Author: Ivan Murashko Date: 2022-08-10T16:37:42+01:00 New Revision: e78c80e3d622d455934102dabd765a60ac917739
URL: https://github.com/llvm/llvm-project/commit/e78c80e3d622d455934102dabd765a60ac917739 DIFF: https://github.com/llvm/llvm-project/commit/e78c80e3d622d455934102dabd765a60ac917739.diff LOG: [clang] SourceManager: fix at SourceManager::getFileIDLoaded for the case of invalid SLockEntry There is a fix for the search procedure at `SourceManager::getFileIDLoaded`. It might return an invalid (not loaded) entry. That might cause clang/clangd crashes. At my case the scenario was the following: - `SourceManager::getFileIDLoaded` returned an invalid file id for a non loaded entry and incorrectly set `SourceManager::LastFileIDLookup` to the value - `getSLocEntry` returned `SourceManager::FakeSLocEntryForRecovery` introduced at [D89748](https://reviews.llvm.org/D89748). - The result entry is not tested at `SourceManager::isOffsetInFileID`and as result the call `return SLocOffset < getSLocEntryByID(FID.ID+1).getOffset();` returned `true` value because `FID.ID+1` pointed to a non-fake entry - The tested offset was marked as one that belonged to the fake `SLockEntry` Such behaviour might cause a weird clangd crash when preamble contains some header files that were removed just after the preamble created. Unfortunately it's not so easy to reproduce the crash in the form of a LIT test thus I provided the fix only. Test Plan: ``` ninja check-clang ``` Reviewed By: aaron.ballman Differential Revision: https://reviews.llvm.org/D130847 Added: Modified: clang/lib/Basic/SourceManager.cpp Removed: ################################################################################ diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp index 98e731eb12e62..38545d1be918f 100644 --- a/clang/lib/Basic/SourceManager.cpp +++ b/clang/lib/Basic/SourceManager.cpp @@ -877,9 +877,12 @@ FileID SourceManager::getFileIDLoaded(SourceLocation::UIntTy SLocOffset) const { I = (-LastID - 2) + 1; unsigned NumProbes; + bool Invalid = false; for (NumProbes = 0; NumProbes < 8; ++NumProbes, ++I) { // Make sure the entry is loaded! - const SrcMgr::SLocEntry &E = getLoadedSLocEntry(I); + const SrcMgr::SLocEntry &E = getLoadedSLocEntry(I, &Invalid); + if (Invalid) + return FileID(); // invalid entry. if (E.getOffset() <= SLocOffset) { FileID Res = FileID::get(-int(I) - 2); LastFileIDLookup = Res; @@ -897,8 +900,8 @@ FileID SourceManager::getFileIDLoaded(SourceLocation::UIntTy SLocOffset) const { while (true) { ++NumProbes; unsigned MiddleIndex = (LessIndex - GreaterIndex) / 2 + GreaterIndex; - const SrcMgr::SLocEntry &E = getLoadedSLocEntry(MiddleIndex); - if (E.getOffset() == 0) + const SrcMgr::SLocEntry &E = getLoadedSLocEntry(MiddleIndex, &Invalid); + if (Invalid) return FileID(); // invalid entry. ++NumProbes; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
