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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-07 05:48:48 +0000
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tree0d494f7e1a38b95c92426f58fe6eaa877303a86c /tests/coverage/README.md
parentReleasing progress-linux version 1.74.1+dfsg1-1~progress7.99u1. (diff)
downloadrustc-ef24de24a82fe681581cc130f342363c47c0969a.tar.xz
rustc-ef24de24a82fe681581cc130f342363c47c0969a.zip
Merging upstream version 1.75.0+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+The tests in this directory are shared by two different test modes, and can be
+run in multiple different ways:
+
+- `./x.py test coverage-map` (compiles to LLVM IR and checks coverage mappings)
+- `./x.py test coverage-run` (runs a test binary and checks its coverage report)
+- `./x.py test coverage` (runs both `coverage-map` and `coverage-run`)
+
+## Maintenance note
+
+These tests can be sensitive to small changes in MIR spans or MIR control flow,
+especially in HIR-to-MIR lowering or MIR optimizations.
+
+If you haven't touched the coverage code directly, and the tests still pass in
+`coverage-run` mode, then it should usually be OK to just re-bless the mappings
+as necessary with `./x.py test coverage-map --bless`, without worrying too much
+about the exact changes.