlir/IR/DialectRegistry.h"
 #include "mlir/Pass/Pass.h"

lib/Support/LoweringOptions.cpp

@@ -13,10 +13,9 @@
 
 #include "circt/Support/LoweringOptions.h"
 #include "mlir/IR/BuiltinOps.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/ManagedStatic.h"
 
 using namespace circt;
+using namespace mlir;
 
 //===----------------------------------------------------------------------===//
 // LoweringOptions
@@ -195,77 +194,3 @@ void LoweringOptions::parseFromAttribute(ModuleOp module) {
   if (auto styleAttr = getAttributeFrom(module))
     parse(styleAttr.getValue(), [&](Twine error) { module.emitError(error); });
 }
-
-//===----------------------------------------------------------------------===//
-// Command Line Option Processing
-//===----------------------------------------------------------------------===//
-
-namespace {
-/// Commandline parser for LoweringOptions.  Delegates to the parser
-/// defined by LoweringOptions.
-struct LoweringOptionsParser : public llvm::cl::parser<LoweringOptions> {
-
-  LoweringOptionsParser(llvm::cl::Option &option)
-      : llvm::cl::parser<LoweringOptions>(option) {}
-
-  bool parse(llvm::cl::Option &option, StringRef argName, StringRef argValue,
-             LoweringOptions &value) {
-    bool failed = false;
-    value.parse(argValue, [&](Twine error) { failed = option.error(error); });
-    return failed;
-  }
-};
-
-/// Commandline arguments for verilog emission.  Used to dynamically register
-/// the command line arguments in multiple tools.
-struct LoweringCLOptions {
-  llvm::cl::opt<LoweringOptions, false, LoweringOptionsParser> loweringOptions{
-      "lowering-options",
-      llvm::cl::desc(
-          "Style options.  Valid flags include: "
-          "noAlwaysComb, exprInEventControl, disallowPackedArrays, "
-          "disallowLocalVariables, verifLabels, emittedLineLength=<n>, "
-          "maximumNumberOfTermsPerExpression=<n>, "
-          "maximumNumberOfTermsInConcat=<n>, explicitBitcast, "
-          "maximumNumberOfVariadicOperands=<n>, "
-          "emitReplicatedOpsToHeader, "
-          "locationInfoStyle={plain,wrapInAtSquareBracket,none}, "
-          "disallowPortDeclSharing, printDebugInfo, useOldEmissionMode, "
-          "disallowExpressionInliningInPorts"),
-      llvm::cl::value_desc("option")};
-};
-} // namespace
-
-/// The staticly initialized command line options.
-static llvm::ManagedStatic<LoweringCLOptions> clOptions;
-
-void circt::registerLoweringCLOptions() { *clOptions; }
-
-void circt::applyLoweringCLOptions(ModuleOp module) {
-  // If the command line options were not registered in the first place, there
-  // is nothing to parse.
-  if (!clOptions.isConstructed())
-    return;
-
-  // If an output style is applied on the command line, all previous options are
-  // discarded.
-  if (clOptions->loweringOptions.getNumOccurrences()) {
-    clOptions->loweringOptions.setAsAttribute(module);
-  }
-}
-
-LoweringOptions
-circt::getLoweringCLIOption(mlir::ModuleOp module,
-                            LoweringOptions::ErrorHandlerT errorHandler) {
-  // If the command line options were not registered in the first place, use the
-  // lowering option associated with module op.
-  if (!clOptions.isConstructed() ||
-      !clOptions->loweringOptions.getNumOccurrences()) {
-    if (auto styleAttr = LoweringOptions::getAttributeFrom(module))
-      return LoweringOptions(styleAttr, errorHandler);
-    // If the module doesn't have a lowering option, then use the default value.
-    return LoweringOptions();
-  }
-
-  return clOptions->loweringOptions.getValue();
-}

test/Conversion/ExportVerilog/debug-info.mlir

@@ -1,10 +1,12 @@
-// RUN: circt-opt --lowering-options=printDebugInfo --export-verilog %s | FileCheck %s
+// RUN: circt-opt --export-verilog %s | FileCheck %s
 
