Revert "[llvm-ar] Fix relative thin archive path handling"

This reverts commit r362407.  It broke compilation of
llvm/lib/Object/ArchiveWriter.cpp:

error: type 'llvm::sys::path::const_iterator' does not provide a call
operator

llvm-svn: 362413

1 files changed, 17 insertions, 34 deletions

diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp
index 68c40054bb9..849d2835772 100644
--- a/llvm/lib/Object/ArchiveWriter.cpp
+++ b/llvm/lib/Object/ArchiveWriter.cpp
@@ -494,46 +494,29 @@ computeMemberData(raw_ostream &StringTable, raw_ostream &SymNames,
 }
 
 namespace llvm {
-
-static ErrorOr<SmallString<128>> canonicalizePath(StringRef P) {
-  SmallString<128> Ret = P;
-  std::error_code Err = sys::fs::make_absolute(Ret);
-  if (Err)
-    return Err;
-  sys::path::remove_dots(Ret, /*removedotdot*/ true);
-  return Ret;
-}
-
 // Compute the relative path from From to To.
-Expected<std::string> computeArchiveRelativePath(StringRef From, StringRef To) {
-  ErrorOr<SmallString<128>> PathToOrErr = canonicalizePath(To);
-  ErrorOr<SmallString<128>> DirFromOrErr = canonicalizePath(From);
-  if (!PathToOrErr || !DirFromOrErr)
-    return errorCodeToError(std::error_code(errno, std::generic_category()));
-
-  const SmallString<128> &PathTo = *PathToOrErr;
-  const SmallString<128> &DirFrom = sys::path::parent_path(*DirFromOrErr);
-
-  // Can't construct a relative path between different roots
-  if (sys::path::root_name(PathTo) != sys::path::root_name(DirFrom))
-    return sys::path::convert_to_slash(PathTo);
-
-  // Skip common prefixes
-  auto FromTo =
-      std::mismatch(sys::path::begin(DirFrom), sys::path::end(DirFrom),
-                    sys::path::begin(PathTo), sys::path::end(PathTo));
-  auto FromI = FromTo.first;
-  auto ToI = FromTo.second;
+std::string computeArchiveRelativePath(StringRef From, StringRef To) {
+  if (sys::path::is_absolute(From) || sys::path::is_absolute(To))
+    return To;
+
+  StringRef DirFrom = sys::path::parent_path(From);
+  auto FromI = sys::path::begin(DirFrom);
+  auto ToI = sys::path::begin(To);
+  while (*FromI == *ToI) {
+    ++FromI;
+    ++ToI;
+  }
 
-  // Construct relative path
   SmallString<128> Relative;
   for (auto FromE = sys::path::end(DirFrom); FromI != FromE; ++FromI)
-    sys::path::append(Relative, sys::path::Style::posix, "..");
+    sys::path::append(Relative, "..");
 
-  for (auto ToE = sys::path::end(PathTo); ToI != ToE; ++ToI)
-    sys::path::append(Relative, sys::path::Style::posix, *ToI);
+  for (auto ToE = sys::path::end(To); ToI != ToE; ++ToI)
+    sys::path::append(Relative, *ToI);
 
-  return Relative.str();
+  // Replace backslashes with slashes so that the path is portable between *nix
+  // and Windows.
+  return sys::path::convert_to_slash(Relative);
 }
 
 Error writeArchive(StringRef ArcName, ArrayRef<NewArchiveMember> NewMembers,