[Object] Replace TimeValue with std::chrono

Summary:
Most of the changes are very straight-forward. The only choice I had to make was
to use second-precision time points in the Archive classes. I did this because
the archive files use that precision in the on-disk representation anyway.

Reviewers: rafael, zturner

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25773

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284974 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Object/Archive.h

@@ -18,11 +18,11 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Object/Binary.h"
+#include "llvm/Support/Chrono.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/TimeValue.h"
 
 namespace llvm {
 namespace object {
@@ -46,7 +46,7 @@ public:
   Expected<uint32_t> getSize() const;
 
   Expected<sys::fs::perms> getAccessMode() const;
-  Expected<sys::TimeValue> getLastModified() const;
+  Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const;
   llvm::StringRef getRawLastModified() const {
     return StringRef(ArMemHdr->LastModified,
                      sizeof(ArMemHdr->LastModified)).rtrim(' ');
@@ -103,7 +103,7 @@ public:
     Expected<StringRef> getName() const;
     Expected<std::string> getFullName() const;
     Expected<StringRef> getRawName() const { return Header.getRawName(); }
-    Expected<sys::TimeValue> getLastModified() const {
+    Expected<sys::TimePoint<std::chrono::seconds>> getLastModified() const {
       return Header.getLastModified();
     }
     StringRef getRawLastModified() const {

include/llvm/Object/ArchiveWriter.h

@@ -22,7 +22,7 @@ namespace llvm {
 
 struct NewArchiveMember {
   std::unique_ptr<MemoryBuffer> Buf;
-  sys::TimeValue ModTime = sys::TimeValue::PosixZeroTime();
+  sys::TimePoint<std::chrono::seconds> ModTime;
   unsigned UID = 0, GID = 0, Perms = 0644;
 
   NewArchiveMember() = default;

lib/Object/Archive.cpp

@@ -239,7 +239,8 @@ Expected<sys::fs::perms> ArchiveMemberHeader::getAccessMode() const {
   return static_cast<sys::fs::perms>(Ret);
 }
 
-Expected<sys::TimeValue> ArchiveMemberHeader::getLastModified() const {
+Expected<sys::TimePoint<std::chrono::seconds>>
+ArchiveMemberHeader::getLastModified() const {
   unsigned Seconds;
   if (StringRef(ArMemHdr->LastModified,
                 sizeof(ArMemHdr->LastModified)).rtrim(' ')
@@ -256,9 +257,7 @@ Expected<sys::TimeValue> ArchiveMemberHeader::getLastModified() const {
                           "archive member header at offset " + Twine(Offset));
   }
 
-  sys::TimeValue Ret;
-  Ret.fromEpochTime(Seconds);
-  return Ret;
+  return sys::toTimePoint(Seconds);
 }
 
 Expected<unsigned> ArchiveMemberHeader::getUID() const {

lib/Object/ArchiveWriter.cpp

@@ -47,7 +47,7 @@ NewArchiveMember::getOldMember(const object::Archive::Child &OldMember,
   NewArchiveMember M;
   M.Buf = MemoryBuffer::getMemBuffer(*BufOrErr, false);
   if (!Deterministic) {
-    Expected<sys::TimeValue> ModTimeOrErr = OldMember.getLastModified();
+    auto ModTimeOrErr = OldMember.getLastModified();
     if (!ModTimeOrErr)
       return ModTimeOrErr.takeError();
     M.ModTime = ModTimeOrErr.get();
@@ -95,7 +95,8 @@ Expected<NewArchiveMember> NewArchiveMember::getFile(StringRef FileName,
   NewArchiveMember M;
   M.Buf = std::move(*MemberBufferOrErr);
   if (!Deterministic) {
-    M.ModTime = Status.getLastModificationTime();
+    M.ModTime = std::chrono::time_point_cast<std::chrono::seconds>(
+        Status.getLastModificationTime());
     M.UID = Status.getUser();
     M.GID = Status.getGroup();
     M.Perms = Status.permissions();
@@ -127,11 +128,10 @@ static void print32(raw_ostream &Out, object::Archive::Kind Kind,
     support::endian::Writer<support::little>(Out).write(Val);
 }
 
