[dwarf] Unify unknown dwarf enum formatting code

Summary:
We have had at least three pieces of code (in DWARFAbbreviationDeclaration,
DWARFAcceleratorTable and DWARFDie) that have hand-rolled support for
dumping unknown dwarf enum values. While not terrible, they are a bit
distracting and enable small differences to creep in (Unknown_ffff vs.
Unknown_0xffff). I ended up needing to add a fourth place
(DWARFVerifier), so it seems it would be a good time to centralize.

This patch creates an alternative to the XXXString dumping functions in
the BinaryFormat library, which formats an unknown value as
DW_TYPE_unknown_1234, instead of just an empty string. It is based on
the formatv function, as that allows us to avoid materializing the
string for unknown values (and because this way I don't have to invent a
name for the new functions :P).

In this patch I add formatters for dwarf attributes, forms, tags, and
index attributes as these are the ones in use currently, but adding
other enums is straight-forward.

Reviewers: dblaikie, JDevlieghere, aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D44570

llvm-svn: 328090

1 files changed, 3 insertions, 17 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp b/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
index 688a85c9da3..adada672af0 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFAbbreviationDeclaration.cpp
@@ -16,6 +16,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstddef>
 #include <cstdint>
@@ -126,26 +127,11 @@ DWARFAbbreviationDeclaration::extract(DataExtractor Data,
 }
 
 void DWARFAbbreviationDeclaration::dump(raw_ostream &OS) const {
-  auto tagString = TagString(getTag());
   OS << '[' << getCode() << "] ";
-  if (!tagString.empty())
-    OS << tagString;
-  else
-    OS << format("DW_TAG_Unknown_%x", getTag());
+  OS << formatv("{0}", getTag());
   OS << "\tDW_CHILDREN_" << (hasChildren() ? "yes" : "no") << '\n';
   for (const AttributeSpec &Spec : AttributeSpecs) {
-    OS << '\t';
-    auto attrString = AttributeString(Spec.Attr);
-    if (!attrString.empty())
-      OS << attrString;
-    else
-      OS << format("DW_AT_Unknown_%x", Spec.Attr);
-    OS << '\t';
-    auto formString = FormEncodingString(Spec.Form);
-    if (!formString.empty())
-      OS << formString;
-    else
-      OS << format("DW_FORM_Unknown_%x", Spec.Form);
+    OS << formatv("\t{0}\t{1}", Spec.Attr, Spec.Form);
     if (Spec.isImplicitConst())
       OS << '\t' << Spec.getImplicitConstValue();
     OS << '\n';