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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:50 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:19:50 +0000 |
commit | 2e00214b3efbdfeefaa0fe9e8b8fd519de7adc35 (patch) | |
tree | d325add32978dbdc1db975a438b3a77d571b1ab8 /src/doc/unstable-book/src/compiler-flags/instrument-xray.md | |
parent | Releasing progress-linux version 1.68.2+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-2e00214b3efbdfeefaa0fe9e8b8fd519de7adc35.tar.xz rustc-2e00214b3efbdfeefaa0fe9e8b8fd519de7adc35.zip |
Merging upstream version 1.69.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/doc/unstable-book/src/compiler-flags/instrument-xray.md')
-rw-r--r-- | src/doc/unstable-book/src/compiler-flags/instrument-xray.md | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/doc/unstable-book/src/compiler-flags/instrument-xray.md b/src/doc/unstable-book/src/compiler-flags/instrument-xray.md new file mode 100644 index 000000000..7fb33cd68 --- /dev/null +++ b/src/doc/unstable-book/src/compiler-flags/instrument-xray.md @@ -0,0 +1,39 @@ +# `instrument-xray` + +The tracking issue for this feature is: [#102921](https://github.com/rust-lang/rust/issues/102921). + +------------------------ + +Enable generation of NOP sleds for XRay function tracing instrumentation. +For more information on XRay, +read [LLVM documentation](https://llvm.org/docs/XRay.html), +and/or the [XRay whitepaper](http://research.google.com/pubs/pub45287.html). + +Set the `-Z instrument-xray` compiler flag in order to enable XRay instrumentation. + + - `-Z instrument-xray` – use the default settings + - `-Z instrument-xray=skip-exit` – configure a custom setting + - `-Z instrument-xray=ignore-loops,instruction-threshold=300` – + multiple settings separated by commas + +Supported options: + + - `always` – force instrumentation of all functions + - `never` – do no instrument any functions + - `ignore-loops` – ignore presence of loops, + instrument functions based only on instruction count + - `instruction-threshold=10` – set a different instruction threshold for instrumentation + - `skip-entry` – do no instrument function entry + - `skip-exit` – do no instrument function exit + +The default settings are: + + - instrument both entry & exit from functions + - instrument functions with at least 200 instructions, + or containing a non-trivial loop + +Note that `-Z instrument-xray` only enables generation of NOP sleds +which on their own don't do anything useful. +In order to actually trace the functions, +you will need to link a separate runtime library of your choice, +such as Clang's [XRay Runtime Library](https://www.llvm.org/docs/XRay.html#xray-runtime-library). |