-static void printRestOfMemberHeader(raw_fd_ostream &Out,
-                                    const sys::TimeValue &ModTime, unsigned UID,
-                                    unsigned GID, unsigned Perms,
-                                    unsigned Size) {
-  printWithSpacePadding(Out, ModTime.toEpochTime(), 12);
+static void printRestOfMemberHeader(
+    raw_fd_ostream &Out, const sys::TimePoint<std::chrono::seconds> &ModTime,
+    unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
+  printWithSpacePadding(Out, sys::toTimeT(ModTime), 12);
   printWithSpacePadding(Out, UID, 6, true);
   printWithSpacePadding(Out, GID, 6, true);
   printWithSpacePadding(Out, format("%o", Perms), 8);
@@ -139,17 +139,20 @@ static void printRestOfMemberHeader(raw_fd_ostream &Out,
   Out << "`\n";
 }
 
-static void printGNUSmallMemberHeader(raw_fd_ostream &Out, StringRef Name,
-                                      const sys::TimeValue &ModTime,
-                                      unsigned UID, unsigned GID,
-                                      unsigned Perms, unsigned Size) {
+static void
+printGNUSmallMemberHeader(raw_fd_ostream &Out, StringRef Name,
+                          const sys::TimePoint<std::chrono::seconds> &ModTime,
+                          unsigned UID, unsigned GID, unsigned Perms,
+                          unsigned Size) {
   printWithSpacePadding(Out, Twine(Name) + "/", 16);
   printRestOfMemberHeader(Out, ModTime, UID, GID, Perms, Size);
 }
 
-static void printBSDMemberHeader(raw_fd_ostream &Out, StringRef Name,
-                                 const sys::TimeValue &ModTime, unsigned UID,
-                                 unsigned GID, unsigned Perms, unsigned Size) {
+static void
+printBSDMemberHeader(raw_fd_ostream &Out, StringRef Name,
+                     const sys::TimePoint<std::chrono::seconds> &ModTime,
+                     unsigned UID, unsigned GID, unsigned Perms,
+                     unsigned Size) {
   uint64_t PosAfterHeader = Out.tell() + 60 + Name.size();
   // Pad so that even 64 bit object files are aligned.
   unsigned Pad = OffsetToAlignment(PosAfterHeader, 8);
@@ -171,8 +174,8 @@ static void
 printMemberHeader(raw_fd_ostream &Out, object::Archive::Kind Kind, bool Thin,
                   StringRef Name,
                   std::vector<unsigned>::iterator &StringMapIndexIter,
-                  const sys::TimeValue &ModTime, unsigned UID, unsigned GID,
-                  unsigned Perms, unsigned Size) {
+                  const sys::TimePoint<std::chrono::seconds> &ModTime,
+                  unsigned UID, unsigned GID, unsigned Perms, unsigned Size) {
   if (Kind == object::Archive::K_BSD)
     return printBSDMemberHeader(Out, Name, ModTime, UID, GID, Perms, Size);
   if (!useStringTable(Thin, Name))
@@ -239,12 +242,12 @@ static void writeStringTable(raw_fd_ostream &Out, StringRef ArcName,
   Out.seek(Pos);
 }
 
-static sys::TimeValue now(bool Deterministic) {
+static sys::TimePoint<std::chrono::seconds> now(bool Deterministic) {
+  using namespace std::chrono;
+
   if (!Deterministic)
-    return sys::TimeValue::now();
-  sys::TimeValue TV;
-  TV.fromEpochTime(0);
-  return TV;
+    return time_point_cast<seconds>(system_clock::now());
+  return sys::TimePoint<seconds>();
 }
 
 // Returns the offset of the first reference to a member offset.

tools/llvm-ar/llvm-ar.cpp

@@ -528,7 +528,7 @@ static InsertAction computeInsertAction(ArchiveOperation Operation,
     failIfError(sys::fs::status(*MI, Status), *MI);
     auto ModTimeOrErr = Member.getLastModified();
     failIfError(ModTimeOrErr.takeError());
-    if (sys::TimeValue(Status.getLastModificationTime()) < ModTimeOrErr.get()) {
+    if (Status.getLastModificationTime() < ModTimeOrErr.get()) {
       if (PosName.empty())
         return IA_AddOldMember;
       return IA_MoveOldMember;