Remove the dependency between lib/DebugInfoDWARF and MC.

This patch had to be reverted because on gcc 7.5.0 we see an error converting from std::unique_ptr<MCRegisterInfo> to Expected<std::unique_ptr<MCRegisterInfo>> as the return type for the function createRegInfo. This has now been fixed.

1 files changed, 55 insertions, 15 deletions

diff --git a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
index cc7f353..c024814 100644
--- a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
+++ b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -18,6 +18,8 @@
 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
 #include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/TargetRegistry.h"
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/MachOUniversal.h"
 #include "llvm/Object/ObjectFile.h"
@@ -341,9 +343,11 @@ using HandlerFn = std::function<bool(ObjectFile &, DWARFContext &DICtx,
                                      const Twine &, raw_ostream &)>;
 
 /// Print only DIEs that have a certain name.
-static bool filterByName(const StringSet<> &Names, DWARFDie Die,
-                         StringRef NameRef, raw_ostream &OS) {
+static bool filterByName(
+    const StringSet<> &Names, DWARFDie Die, StringRef NameRef, raw_ostream &OS,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg) {
   DIDumpOptions DumpOpts = getDumpOpts(Die.getDwarfUnit()->getContext());
+  DumpOpts.GetNameForDWARFReg = GetNameForDWARFReg;
   std::string Name =
       (IgnoreCase && !UseRegex) ? NameRef.lower() : NameRef.str();
   if (UseRegex) {
@@ -369,17 +373,18 @@ static bool filterByName(const StringSet<> &Names, DWARFDie Die,
 }
 
 /// Print only DIEs that have a certain name.
-static void filterByName(const StringSet<> &Names,
-                         DWARFContext::unit_iterator_range CUs,
-                         raw_ostream &OS) {
+static void filterByName(
+    const StringSet<> &Names, DWARFContext::unit_iterator_range CUs,
+    raw_ostream &OS,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg) {
   for (const auto &CU : CUs)
     for (const auto &Entry : CU->dies()) {
       DWARFDie Die = {CU.get(), &Entry};
       if (const char *Name = Die.getName(DINameKind::ShortName))
-        if (filterByName(Names, Die, Name, OS))
+        if (filterByName(Names, Die, Name, OS, GetNameForDWARFReg))
           continue;
       if (const char *Name = Die.getName(DINameKind::LinkageName))
-        filterByName(Names, Die, Name, OS);
+        filterByName(Names, Die, Name, OS, GetNameForDWARFReg);
     }
 }
 
@@ -423,8 +428,9 @@ static void getDies(DWARFContext &DICtx, const DWARFDebugNames &Accel,
 }
 
 /// Print only DIEs that have a certain name.
-static void filterByAccelName(ArrayRef<std::string> Names, DWARFContext &DICtx,
-                              raw_ostream &OS) {
+static void filterByAccelName(
+    ArrayRef<std::string> Names, DWARFContext &DICtx, raw_ostream &OS,
+    std::function<StringRef(uint64_t RegNum, bool IsEH)> GetNameForDWARFReg) {
   SmallVector<DWARFDie, 4> Dies;
   for (const auto &Name : Names) {
     getDies(DICtx, DICtx.getAppleNames(), Name, Dies);
@@ -436,6 +442,7 @@ static void filterByAccelName(ArrayRef<std::string> Names, DWARFContext &DICtx,
   Dies.erase(std::unique(Dies.begin(), Dies.end()), Dies.end());
 
   DIDumpOptions DumpOpts = getDumpOpts(DICtx);
+  DumpOpts.GetNameForDWARFReg = GetNameForDWARFReg;
   for (DWARFDie Die : Dies)
     Die.dump(OS, 0, DumpOpts);
 }
@@ -552,10 +559,41 @@ static bool collectObjectSources(ObjectFile &Obj, DWARFContext &DICtx,
   return Result;
 }
 
+static std::unique_ptr<MCRegisterInfo>
+createRegInfo(const object::ObjectFile &Obj) {
+  std::unique_ptr<MCRegisterInfo> MCRegInfo;
+  Triple TT;
+  TT.setArch(Triple::ArchType(Obj.getArch()));
+  TT.setVendor(Triple::UnknownVendor);
+  TT.setOS(Triple::UnknownOS);
+  std::string TargetLookupError;
+  const Target *TheTarget =
+      TargetRegistry::lookupTarget(TT.str(), TargetLookupError);
+  if (!TargetLookupError.empty())
+    return nullptr;
+  MCRegInfo.reset(TheTarget->createMCRegInfo(TT.str()));
+  return MCRegInfo;
+}
+
 static bool dumpObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
                            const Twine &Filename, raw_ostream &OS) {
-  logAllUnhandledErrors(DICtx.loadRegisterInfo(Obj), errs(),
-                        Filename.str() + ": ");
+
+  auto MCRegInfo = createRegInfo(Obj);
+  if (!MCRegInfo)
+    logAllUnhandledErrors(createStringError(inconvertibleErrorCode(),
+                                            "Error in creating MCRegInfo"),
+                          errs(), Filename.str() + ": ");
+
+  auto GetRegName = [&MCRegInfo](uint64_t DwarfRegNum, bool IsEH) -> StringRef {
+    if (!MCRegInfo)
+      return {};
+    if (llvm::Optional<unsigned> LLVMRegNum =
+            MCRegInfo->getLLVMRegNum(DwarfRegNum, IsEH))
+      if (const char *RegName = MCRegInfo->getName(*LLVMRegNum))
+        return StringRef(RegName);
+    return {};
+  };
+
   // The UUID dump already contains all the same information.
   if (!(DumpType & DIDT_UUID) || DumpType == DIDT_All)
     OS << Filename << ":\tfile format " << Obj.getFileFormatName() << '\n';
@@ -570,19 +608,21 @@ static bool dumpObjectFile(ObjectFile &Obj, DWARFContext &DICtx,
     for (auto name : Name)
       Names.insert((IgnoreCase && !UseRegex) ? StringRef(name).lower() : name);
 
-    filterByName(Names, DICtx.normal_units(), OS);
-    filterByName(Names, DICtx.dwo_units(), OS);
+    filterByName(Names, DICtx.normal_units(), OS, GetRegName);
+    filterByName(Names, DICtx.dwo_units(), OS, GetRegName);
     return true;
   }
 
   // Handle the --find option and lower it to --debug-info=<offset>.
   if (!Find.empty()) {
-    filterByAccelName(Find, DICtx, OS);
+    filterByAccelName(Find, DICtx, OS, GetRegName);
     return true;
   }
 
   // Dump the complete DWARF structure.
-  DICtx.dump(OS, getDumpOpts(DICtx), DumpOffsets);
+  auto DumpOpts = getDumpOpts(DICtx);
+  DumpOpts.GetNameForDWARFReg = GetRegName;
+  DICtx.dump(OS, DumpOpts, DumpOffsets);
   return true;
 }