This error model should be rich enough for most applications. It comprises:
- a name for the root object, so the user knows what we're parsing
- a path from the root object to the JSON node most associated with the error
- a local error message
This can be presented as an llvm::Error e.g.
"expected string at ConfigFile.credentials[0].username"
It's designed to be cheap: Paths are a linked list of lightweight
objects on the stack. No heap allocations unless errors are encountered.
A subsequent commit will make use of this in the JSON-to-object
translation facilities: fromJSON and ObjectMapper.
However it's independent of these and can be used for e.g. validation alone.
Another subsequent commit will support showing the error in its context
within the parsed value.
Differential Revision: https://reviews.llvm.org/D88103
This isn't standard JSON, but is a popular extension.
It will be used to show errors in context, rendering pseudo-json for humans.
Differential Revision: https://reviews.llvm.org/D88103
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
Summary:
There's still a little bit of constant factor that could be trimmed (e.g.
more overloads to avoid round-tripping primitives through json::Value).
But this solves the memory scaling problem, and greatly improves the performance
constant factor, and the API should leave room for optimization if needed.
Adapt TimeProfiler to use it, eliminating almost all the performance regression
from r358476.
Performance test on my machine:
perf stat -r 5 ~/llvmbuild-opt/bin/clang++ -w -S -ftime-trace -mllvm -time-trace-granularity=0 spirit.cpp
Handcrafted JSON (HEAD=r358532 with r358476 reverted): 2480ms
json::Value (HEAD): 2757ms (+11%)
After this patch: 2520 ms (+1.6%)
Reviewers: anton-afanasyev, lebedev.ri
Subscribers: kristina, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60804
llvm-svn: 359186
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Parsing invalid UTF-8 input is now a parse error.
Creating JSON values from invalid UTF-8 now triggers an assertion, and
(in no-assert builds) substitutes the unicode replacement character.
Strings retrieved from json::Value are always valid UTF-8.
llvm-svn: 336657
Summary:
This patch adds a new "integer" ValueType, and renames Number -> Double.
This allows us to preserve the full precision of int64_t when parsing integers
from the wire, or constructing from an integer.
The API is unchanged, other than giving asInteger() a clearer contract.
In addition, always output doubles with enough precision that parsing will
reconstruct the same double.
Reviewers: simon_tatham
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46209
llvm-svn: 336541
Summary:
This consists of four main parts:
- an type json::Expr representing JSON values of dynamic kind, which can be
composed, inspected, and modified
- a JSON parser from string -> json::Expr
- a JSON printer from json::Expr -> string, with optional pretty-printing
- a convention for mapping json::Expr <=> native types (fromJSON/toJSON)
Mapping functions are provided for primitives (e.g. int, vector) and the
ObjectMapper helper helps implement fromJSON for struct/object types.
Based on clangd's usage, a couple of places I'd appreciate review attention:
- fromJSON returns only bool. A richer error-signaling mechanism may be useful
to provide useful messages, or let recursive fromJSONs (containers/structs)
do careful error recovery.
- should json::obj be always explicitly written (like json::ary)
- there's no streaming parse API. I suspect there are some simple wins like
a callback API where the document is a long array, and each element is small.
But this can probably be bolted on easily when we see the need.
Reviewers: bkramer, labath
Subscribers: mgorny, ilya-biryukov, ioeric, MaskRay, llvm-commits
Differential Revision: https://reviews.llvm.org/D45753
llvm-svn: 336534
