[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

3 files changed, 32 insertions, 12 deletions

diff --git a/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp b/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp
index 334c5e002bb..d69eca018e0 100644
--- a/llvm/lib/DebugInfo/CodeView/DebugSubsectionRecord.cpp
+++ b/llvm/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;
 
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
index 81a9d3eeec6..59ecbb50143 100644
--- a/llvm/lib/DebugInfo/PDB/Native/DbiModuleDescriptorBuilder.cpp
+++ b/llvm/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));
+}
diff --git a/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp b/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
index e7304b444f2..0ad461546d7 100644
--- a/llvm/lib/DebugInfo/PDB/Native/DbiStreamBuilder.cpp
+++ b/llvm/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();
 }