[ObjectYAML] Support for DWARF __debug_abbrev section

This patch adds support for round-tripping DWARF debug abbreviations through the obj<->yaml tools.

llvm-svn: 288955

2 files changed, 40 insertions, 1 deletions

diff --git a/llvm/tools/obj2yaml/macho2yaml.cpp b/llvm/tools/obj2yaml/macho2yaml.cpp
index 0953d284e11..16f25fc4668 100644
--- a/llvm/tools/obj2yaml/macho2yaml.cpp
+++ b/llvm/tools/obj2yaml/macho2yaml.cpp
@@ -36,7 +36,10 @@ class MachODumper {
   void dumpExportTrie(std::unique_ptr<MachOYAML::Object> &Y);
   void dumpSymbols(std::unique_ptr<MachOYAML::Object> &Y);
   void dumpDWARF(std::unique_ptr<MachOYAML::Object> &Y);
-  void dumpDebugStrings(DWARFContextInMemory &DCtx, std::unique_ptr<MachOYAML::Object> &Y);
+  void dumpDebugAbbrev(DWARFContextInMemory &DCtx,
+                        std::unique_ptr<MachOYAML::Object> &Y);
+  void dumpDebugStrings(DWARFContextInMemory &DCtx,
+                        std::unique_ptr<MachOYAML::Object> &Y);
 
 public:
   MachODumper(const object::MachOObjectFile &O) : Obj(O) {}
@@ -466,6 +469,7 @@ void MachODumper::dumpSymbols(std::unique_ptr<MachOYAML::Object> &Y) {
 void MachODumper::dumpDWARF(std::unique_ptr<MachOYAML::Object> &Y) {
   DWARFContextInMemory DICtx(Obj);
   dumpDebugStrings(DICtx, Y);
+  dumpDebugAbbrev(DICtx, Y);
 }
 
 void MachODumper::dumpDebugStrings(DWARFContextInMemory &DICtx,
@@ -478,6 +482,29 @@ void MachODumper::dumpDebugStrings(DWARFContextInMemory &DICtx,
   }
 }
 
+void MachODumper::dumpDebugAbbrev(DWARFContextInMemory &DCtx,
+                        std::unique_ptr<MachOYAML::Object> &Y) {
+  auto AbbrevSetPtr = DCtx.getDebugAbbrev();
+  if(AbbrevSetPtr) {
+    for(auto AbbrvDeclSet : *AbbrevSetPtr) {
+      for(auto AbbrvDecl : AbbrvDeclSet.second) {
+        MachOYAML::DWARFAbbrev Abbrv;
+        Abbrv.Code = AbbrvDecl.getCode();
+        Abbrv.Tag = AbbrvDecl.getTag();
+        Abbrv.Children = AbbrvDecl.hasChildren() ? dwarf::DW_CHILDREN_yes
+                                                 : dwarf::DW_CHILDREN_no;
+        for(auto Attribute : AbbrvDecl.attributes()) {
+          MachOYAML::DWARFAttributeAbbrev AttAbrv;
+          AttAbrv.Attribute = Attribute.Attr;
+          AttAbrv.Form = Attribute.Form;
+          Abbrv.Attributes.push_back(AttAbrv);
+        }
+        Y->DWARF.AbbrevDecls.push_back(Abbrv);
+      }
+    }
+  }
+}
+
 Error macho2yaml(raw_ostream &Out, const object::MachOObjectFile &Obj) {
   MachODumper Dumper(Obj);
   Expected<std::unique_ptr<MachOYAML::Object>> YAML = Dumper.dump();
diff --git a/llvm/tools/yaml2obj/yaml2macho.cpp b/llvm/tools/yaml2obj/yaml2macho.cpp
index 3312cd45fb7..48bd9e83ad3 100644
--- a/llvm/tools/yaml2obj/yaml2macho.cpp
+++ b/llvm/tools/yaml2obj/yaml2macho.cpp
@@ -393,6 +393,18 @@ Error MachOWriter::writeDWARFData(raw_ostream &OS,
         OS.write(Str.data(), Str.size());
         OS.write('\0');
       }
+    } else if (0 == strncmp(&Section.sectname[0], "__debug_abbrev", 16)) {
+      for (auto AbbrevDecl : Obj.DWARF.AbbrevDecls) {
+        encodeULEB128(AbbrevDecl.Code, OS);
+        encodeULEB128(AbbrevDecl.Tag, OS);
+        OS.write(AbbrevDecl.Children);
+        for (auto Attr : AbbrevDecl.Attributes) {
+          encodeULEB128(Attr.Attribute, OS);
+          encodeULEB128(Attr.Form, OS);
+        }
+        encodeULEB128(0, OS);
+        encodeULEB128(0, OS);
+      }
     }
   }
   return Error::success();