Add convenience methods to convert LLDB to LLVM data structures.

This patch adds two convenience methods named GetAsLLVM to the LLDB
counterparts of the DWARF DataExtractor and the DWARF context. The
DWARFContext, once created, is cached for future usage.

Differential revision: https://reviews.llvm.org/D64535

llvm-svn: 365819

7 files changed, 57 insertions, 10 deletions

diff --git a/lldb/include/lldb/Core/Section.h b/lldb/include/lldb/Core/Section.h
index 542849b8042..881d43702ce 100644
--- a/lldb/include/lldb/Core/Section.h
+++ b/lldb/include/lldb/Core/Section.h
@@ -38,6 +38,11 @@ public:
   typedef collection::iterator iterator;
   typedef collection::const_iterator const_iterator;
 
+  const_iterator begin() const { return m_sections.begin(); }
+  const_iterator end() const { return m_sections.end(); }
+  const_iterator begin() { return m_sections.begin(); }
+  const_iterator end() { return m_sections.end(); }
+
   SectionList();
 
   ~SectionList();
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.cpp
index 9fd4ec616e2..2f693fe5c32 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.cpp
@@ -100,3 +100,37 @@ const DWARFDataExtractor &DWARFContext::getOrLoadDebugTypesData() {
   return LoadOrGetSection(eSectionTypeDWARFDebugTypes,
                           eSectionTypeDWARFDebugTypesDwo, m_data_debug_types);
 }
+
+llvm::DWARFContext &DWARFContext::GetAsLLVM() {
+  if (!m_llvm_context) {
+    llvm::StringMap<std::unique_ptr<llvm::MemoryBuffer>> section_map;
+    uint8_t addr_size = 0;
+
+    auto AddSection = [&](Section &section) {
+      DataExtractor section_data;
+      section.GetSectionData(section_data);
+
+      // Set the address size the first time we see it.
+      if (addr_size == 0)
+        addr_size = section_data.GetByteSize();
+
+      llvm::StringRef data = llvm::toStringRef(section_data.GetData());
+      llvm::StringRef name = section.GetName().GetStringRef();
+      section_map.try_emplace(
+          name, llvm::MemoryBuffer::getMemBuffer(data, name, false));
+    };
+
+    if (m_main_section_list) {
+      for (auto &section : *m_main_section_list)
+        AddSection(*section);
+    }
+
+    if (m_dwo_section_list) {
+      for (auto &section : *m_dwo_section_list)
+        AddSection(*section);
+    }
+
+    m_llvm_context = llvm::DWARFContext::create(section_map, addr_size);
+  }
+  return *m_llvm_context;
+}
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.h
index bb794a0d87d..add04238403 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFContext.h
@@ -12,6 +12,7 @@
 #include "DWARFDataExtractor.h"
 #include "lldb/Core/Section.h"
 #include "llvm/ADT/Optional.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/Support/Threading.h"
 #include <memory>
 
@@ -20,6 +21,7 @@ class DWARFContext {
 private:
   SectionList *m_main_section_list;
   SectionList *m_dwo_section_list;
+  mutable std::unique_ptr<llvm::DWARFContext> m_llvm_context;
 
   struct SectionData {
     llvm::once_flag flag;
@@ -64,6 +66,8 @@ public:
   const DWARFDataExtractor &getOrLoadStrData();
   const DWARFDataExtractor &getOrLoadStrOffsetsData();
   const DWARFDataExtractor &getOrLoadDebugTypesData();
+
+  llvm::DWARFContext &GetAsLLVM();
 };
 } // namespace lldb_private
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.cpp
index 52c94c99035..1678b228137 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "DWARFDataExtractor.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace lldb_private {
 
@@ -19,4 +20,11 @@ dw_offset_t
 DWARFDataExtractor::GetDWARFOffset(lldb::offset_t *offset_ptr) const {
   return GetMaxU64(offset_ptr, GetDWARFSizeOfOffset());
 }
+
+llvm::DWARFDataExtractor DWARFDataExtractor::GetAsLLVM() const {
+  return llvm::DWARFDataExtractor(
+      llvm::StringRef(reinterpret_cast<const char *>(GetDataStart()),
+                      GetByteSize()),
+      GetByteOrder() == lldb::eByteOrderLittle, GetAddressByteSize());
 }
+} // namespace lldb_private
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.h b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.h
index b7924688dd6..22db5e8c0b7 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.h
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DWARFDataExtractor.h
@@ -11,6 +11,7 @@
 
 #include "lldb/Core/dwarf.h"
 #include "lldb/Utility/DataExtractor.h"
+#include "llvm/DebugInfo/DWARF/DWARFDataExtractor.h"
 
 namespace lldb_private {
 
@@ -28,6 +29,8 @@ public:
 
   size_t GetDWARFSizeofInitialLength() const { return 4; }
   size_t GetDWARFSizeOfOffset() const { return 4; }
+
+  llvm::DWARFDataExtractor GetAsLLVM() const;
 };
 }
 
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
index 01cac49a7aa..9746ad76c93 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
@@ -16,13 +16,6 @@
 using namespace lldb_private;
 using namespace lldb;
 
-static llvm::DWARFDataExtractor ToLLVM(const DWARFDataExtractor &data) {
-  return llvm::DWARFDataExtractor(
-      llvm::StringRef(reinterpret_cast<const char *>(data.GetDataStart()),
-                      data.GetByteSize()),
-      data.GetByteOrder() == eByteOrderLittle, data.GetAddressByteSize());
-}
-
 llvm::Expected<std::unique_ptr<DebugNamesDWARFIndex>>
 DebugNamesDWARFIndex::Create(Module &module, DWARFDataExtractor debug_names,
                              DWARFDataExtractor debug_str,
@@ -31,8 +24,8 @@ DebugNamesDWARFIndex::Create(Module &module, DWARFDataExtractor debug_names,
     return llvm::make_error<llvm::StringError>("debug info null",
                                                llvm::inconvertibleErrorCode());
   }
-  auto index_up =
-      llvm::make_unique<DebugNames>(ToLLVM(debug_names), ToLLVM(debug_str));
+  auto index_up = llvm::make_unique<DebugNames>(debug_names.GetAsLLVM(),
+                                                debug_str.GetAsLLVM());
   if (llvm::Error E = index_up->extract())
     return std::move(E);
 
diff --git a/lldb/tools/lldb-test/lldb-test.cpp b/lldb/tools/lldb-test/lldb-test.cpp
index 471a9988287..478da8c0b73 100644
--- a/lldb/tools/lldb-test/lldb-test.cpp
+++ b/lldb/tools/lldb-test/lldb-test.cpp
@@ -739,7 +739,7 @@ static void dumpSectionList(LinePrinter &Printer, const SectionList &List, bool
     Printer.formatLine("File size: {0}", S->GetFileSize());
 
     if (opts::object::SectionContents) {
-      DataExtractor Data;
+      lldb_private::DataExtractor Data;
       S->GetSectionData(Data);
       ArrayRef<uint8_t> Bytes = {Data.GetDataStart(), Data.GetDataEnd()};
       Printer.formatBinary("Data: ", Bytes, 0);