diff options
author | Fangrui Song <i@maskray.me> | 2021-09-09 09:27:14 -0700 |
---|---|---|
committer | Fangrui Song <i@maskray.me> | 2021-09-09 09:27:14 -0700 |
commit | 0db402c5b4ef60ca8d20dda8bb59c7288a534e2a (patch) | |
tree | 93e760672d597379d475b037382ebad27e5e0450 /lld/Common | |
parent | 0782e55c26bf56cd28c26793920fa37883bcf689 (diff) | |
download | llvm-0db402c5b4ef60ca8d20dda8bb59c7288a534e2a.tar.gz |
[lld] Buffer writes when composing a single diagnostic
llvm::errs() is unbuffered. On a POSIX platform, composing a diagnostic
string may invoke the ::write syscall multiple times, which can be slow.
Buffer writes to a temporary SmallString when composing a single diagnostic to
reduce the number of ::write syscalls to one (also easier to read under
strace/truss).
For an invocation of ld.lld with 62000+ lines of
`ld.lld: warning: symbol ordering file: no such symbol: ` warnings (D87121),
the buffering decreases the write time from 1s to 0.4s (for /dev/tty) and
from 0.4s to 0.1s (for a tmpfs file). This can speed up
`relocation R_X86_64_PC32 out of range` diagnostic printing as well
with `--noinhibit-exec --no-fatal-warnings`.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D87272
Diffstat (limited to 'lld/Common')
-rw-r--r-- | lld/Common/ErrorHandler.cpp | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/lld/Common/ErrorHandler.cpp b/lld/Common/ErrorHandler.cpp index 269a0f62ec65..c8c5ffed7126 100644 --- a/lld/Common/ErrorHandler.cpp +++ b/lld/Common/ErrorHandler.cpp @@ -168,11 +168,28 @@ std::string ErrorHandler::getLocation(const Twine &msg) { return std::string(logName); } +void ErrorHandler::reportDiagnostic(StringRef location, Colors c, + StringRef diagKind, const Twine &msg) { + SmallString<256> buf; + raw_svector_ostream os(buf); + os << sep << location << ": "; + if (!diagKind.empty()) { + if (lld::errs().colors_enabled()) { + os.enable_colors(true); + os << c << diagKind << ": " << Colors::RESET; + } else { + os << diagKind << ": "; + } + } + os << msg << '\n'; + lld::errs() << buf; +} + void ErrorHandler::log(const Twine &msg) { if (!verbose || disableOutput) return; std::lock_guard<std::mutex> lock(mu); - lld::errs() << logName << ": " << msg << "\n"; + reportDiagnostic(logName, Colors::RESET, "", msg); } void ErrorHandler::message(const Twine &msg) { @@ -190,8 +207,7 @@ void ErrorHandler::warn(const Twine &msg) { } std::lock_guard<std::mutex> lock(mu); - lld::errs() << sep << getLocation(msg) << ": " << Colors::MAGENTA - << "warning: " << Colors::RESET << msg << "\n"; + reportDiagnostic(getLocation(msg), Colors::MAGENTA, "warning", msg); sep = getSeparator(msg); } @@ -217,12 +233,9 @@ void ErrorHandler::error(const Twine &msg) { std::lock_guard<std::mutex> lock(mu); if (errorLimit == 0 || errorCount < errorLimit) { - lld::errs() << sep << getLocation(msg) << ": " << Colors::RED - << "error: " << Colors::RESET << msg << "\n"; + reportDiagnostic(getLocation(msg), Colors::RED, "error", msg); } else if (errorCount == errorLimit) { - lld::errs() << sep << getLocation(msg) << ": " << Colors::RED - << "error: " << Colors::RESET << errorLimitExceededMsg - << "\n"; + reportDiagnostic(logName, Colors::RED, "error", errorLimitExceededMsg); exit = exitEarly; } |