cc: Refactor mlir pipeline to be used in any workflow.

include/vast/Frontend/Consumer.hpp

@@ -98,6 +98,10 @@ namespace vast::cc {
             target_dialect target, owning_module_ref mod, mcontext_t *mctx
         );
 
+        void process_mlir_module(
+            target_dialect target, mlir::ModuleOp mod, mcontext_t *mctx
+        );
+
         output_type action;
         output_stream_ptr output_stream;
     };

include/vast/Frontend/Pipelines.hpp

@@ -37,7 +37,7 @@ namespace vast::cc {
     // scheduled pipeline.
     //
     std::unique_ptr< pipeline_t > setup_pipeline(
-        pipeline_source src, output_type trg,
+        pipeline_source src, target_dialect trg,
         mcontext_t &mctx,
         const vast_args &vargs,
         const pipelines_config &config

lib/vast/Frontend/Consumer.cpp

@@ -149,8 +149,10 @@ namespace vast::cc {
                     backend::Backend_EmitAssembly, std::move(mod), mctx.get()
                 );
             case output_type::emit_mlir: {
-                auto trg = parse_target_dialect(vargs.get_option(opt::emit_mlir).value());
-                return emit_mlir_output(trg, std::move(mod), mctx.get());
+                if (auto trg = vargs.get_option(opt::emit_mlir)) {
+                    return emit_mlir_output(parse_target_dialect(trg.value()), std::move(mod), mctx.get());
+                }
+                VAST_FATAL("no target dialect specified for MLIR output");
             }
             case output_type::emit_llvm:
                 return emit_backend_output(
@@ -170,21 +172,20 @@ namespace vast::cc {
     ) {
         llvm::LLVMContext llvm_context;
 
+        process_mlir_module(target_dialect::llvm, mlir_module.get(), mctx);
+
         auto mod = target::llvmir::translate(mlir_module.get(), llvm_context);
         auto dl  = cgctx->actx.getTargetInfo().getDataLayoutString();
+
         clang::EmitBackendOutput(
             opts.diags, opts.headers, opts.codegen, opts.target, opts.lang, dl, mod.get(),
             backend_action, &opts.vfs, std::move(output_stream)
         );
     }
 
-    void vast_stream_consumer::emit_mlir_output(
-        target_dialect target, owning_module_ref mod, mcontext_t *mctx
+    void vast_stream_consumer::process_mlir_module(
+        target_dialect target, mlir::ModuleOp mod, mcontext_t *mctx
     ) {
-        if (!output_stream || !mod) {
-            return;
-        }
-
         // Handle source manager properly given that lifetime analysis
         // might emit warnings and remarks.
         auto &src_mgr     = cgctx->actx.getSourceManager();
@@ -209,12 +210,12 @@ namespace vast::cc {
 
         // Setup and execute vast pipeline
         auto pipeline = setup_pipeline(
-            pipeline_source::ast, output_type::emit_mlir, *mctx, vargs,
+            pipeline_source::ast, target, *mctx, vargs,
             default_pipelines_config()
         );
         VAST_CHECK(pipeline, "failed to setup pipeline");
 
-        auto result = pipeline->run(mod.get());
+        auto result = pipeline->run(mod);
         VAST_CHECK(mlir::succeeded(result), "MLIR pass manager failed when running vast passes");
 
         // Verify the diagnostic handler to make sure that each of the
@@ -228,6 +229,16 @@ namespace vast::cc {
         // if (!vargs.has_option(opt::disable_emit_cxx_default)) {
         //     generator->build_default_methods();
         // }
+    }
+
+    void vast_stream_consumer::emit_mlir_output(
+        target_dialect target, owning_module_ref mod, mcontext_t *mctx
+    ) {
+        if (!output_stream || !mod) {
+            return;
+        }
+
+        process_mlir_module(target, mod.get(), mctx);
 
         // FIXME: we cannot roundtrip prettyForm=true right now.
         mlir::OpPrintingFlags flags;

lib/vast/Frontend/Pipelines.cpp

@@ -62,25 +62,17 @@ namespace vast::cc {
 
         gap::generator< pipeline_step_ptr > conversion(
             pipeline_source src,
-            output_type trg,
+            target_dialect trg,
             const vast_args &vargs,
             const pipelines_config &config
         ) {
             // TODO: add support for custom conversion paths
             // deduced from source, target and vargs
             auto path = default_conversion_path;
 
-            auto target_dialect =  [&] () -> enum target_dialect {
-                if (trg == output_type::emit_mlir) {
-                    return parse_target_dialect(vargs.get_option(opt::emit_mlir).value());
-                }
-                // if we user do not specify target dialect, we convert all the way to llvm
-                return target_dialect::llvm;
-            } ();
-
             bool simplify = vargs.has_option(opt::simplify);
 
-            if (target_dialect == target_dialect::high_level && !simplify) {
+            if (trg == target_dialect::high_level && !simplify) {
                 co_return;
             }
 
@@ -89,7 +81,7 @@ namespace vast::cc {
                     co_yield step();
                 }
 
-                if (target_dialect == dialect) {
+                if (trg == dialect) {
                     break;
                 }
             }
@@ -99,7 +91,7 @@ namespace vast::cc {
 
     std::unique_ptr< pipeline_t > setup_pipeline(
         pipeline_source src,
-        output_type trg,
+        target_dialect trg,
         mcontext_t &mctx,
         const vast_args &vargs,
         const pipelines_config &config