[llvm] [mlir] [LLVM][MLIR] Move LSP server support library from MLIR into LLVM (PR #157885)

[Michał Górny via llvm-commits]

mgorny wrote:

Unfortunately, according to git bisect, this change is also responsible for the following test regression:

```
FAIL: MLIR :: mlir-pdll-lsp-server/view-output.test (2448 of 3394)
******************** TEST 'MLIR :: mlir-pdll-lsp-server/view-output.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
mlir-pdll-lsp-server -lit-test < /var/tmp/portage/llvm-core/mlir-22.0.0.9999/work/mlir/test/mlir-pdll-lsp-server/view-output.test | /usr/lib/llvm/22/bin/FileCheck -strict-whitespace /var/tmp/portage/llvm-core/mlir-22.0.0.9999/work/mlir/test/mlir-pdll-lsp-server/view-output.test
# executed command: mlir-pdll-lsp-server -lit-test
# .---command stderr------------
# | I[10:15:47.338] --> initialize(0)
# | I[10:15:47.339] --> reply:initialize(0)
# | D[10:15:47.339] >>> {
# |   "id": 0,
# |   "jsonrpc": "2.0",
# |   "result": {
# |     "capabilities": {
# |       "completionProvider": {
# |         "allCommitCharacters": [
# |           "\t",
# |           "(",
# |           ")",
# |           "[",
# |           "]",
# |           "{",
# |           "}",
# |           "<",
# |           ">",
# |           ":",
# |           ";",
# |           ",",
# |           "+",
# |           "-",
# |           "/",
# |           "*",
# |           "%",
# |           "^",
# |           "&",
# |           "#",
# |           "?",
# |           ".",
# |           "=",
# |           "\"",
# |           "'",
# |           "|"
# |         ],
# |         "resolveProvider": false,
# |         "triggerCharacters": [
# |           ".",
# |           ">",
# |           "(",
# |           "{",
# |           ",",
# |           "<",
# |           ":",
# |           "[",
# |           " ",
# |           "\"",
# |           "/"
# |         ]
# |       },
# |       "definitionProvider": true,
# |       "documentLinkProvider": {
# |         "resolveProvider": false
# |       },
# |       "documentSymbolProvider": true,
# |       "hoverProvider": true,
# |       "inlayHintProvider": true,
# |       "referencesProvider": true,
# |       "signatureHelpProvider": {
# |         "triggerCharacters": [
# |           "(",
# |           ","
# |         ]
# |       },
# |       "textDocumentSync": {
# |         "change": 2,
# |         "openClose": true,
# |         "save": true
# |       }
# |     },
# |     "serverInfo": {
# |       "name": "mlir-pdll-lsp-server",
# |       "version": "0.0.1"
# |     }
# |   }
# | }
# | 
# | 
# | I[10:15:47.339] --> textDocument/didOpen
# | I[10:15:47.339] --> textDocument/publishDiagnostics
# | D[10:15:47.339] >>> {
# |   "jsonrpc": "2.0",
# |   "method": "textDocument/publishDiagnostics",
# |   "params": {
# |     "diagnostics": [],
# |     "uri": "test:///foo.pdll",
# |     "version": 1
# |   }
# | }
# | 
# | 
# | I[10:15:47.339] --> pdll/viewOutput(1)
# | I[10:15:47.339] --> reply:pdll/viewOutput(1): -32602: failed to decode pdll/viewOutput request: missing value at (root).uri
# | D[10:15:47.339] >>> {
# |   "error": {
# |     "code": -32602,
# |     "message": "failed to decode pdll/viewOutput request: missing value at (root).uri"
# |   },
# |   "id": 1,
# |   "jsonrpc": "2.0"
# | }
# | 
# | 
# | I[10:15:47.339] --> pdll/viewOutput(2)
# | I[10:15:47.339] --> reply:pdll/viewOutput(2): -32602: failed to decode pdll/viewOutput request: missing value at (root).uri
# | D[10:15:47.339] >>> {
# |   "error": {
# |     "code": -32602,
# |     "message": "failed to decode pdll/viewOutput request: missing value at (root).uri"
# |   },
# |   "id": 2,
# |   "jsonrpc": "2.0"
# | }
# | 
# | 
# | I[10:15:47.339] --> pdll/viewOutput(3)
# | I[10:15:47.339] --> reply:pdll/viewOutput(3): -32602: failed to decode pdll/viewOutput request: missing value at (root).uri
# | D[10:15:47.339] >>> {
# |   "error": {
# |     "code": -32602,
# |     "message": "failed to decode pdll/viewOutput request: missing value at (root).uri"
# |   },
# |   "id": 3,
# |   "jsonrpc": "2.0"
# | }
# | 
# | 
# | I[10:15:47.339] --> shutdown(3)
# | I[10:15:47.339] --> reply:shutdown(3)
# | D[10:15:47.339] >>> {
# |   "id": 3,
# |   "jsonrpc": "2.0",
# |   "result": null
# | }
# | 
# | 
# | I[10:15:47.339] --> exit
# `-----------------------------
# executed command: /usr/lib/llvm/22/bin/FileCheck -strict-whitespace /var/tmp/portage/llvm-core/mlir-22.0.0.9999/work/mlir/test/mlir-pdll-lsp-server/view-output.test
# .---command stderr------------
# | /var/tmp/portage/llvm-core/mlir-22.0.0.9999/work/mlir/test/mlir-pdll-lsp-server/view-output.test:16:17: error: CHECK-NEXT: is not on the line after the previous match
# | // CHECK-NEXT:  "jsonrpc": "2.0",
# |                 ^
# | <stdin>:123:3: note: 'next' match was here
# |   "jsonrpc": "2.0",
# |   ^
# | <stdin>:96:10: note: previous match ended here
# |   "id": 1,
# |          ^
# | <stdin>:97:1: note: non-matching line after previous match is here
# |   "jsonrpc": "2.0"
# | ^
# | 
# | Input file: <stdin>
# | Check file: /var/tmp/portage/llvm-core/mlir-22.0.0.9999/work/mlir/test/mlir-pdll-lsp-server/view-output.test
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |          .
# |          .
# |          .
# |        118: } 
# |        119: Content-Length: 52 
# |        120:  
# |        121: { 
# |        122:   "id": 3, 
# |        123:   "jsonrpc": "2.0", 
# | next:16       !~~~~~~~~~~~~~~~~  error: match on wrong line
# |        124:   "result": null 
# |        125: } 
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

********************
```

Full logs (with CMake invocations, etc.):
- [llvm.txt.gz](https://github.com/user-attachments/files/22310380/llvm.txt.gz)
- [mlir.txt.gz](https://github.com/user-attachments/files/22310381/mlir.txt.gz)


https://github.com/llvm/llvm-project/pull/157885