47721d4618
Improve the chance of resolving file/line breakpoints by realpath'ing the support files before doing a second match attempt, with some conditions applied. A working [hello-world example](https://github.com/royitaqi/lldb_demos/blob/main/realpath/README.md). See [patch](https://github.com/llvm/llvm-project/pull/102223) for more info about problem/motivation, details of the feature, new settings, telemetries and tests.
71 lines
2.6 KiB
C++
71 lines
2.6 KiB
C++
//===-- RealpathPrefixes.cpp ----------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "lldb/Utility/RealpathPrefixes.h"
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#include "lldb/Utility/FileSpec.h"
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#include "lldb/Utility/FileSpecList.h"
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#include "lldb/Utility/LLDBLog.h"
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#include "lldb/Utility/Log.h"
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using namespace lldb_private;
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RealpathPrefixes::RealpathPrefixes(
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const FileSpecList &file_spec_list,
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llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs)
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: m_fs(fs) {
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m_prefixes.reserve(file_spec_list.GetSize());
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for (const FileSpec &file_spec : file_spec_list) {
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m_prefixes.emplace_back(file_spec.GetPath());
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}
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}
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std::optional<FileSpec>
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RealpathPrefixes::ResolveSymlinks(const FileSpec &file_spec) {
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if (m_prefixes.empty())
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return std::nullopt;
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// Test if `b` is a *path* prefix of `a` (not just *string* prefix).
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// E.g. "/foo/bar" is a path prefix of "/foo/bar/baz" but not "/foo/barbaz".
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auto is_path_prefix = [](llvm::StringRef a, llvm::StringRef b,
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bool case_sensitive,
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llvm::sys::path::Style style) -> bool {
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if (case_sensitive ? a.consume_front(b) : a.consume_front_insensitive(b))
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// If `b` isn't "/", then it won't end with "/" because it comes from
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// `FileSpec`. After `a` consumes `b`, `a` should either be empty (i.e.
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// `a` == `b`) or end with "/" (the remainder of `a` is a subdirectory).
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return b == "/" || a.empty() ||
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llvm::sys::path::is_separator(a[0], style);
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return false;
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};
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std::string file_spec_path = file_spec.GetPath();
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for (const std::string &prefix : m_prefixes) {
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if (is_path_prefix(file_spec_path, prefix, file_spec.IsCaseSensitive(),
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file_spec.GetPathStyle())) {
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// Stats and logging.
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IncreaseSourceRealpathAttemptCount();
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Log *log = GetLog(LLDBLog::Source);
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LLDB_LOGF(log, "Realpath'ing support file %s", file_spec_path.c_str());
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// One prefix matched. Try to realpath.
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llvm::SmallString<PATH_MAX> buff;
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std::error_code ec = m_fs->getRealPath(file_spec_path, buff);
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if (ec)
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return std::nullopt;
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FileSpec realpath(buff, file_spec.GetPathStyle());
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// Only return realpath if it is different from the original file_spec.
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if (realpath != file_spec)
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return realpath;
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return std::nullopt;
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}
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}
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// No prefix matched
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return std::nullopt;
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}
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