From 6a13a4e3f29fc4ce5eff96d74ba965c9fdc02184 Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Thu, 6 Aug 2020 18:44:50 +0100 Subject: [PATCH] libstdc++: Fix unnecessary allocations in read_symlink [PR 96484] libstdc++-v3/ChangeLog: PR libstdc++/96484 * src/c++17/fs_ops.cc (fs::read_symlink): Return an error immediately for non-symlinks. * src/filesystem/ops.cc (fs::read_symlink): Likewise. --- libstdc++-v3/src/c++17/fs_ops.cc | 6 ++++++ libstdc++-v3/src/filesystem/ops.cc | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/libstdc++-v3/src/c++17/fs_ops.cc b/libstdc++-v3/src/c++17/fs_ops.cc index 873f93aacfc..c685b1824f9 100644 --- a/libstdc++-v3/src/c++17/fs_ops.cc +++ b/libstdc++-v3/src/c++17/fs_ops.cc @@ -1180,6 +1180,12 @@ fs::path fs::read_symlink(const path& p, error_code& ec) ec.assign(errno, std::generic_category()); return result; } + else if (!fs::is_symlink(make_file_status(st))) + { + ec.assign(EINVAL, std::generic_category()); + return result; + } + std::string buf(st.st_size ? st.st_size + 1 : 128, '\0'); do { diff --git a/libstdc++-v3/src/filesystem/ops.cc b/libstdc++-v3/src/filesystem/ops.cc index 29ea9c0ce87..8c8854bf28e 100644 --- a/libstdc++-v3/src/filesystem/ops.cc +++ b/libstdc++-v3/src/filesystem/ops.cc @@ -998,6 +998,12 @@ fs::path fs::read_symlink(const path& p [[gnu::unused]], error_code& ec) ec.assign(errno, std::generic_category()); return result; } + else if (!fs::is_symlink(make_file_status(st))) + { + ec.assign(EINVAL, std::generic_category()); + return result; + } + std::string buf(st.st_size ? st.st_size + 1 : 128, '\0'); do { -- 2.30.2