From 0e828958264734e60115ba2482437008c822d7db Mon Sep 17 00:00:00 2001 From: JF Bastien Date: Wed, 26 Jun 2019 19:50:12 +0000 Subject: BitStream reader: propagate errors The bitstream reader handles errors poorly. This has two effects: * Bugs in file handling (especially modules) manifest as an "unexpected end of file" crash * Users of clang as a library end up aborting because the code unconditionally calls `report_fatal_error` The bitstream reader should be more resilient and return Expected / Error as soon as an error is encountered, not way late like it does now. This patch starts doing so and adopting the error handling where I think it makes sense. There's plenty more to do: this patch propagates errors to be minimally useful, and follow-ups will propagate them further and improve diagnostics. https://bugs.llvm.org/show_bug.cgi?id=42311 Differential Revision: https://reviews.llvm.org/D63518 llvm-svn: 364464 --- clang/lib/Frontend/TestModuleFileExtension.cpp | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'clang/lib/Frontend/TestModuleFileExtension.cpp') diff --git a/clang/lib/Frontend/TestModuleFileExtension.cpp b/clang/lib/Frontend/TestModuleFileExtension.cpp index 561fe10..f8ed341 100644 --- a/clang/lib/Frontend/TestModuleFileExtension.cpp +++ b/clang/lib/Frontend/TestModuleFileExtension.cpp @@ -48,7 +48,12 @@ TestModuleFileExtension::Reader::Reader(ModuleFileExtension *Ext, // Read the extension block. SmallVector Record; while (true) { - llvm::BitstreamEntry Entry = Stream.advanceSkippingSubblocks(); + llvm::Expected MaybeEntry = + Stream.advanceSkippingSubblocks(); + if (!MaybeEntry) + (void)MaybeEntry.takeError(); + llvm::BitstreamEntry Entry = MaybeEntry.get(); + switch (Entry.Kind) { case llvm::BitstreamEntry::SubBlock: case llvm::BitstreamEntry::EndBlock: @@ -61,8 +66,12 @@ TestModuleFileExtension::Reader::Reader(ModuleFileExtension *Ext, Record.clear(); StringRef Blob; - unsigned RecCode = Stream.readRecord(Entry.ID, Record, &Blob); - switch (RecCode) { + Expected MaybeRecCode = + Stream.readRecord(Entry.ID, Record, &Blob); + if (!MaybeRecCode) + fprintf(stderr, "Failed reading rec code: %s\n", + toString(MaybeRecCode.takeError()).c_str()); + switch (MaybeRecCode.get()) { case FIRST_EXTENSION_RECORD_ID: { StringRef Message = Blob.substr(0, Record[0]); fprintf(stderr, "Read extension block message: %s\n", -- cgit v1.1