Compilation database might have empty string as a command line argument.
But ExpandResponseFilesDatabase::expand doesn't expect this and assumes
that string.front() can be used for any argument. It is undefined behaviour if
string is empty. With debug build mode it causes crash in clangd.
Test Plan: check-clang
Differential Revision: https://reviews.llvm.org/D105120
CommandLine.h is indirectly included in ~50% of TUs when building
clang, and VirtualFileSystem.h is large.
(Already remarked by jhenderson on D70769.)
No behavior change.
Differential Revision: https://reviews.llvm.org/D100957
Summary:
This is a follow-up to D70769 and D70222, which allows propagation of
current directory down to ExpandResponseFiles for handling of relative paths.
Previously clients had to mutate FS to achieve that, which is not thread-safe
and can even be thread-hostile in the case of real file system.
Reviewers: sammccall
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D70857
Dmitry Polukhin