[CodeView] Support CodeView subsections in any order.

Previously we would expect certain subsections to appear
in a certain order because some subsections would reference
other subsections, but in practice we need to support
arbitrary orderings since some object file and PDB file
producers generate them this way.  This also paves the
way for supporting Yaml <-> Object File conversion of
CodeView, since Object Files typically have quite a
large number of subsections in their debug info.

Differential Revision: https://reviews.llvm.org/D33807

llvm-svn: 304588

5 files changed, 39 insertions, 54 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp b/llvm/lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp
index b8741eb0b67..2e72242181b 100644
--- a/llvm/lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp
+++ b/llvm/lib/DebugInfo/CodeView/DebugStringTableSubsection.cpp
@@ -72,7 +72,7 @@ Error DebugStringTableSubsection::commit(BinaryStreamWriter &Writer) const {
 uint32_t DebugStringTableSubsection::size() const { return Strings.size(); }
 
 uint32_t DebugStringTableSubsection::getStringId(StringRef S) const {
-  auto P = Strings.find(S);
-  assert(P != Strings.end());
-  return P->second;
+  auto Iter = Strings.find(S);
+  assert(Iter != Strings.end());
+  return Iter->second;
 }
diff --git a/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp b/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp
index 5ecfaf2f23a..cfd1c5d3ab0 100644
--- a/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp
+++ b/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp
@@ -60,13 +60,13 @@ DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
 
 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
-    DebugSubsectionKind Kind, DebugSubsection &Frag,
-    CodeViewContainer Container)
-    : Container(Container), Kind(Kind), Frag(Frag) {}
+    std::unique_ptr<DebugSubsection> Subsection, CodeViewContainer Container)
+    : Subsection(std::move(Subsection)), Container(Container) {}
 
 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
-  uint32_t Size = sizeof(DebugSubsectionHeader) +
-                  alignTo(Frag.calculateSerializedSize(), alignOf(Container));
+  uint32_t Size =
+      sizeof(DebugSubsectionHeader) +
+      alignTo(Subsection->calculateSerializedSize(), alignOf(Container));
   return Size;
 }
 
@@ -75,12 +75,12 @@ Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) {
          "Debug Subsection not properly aligned");
 
   DebugSubsectionHeader Header;
-  Header.Kind = uint32_t(Kind);
+  Header.Kind = uint32_t(Subsection->kind());
   Header.Length = calculateSerializedLength() - sizeof(DebugSubsectionHeader);
 
   if (auto EC = Writer.writeObject(Header))
     return EC;
-  if (auto EC = Frag.commit(Writer))
+  if (auto EC = Subsection->commit(Writer))
     return EC;
   if (auto EC = Writer.padToAlignment(alignOf(Container)))
     return EC;
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
index bf3f83741ae..9aea4acb74a 100644
--- a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
@@ -174,42 +174,9 @@ Error DbiModuleDescriptorBuilder::commit(BinaryStreamWriter &ModiWriter,
   return Error::success();
 }
 
-void DbiModuleDescriptorBuilder::addC13Fragment(
-    std::unique_ptr<DebugLinesSubsection> Lines) {
-  DebugLinesSubsection &Frag = *Lines;
-
-  // File Checksums have to come first, so push an empty entry on if this
-  // is the first.
-  if (C13Builders.empty())
-    C13Builders.push_back(nullptr);
-
-  this->LineInfo.push_back(std::move(Lines));
+void DbiModuleDescriptorBuilder::addDebugSubsection(
+    std::unique_ptr<DebugSubsection> Subsection) {
+  assert(Subsection);
   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
-      Frag.kind(), Frag, CodeViewContainer::Pdb));
-}
-
-void DbiModuleDescriptorBuilder::addC13Fragment(
-    std::unique_ptr<codeview::DebugInlineeLinesSubsection> Inlinees) {
-  DebugInlineeLinesSubsection &Frag = *Inlinees;
-
-  // File Checksums have to come first, so push an empty entry on if this
-  // is the first.
-  if (C13Builders.empty())
-    C13Builders.push_back(nullptr);
-
-  this->Inlinees.push_back(std::move(Inlinees));
-  C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
-      Frag.kind(), Frag, CodeViewContainer::Pdb));
-}
-
-void DbiModuleDescriptorBuilder::setC13FileChecksums(
-    std::unique_ptr<DebugChecksumsSubsection> Checksums) {
-  assert(!ChecksumInfo && "Can't have more than one checksum info!");
-
-  if (C13Builders.empty())
-    C13Builders.push_back(nullptr);
-
-  ChecksumInfo = std::move(Checksums);
-  C13Builders[0] = llvm::make_unique<DebugSubsectionRecordBuilder>(
-      ChecksumInfo->kind(), *ChecksumInfo, CodeViewContainer::Pdb);
+      std::move(Subsection), CodeViewContainer::Pdb));
 }
diff --git a/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp b/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
index d7a203746a0..c4ff30011a1 100644
--- a/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
@@ -55,9 +55,9 @@ Error ModuleDebugStreamRef::reload() {
   if (auto EC = Reader.readStreamRef(C13LinesSubstream, C13Size))
     return EC;
 
-  BinaryStreamReader LineReader(C13LinesSubstream);
-  if (auto EC =
-          LineReader.readArray(LinesAndChecksums, LineReader.bytesRemaining()))
+  BinaryStreamReader SubsectionsReader(C13LinesSubstream);
+  if (auto EC = SubsectionsReader.readArray(Subsections,
+                                            SubsectionsReader.bytesRemaining()))
     return EC;
 
   uint32_t GlobalRefsSize;
@@ -77,13 +77,27 @@ ModuleDebugStreamRef::symbols(bool *HadError) const {
   return make_range(SymbolsSubstream.begin(HadError), SymbolsSubstream.end());
 }
 
-llvm::iterator_range<ModuleDebugStreamRef::LinesAndChecksumsIterator>
-ModuleDebugStreamRef::linesAndChecksums() const {
-  return make_range(LinesAndChecksums.begin(), LinesAndChecksums.end());
+llvm::iterator_range<ModuleDebugStreamRef::DebugSubsectionIterator>
+ModuleDebugStreamRef::subsections() const {
+  return make_range(Subsections.begin(), Subsections.end());
 }
 
-bool ModuleDebugStreamRef::hasLineInfo() const {
+bool ModuleDebugStreamRef::hasDebugSubsections() const {
   return C13LinesSubstream.getLength() > 0;
 }
 
 Error ModuleDebugStreamRef::commit() { return Error::success(); }
+
+Expected<codeview::DebugChecksumsSubsectionRef>
+ModuleDebugStreamRef::findChecksumsSubsection() const {
+  for (const auto &SS : subsections()) {
+    if (SS.kind() != DebugSubsectionKind::FileChecksums)
+      continue;
+
+    codeview::DebugChecksumsSubsectionRef Result;
+    if (auto EC = Result.initialize(SS.getRecordData()))
+      return std::move(EC);
+    return Result;
+  }
+  return make_error<RawError>(raw_error_code::no_entry);
+}
diff --git a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
index e84573fe07b..6013c342cf0 100644
--- a/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/PDBStringTable.cpp
@@ -56,6 +56,10 @@ Error PDBStringTable::readStrings(BinaryStreamReader &Reader) {
   return Error::success();
 }
 
+codeview::DebugStringTableSubsectionRef PDBStringTable::getStringTable() const {
+  return Strings;
+}
+
 Error PDBStringTable::readHashTable(BinaryStreamReader &Reader) {
   const support::ulittle32_t *HashCount;
   if (auto EC = Reader.readObject(HashCount))