2d13386783
Delete the output streams coming from CompilerInstance::createOutputFile() and friends once writes are finished. Concretely, replacing `OS->flush()` with `OS.reset()` in: - `ExtractAPIAction::EndSourceFileAction()` - `PrecompiledPreambleAction::setEmittedPreamblePCH()` - `cc1_main()'s support for `-ftime-trace` This fixes theoretical bugs related to proxy streams, which may have cleanups to run in their destructor. For example, a proxy that CompilerInstance sometimes uses is `buffer_ostream`, which wraps a `raw_ostream` lacking pwrite support and adds it. `flush()` does not promise that output is complete; `buffer_ostream` needs to wait until the destructor to forward anything so that it can service later calls to `pwrite()`. If the destructor isn't called then the proxied stream hasn't received any content. This also protects against some logic bugs, triggering a null dereference on a later attempt to write to the stream. No tests, since in practice these particular code paths never use use `buffer_ostream`; you need to be writing a binary file to a pipe (such as stdout) to hit it, but `-extract-api` writes a text file and the other two use computed filenames that will never (in practice) be a pipe. This is effectively NFC, for now. But I have some other patches in the works that add guard rails, crashing if the stream hasn't been destructed by the time the CompilerInstance is told to keep the output file, since in most cases this is a problem. Differential Revision: https://reviews.llvm.org/D124635
//===----------------------------------------------------------------------===// // C Language Family Front-end //===----------------------------------------------------------------------===// Welcome to Clang. This is a compiler front-end for the C family of languages (C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM compiler infrastructure project. Unlike many other compiler frontends, Clang is useful for a number of things beyond just compiling code: we intend for Clang to be host to a number of different source-level tools. One example of this is the Clang Static Analyzer. If you're interested in more (including how to build Clang) it is best to read the relevant web sites. Here are some pointers: Information on Clang: http://clang.llvm.org/ Building and using Clang: http://clang.llvm.org/get_started.html Clang Static Analyzer: http://clang-analyzer.llvm.org/ Information on the LLVM project: http://llvm.org/ If you have questions or comments about Clang, a great place to discuss them is on the Clang forums: https://discourse.llvm.org/c/clang/ If you find a bug in Clang, please file it in the LLVM bug tracker: http://llvm.org/bugs/