[PDB] Start emitting source file and line information

Summary:
This is a first step towards getting line info to show up in VS and
windbg. So far, only llvm-pdbutil can parse the PDBs that we produce.
cvdump doesn't like something about our file checksum tables. I'll have
to dig into that next.

This patch adds a new DebugSubsectionRecordBuilder which takes bytes
directly from some other producer, such as a linker, and sticks it into
the PDB. Line tables only need to be relocated. No data needs to be
rewritten.

File checksums and string tables, on the other hand, need to be re-done.

Reviewers: zturner, ruiu

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D34257

llvm-svn: 305713

include/llvm/DebugInfo/CodeView/DebugSubsectionRecord.h

@@ -51,11 +51,23 @@ class DebugSubsectionRecordBuilder {
 public:
   DebugSubsectionRecordBuilder(std::shared_ptr<DebugSubsection> Subsection,
                                CodeViewContainer Container);
+
+  /// Use this to copy existing subsections directly from source to destination.
+  /// For example, line table subsections in an object file only need to be
+  /// relocated before being copied into the PDB.
+  DebugSubsectionRecordBuilder(const DebugSubsectionRecord &Contents,
+                               CodeViewContainer Container);
+
   uint32_t calculateSerializedLength();
   Error commit(BinaryStreamWriter &Writer) const;
 
 private:
+  /// The subsection to build. Will be null if Contents is non-empty.
   std::shared_ptr<DebugSubsection> Subsection;
+
+  /// The bytes of the subsection. Only non-empty if Subsection is null.
+  DebugSubsectionRecord Contents;
+
   CodeViewContainer Container;
 };
 

include/llvm/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.h

@@ -14,6 +14,7 @@
 #include "llvm/DebugInfo/CodeView/DebugChecksumsSubsection.h"
 #include "llvm/DebugInfo/CodeView/DebugInlineeLinesSubsection.h"
 #include "llvm/DebugInfo/CodeView/DebugLinesSubsection.h"
+#include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
 #include "llvm/DebugInfo/PDB/Native/RawTypes.h"
 #include "llvm/Support/Error.h"
@@ -52,6 +53,9 @@ public:
   void
   addDebugSubsection(std::shared_ptr<codeview::DebugSubsection> Subsection);
 
+  void
+  addDebugSubsection(const codeview::DebugSubsectionRecord &SubsectionContents);
+
   uint16_t getStreamIndex() const;
   StringRef getModuleName() const { return ModuleName; }
   StringRef getObjFileName() const { return ObjFileName; }

include/llvm/DebugInfo/PDB/Native/DbiStreamBuilder.h

@@ -58,6 +58,7 @@ public:
 
   Expected<DbiModuleDescriptorBuilder &> addModuleInfo(StringRef ModuleName);
   Error addModuleSourceFile(StringRef Module, StringRef File);
+  Error addModuleSourceFile(DbiModuleDescriptorBuilder &Module, StringRef File);
   Expected<uint32_t> getSourceFileNameIndex(StringRef FileName);
 
   Error finalizeMsfLayout();

lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp

@@ -53,12 +53,16 @@ DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
     std::shared_ptr<DebugSubsection> Subsection, CodeViewContainer Container)
     : Subsection(std::move(Subsection)), Container(Container) {}
 
+DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
+    const DebugSubsectionRecord &Contents, CodeViewContainer Container)
+    : Contents(Contents), Container(Container) {}
+
 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
-  // The length of the entire subsection is always padded to 4 bytes, regardless
-  // of the container kind.
-  uint32_t Size = sizeof(DebugSubsectionHeader) +
-                  alignTo(Subsection->calculateSerializedSize(), 4);
-  return Size;
+  uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
+                                 : Contents.getRecordData().getLength();
+  // The length of the entire subsection is always padded to 4 bytes,
+  // regardless of the container kind.
+  return sizeof(DebugSubsectionHeader) + alignTo(DataSize, 4);
 }
 
 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) const {
@@ -66,16 +70,22 @@ Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) const {
          "Debug Subsection not properly aligned");
 
   DebugSubsectionHeader Header;
-  Header.Kind = uint32_t(Subsection->kind());
+  Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind());
   // The value written into the Header's Length field is only padded to the
   // container's alignment
-  Header.Length =
-      alignTo(Subsection->calculateSerializedSize(), alignOf(Container));
+  uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
+                                 : Contents.getRecordData().getLength();
+  Header.Length = alignTo(DataSize, alignOf(Container));
 
   if (auto EC = Writer.writeObject(Header))
     return EC;
-  if (auto EC = Subsection->commit(Writer))
-    return EC;
+  if (Subsection) {
+    if (auto EC = Subsection->commit(Writer))
+      return EC;
+  } else {
+    if (auto EC = Writer.writeStreamRef(Contents.getRecordData()))
+      return EC;
+  }
   if (auto EC = Writer.padToAlignment(4))
     return EC;
 

lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp

@@ -182,3 +182,9 @@ void DbiModuleDescriptorBuilder::addDebugSubsection(
   C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
       std::move(Subsection), CodeViewContainer::Pdb));
 }
+
+void DbiModuleDescriptorBuilder::addDebugSubsection(
+    const DebugSubsectionRecord &SubsectionContents) {
+  C13Builders.push_back(llvm::make_unique<DebugSubsectionRecordBuilder>(
+      SubsectionContents, CodeViewContainer::Pdb));
+}

lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp

@@ -90,10 +90,14 @@ Error DbiStreamBuilder::addModuleSourceFile(StringRef Module, StringRef File) {
   if (ModIter == ModiMap.end())
     return make_error<RawError>(raw_error_code::no_entry,
                                 "The specified module was not found");
+  return addModuleSourceFile(*ModIter->second, File);
+}
+
+Error DbiStreamBuilder::addModuleSourceFile(DbiModuleDescriptorBuilder &Module,
+                                            StringRef File) {
   uint32_t Index = SourceFileNames.size();
   SourceFileNames.insert(std::make_pair(File, Index));
-  auto &ModEntry = *ModIter;
-  ModEntry.second->addSourceFile(File);
+  Module.addSourceFile(File);
   return Error::success();
 }