Summary:
The Language Server Protocol unfortunately mandates that locations in files
be represented by line/column pairs, where the "column" is actually an index
into the UTF-16-encoded text of the line.
(This is because VSCode is written in JavaScript, which is UTF-16-native).
Internally clangd treats source files at UTF-8, the One True Encoding, and
generally deals with byte offsets (though there are exceptions).
Before this patch, conversions between offsets and LSP Position pretended
that Position.character was UTF-8 bytes, which is only true for ASCII lines.
Now we examine the text to convert correctly (but don't actually need to
transcode it, due to some nice details of the encodings).
The updated functions in SourceCode are the blessed way to interact with
the Position.character field, and anything else is likely to be wrong.
So I also updated the other accesses:
- CodeComplete needs a "clang-style" line/column, with column in utf-8 bytes.
This is now converted via Position -> offset -> clang line/column
(a new function is added to SourceCode.h for the second conversion).
- getBeginningOfIdentifier skipped backwards in UTF-16 space, which is will
behave badly when it splits a surrogate pair. Skipping backwards in UTF-8
coordinates gives the lexer a fighting chance of getting this right.
While here, I clarified(?) the logic comments, fixed a bug with identifiers
containing digits, simplified the signature slightly and added a test.
This seems likely to cause problems with editors that have the same bug, and
treat the protocol as if columns are UTF-8 bytes. But we can find and fix those.
Reviewers: hokein
Subscribers: klimek, ilya-biryukov, ioeric, MaskRay, jkorous, cfe-commits
Differential Revision: https://reviews.llvm.org/D46035
llvm-svn: 331029
Summary:
To implement incremental document syncing, we want to verify that the
ranges provided by the front-end are valid. Currently, positionToOffset
deals with invalid Positions by returning 0 or Code.size(), which are
two valid offsets. Instead, return an llvm:Expected<size_t> with an
error if the position is invalid.
According to the LSP, if the character value exceeds the number of
characters of the given line, it should default back to the end of the
line. It makes sense in some contexts to have this behavior, and does
not in other contexts. The AllowColumnsBeyondLineLength parameter
allows to decide what to do in that case, default back to the end of the
line, or return an error.
Reviewers: ilya-biryukov
Subscribers: klimek, ilya-biryukov, jkorous-apple, ioeric, cfe-commits
Differential Revision: https://reviews.llvm.org/D44673
llvm-svn: 328100
Summary:
Some of the existing structs had primimtive fields that were
not explicitly initialized on construction.
After this commit every struct consistently sets a defined value for
every field when default-initialized.
Reviewers: hokein, ioeric, sammccall
Reviewed By: sammccall
Subscribers: klimek, cfe-commits, jkorous-apple
Differential Revision: https://reviews.llvm.org/D43230
llvm-svn: 325113
Summary:
- Moved these functions to SourceCode.h
- added unit tests
- fix off by one in positionToOffset: Offset - 1 in final calculation was wrong
- fixed formatOnType which had an equal and opposite off-by-one
- positionToOffset and offsetToPosition both consistently clamp to beginning/end
of file when input is out of range
- gave variables more descriptive names
- removed windows line ending fixmes where there is nothing to fix
- elaborated on UTF-8 fixmes
This will conflict with Eric's D41281, but in a pretty easy-to-resolve way.
Reviewers: ioeric
Subscribers: klimek, mgorny, ilya-biryukov, cfe-commits
Differential Revision: https://reviews.llvm.org/D41351
llvm-svn: 321073
Kadir Cetinkaya