[mlir][lsp] Enable registering dialects based on URI.

Previously the dialects registered were fixed per LSP binary. This works
as long as all the dialects of interest from the different projects
across which one uses the LSP, are disjoint. This expands this to
support cases where there are dialects that overlap in dialect name but
usage of these are separate wrt projects. The alternative is multiple
binaries and switching LSP used in editor per project (there is some
extra complexity in hosted instances).

This handles a simple (I believe common case) where one can determine
based on path and have single binary - the cost of dynamically doing so
based on path would be either keeping different registries to return or
repopulating dialect & extension maps.

Author: jpienaar

mlir/include/mlir/Tools/mlir-lsp-server/MlirLspRegistryFunction.h

@@ -0,0 +1,29 @@
+//===- MlirLspRegistryFunction.h - LSP registry functions -------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Registry function types for MLIR LSP.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPREGISTRYFUNCTION_H
+#define MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPREGISTRYFUNCTION_H
+
+namespace llvm {
+template <typename Fn> class function_ref;
+} // namespace llvm
+
+namespace mlir {
+class DialectRegistry;
+namespace lsp {
+class URIForFile;
+using DialectRegistryFn =
+    llvm::function_ref<DialectRegistry &(const URIForFile &uri)>;
+} // namespace lsp
+} // namespace mlir
+
+#endif // MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPREGISTRYFUNCTION_H

mlir/include/mlir/Tools/mlir-lsp-server/MlirLspServerMain.h

@@ -12,20 +12,27 @@
 
 #ifndef MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPSERVERMAIN_H
 #define MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPSERVERMAIN_H
+#include "mlir/Tools/mlir-lsp-server/MlirLspRegistryFunction.h"
 
 namespace llvm {
 struct LogicalResult;
 } // namespace llvm
 
 namespace mlir {
-class DialectRegistry;
 
 /// Implementation for tools like `mlir-lsp-server`.
 /// - registry should contain all the dialects that can be parsed in source IR
-/// passed to the server.
+///   passed to the server.
 llvm::LogicalResult MlirLspServerMain(int argc, char **argv,
                                       DialectRegistry &registry);
 
+/// Implementation for tools like `mlir-lsp-server`.
+/// - registry should contain all the dialects that can be parsed in source IR
+///   passed to the server and may register different dialects depending on the
+///   input URI.
+llvm::LogicalResult MlirLspServerMain(int argc, char **argv,
+                                      lsp::DialectRegistryFn registry_fn);
+
 } // namespace mlir
 
 #endif // MLIR_TOOLS_MLIR_LSP_SERVER_MLIRLSPSERVERMAIN_H

mlir/lib/Tools/mlir-lsp-server/MLIRServer.cpp

@@ -997,7 +997,7 @@ namespace {
 class MLIRTextFile {
 public:
   MLIRTextFile(const lsp::URIForFile &uri, StringRef fileContents,
-               int64_t version, DialectRegistry &registry,
+               int64_t version, lsp::DialectRegistryFn registry_fn,
                std::vector<lsp::Diagnostic> &diagnostics);
 
   /// Return the current version of this text file.
@@ -1046,9 +1046,9 @@ class MLIRTextFile {
 } // namespace
 
 MLIRTextFile::MLIRTextFile(const lsp::URIForFile &uri, StringRef fileContents,
-                           int64_t version, DialectRegistry &registry,
+                           int64_t version, lsp::DialectRegistryFn registry_fn,
                            std::vector<lsp::Diagnostic> &diagnostics)
-    : context(registry, MLIRContext::Threading::DISABLED),
+    : context(registry_fn(uri), MLIRContext::Threading::DISABLED),
       contents(fileContents.str()), version(version) {
   context.allowUnregisteredDialects();
 
@@ -1263,11 +1263,11 @@ MLIRTextFileChunk &MLIRTextFile::getChunkFor(lsp::Position &pos) {
 //===----------------------------------------------------------------------===//
 
 struct lsp::MLIRServer::Impl {
-  Impl(DialectRegistry &registry) : registry(registry) {}
+  Impl(lsp::DialectRegistryFn registry_fn) : registry_fn(registry_fn) {}
 
-  /// The registry containing dialects that can be recognized in parsed .mlir
-  /// files.
-  DialectRegistry &registry;
+  /// The registry factory for containing dialects that can be recognized in
+  /// parsed .mlir files.
+  lsp::DialectRegistryFn registry_fn;
 
