From 879c15e890b4d25d28ea904e92497f091f796019 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Martin=20Storsj=C3=B6?= Date: Thu, 3 Dec 2020 11:20:57 +0200 Subject: [PATCH] [llvm-rc] Handle driveless absolute windows paths when loading external files When llvm-rc loads an external file, it looks for it relative to a number of include directories and the current working directory. If the path is considered absolute, llvm-rc tries to open the filename as such, and doesn't try to open it relative to other paths. On Windows, a path name like "\dir\file" isn't considered absolute as it lacks the drive name, but by appending it on top of the search dirs, it's not found. LLVM's sys::path::append just appends such a path (same with a properly absolute posix path) after the paths it's supposed to be relative to. This fix doesn't handle the case if the resource script and the external file are on a different drive than the current working directory; to fix that, we'd have to make LLVM's sys::path::append handle appending fully absolute and partially absolute paths (ones lacking a drive prefix but containing a root directory), or switch to C++17's std::filesystem. Differential Revision: https://reviews.llvm.org/D92558 --- llvm/test/tools/llvm-rc/absolute.test | 4 ++++ llvm/tools/llvm-rc/ResourceFileWriter.cpp | 12 ++++++++++-- 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/llvm/test/tools/llvm-rc/absolute.test b/llvm/test/tools/llvm-rc/absolute.test index 95aff3e..fd8b2d6 100644 --- a/llvm/test/tools/llvm-rc/absolute.test +++ b/llvm/test/tools/llvm-rc/absolute.test @@ -1,3 +1,7 @@ ; RUN: touch %t.manifest ; RUN: echo "1 24 \"%t.manifest\"" > %t.rc ; RUN: llvm-rc -- %t.rc +;; On Windows, try stripping out the drive name from the absolute path, +;; and make sure the path still is found. +; RUN: cat %t.rc | sed 's/"[a-zA-Z]:/"/' > %t2.rc +; RUN: llvm-rc -- %t2.rc diff --git a/llvm/tools/llvm-rc/ResourceFileWriter.cpp b/llvm/tools/llvm-rc/ResourceFileWriter.cpp index c80605a..553bb75 100644 --- a/llvm/tools/llvm-rc/ResourceFileWriter.cpp +++ b/llvm/tools/llvm-rc/ResourceFileWriter.cpp @@ -1514,8 +1514,16 @@ ResourceFileWriter::loadFile(StringRef File) const { SmallString<128> Cwd; std::unique_ptr Result; - // 0. The file path is absolute and the file exists. - if (sys::path::is_absolute(File)) + // 0. The file path is absolute or has a root directory, so we shouldn't + // try to append it on top of other base directories. (An absolute path + // must have a root directory, but e.g. the path "\dir\file" on windows + // isn't considered absolute, but it does have a root directory. As long as + // sys::path::append doesn't handle appending an absolute path or a path + // starting with a root directory on top of a base, we must handle this + // case separately at the top. C++17's path::append handles that case + // properly though, so if using that to append paths below, this early + // exception case could be removed.) + if (sys::path::has_root_directory(File)) return errorOrToExpected(MemoryBuffer::getFile(File, -1, false)); // 1. The current working directory. -- 2.7.4