[llvm] [z/OS] Add z/OS archive reading support (PR #187110)

[James Henderson via llvm-commits]

================
@@ -368,6 +373,118 @@ Expected<uint64_t> BigArchiveMemberHeader::getSize() const {
   return *SizeOrErr + alignTo(*NameLenOrErr, 2);
 }
 
+template <std::size_t N>
+StringRef getFieldRawStringE2A(const char (&Field)[N], SmallString<64> &Dst) {
+  Dst.clear();
+  StringRef Src = StringRef(Field, N);
+  ConverterEBCDIC::convertToUTF8(Src, Dst);
+  return Dst.str().rtrim(" ");
+}
+
+ZOSArchiveMemberHeader::ZOSArchiveMemberHeader(const Archive *Parent,
+                                               const char *RawHeaderPtr,
+                                               uint64_t Size, Error *Err)
+    : ArchiveMemberHeader(Parent, RawHeaderPtr, Size, Err) {
+  ErrorAsOutParameter ErrAsOutParam(Err);
+  setMemberHeaderStrings(Err, Size);
+}
+
+Expected<uint64_t> ZOSArchiveMemberHeader::getSize() const {
+  SmallString<64> Dst;
+  return getArchiveMemberDecField(
+      "size", getFieldRawStringE2A(ArMemHdr->Size, Dst), Parent, this);
+}
+
+Expected<StringRef> ZOSArchiveMemberHeader::getRawName() const {
+  return StringRef(RawMemberName);
+}
+
+Expected<StringRef> ZOSArchiveMemberHeader::getName(uint64_t Size) const {
+  return StringRef(MemberName);
+}
+
+StringRef ZOSArchiveMemberHeader::getRawAccessMode() const {
+  return StringRef(AccessMode);
+}
+
+StringRef ZOSArchiveMemberHeader::getRawLastModified() const {
+  return StringRef(LastModified);
+}
+
+StringRef ZOSArchiveMemberHeader::getRawUID() const { return StringRef(UID); }
+
+StringRef ZOSArchiveMemberHeader::getRawGID() const { return StringRef(GID); }
+
+void ZOSArchiveMemberHeader::setMemberHeaderStrings(Error *Err, uint64_t Size) {
+  SmallString<64> Dst;
+  uint64_t Offset =
+      reinterpret_cast<const char *>(ArMemHdr) - Parent->getData().data();
+
+  // Set RawMemberName.
+  StringRef RawNameSR = getFieldRawStringE2A(ArMemHdr->Name, Dst);
+  if (RawNameSR.empty() || RawNameSR[0] == ' ') {
+    *Err = malformedError("name contains a leading space for archive member "
+                          "header at offset " +
+                          Twine(Offset));
+    return;
+  }
+  RawMemberName.append(RawNameSR);
+
+  // Set MemberName.
+  if (RawNameSR.starts_with("#1/")) {
+    Expected<StringRef> NameOrErr = ArchiveMemberHeader::getName(Size);
+    if (!NameOrErr) {
+      *Err = NameOrErr.takeError();
+      return;
+    }
+    StringRef Name = NameOrErr.get();
+    Dst.clear();
+    ConverterEBCDIC::convertToUTF8(Name, Dst);
+    MemberName.append(Dst.str());
+  } else
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jh7370 wrote:

Nit: LLVM coding standards say that if curly braces are needed for one part of an if/else chain, they should be used for all parts.

https://github.com/llvm/llvm-project/pull/187110