   /// The files held by the server, mapped by their URI file name.
   llvm::StringMap<std::unique_ptr<MLIRTextFile>> files;
@@ -1277,15 +1277,15 @@ struct lsp::MLIRServer::Impl {
 // MLIRServer
 //===----------------------------------------------------------------------===//
 
-lsp::MLIRServer::MLIRServer(DialectRegistry &registry)
-    : impl(std::make_unique<Impl>(registry)) {}
+lsp::MLIRServer::MLIRServer(lsp::DialectRegistryFn registry_fn)
+    : impl(std::make_unique<Impl>(registry_fn)) {}
 lsp::MLIRServer::~MLIRServer() = default;
 
 void lsp::MLIRServer::addOrUpdateDocument(
     const URIForFile &uri, StringRef contents, int64_t version,
     std::vector<Diagnostic> &diagnostics) {
   impl->files[uri.file()] = std::make_unique<MLIRTextFile>(
-      uri, contents, version, impl->registry, diagnostics);
+      uri, contents, version, impl->registry_fn, diagnostics);
 }
 
 std::optional<int64_t> lsp::MLIRServer::removeDocument(const URIForFile &uri) {
@@ -1348,7 +1348,7 @@ void lsp::MLIRServer::getCodeActions(const URIForFile &uri, const Range &pos,
 
 llvm::Expected<lsp::MLIRConvertBytecodeResult>
 lsp::MLIRServer::convertFromBytecode(const URIForFile &uri) {
-  MLIRContext tempContext(impl->registry);
+  MLIRContext tempContext(impl->registry_fn(uri));
   tempContext.allowUnregisteredDialects();
 
   // Collect any errors during parsing.

mlir/lib/Tools/mlir-lsp-server/MLIRServer.h

@@ -10,6 +10,7 @@
 #define LIB_MLIR_TOOLS_MLIRLSPSERVER_SERVER_H_
 
 #include "mlir/Support/LLVM.h"
+#include "mlir/Tools/mlir-lsp-server/MlirLspRegistryFunction.h"
 #include "llvm/Support/Error.h"
 #include <memory>
 #include <optional>
@@ -28,15 +29,14 @@ struct Location;
 struct MLIRConvertBytecodeResult;
 struct Position;
 struct Range;
-class URIForFile;
 
 /// This class implements all of the MLIR related functionality necessary for a
 /// language server. This class allows for keeping the MLIR specific logic
 /// separate from the logic that involves LSP server/client communication.
 class MLIRServer {
 public:
-  /// Construct a new server with the given dialect regitstry.
-  MLIRServer(DialectRegistry &registry);
+  /// Construct a new server with the given dialect registry function.
+  MLIRServer(DialectRegistryFn registry_fn);
   ~MLIRServer();
 
   /// Add or update the document, with the provided `version`, at the given URI.

mlir/lib/Tools/mlir-lsp-server/MlirLspServerMain.cpp

@@ -19,7 +19,7 @@ using namespace mlir;
 using namespace mlir::lsp;
 
 LogicalResult mlir::MlirLspServerMain(int argc, char **argv,
-                                      DialectRegistry &registry) {
+                                      DialectRegistryFn registry_fn) {
   llvm::cl::opt<JSONStreamStyle> inputStyle{
       "input-style",
       llvm::cl::desc("Input JSON stream encoding"),
@@ -72,6 +72,15 @@ LogicalResult mlir::MlirLspServerMain(int argc, char **argv,
   URIForFile::registerSupportedScheme("mlir.bytecode-mlir");
 
   // Configure the servers and start the main language server.
-  MLIRServer server(registry);
+  MLIRServer server(registry_fn);
   return runMlirLSPServer(server, transport);
 }
+
+llvm::LogicalResult mlir::MlirLspServerMain(int argc, char **argv,
+                                            DialectRegistry &registry) {
+  auto registry_fn =
+      [&registry](const lsp::URIForFile &uri) -> DialectRegistry & {
+    return registry;
+  };
+  return MlirLspServerMain(argc, argv, registry_fn);
+}

mlir/test/mlir-lsp-server/uri-based-registration.test

@@ -0,0 +1,22 @@
+// RUN: not mlir-lsp-server -lit-test < %s | FileCheck -strict-whitespace %s
+{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"processId":123,"rootPath":"mlir","capabilities":{},"trace":"off"}}
+// -----
+// Just regular parse, successful.
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{
+  "uri":"test:///foo-regular-registration.mlir",
+  "languageId":"mlir",
+  "version":1,
+  "text":"func.func @fail_with_empty_registry() { return }"
+}}}
+// CHECK: "method": "textDocument/publishDiagnostics",
+// CHECK:     "diagnostics": []
+// -----
+// Just regular parse, successful.
+{"jsonrpc":"2.0","method":"textDocument/didOpen","params":{"textDocument":{
+  "uri":"test:///foo-disable-lsp-registration.mlir",
+  "languageId":"mlir",
+  "version":1,
+  "text":"func.func @fail_with_empty_registry() { return }"
+}}}
+// CHECK: "method": "textDocument/publishDiagnostics",
+// CHECK: "message": "Dialect `func' not found for custom op 'func.func'

