35 lines
2.1 KiB
Markdown
35 lines
2.1 KiB
Markdown
# Debugging
|
|
|
|
This page collects the library's built-in debugger integrations and other debugging-related features. They are
|
|
not linked from a single place elsewhere in the docs, so are collected here.
|
|
|
|
## Visual Studio (natvis)
|
|
|
|
The repository ships [`nlohmann_json.natvis`](https://github.com/nlohmann/json/blob/develop/nlohmann_json.natvis)
|
|
at its root, a [Natvis](https://learn.microsoft.com/en-us/visualstudio/debugger/create-custom-views-of-native-objects)
|
|
file that gives `json`/`ordered_json` values a friendly, key/value debugger view instead of showing raw internal
|
|
fields, when debugging with the MSVC debug engine (`cppvsdbg`) in Visual Studio or VS Code.
|
|
|
|
The checked-in visualizers cover namespace variants with zero, one, or two ABI tags. Configurations with three or more
|
|
ABI tags are not covered and may show raw internal fields instead.
|
|
|
|
Debug engines that wrap LLDB instead of the MSVC debug engine (for example, `codelldb` in VS Code) only have
|
|
partial/experimental Natvis support, and commonly fall back to showing raw internal fields even with the
|
|
`.natvis` file present. Switching to `cppvsdbg` where available, or checking your debug extension's own Natvis
|
|
support/version, are the next things to try if this happens. There is currently no bundled LLDB-native
|
|
pretty-printer script in this repository.
|
|
|
|
## GDB
|
|
|
|
The repository ships a [GDB Python pretty printer](https://github.com/nlohmann/json/tree/develop/tools/gdb_pretty_printer)
|
|
under `tools/gdb_pretty_printer`, with its own usage instructions in that directory's `README.md`.
|
|
|
|
## Extended exception diagnostics
|
|
|
|
Defining [`JSON_DIAGNOSTICS`](../api/macros/json_diagnostics.md) before including the library augments
|
|
`type_error`/`out_of_range`-style exceptions with a JSON Pointer to the offending value, which can help pinpoint
|
|
where in a large document a runtime error occurred. This only applies to exceptions thrown *after* a value
|
|
exists (e.g. during element access); parse errors, which happen before any value exists to point at, are not
|
|
covered by this mechanism -- see [Parsing and exceptions](../features/parsing/parse_exceptions.md) for how parse
|
|
errors report their own location instead.
|