Merlin_analysis.Destruct.Ill_typed exception crashes LSP server #617
Description
Hello!
I've noticed a consistent crash in the LSP server when hovering over a destructed record that has fields mixed in with multiple types. This seems to raise a Merlin_analysis.Destruct.Ill_typed exception via ocaml LSP.
e.g. putting the cursor in the destructed record for the argument for f below:
type a =
{ one : int
; two : int
}
type b =
{ two : int
; three : int
}
let f { one = a; three = _ } = a + b
Gives this response from the LSP:
[Trace - 11:05:19 AM] Sending request 'textDocument/codeAction - (1193)'.
Params: {
"textDocument": {
"uri": "file:///home/dave/dev/own/ocaml-lsp/lsp/src/dave_test.ml"
},
"range": {
"start": {
"line": 10,
"character": 14
},
"end": {
"line": 10,
"character": 14
}
},
"context": {
"diagnostics": [
{
"range": {
"start": {
"line": 10,
"character": 17
},
"end": {
"line": 10,
"character": 22
}
},
"severity": 1,
"source": "ocamllsp",
"message": "The record field three belongs to the type b\nbut is mixed here with fields of type a"
},
{
"range": {
"start": {
"line": 10,
"character": 35
},
"end": {
"line": 10,
"character": 36
}
},
"severity": 1,
"source": "ocamllsp",
"message": "Unbound value b"
}
]
}
}
[Trace - 11:05:19 AM] Sending request 'textDocument/documentHighlight - (1194)'.
Params: {
"textDocument": {
"uri": "file:///home/dave/dev/own/ocaml-lsp/lsp/src/dave_test.ml"
},
"position": {
"line": 10,
"character": 14
}
}
[Trace - 11:05:19 AM] Received response 'textDocument/codeAction - (1193)' in 9ms.
Result: {
"data": {
"exn": "Merlin_analysis.Destruct.Ill_typed",
"backtrace": "Raised at Merlin_analysis__Destruct.get_every_pattern.(fun) in file \"ocaml-lsp-server/vendor/merlin/src/analysis/destruct.ml\", line 308, characters 22-37\nCalled from Browse_raw.(**) in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\" (inlined), line 223, characters 11-25\nCalled from Browse_raw.of_pattern in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\", line 264, characters 2-55\nCalled from Browse_raw.(**) in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\" (inlined), line 223, characters 11-25\nCalled from Browse_raw.of_node in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\", line 561, characters 4-84\nCalled from Browse_raw.list_fold in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\" (inlined), line 226, characters 37-53\nCalled from Browse_raw.of_expression_desc in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/merlin_specific/browse_raw.ml\", line 321, characters 4-27\nCalled from Merlin_analysis__Destruct.get_every_pattern in file \"ocaml-lsp-server/vendor/merlin/src/analysis/destruct.ml\", line 295, characters 8-1023\nCalled from Merlin_analysis__Destruct.node in file \"ocaml-lsp-server/vendor/merlin/src/analysis/destruct.ml\", line 556, characters 40-65\nCalled from Merlin_utils__Misc.try_finally in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 45, characters 8-15\nRe-raised at Merlin_utils__Misc.try_finally in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 62, characters 10-24\nCalled from Merlin_utils__Misc.protect_refs.(fun) in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 82, characters 10-14\nRe-raised at Merlin_utils__Misc.protect_refs.(fun) in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 84, characters 38-45\nCalled from Persistent_env.without_cmis in file \"ocaml-lsp-server/vendor/merlin/src/ocaml/typing/persistent_env.ml\", line 151, characters 10-109\nCalled from Merlin_utils__Std.let_ref in file \"ocaml-lsp-server/vendor/merlin/src/utils/std.ml\", line 685, characters 8-12\nRe-raised at Merlin_utils__Std.let_ref in file \"ocaml-lsp-server/vendor/merlin/src/utils/std.ml\", line 687, characters 30-39\nCalled from Merlin_utils__Std.let_ref in file \"ocaml-lsp-server/vendor/merlin/src/utils/std.ml\", line 685, characters 8-12\nRe-raised at Merlin_utils__Std.let_ref in file \"ocaml-lsp-server/vendor/merlin/src/utils/std.ml\", line 687, characters 30-39\nCalled from Merlin_utils__Misc.try_finally in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 45, characters 8-15\nRe-raised at Merlin_utils__Misc.try_finally in file \"ocaml-lsp-server/vendor/merlin/src/utils/misc.ml\", line 62, characters 10-24\nCalled from Stdlib__Fun.protect in file \"fun.ml\", line 33, characters 8-15\nRe-raised at Stdlib__Fun.protect in file \"fun.ml\", line 38, characters 6-52\nCalled from Mocaml.with_state in file \"ocaml-lsp-server/vendor/merlin/src/kernel/mocaml.ml\", line 18, characters 8-38\nRe-raised at Mocaml.with_state in file \"ocaml-lsp-server/vendor/merlin/src/kernel/mocaml.ml\", line 20, characters 42-53\nCalled from Stdune__Exn_with_backtrace.try_with in file \"submodules/dune/otherlibs/stdune-unstable/exn_with_backtrace.ml\", line 9, characters 8-12\nRe-raised at Stdune__Exn.raise_with_backtrace in file \"submodules/dune/otherlibs/stdune-unstable/exn.ml\" (inlined), line 36, characters 27-56\nCalled from Stdune__Exn_with_backtrace.reraise in file \"submodules/dune/otherlibs/stdune-unstable/exn_with_backtrace.ml\", line 18, characters 33-71\nCalled from Fiber.Execution_context.run_jobs in file \"submodules/dune/src/fiber/fiber.ml\", line 204, characters 8-13\n"
},
"code": -32603,
"message": "uncaught exception"
}
[Trace - 11:05:19 AM] Received response 'textDocument/documentHighlight - (1194)' in 9ms.
Result: []
I would expect a message similar to the usual output from e.g. dune:
File "lsp/src/test.ml", line 11, characters 17-22:
11 | let f { one = a; three = b } = a + b
^^^^^
Error: The record field three belongs to the type b
but is mixed here with fields of type a
Thanks for all your great work!