[llvm] [GOFF] Refactor writing GOFF records (PR #93855)

[Kevin P. Neal via llvm-commits]

================
@@ -185,81 +158,71 @@ class GOFFState {
             yaml::ErrorHandler ErrHandler)
       : GW(OS), Doc(Doc), ErrHandler(ErrHandler), HasError(false) {}
 
-  ~GOFFState() { GW.finalize(); }
-
   bool writeObject();
 
 public:
   static bool writeGOFF(raw_ostream &OS, GOFFYAML::Object &Doc,
                         yaml::ErrorHandler ErrHandler);
 
 private:
-  GOFFOstream GW;
+  GOFFOStream GW;
   GOFFYAML::Object &Doc;
   yaml::ErrorHandler ErrHandler;
   bool HasError;
 };
 
-void GOFFState::writeHeader(GOFFYAML::FileHeader &FileHdr) {
-  SmallString<16> CCSIDName;
-  if (std::error_code EC =
-          ConverterEBCDIC::convertToEBCDIC(FileHdr.CharacterSetName, CCSIDName))
-    reportError("Conversion error on " + FileHdr.CharacterSetName);
-  if (CCSIDName.size() > 16) {
-    reportError("CharacterSetName too long");
-    CCSIDName.resize(16);
-  }
-  SmallString<16> LangProd;
-  if (std::error_code EC = ConverterEBCDIC::convertToEBCDIC(
-          FileHdr.LanguageProductIdentifier, LangProd))
-    reportError("Conversion error on " + FileHdr.LanguageProductIdentifier);
-  if (LangProd.size() > 16) {
-    reportError("LanguageProductIdentifier too long");
-    LangProd.resize(16);
-  }
-
-  GW.makeNewRecord(GOFF::RT_HDR, GOFF::PayloadLength);
-  GW << binaryBe(FileHdr.TargetEnvironment)     // TargetEnvironment
-     << binaryBe(FileHdr.TargetOperatingSystem) // TargetOperatingSystem
-     << zeros(2)                                // Reserved
-     << binaryBe(FileHdr.CCSID)                 // CCSID
-     << CCSIDName                               // CharacterSetName
-     << zeros(16 - CCSIDName.size())            // Fill bytes
-     << LangProd                                // LanguageProductIdentifier
-     << zeros(16 - LangProd.size())             // Fill bytes
-     << binaryBe(FileHdr.ArchitectureLevel);    // ArchitectureLevel
-  // The module propties are optional. Figure out if we need to write them.
-  uint16_t ModPropLen = 0;
-  if (FileHdr.TargetSoftwareEnvironment)
-    ModPropLen = 3;
-  else if (FileHdr.InternalCCSID)
-    ModPropLen = 2;
-  if (ModPropLen) {
-    GW << binaryBe(ModPropLen) << zeros(6);
-    if (ModPropLen >= 2)
-      GW << binaryBe(FileHdr.InternalCCSID ? *FileHdr.InternalCCSID : 0);
-    if (ModPropLen >= 3)
-      GW << binaryBe(FileHdr.TargetSoftwareEnvironment
-                         ? *FileHdr.TargetSoftwareEnvironment
-                         : 0);
-  }
+void GOFFState::writeHeader(const GOFFYAML::ModuleHeader &ModHdr) {
+  // See
+  // https://www.ibm.com/docs/en/zos/3.1.0?topic=formats-module-header-record.
+  GW.newRecord(GOFF::RT_HDR);
+  LogicalRecord LR(GW);
+  LR << zeros(45)                          // Reserved.
+     << binaryBe(ModHdr.ArchitectureLevel) // The architecture level.
+     << binaryBe(ModHdr.PropertiesLength)  // Length of module properties.
+     << zeros(6);                          // Reserved.
+  if (ModHdr.Properties)
+    LR << *ModHdr.Properties; // Module properties.
 }
 
-void GOFFState::writeEnd() {
-  GW.makeNewRecord(GOFF::RT_END, GOFF::PayloadLength);
-  GW << binaryBe(uint8_t(0)) // No entry point
-     << binaryBe(uint8_t(0)) // No AMODE
-     << zeros(3)             // Reserved
-     << binaryBe(GW.logicalRecords());
-  // No entry point yet. Automatically fill remaining space with zero bytes.
-  GW.finalize();
+void GOFFState::writeEnd(const GOFFYAML::EndOfModule &EndMod) {
+  // See https://www.ibm.com/docs/en/zos/3.1.0?topic=formats-end-module-record.
+  SmallString<16> EntryName;
+  if (std::error_code EC =
+          ConverterEBCDIC::convertToEBCDIC(EndMod.EntryName, EntryName))
+    reportError("failed to convert '" + EndMod.EntryName + "' to EBCDIC 1047");
+
+  GW.newRecord(GOFF::RT_END);
+  LogicalRecord LR(GW);
+  LR << binaryBe(uint8_t(EndMod.Flags)) // The flags.
+     << binaryBe(uint8_t(EndMod.AMODE)) // The addressing mode.
+     << zeros(3)                        // Reserved.
+     << binaryBe(EndMod.RecordCount)    // The record count.
----------------
kpneal wrote:

I've run into trouble with the record count field. If it is zero, and the binder abends when trying to do a link, then I can use the Unix "dd" command to slice up the object and try and narrow down what is causing the abend. If the record count is correct to start with then slicing up the object will make it incorrect and remove a tool from my toolbox which then made my life more difficult. 

https://github.com/llvm/llvm-project/pull/93855