r368322 - clang: Diag running out of file handles while looking for files
Nico Weber via cfe-commits
cfe-commits at lists.llvm.org
Thu Aug 8 10:58:32 PDT 2019
Author: nico
Date: Thu Aug 8 10:58:32 2019
New Revision: 368322
URL: http://llvm.org/viewvc/llvm-project?rev=368322&view=rev
Log:
clang: Diag running out of file handles while looking for files
clang would only print "file not found" when it's unable to find a
header file. If the reason for that is a file handle leak, that's not a
very useful error message. For errors that aren't in a small whitelist
("file not found", "file is directory"), print an error with the
strerror() output.
This changes behavior in corner cases: If clang was out of file handles
while looking in one -I dir but then suddenly wasn't when looking in the
next -I dir, and both directories contained a file with the desired
name, previously we'd silently return the file from the second
directory. For this reason, it's important to ignore "is a directory"
for this new diag: if a file foo/foo exists and -I -Ifoo are passed, an
include of "foo" should successfully open file "foo" in directory "foo/"
instead of complaining that "./foo" is a directory.
No test since we mostly hit this when there's a handle leak somewhere,
and currently there isn't one. I manually tested this with the repro
steps in comment 2 on the bug below.
Fixes PR42524.
Differential Revision: https://reviews.llvm.org/D65956
Modified:
cfe/trunk/lib/Lex/HeaderSearch.cpp
Modified: cfe/trunk/lib/Lex/HeaderSearch.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Lex/HeaderSearch.cpp?rev=368322&r1=368321&r2=368322&view=diff
==============================================================================
--- cfe/trunk/lib/Lex/HeaderSearch.cpp (original)
+++ cfe/trunk/lib/Lex/HeaderSearch.cpp Thu Aug 8 10:58:32 2019
@@ -309,9 +309,18 @@ const FileEntry *HeaderSearch::getFileAn
ModuleMap::KnownHeader *SuggestedModule) {
// If we have a module map that might map this header, load it and
// check whether we'll have a suggestion for a module.
- auto File = getFileMgr().getFile(FileName, /*OpenFile=*/true);
- if (!File)
+ llvm::ErrorOr<const FileEntry *> File =
+ getFileMgr().getFile(FileName, /*OpenFile=*/true);
+ if (!File) {
+ // For rare, surprising errors (e.g. "out of file handles"), diag the EC
+ // message.
+ std::error_code EC = File.getError();
+ if (EC != std::errc::no_such_file_or_directory &&
+ EC != std::errc::is_a_directory) {
+ Diags.Report(IncludeLoc, diag::err_cannot_open_file) << EC.message();
+ }
return nullptr;
+ }
// If there is a module that corresponds to this header, suggest it.
if (!findUsableModuleForHeader(*File, Dir ? Dir : (*File)->getDir(),
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