[dwarfdump] Pretty print location expressions and location lists

Summary:
Based on Fred's patch here: https://reviews.llvm.org/D6771

I can't seem to commandeer the old review, so I'm creating a new one.

With that change the locations exrpessions are pretty printed inline in the
DIE tree. The output looks like this for debug_loc entries:

    DW_AT_location [DW_FORM_data4]        (0x00000000
       0x0000000000000001 - 0x000000000000000b: DW_OP_consts +3
       0x000000000000000b - 0x0000000000000012: DW_OP_consts +7
       0x0000000000000012 - 0x000000000000001b: DW_OP_reg0 RAX, DW_OP_piece 0x4
       0x000000000000001b - 0x0000000000000024: DW_OP_breg5 RDI+0)

And like this for debug_loc.dwo entries:
    DW_AT_location [DW_FORM_sec_offset]   (0x00000000
      Addr idx 2 (w/ length 190): DW_OP_consts +0, DW_OP_stack_value
      Addr idx 3 (w/ length 23): DW_OP_reg0 RAX, DW_OP_piece 0x4)

Simple locations without ranges are printed inline:

   DW_AT_location [DW_FORM_block1]       (DW_OP_reg4 RSI, DW_OP_piece 0x4, DW_OP_bit_piece 0x20 0x0)

The debug_loc(.dwo) dumping in changed accordingly to factor the code.

Reviewers: dblaikie, aprantl, friss

Subscribers: mgorny, javed.absar, hiraditya, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D37123

llvm-svn: 312042

1 files changed, 26 insertions, 2 deletions

diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 0bd9c927b0a..27d9db643bf 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -31,6 +31,7 @@
 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
 #include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
+#include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Object/Decompressor.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Object/ObjectFile.h"
@@ -40,6 +41,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cstdint>
@@ -59,6 +61,12 @@ using DWARFLineTable = DWARFDebugLine::LineTable;
 using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind;
 using FunctionNameKind = DILineInfoSpecifier::FunctionNameKind;
 
+DWARFContext::DWARFContext(std::unique_ptr<const DWARFObject> DObj,
+                           std::string DWPName)
+    : DIContext(CK_DWARF), DWPName(std::move(DWPName)), DObj(std::move(DObj)) {}
+
+DWARFContext::~DWARFContext() = default;
+
 static void dumpAccelSection(raw_ostream &OS, StringRef Name,
                              const DWARFObject &Obj,
                              const DWARFSection &Section,
@@ -237,12 +245,12 @@ void DWARFContext::dump(raw_ostream &OS, DIDumpOptions DumpOpts) {
 
   if (DumpType == DIDT_All || DumpType == DIDT_Loc) {
     OS << "\n.debug_loc contents:\n";
-    getDebugLoc()->dump(OS);
+    getDebugLoc()->dump(OS, getRegisterInfo());
   }
 
   if (DumpType == DIDT_All || DumpType == DIDT_LocDwo) {
     OS << "\n.debug_loc.dwo contents:\n";
-    getDebugLocDWO()->dump(OS);
+    getDebugLocDWO()->dump(OS, getRegisterInfo());
   }
 
   if (DumpType == DIDT_All || DumpType == DIDT_Frames) {
@@ -1295,3 +1303,19 @@ DWARFContext::create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
       llvm::make_unique<DWARFObjInMemory>(Sections, AddrSize, isLittleEndian);
   return llvm::make_unique<DWARFContext>(std::move(DObj), "");
 }
+
+Error DWARFContext::loadRegisterInfo(const object::ObjectFile &Obj) {
+  // Detect the architecture from the object file. We usually don't need OS
+  // info to lookup a target and create register info.
+  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 make_error<StringError>(TargetLookupError, inconvertibleErrorCode());
+  RegInfo.reset(TheTarget->createMCRegInfo(TT.str()));
+  return Error::success();
+}