 // CHECK-LABEL: module symbols
 // CHECK-NEXT: input baz /* inner_sym: bazSym */
+module attributes {circt.loweringOptions="printDebugInfo"} {
 hw.module @symbols(%baz: i1 {hw.exportPort = @bazSym}) -> () {
     // CHECK: wire foo /* inner_sym: fooSym */;
     %foo = sv.wire sym @fooSym : !hw.inout<i1>
     // CHECK: reg bar /* inner_sym: barSym */;
     %bar = sv.reg sym @barSym : !hw.inout<i1>
 }
+}

test/Conversion/ExportVerilog/disallow-local-vars.mlir

@@ -1,5 +1,5 @@
 // RUN: circt-opt --export-verilog %s | FileCheck %s
-// RUN: circt-opt --lowering-options=disallowLocalVariables --export-verilog %s | FileCheck %s --check-prefix=DISALLOW -strict-whitespace
+// RUN: circt-opt --test-apply-lowering-options='options=disallowLocalVariables' --export-verilog %s | FileCheck %s --check-prefix=DISALLOW -strict-whitespace
 
 // This checks ExportVerilog's support for "disallowLocalVariables" which
 // prevents emitting 'automatic logic' and other local declarations.

test/Conversion/ExportVerilog/hw-dialect.mlir

@@ -1,4 +1,4 @@
-// RUN: circt-opt %s -export-verilog -verify-diagnostics -o %t.mlir --lowering-options=useOldEmissionMode | FileCheck %s --strict-whitespace --check-prefixes=CHECK,OLD
+// RUN: circt-opt %s -test-apply-lowering-options="options=useOldEmissionMode" -export-verilog -verify-diagnostics -o %t.mlir | FileCheck %s --strict-whitespace --check-prefixes=CHECK,OLD
 // RUN: circt-opt %s -export-verilog -verify-diagnostics -o %t.mlir | FileCheck %s --check-prefixes=CHECK,NEW
 
 // CHECK-LABEL: // external module E

test/Conversion/ExportVerilog/line-length.mlir

@@ -1,8 +1,8 @@
-// RUN: circt-opt --lowering-options=emittedLineLength=40 --export-verilog %s | FileCheck %s --check-prefixes=CHECK,SHORT
+// RUN: circt-opt --test-apply-lowering-options='options=emittedLineLength=40' --export-verilog %s | FileCheck %s --check-prefixes=CHECK,SHORT
 // RUN: circt-opt --export-verilog %s | FileCheck %s --check-prefixes=CHECK,DEFAULT
-// RUN: circt-opt --lowering-options=emittedLineLength=180 --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LONG
-// RUN: circt-opt --lowering-options=emittedLineLength=40,maximumNumberOfTermsPerExpression=16 --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LIMIT_SHORT
-// RUN: circt-opt --lowering-options=maximumNumberOfTermsPerExpression=32 --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LIMIT_LONG
+// RUN: circt-opt --test-apply-lowering-options='options=emittedLineLength=180' --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LONG
+// RUN: circt-opt --test-apply-lowering-options='options=emittedLineLength=40,maximumNumberOfTermsPerExpression=16' --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LIMIT_SHORT
+// RUN: circt-opt --test-apply-lowering-options='options=maximumNumberOfTermsPerExpression=32' --export-verilog %s | FileCheck %s --check-prefixes=CHECK,LIMIT_LONG
 
 hw.module @longvariadic(%a: i8) -> (b: i8) {
   %1 = comb.add %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a, %a,

test/Conversion/ExportVerilog/max-terms.mlir

@@ -1,4 +1,4 @@
-// RUN: circt-opt -lowering-options=maximumNumberOfTermsPerExpression=4,disallowLocalVariables --export-verilog %s | FileCheck %s
+// RUN: circt-opt -test-apply-lowering-options='options=maximumNumberOfTermsPerExpression=4,disallowLocalVariables' --export-verilog %s | FileCheck %s
 
 // CHECK-LABEL: module large_use_in_procedural
 hw.module @large_use_in_procedural(%clock: i1, %a: i1) {

test/Conversion/ExportVerilog/prepare-for-emission.mlir

@@ -1,4 +1,4 @@
-// RUN: circt-opt %s -test-prepare-for-emission --split-input-file -verify-diagnostics | FileCheck %s
+// RUN: circt-opt %s -prepare-for-emission --split-input-file -verify-diagnostics | FileCheck %s
 
