From 9e306ad4600c4d3392c194a8be88919ee758425c Mon Sep 17 00:00:00 2001 From: Jan Svoboda Date: Thu, 22 May 2025 12:33:52 -0700 Subject: [clang] Remove intrusive reference count from `DiagnosticOptions` (#139584) The `DiagnosticOptions` class is currently intrusively reference-counted, which makes reasoning about its lifetime very difficult in some cases. For example, `CompilerInvocation` owns the `DiagnosticOptions` instance (wrapped in `llvm::IntrusiveRefCntPtr`) and only exposes an accessor returning `DiagnosticOptions &`. One would think this gives `CompilerInvocation` exclusive ownership of the object, but that's not the case: ```c++ void shareOwnership(CompilerInvocation &CI) { llvm::IntrusiveRefCntPtr CoOwner = &CI.getDiagnosticOptions(); // ... } ``` This is a perfectly valid pattern that is being actually used in the codebase. I would like to ensure the ownership of `DiagnosticOptions` by `CompilerInvocation` is guaranteed to be exclusive. This can be leveraged for a copy-on-write optimization later on. This PR changes usages of `DiagnosticOptions` across `clang`, `clang-tools-extra` and `lldb` to not be intrusively reference-counted. --- clang/unittests/Frontend/CompilerInvocationTest.cpp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'clang/unittests/Frontend/CompilerInvocationTest.cpp') diff --git a/clang/unittests/Frontend/CompilerInvocationTest.cpp b/clang/unittests/Frontend/CompilerInvocationTest.cpp index 94ab9fe..75390aa 100644 --- a/clang/unittests/Frontend/CompilerInvocationTest.cpp +++ b/clang/unittests/Frontend/CompilerInvocationTest.cpp @@ -29,6 +29,7 @@ using ::testing::StartsWith; namespace { class CommandLineTest : public ::testing::Test { public: + DiagnosticOptions DiagOpts; IntrusiveRefCntPtr Diags; SmallVector GeneratedArgs; BumpPtrAllocator Alloc; @@ -41,7 +42,7 @@ public: CommandLineTest() : Diags(CompilerInstance::createDiagnostics( - *llvm::vfs::getRealFileSystem(), new DiagnosticOptions(), + *llvm::vfs::getRealFileSystem(), DiagOpts, new TextDiagnosticBuffer())), StringPool(Alloc) {} }; -- cgit v1.1