[MachineVerifier] Report errors from one thread at a time #111605
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ellishg
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| # RUN: not --crash llc -mtriple=aarch64 -o /dev/null -run-pass=none -verify-machineinstrs %s 2>&1 | FileCheck %s --implicit-check-not="Bad machine code" | ||
| # REQUIRES: aarch64-registered-target | ||
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| # Check that errors are reported from only one function. |
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This behavior is really annoying if it's fixable
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Even before this patch, AbortOnError defaults to true which means we will abort after reporting the first error.
llvm-project/llvm/lib/CodeGen/MachineVerifier.cpp
Lines 393 to 394 in a075e78
The problem I encountered is that if the report is super long, it's possible that the verifier would find another error and start print it before the program aborts. The output would be unreadable since two separate errors were printing at the same time.
This patch aims to fix that scenario by ensuring a single error gets reported at a time. Since we abort after the first error, this test checks that we only print errors from one function.
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I updated the wording to be a bit more clear.
I did find a reproducer, but because it included multiple failing modules, the error was scrambled, so I couldn't minimize the reproducer easily. I couldn't even tell which modules were failing until I introduced a lock in the reporting code.
Makes sense to me, but that should probably be a separate PR. |
Create the `ReportedErrors` class to track the number of reported errors during verification. The class will block reporting errors if some other thread is currently reporting an error. I've encountered a case where there were many different verifications reporting errors at the same time on different threads. This ensures that we don't start printing the error from one case until we are completely done printing errors from other cases. Most of the time `AbortOnError = true` so we usually abort after reporting the first error. Depends on llvm#111602.
Create the
ReportedErrorsclass to track the number of reported errors during verification. The class will block reporting errors if some other thread is currently reporting an error.I've encountered a case where there were many different verifications reporting errors at the same time on different threads. This ensures that we don't start printing the error from one case until we are completely done printing errors from other cases. Most of the time
AbortOnError = trueso we usually abort after reporting the first error.Depends on #111602.