 // CHECK: @namehint_variadic
 hw.module @namehint_variadic(%a: i3) -> (b: i3) {

test/Conversion/ExportVerilog/sv-alwayscomb.mlir

@@ -1,6 +1,6 @@
 // RUN: circt-opt --split-input-file --export-verilog %s | FileCheck %s --check-prefix=DEFAULT
-// RUN: circt-opt --lowering-options= --split-input-file --export-verilog %s | FileCheck %s --check-prefix=CLEAR
-// RUN: circt-opt --lowering-options=noAlwaysComb --split-input-file --export-verilog %s | FileCheck %s --check-prefix=NOALWAYSCOMB
+// RUN: circt-opt --test-apply-lowering-options='options=' --split-input-file --export-verilog %s | FileCheck %s --check-prefix=CLEAR
+// RUN: circt-opt --test-apply-lowering-options='options=noAlwaysComb' --split-input-file --export-verilog %s | FileCheck %s --check-prefix=NOALWAYSCOMB
 
 hw.module @test() {
   sv.alwayscomb {

test/Conversion/ExportVerilog/sv-dialect.mlir

@@ -1,5 +1,5 @@
-// RUN: circt-opt %s -export-verilog -verify-diagnostics --lowering-options=exprInEventControl,explicitBitcast,maximumNumberOfTermsInConcat=10,useOldEmissionMode | FileCheck %s --strict-whitespace --check-prefixes=CHECK,OLD
-// RUN: circt-opt %s -export-verilog -verify-diagnostics --lowering-options=exprInEventControl,explicitBitcast,maximumNumberOfTermsInConcat=10 | FileCheck %s --check-prefixes=CHECK,NEW
+// RUN: circt-opt %s -test-apply-lowering-options='options=exprInEventControl,explicitBitcast,maximumNumberOfTermsInConcat=10,useOldEmissionMode' -export-verilog -verify-diagnostics | FileCheck %s --strict-whitespace --check-prefixes=CHECK,OLD
+// RUN: circt-opt %s -test-apply-lowering-options='options=exprInEventControl,explicitBitcast,maximumNumberOfTermsInConcat=10' -export-verilog -verify-diagnostics | FileCheck %s --check-prefixes=CHECK,NEW
 
 // CHECK-LABEL: module M1
 // CHECK-NEXT:    #(parameter [41:0] param1) (

test/Conversion/ExportVerilog/sv-verifLabels.mlir

@@ -1,5 +1,5 @@
-// RUN: circt-opt --lowering-options= --export-verilog %s | FileCheck %s --check-prefix=CHECK-OFF
-// RUN: circt-opt --lowering-options=verifLabels --export-verilog %s | FileCheck %s --check-prefix=CHECK-ON
+// RUN: circt-opt --export-verilog %s | FileCheck %s --check-prefix=CHECK-OFF
+// RUN: circt-opt --test-apply-lowering-options='options=verifLabels' --export-verilog %s | FileCheck %s --check-prefix=CHECK-ON
 
 hw.module @foo(%clock: i1, %cond: i1) {
   sv.initial {

test/Conversion/ExportVerilog/variadic-operand-splitting.mlir

@@ -1,5 +1,5 @@
-// RUN: circt-opt -lowering-options=maximumNumberOfVariadicOperands=8 -export-verilog %s | FileCheck %s -check-prefixes=CHECK,MAX_8
-// RUN: circt-opt -lowering-options=maximumNumberOfVariadicOperands=4 -export-verilog %s | FileCheck %s -check-prefixes=CHECK,MAX_4
+// RUN: circt-opt -test-apply-lowering-options='options=maximumNumberOfVariadicOperands=8' -export-verilog %s | FileCheck %s -check-prefixes=CHECK,MAX_8
+// RUN: circt-opt -test-apply-lowering-options='options=maximumNumberOfVariadicOperands=4' -export-verilog %s | FileCheck %s -check-prefixes=CHECK,MAX_4
 
 hw.module @Baz(
   %a0: i1, %a1: i1, %a2: i1, %a3: i1,

test/firtool/commandline.mlir

@@ -2,6 +2,6 @@
 
 // CHECK: OVERVIEW: MLIR-based FIRRTL compiler
 // CHECK: General {{[Oo]}}ptions
-// CHECK: --lowering-options=
 // CHECK: Generic Options
 // CHECK: firtool Options
+// CHECK: --lowering-options=

test/hlstool/commandline.mlir

@@ -2,6 +2,6 @@
 
 // CHECK: OVERVIEW: CIRCT HLS tool
 // CHECK: General {{[Oo]}}ptions
-// CHECK: --lowering-options=
 // CHECK: Generic Options
 // CHECK: hlstool Options
+// CHECK: --lowering-options=

tools/circt-opt/circt-opt.cpp

@@ -61,9 +61,6 @@ int main(int argc, char **argv) {
   circt::test::registerAnalysisTestPasses();
   circt::test::registerSchedulingTestPasses();
 