mlir/tools/mlir-lsp-server/mlir-lsp-server.cpp

@@ -6,10 +6,10 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "mlir/IR/Dialect.h"
 #include "mlir/IR/MLIRContext.h"
 #include "mlir/InitAllDialects.h"
 #include "mlir/InitAllExtensions.h"
+#include "mlir/Tools/lsp-server-support/Protocol.h"
 #include "mlir/Tools/mlir-lsp-server/MlirLspServerMain.h"
 
 using namespace mlir;
@@ -23,7 +23,7 @@ void registerTestTransformDialectExtension(DialectRegistry &);
 #endif
 
 int main(int argc, char **argv) {
-  DialectRegistry registry;
+  DialectRegistry registry, empty;
   registerAllDialects(registry);
   registerAllExtensions(registry);
 
@@ -32,5 +32,18 @@ int main(int argc, char **argv) {
   ::test::registerTestTransformDialectExtension(registry);
   ::test::registerTestDynDialect(registry);
 #endif
-  return failed(MlirLspServerMain(argc, argv, registry));
+
+  // Returns the registry, except in testing mode when the URI contains
+  // "_disable_lsp_registration".
+  auto registryFn = [&registry,
+                     &empty](const lsp::URIForFile &uri) -> DialectRegistry & {
+    (void)empty;
+#ifdef MLIR_INCLUDE_TESTS
+    llvm::errs() << "uri: " << uri.uri() << "\n";
+    if (uri.uri().contains("-disable-lsp-registration"))
+      return empty;
+#endif
+    return registry;
+  };
+  return failed(MlirLspServerMain(argc, argv, registryFn));
 }

utils/bazel/llvm-project-overlay/mlir/BUILD.bazel

@@ -8835,11 +8835,51 @@ cc_binary(
     name = "mlir-lsp-server",
     srcs = ["tools/mlir-lsp-server/mlir-lsp-server.cpp"],
     includes = ["include"],
+    local_defines = ["MLIR_INCLUDE_TESTS"],
     deps = [
         ":AllExtensions",
         ":AllPassesAndDialects",
         ":IR",
         ":MlirLspServerLib",
+        ":MlirLspServerSupportLib",
+        "//mlir/test:TestAffine",
+        "//mlir/test:TestAnalysis",
+        "//mlir/test:TestArith",
+        "//mlir/test:TestArmNeon",
+        "//mlir/test:TestArmSME",
+        "//mlir/test:TestBufferization",
+        "//mlir/test:TestControlFlow",
+        "//mlir/test:TestConvertToSPIRV",
+        "//mlir/test:TestDLTI",
+        "//mlir/test:TestDialect",
+        "//mlir/test:TestFunc",
+        "//mlir/test:TestFuncToLLVM",
+        "//mlir/test:TestGPU",
+        "//mlir/test:TestIR",
+        "//mlir/test:TestLLVM",
+        "//mlir/test:TestLinalg",
+        "//mlir/test:TestLoopLikeInterface",
+        "//mlir/test:TestMath",
+        "//mlir/test:TestMathToVCIX",
+        "//mlir/test:TestMemRef",
+        "//mlir/test:TestMesh",
+        "//mlir/test:TestNVGPU",
+        "//mlir/test:TestPDLL",
+        "//mlir/test:TestPass",
+        "//mlir/test:TestReducer",
+        "//mlir/test:TestRewrite",
+        "//mlir/test:TestSCF",
+        "//mlir/test:TestSPIRV",
+        "//mlir/test:TestShapeDialect",
+        "//mlir/test:TestTensor",
+        "//mlir/test:TestTestDynDialect",
+        "//mlir/test:TestTilingInterface",
+        "//mlir/test:TestTosaDialect",
+        "//mlir/test:TestTransformDialect",
+        "//mlir/test:TestTransforms",
+        "//mlir/test:TestVector",
+        "//mlir/test:TestVectorToSPIRV",
+        "//mlir/test:TestXeGPU",
     ],
 )