From a2ed0b0babca5c82ac547feb1502e7392db98066 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 8 Jul 2015 20:47:32 +0000
Subject: Start adding support for writing archives in BSD format.

No support for the symbol table yet (but will hopefully add it today).
We always use the long filename format so that we can align the member,
which is an advantage of the BSD format.

llvm-svn: 241721
---
 llvm/lib/Object/ArchiveWriter.cpp | 40 +++++++++++++++++++++++++++++----------
 1 file changed, 30 insertions(+), 10 deletions(-)

(limited to 'llvm/lib/Object/ArchiveWriter.cpp')

diff --git a/llvm/lib/Object/ArchiveWriter.cpp b/llvm/lib/Object/ArchiveWriter.cpp
index 41c82e7da74..99706a9bd5b 100644
--- a/llvm/lib/Object/ArchiveWriter.cpp
+++ b/llvm/lib/Object/ArchiveWriter.cpp
@@ -117,10 +117,25 @@ static void printMemberHeader(raw_fd_ostream &Out, StringRef Name,
 }
 
 static void
-printMemberHeader(raw_fd_ostream &Out, StringRef Name,
+printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind,
+                  StringRef Name,
                   std::vector<unsigned>::iterator &StringMapIndexIter,
                   const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
                   unsigned Perms, unsigned Size) {
+  if (Kind == object::Archive::K_BSD) {
+    uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
+    // Pad so that even 64 bit object files are aligned.
+    unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
+    unsigned NameWithPadding = Name.size() + Pad;
+    printWithSpacePadding(Out, Twine("#1/") + Twine(NameWithPadding), 16);
+    printRestOfMemberHeader(Out, ModTime, UID, GID, Perms,
+                            NameWithPadding + Size);
+    Out << Name;
+    assert(PosAfterHeader == Out.tell());
+    while (Pad--)
+      Out.write(uint8_t(0));
+    return;
+  }
   if (Name.size() < 16) {
     printMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
     return;
@@ -160,9 +175,13 @@ static void writeStringTable(raw_fd_ostream &Out,
 
 // Returns the offset of the first reference to a member offset.
 static ErrorOr<unsigned>
-writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
+writeSymbolTable(raw_fd_ostream &Out, object::Archive::Kind Kind,
+                 ArrayRef<NewArchiveIterator> Members,
                  ArrayRef<MemoryBufferRef> Buffers,
                  std::vector<unsigned> &MemberOffsetRefs) {
+  if (Kind != object::Archive::K_GNU)
+    return 0;
+
   unsigned StartOffset = 0;
   unsigned MemberNum = 0;
   std::string NameBuf;
@@ -222,7 +241,7 @@ writeSymbolTable(raw_fd_ostream &Out, ArrayRef<NewArchiveIterator> Members,
 std::pair<StringRef, std::error_code>
 llvm::writeArchive(StringRef ArcName,
                    std::vector<NewArchiveIterator> &NewMembers,
-                   bool WriteSymtab) {
+                   bool WriteSymtab, object::Archive::Kind Kind) {
   SmallString<128> TmpArchive;
   int TmpArchiveFD;
   if (auto EC = sys::fs::createUniqueFile(ArcName + ".temp-archive-%%%%%%%.a",
@@ -274,14 +293,15 @@ llvm::writeArchive(StringRef ArcName,
   unsigned MemberReferenceOffset = 0;
   if (WriteSymtab) {
     ErrorOr<unsigned> MemberReferenceOffsetOrErr =
-        writeSymbolTable(Out, NewMembers, Members, MemberOffsetRefs);
+        writeSymbolTable(Out, Kind, NewMembers, Members, MemberOffsetRefs);
     if (auto EC = MemberReferenceOffsetOrErr.getError())
       return std::make_pair(ArcName, EC);
     MemberReferenceOffset = MemberReferenceOffsetOrErr.get();
   }
 
   std::vector<unsigned> StringMapIndexes;
-  writeStringTable(Out, NewMembers, StringMapIndexes);
+  if (Kind != object::Archive::K_BSD)
+    writeStringTable(Out, NewMembers, StringMapIndexes);
 
   unsigned MemberNum = 0;
   unsigned NewMemberNum = 0;
@@ -296,13 +316,13 @@ llvm::writeArchive(StringRef ArcName,
     if (I.isNewMember()) {
       StringRef FileName = I.getNew();
       const sys::fs::file_status &Status = NewMemberStatus[NewMemberNum++];
-      printMemberHeader(Out, sys::path::filename(FileName), StringMapIndexIter,
-                        Status.getLastModificationTime(), Status.getUser(),
-                        Status.getGroup(), Status.permissions(),
-                        Status.getSize());
+      printMemberHeader(Out, Kind, sys::path::filename(FileName),
+                        StringMapIndexIter, Status.getLastModificationTime(),
+                        Status.getUser(), Status.getGroup(),
+                        Status.permissions(), Status.getSize());
     } else {
       object::Archive::child_iterator OldMember = I.getOld();
-      printMemberHeader(Out, I.getName(), StringMapIndexIter,
+      printMemberHeader(Out, Kind, I.getName(), StringMapIndexIter,
                         OldMember->getLastModified(), OldMember->getUID(),
                         OldMember->getGID(), OldMember->getAccessMode(),
                         OldMember->getSize());
-- 
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