In openFileForRead, attempt to fetch the actual name of the file on disk -- including case -- so that clang can later warn about non-portable #include and #import directives.
Differential Revision: http://reviews.llvm.org/D19842
Corresponding clang patch: http://reviews.llvm.org/D19843
Re-commit after addressing issues with of generating too many warnings for Windows and asan test failures
Patch by Eric Niebler
llvm-svn: 272555
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 0ccca59..84aafcb 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -25,6 +25,9 @@
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
@@ -47,6 +50,7 @@
#ifdef __APPLE__
#include <mach-o/dyld.h>
+#include <sys/attr.h>
#endif
// Both stdio.h and cstdio are included via different pathes and
@@ -544,13 +548,47 @@
return std::error_code();
}
-std::error_code openFileForRead(const Twine &Name, int &ResultFD) {
+#if !defined(F_GETPATH)
+static bool hasProcSelfFD() {
+ // If we have a /proc filesystem mounted, we can quickly establish the
+ // real name of the file with readlink
+ static const bool Result = (::access("/proc/self/fd", R_OK) == 0);
+ return Result;
+}
+#endif
+
+std::error_code openFileForRead(const Twine &Name, int &ResultFD,
+ SmallVectorImpl<char> *RealPath) {
SmallString<128> Storage;
StringRef P = Name.toNullTerminatedStringRef(Storage);
while ((ResultFD = open(P.begin(), O_RDONLY)) < 0) {
if (errno != EINTR)
return std::error_code(errno, std::generic_category());
}
+ // Attempt to get the real name of the file, if the user asked
+ if(!RealPath)
+ return std::error_code();
+ RealPath->clear();
+#if defined(F_GETPATH)
+ // When F_GETPATH is availble, it is the quickest way to get
+ // the real path name.
+ char Buffer[MAXPATHLEN];
+ if (::fcntl(ResultFD, F_GETPATH, Buffer) != -1)
+ RealPath->append(Buffer, Buffer + strlen(Buffer));
+#else
+ char Buffer[PATH_MAX];
+ if (hasProcSelfFD()) {
+ char ProcPath[64];
+ snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", ResultFD);
+ ssize_t CharCount = ::readlink(ProcPath, Buffer, sizeof(Buffer));
+ if (CharCount > 0)
+ RealPath->append(Buffer, Buffer + CharCount);
+ } else {
+ // Use ::realpath to get the real path name
+ if (::realpath(P.begin(), Buffer) != nullptr)
+ RealPath->append(Buffer, Buffer + strlen(Buffer));
+ }
+#endif
return std::error_code();
}
@@ -584,6 +622,53 @@
return std::error_code();
}
+std::error_code getPathFromOpenFD(int FD, SmallVectorImpl<char> &ResultPath) {
+ if (FD < 0)
+ return make_error_code(errc::bad_file_descriptor);
+
+#if defined(F_GETPATH)
+ // When F_GETPATH is availble, it is the quickest way to get
+ // the path from a file descriptor.
+ ResultPath.reserve(MAXPATHLEN);
+ if (::fcntl(FD, F_GETPATH, ResultPath.begin()) == -1)
+ return std::error_code(errno, std::generic_category());
+
+ ResultPath.set_size(strlen(ResultPath.begin()));
+#else
+ // If we have a /proc filesystem mounted, we can quickly establish the
+ // real name of the file with readlink. Otherwise, we don't know how to
+ // get the filename from a file descriptor. Give up.
+ if (!fs::hasProcSelfFD())
+ return make_error_code(errc::function_not_supported);
+
+ ResultPath.reserve(PATH_MAX);
+ char ProcPath[64];
+ snprintf(ProcPath, sizeof(ProcPath), "/proc/self/fd/%d", FD);
+ ssize_t CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
+ if (CharCount < 0)
+ return std::error_code(errno, std::generic_category());
+
+ // Was the filename truncated?
+ if (static_cast<size_t>(CharCount) == ResultPath.capacity()) {
+ // Use lstat to get the size of the filename
+ struct stat sb;
+ if (::lstat(ProcPath, &sb) < 0)
+ return std::error_code(errno, std::generic_category());
+
+ ResultPath.reserve(sb.st_size + 1);
+ CharCount = ::readlink(ProcPath, ResultPath.begin(), ResultPath.capacity());
+ if (CharCount < 0)
+ return std::error_code(errno, std::generic_category());
+
+ // Test for race condition: did the link size change?
+ if (CharCount > sb.st_size)
+ return std::error_code(ENAMETOOLONG, std::generic_category());
+ }
+ ResultPath.set_size(static_cast<size_t>(CharCount));
+#endif
+ return std::error_code();
+}
+
} // end namespace fs
namespace path {