-  // Other command line options.
-  circt::registerLoweringCLOptions();
-
   return mlir::failed(mlir::MlirOptMain(
       argc, argv, "CIRCT modular optimizer driver", registry));
 }

tools/firtool/firtool.cpp

@@ -26,6 +26,7 @@
 #include "circt/Dialect/Seq/SeqDialect.h"
 #include "circt/Dialect/Seq/SeqPasses.h"
 #include "circt/Support/LoweringOptions.h"
+#include "circt/Support/LoweringOptionsParser.h"
 #include "circt/Support/Version.h"
 #include "circt/Transforms/Passes.h"
 #include "mlir/Bytecode/BytecodeReader.h"
@@ -408,6 +409,8 @@ static cl::opt<BuildMode> buildMode(
       }
     }));
 
+static LoweringOptionsOption loweringOptions(mainCategory);
+
 /// Create a simple canonicalizer pass.
 static std::unique_ptr<Pass> createSimpleCanonicalizerPass() {
   mlir::GreedyRewriteConfig config;
@@ -757,7 +760,8 @@ processBuffer(MLIRContext &context, TimingScope &ts, llvm::SourceMgr &sourceMgr,
 
   // Load the emitter options from the command line. Command line options if
   // specified will override any module options.
-  applyLoweringCLOptions(module.get());
+  if (loweringOptions.getNumOccurrences())
+    loweringOptions.setAsAttribute(module.get());
 
   if (failed(pm.run(module.get())))
     return failure();
@@ -812,10 +816,6 @@ processBuffer(MLIRContext &context, TimingScope &ts, llvm::SourceMgr &sourceMgr,
     if (exportModuleHierarchy)
       exportPm.addPass(sv::createHWExportModuleHierarchyPass(outputFilename));
 
-    // Load the emitter options from the command line. Command line options if
-    // specified will override any module options.
-    applyLoweringCLOptions(module.get());
-
     if (failed(exportPm.run(module.get())))
       return failure();
   }
@@ -1004,7 +1004,6 @@ int main(int argc, char **argv) {
   registerPassManagerCLOptions();
   registerDefaultTimingManagerCLOptions();
   registerAsmPrinterCLOptions();
-  registerLoweringCLOptions();
   cl::AddExtraVersionPrinter(
       [](raw_ostream &os) { os << getCirctVersion() << '\n'; });
   // Parse pass names in main to ensure static initialization completed.

tools/hlstool/hlstool.cpp

@@ -50,6 +50,7 @@
 #include "circt/Dialect/SV/SVPasses.h"
 #include "circt/Dialect/Seq/SeqPasses.h"
 #include "circt/Support/LoweringOptions.h"
+#include "circt/Support/LoweringOptionsParser.h"
 #include "circt/Transforms/Passes.h"
 
 #include "circt/InitAllDialects.h"
@@ -173,6 +174,8 @@ static cl::opt<unsigned> bufferSize("buffer-size",
                                     cl::desc("Number of slots in each buffer"),
                                     cl::init(2), cl::cat(mainCategory));
 
+static LoweringOptionsOption loweringOptions(mainCategory);
+
 // --------------------------------------------------------------------------
 // (Configurable) pass pipelines
 // --------------------------------------------------------------------------
@@ -362,7 +365,8 @@ doHLSFlowDynamic(PassManager &pm, ModuleOp module,
     pm.addPass(circt::sv::createSVTraceIVerilogPass());
 
   if (outputFormat == OutputVerilog) {
-    applyLoweringCLOptions(module);
+    if (loweringOptions.getNumOccurrences())
+      loweringOptions.setAsAttribute(module);
     pm.addPass(createExportVerilogPass(outputFile.value()->os()));
   }
 
@@ -508,7 +512,6 @@ int main(int argc, char **argv) {
   registerPassManagerCLOptions();
   registerDefaultTimingManagerCLOptions();
   registerAsmPrinterCLOptions();
-  registerLoweringCLOptions();
 
   // Parse pass names in main to ensure static initialization completed.
   cl::ParseCommandLineOptions(argc, argv, "CIRCT HLS tool\n");