Extension point so private/unsupported platforms can plug in their own implementations of the kernel/libc primitives Tracy depends on, without patching the `#if`/`#elif` chains.
Projects supply a platform header via `-DTRACY_PLATFORM_HEADER="\"my_platform.h\""` at build time. Tracy includes it in any TU that needs the hooks. The header toggles per-category `TRACY_HAS_CUSTOM_*` macros and declares matching `tracy::Platform*` functions.
Available hooks:
- `TRACY_HAS_CUSTOM_THREAD_ID` → `PlatformGetThreadId`
- `TRACY_HAS_CUSTOM_USER_INFO` → `PlatformGetHostname`, `PlatformGetUserLogin`, `PlatformGetUserFullName`
- `TRACY_HAS_CUSTOM_SAFE_COPY` → `PlatformSafeMemcpy`
- `TRACY_HAS_CUSTOM_ALLOCATOR` → `PlatformMalloc`, `PlatformFree`, `PlatformRealloc`, `PlatformAllocatorInit`, `PlatformAllocatorThreadInit`, `PlatformAllocatorFinalize`, `PlatformAllocatorThreadFinalize`
Each hook is wired as the first arm of its respective `#if`/`#elif` chain, so existing supported platforms are unaffected.
Template files in `examples/CustomPlatform/` and a new subsection in `manual/tracy.tex` document the mechanism.
previous check tested for compiler ID, fixed the detection to an specific MSVC macro and the current C++ version so it does not override an user specified version
We (Julia) ship both support for using tracy to trace julia applications,
as well as using `rr` (https://github.com/rr-debugger/rr) for record-replay debugging.
After our most recent rebuild of tracy, users have been reporting signfificant performance
slowdowns when `rr` recording a session that happens to also load the tracy library
(even if tracing is not enabled). Upon further examination, the recompile happened
to trigger a protective heuristic that disabled rr's patching of tracy's use of
`rdtsc` because an earlier part of the same function happened to look like a
conditional branch into the patch region. See https://github.com/rr-debugger/rr/pull/3580
for details. To avoid this issue occurring again in future rebuilds of tracy,
adjust tracy's `rdtsc` sequence to be `nopl; rdtsc`, which (as of of the
linked PR) is a sequence that is guaranteed to bypass this heuristic
and not incur the additional overhead when run under rr.
This functionality is kept behind a compile-time flag `TRACY_PATCHABLE_NOPSLEDS`
in order to avoid polluting the instruction cache unnecessarily.
