https://github.com/alanzhao1 updated https://github.com/llvm/llvm-project/pull/154231
>From 9f07859077fb6df79388d1cc346f3e57f2832f7c Mon Sep 17 00:00:00 2001 From: Alan Zhao <ayz...@google.com> Date: Mon, 18 Aug 2025 16:46:48 -0700 Subject: [PATCH 1/3] [clang][timers][modules] Fix a timer being started when it's running `ASTReader::FinishedDeserializing()` calls `adjustDeductedFunctionResultType(...)` [0], which in turn calls `FunctionDecl::getMostRecentDecl()`[1]. In modules builds, `getMostRecentDecl()` may reach out to the `ASTReader` and start deserializing again. Starting deserialization starts `ReadTimer`; however, `FinishedDeserializing()` doesn't call `stopTimer()` until after it's call to `adjustDeductedFunctionResultType(...)` [2]. As a result, we hit an assert checking that we don't start an already started timer [3]. To fix this, we simply don't start the timer if it's already running. Unfortunately I don't have a test case for this yet as modules builds are notoriously difficult to reduce. [0]: https://github.com/llvm/llvm-project/blob/4d2288d31866013bd361800df4746fbc2fcf742a/clang/lib/Serialization/ASTReader.cpp#L11053 [1]: https://github.com/llvm/llvm-project/blob/4d2288d31866013bd361800df4746fbc2fcf742a/clang/lib/AST/ASTContext.cpp#L3804 [2]: https://github.com/llvm/llvm-project/blob/4d2288d31866013bd361800df4746fbc2fcf742a/clang/lib/Serialization/ASTReader.cpp#L11065-L11066 [3]: https://github.com/llvm/llvm-project/blob/4d2288d31866013bd361800df4746fbc2fcf742a/llvm/lib/Support/Timer.cpp#L150 --- clang/lib/Serialization/ASTReader.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp index e8dddda584a9b..bff289f1c1b76 100644 --- a/clang/lib/Serialization/ASTReader.cpp +++ b/clang/lib/Serialization/ASTReader.cpp @@ -11003,7 +11003,8 @@ void ASTReader::diagnoseOdrViolations() { } void ASTReader::StartedDeserializing() { - if (++NumCurrentElementsDeserializing == 1 && ReadTimer.get()) + if (Timer *T = ReadTimer.get(); + ++NumCurrentElementsDeserializing == 1 && T && !T->isRunning()) ReadTimer->startTimer(); } >From 686c6c3d28e945fc56a0fbd565b5b9a21f99dcd5 Mon Sep 17 00:00:00 2001 From: Alan Zhao <ayz...@google.com> Date: Mon, 18 Aug 2025 17:22:44 -0700 Subject: [PATCH 2/3] fix namespace identifier issue --- clang/lib/Serialization/ASTReader.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp index bff289f1c1b76..a61238fb7698d 100644 --- a/clang/lib/Serialization/ASTReader.cpp +++ b/clang/lib/Serialization/ASTReader.cpp @@ -11003,7 +11003,7 @@ void ASTReader::diagnoseOdrViolations() { } void ASTReader::StartedDeserializing() { - if (Timer *T = ReadTimer.get(); + if (llvm::Timer *T = ReadTimer.get(); ++NumCurrentElementsDeserializing == 1 && T && !T->isRunning()) ReadTimer->startTimer(); } >From b45ce002b10987c0a6c8d8bda15f572c58c75e9d Mon Sep 17 00:00:00 2001 From: Alan Zhao <ayz...@google.com> Date: Mon, 18 Aug 2025 21:47:07 -0700 Subject: [PATCH 3/3] use T instead of ReadTimer --- clang/lib/Serialization/ASTReader.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp index a61238fb7698d..51222956ae0e1 100644 --- a/clang/lib/Serialization/ASTReader.cpp +++ b/clang/lib/Serialization/ASTReader.cpp @@ -11005,7 +11005,7 @@ void ASTReader::diagnoseOdrViolations() { void ASTReader::StartedDeserializing() { if (llvm::Timer *T = ReadTimer.get(); ++NumCurrentElementsDeserializing == 1 && T && !T->isRunning()) - ReadTimer->startTimer(); + T->startTimer(); } void ASTReader::FinishedDeserializing() { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
