[llvm-readobj] Update readobj to re-use parsing code.

llvm-readobj hand rolls some CodeView parsing code for string
tables, so this patch updates it to re-use some of the newly
introduced parsing code in LLVMDebugInfoCodeView.

Differential Revision: https://reviews.llvm.org/D32772

llvm-svn: 302052

3 files changed, 32 insertions, 25 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/StringTable.cpp b/llvm/lib/DebugInfo/CodeView/StringTable.cpp
index 5d3a0dd9cfa..f496854ffaf 100644
--- a/llvm/lib/DebugInfo/CodeView/StringTable.cpp
+++ b/llvm/lib/DebugInfo/CodeView/StringTable.cpp
@@ -18,17 +18,17 @@ using namespace llvm::codeview;
 
 StringTableRef::StringTableRef() {}
 
-Error StringTableRef::initialize(BinaryStreamReader &Reader) {
-  return Reader.readStreamRef(Stream, Reader.bytesRemaining());
+Error StringTableRef::initialize(BinaryStreamRef Contents) {
+  Stream = Contents;
+  return Error::success();
 }
 
-StringRef StringTableRef::getString(uint32_t Offset) const {
+Expected<StringRef> StringTableRef::getString(uint32_t Offset) const {
   BinaryStreamReader Reader(Stream);
   Reader.setOffset(Offset);
   StringRef Result;
-  Error EC = Reader.readCString(Result);
-  assert(!EC);
-  consumeError(std::move(EC));
+  if (auto EC = Reader.readCString(Result))
+    return std::move(EC);
   return Result;
 }
 
diff --git a/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp b/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
index 134471e81ca..5395e4349b2 100644
--- a/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
+++ b/llvm/lib/DebugInfo/CodeView/SymbolDumper.cpp
@@ -13,6 +13,7 @@
 #include "llvm/DebugInfo/CodeView/CVSymbolVisitor.h"
 #include "llvm/DebugInfo/CodeView/CVTypeDumper.h"
 #include "llvm/DebugInfo/CodeView/EnumTables.h"
+#include "llvm/DebugInfo/CodeView/StringTable.h"
 #include "llvm/DebugInfo/CodeView/SymbolDeserializer.h"
 #include "llvm/DebugInfo/CodeView/SymbolDumpDelegate.h"
 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
@@ -369,14 +370,14 @@ Error CVSymbolDumperImpl::visitKnownRecord(
   DictScope S(W, "DefRangeSubfield");
 
   if (ObjDelegate) {
-    StringRef StringTable = ObjDelegate->getStringTable();
-    auto ProgramStringTableOffset = DefRangeSubfield.Program;
-    if (ProgramStringTableOffset >= StringTable.size())
+    StringTableRef Strings = ObjDelegate->getStringTable();
+    auto ExpectedProgram = Strings.getString(DefRangeSubfield.Program);
+    if (!ExpectedProgram) {
+      consumeError(ExpectedProgram.takeError());
       return llvm::make_error<CodeViewError>(
           "String table offset outside of bounds of String Table!");
-    StringRef Program =
-        StringTable.drop_front(ProgramStringTableOffset).split('\0').first;
-    W.printString("Program", Program);
+    }
+    W.printString("Program", *ExpectedProgram);
   }
   W.printNumber("OffsetInParent", DefRangeSubfield.OffsetInParent);
   printLocalVariableAddrRange(DefRangeSubfield.Range,
@@ -390,14 +391,14 @@ Error CVSymbolDumperImpl::visitKnownRecord(CVSymbol &CVR,
   DictScope S(W, "DefRange");
 
   if (ObjDelegate) {
-    StringRef StringTable = ObjDelegate->getStringTable();
-    auto ProgramStringTableOffset = DefRange.Program;
-    if (ProgramStringTableOffset >= StringTable.size())
+    StringTableRef Strings = ObjDelegate->getStringTable();
+    auto ExpectedProgram = Strings.getString(DefRange.Program);
+    if (!ExpectedProgram) {
+      consumeError(ExpectedProgram.takeError());
       return llvm::make_error<CodeViewError>(
           "String table offset outside of bounds of String Table!");
-    StringRef Program =
-        StringTable.drop_front(ProgramStringTableOffset).split('\0').first;
-    W.printString("Program", Program);
+    }
+    W.printString("Program", *ExpectedProgram);
   }
   printLocalVariableAddrRange(DefRange.Range, DefRange.getRelocationOffset());
   printLocalVariableAddrGap(DefRange.Gaps);
diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
index ee32f61f16f..e84573fe07b 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
@@ -42,7 +42,11 @@ Error PDBStringTable::readHeader(BinaryStreamReader &Reader) {
 }
 
 Error PDBStringTable::readStrings(BinaryStreamReader &Reader) {
-  if (auto EC = Strings.initialize(Reader)) {
+  BinaryStreamRef Stream;
+  if (auto EC = Reader.readStreamRef(Stream))
+    return EC;
+
+  if (auto EC = Strings.initialize(Stream)) {
     return joinErrors(std::move(EC),
                       make_error<RawError>(raw_error_code::corrupt_file,
                                            "Invalid hash table byte length"));
@@ -99,11 +103,11 @@ Error PDBStringTable::reload(BinaryStreamReader &Reader) {
   return Error::success();
 }
 
-StringRef PDBStringTable::getStringForID(uint32_t ID) const {
+Expected<StringRef> PDBStringTable::getStringForID(uint32_t ID) const {
   return Strings.getString(ID);
 }
 
-uint32_t PDBStringTable::getIDForString(StringRef Str) const {
+Expected<uint32_t> PDBStringTable::getIDForString(StringRef Str) const {
   uint32_t Hash =
       (Header->HashVersion == 1) ? hashStringV1(Str) : hashStringV2(Str);
   size_t Count = IDs.size();
@@ -115,12 +119,14 @@ uint32_t PDBStringTable::getIDForString(StringRef Str) const {
     uint32_t Index = (Start + I) % Count;
 
     uint32_t ID = IDs[Index];
-    StringRef S = getStringForID(ID);
-    if (S == Str)
+    auto ExpectedStr = getStringForID(ID);
+    if (!ExpectedStr)
+      return ExpectedStr.takeError();
+
+    if (*ExpectedStr == Str)
       return ID;
   }
-  // IDs[0] contains the ID of the "invalid" entry.
-  return IDs[0];
+  return make_error<RawError>(raw_error_code::no_entry);
 }
 
 FixedStreamArray<support::ulittle32_t> PDBStringTable::name_ids() const {