[CodeView] Modify emitTypeInformation to use MemoryTypeTableBuilder

[amccarth]

Summary

A baby step toward translating DIType records to CodeView.

This does not (yet) combine the record length with the record data. I'm going back and forth trying to determine if that's a good idea.

Sorry this took so long to figure out. Before adding the explicit conversion to a StringRef, I was losing trailing zeros in the implicit conversion to StringRef.

[rnk]

lgtm

[Eugene.Zelenko]

Committed in r270106.

lib/CodeGen/AsmPrinter/CodeViewDebug.h

 #define LLVM_LIB_CODEGEN_ASMPRINTER_CODEVIEWDEBUG_H
 
 #include "DebugHandlerBase.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/DebugInfo/CodeView/MemoryTypeTableBuilder.h"
 #include "llvm/DebugInfo/CodeView/TypeIndex.h"
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DebugLoc.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 
 namespace llvm {
 
 class StringRef;
 class LexicalScope;
 
 /// \brief Collects and handles line tables information in a CodeView format.
 class LLVM_LIBRARY_VISIBILITY CodeViewDebug : public DebugHandlerBase {
   MCStreamer &OS;
+  codeview::MemoryTypeTableBuilder TypeTable;
 
   /// Represents the most general definition range.
   struct LocalVarDefRange {
     /// Indicates that variable data is stored in memory relative to the
     /// specified register.
     int InMemory : 1;
 
     /// Offset of variable data in memory.

lib/CodeGen/AsmPrinter/CodeViewDebug.cpp

void CodeViewDebug::emitTypeInformation() {
   // Start the .debug$T section with 0x4.
   OS.SwitchSection(Asm->getObjFileLowering().getCOFFDebugTypesSection());
   OS.AddComment("Debug section magic");
   OS.EmitIntValue(COFF::DEBUG_SECTION_MAGIC, 4);
 
   // This type info currently only holds function ids for use with inline call
   // frame info. All functions are assigned a simple 'void ()' type. Emit that
   // type here.
-  unsigned ArgListIndex = getNextTypeIndex();
-  OS.AddComment("Type record length");
-  OS.EmitIntValue(ArgListRecord::getLayoutSize(), 2);
-  OS.AddComment("Leaf type: LF_ARGLIST");
-  OS.EmitIntValue(LF_ARGLIST, 2);
-  OS.AddComment("Number of arguments");
-  OS.EmitIntValue(0, 4);
-
-  unsigned VoidFnTyIdx = getNextTypeIndex();
-  OS.AddComment("Type record length");
-  OS.EmitIntValue(ProcedureRecord::getLayoutSize(), 2);
-  OS.AddComment("Leaf type: LF_PROCEDURE");
-  OS.EmitIntValue(LF_PROCEDURE, 2);
-  OS.AddComment("Return type index");
-  OS.EmitIntValue(TypeIndex::Void().getIndex(), 4);
-  OS.AddComment("Calling convention");
-  OS.EmitIntValue(char(CallingConvention::NearC), 1);
-  OS.AddComment("Function options");
-  OS.EmitIntValue(char(FunctionOptions::None), 1);
-  OS.AddComment("# of parameters");
-  OS.EmitIntValue(0, 2);
-  OS.AddComment("Argument list type index");
-  OS.EmitIntValue(ArgListIndex, 4);
+  ArrayRef<TypeIndex> NoArgs;
+  ArgListRecord ArgListRec(TypeRecordKind::ArgList, NoArgs);
+  TypeIndex ArgListIndex = TypeTable.writeArgList(ArgListRec);
+
+  ProcedureRecord Procedure(TypeIndex::Void(), CallingConvention::NearC,
+                            FunctionOptions::None, 0, ArgListIndex);
+  TypeIndex VoidFnTyIdx = TypeTable.writeProcedure(Procedure);
 
   // Emit LF_FUNC_ID records for all inlined subprograms to the type stream.
   // Allocate one type index for each func id.
-  unsigned NextIdx = getNextTypeIndex(InlinedSubprograms.size());
-  (void)NextIdx;
-  assert(NextIdx == FuncIdTypeIndexStart && "func id type indices broken");
   for (auto *SP : InlinedSubprograms) {
+    TypeIndex ParentScope = TypeIndex(0);
     StringRef DisplayName = SP->getDisplayName();
-    OS.AddComment("Type record length");
-    MCSymbol *FuncBegin = MMI->getContext().createTempSymbol(),
-             *FuncEnd = MMI->getContext().createTempSymbol();
-    OS.emitAbsoluteSymbolDiff(FuncEnd, FuncBegin, 2);
-    OS.EmitLabel(FuncBegin);
-    OS.AddComment("Leaf type: LF_FUNC_ID");
-    OS.EmitIntValue(LF_FUNC_ID, 2);
-
-    OS.AddComment("Scope type index");
-    OS.EmitIntValue(0, 4);
-    OS.AddComment("Function type");
-    OS.EmitIntValue(VoidFnTyIdx, 4);
-    {
-      OS.AddComment("Function name");
-      emitNullTerminatedSymbolName(OS, DisplayName);
-    }
-    OS.EmitLabel(FuncEnd);
+    FuncIdRecord FuncId(ParentScope, VoidFnTyIdx, DisplayName);
+    TypeTable.writeFuncId(FuncId);
   }
+
+  TypeTable.ForEachRecord(
+      [&](TypeIndex Index, const MemoryTypeTableBuilder::Record *R) {
+        OS.AddComment("Type record length");
+        OS.EmitIntValue(R->size(), 2);
+        OS.AddComment("Type record data");
+        OS.EmitBytes(StringRef(R->data(), R->size()));
+      });
 }
 
 void CodeViewDebug::emitInlineeFuncIdsAndLines() {
   if (InlinedSubprograms.empty())
     return;
 
   MCSymbol *InlineBegin = MMI->getContext().createTempSymbol(),
            *InlineEnd = MMI->getContext().createTempSymbol();