[dwarfdump] Add flag to limit the number of parents DIEs

This adds `-parent-recurse-depth` which limits the number of parent DIEs
being dumped.

Differential revision: https://reviews.llvm.org/D62359

llvm-svn: 361671

llvm/include/llvm/DebugInfo/DIContext.h

@@ -97,11 +97,10 @@ class DIInliningInfo {
   void addFrame(const DILineInfo &Frame) {
     Frames.push_back(Frame);
   }
-  
+
   void resize(unsigned i) {
     Frames.resize(i);
   }
-
 };
 
 /// Container for description of a global variable.
@@ -157,7 +156,8 @@ enum DIDumpType : unsigned {
 /// dumped.
 struct DIDumpOptions {
   unsigned DumpType = DIDT_All;
-  unsigned RecurseDepth = -1U;
+  unsigned ChildRecurseDepth = -1U;
+  unsigned ParentRecurseDepth = -1U;
   uint16_t Version = 0; // DWARF version to assume when extracting.
   uint8_t AddrSize = 4; // Address byte size to assume when extracting.
   bool ShowAddresses = true;
@@ -171,15 +171,18 @@ struct DIDumpOptions {
   /// Return default option set for printing a single DIE without children.
   static DIDumpOptions getForSingleDIE() {
     DIDumpOptions Opts;
-    Opts.RecurseDepth = 0;
+    Opts.ChildRecurseDepth = 0;
+    Opts.ParentRecurseDepth = 0;
     return Opts;
   }
 
   /// Return the options with RecurseDepth set to 0 unless explicitly required.
   DIDumpOptions noImplicitRecursion() const {
     DIDumpOptions Opts = *this;
-    if (RecurseDepth == -1U && !ShowChildren)
-      Opts.RecurseDepth = 0;
+    if (ChildRecurseDepth == -1U && !ShowChildren)
+      Opts.ChildRecurseDepth = 0;
+    if (ParentRecurseDepth == -1U && !ShowParents)
+      Opts.ParentRecurseDepth = 0;
     return Opts;
   }
 };

llvm/lib/DebugInfo/DWARF/DWARFDie.cpp

@@ -553,10 +553,12 @@ void DWARFDie::getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
 
 /// Helper to dump a DIE with all of its parents, but no siblings.
 static unsigned dumpParentChain(DWARFDie Die, raw_ostream &OS, unsigned Indent,
-                                DIDumpOptions DumpOpts) {
+                                DIDumpOptions DumpOpts, unsigned Depth = 0) {
   if (!Die)
     return Indent;
-  Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts);
+  if (DumpOpts.ParentRecurseDepth > 0 && Depth >= DumpOpts.ParentRecurseDepth)
+    return Indent;
+  Indent = dumpParentChain(Die.getParent(), OS, Indent, DumpOpts, Depth + 1);
   Die.dump(OS, Indent, DumpOpts);
   return Indent + 2;
 }
@@ -604,8 +606,8 @@ void DWARFDie::dump(raw_ostream &OS, unsigned Indent,
         }
 
         DWARFDie child = getFirstChild();
-        if (DumpOpts.ShowChildren && DumpOpts.RecurseDepth > 0 && child) {
-          DumpOpts.RecurseDepth--;
+        if (DumpOpts.ShowChildren && DumpOpts.ChildRecurseDepth > 0 && child) {
+          DumpOpts.ChildRecurseDepth--;
           DIDumpOptions ChildDumpOpts = DumpOpts;
           ChildDumpOpts.ShowParents = false;
           while (child) {

llvm/test/tools/llvm-dwarfdump/X86/enum.s

@@ -2,11 +2,16 @@
 # RUN: llvm-dwarfdump --debug-info=0x0000002a -p %t | FileCheck %s --check-prefix=PARENTS
 # RUN: llvm-dwarfdump --debug-info=0x0000002a -c %t | FileCheck %s --check-prefix=CHILDREN
 # RUN: llvm-dwarfdump --debug-info=0x0000002a -p -c %t | FileCheck %s --check-prefix=BOTH
+# RUN: llvm-dwarfdump  --debug-info=0x00000032 -p -parent-recurse-depth 1 -c %t | FileCheck %s --check-prefix=ONEPARENT
 
 # PARENTS: DW_TAG_compile_unit
 # PARENTS: DW_TAG_enumeration_type
 # PARENTS-NOT: DW_TAG_enumerator
 
+# ONEPARENT-NOT: DW_TAG_compile_unit
+# ONEPARENT: DW_TAG_enumeration_type
+# ONEPARENT: DW_TAG_enumerator
+
 # CHILDREN-NOT: DW_TAG_compile_unit
 # CHILDREN:   DW_TAG_enumerator
 # CHILDREN:     DW_AT_name	("first")

llvm/test/tools/llvm-dwarfdump/cmdline.test

@@ -13,6 +13,7 @@ HELP: -find
 HELP: -ignore-case
 HELP: -lookup
 HELP: -name
+HELP: -parent-recurse-depth=<N>
 HELP: -recurse-depth=<N>
 HELP: -regex
 HELP: -show-children

llvm/tools/dsymutil/DwarfLinker.cpp

@@ -227,7 +227,7 @@ void DwarfLinker::reportWarning(const Twine &Warning, const DebugMapObject &DMO,
     return;
 
   DIDumpOptions DumpOpts;
-  DumpOpts.RecurseDepth = 0;
+  DumpOpts.ChildRecurseDepth = 0;
   DumpOpts.Verbose = Options.Verbose;
 
   WithColor::note() << "    in DIE:\n";
@@ -649,7 +649,7 @@ unsigned DwarfLinker::shouldKeepVariableDIE(RelocationManager &RelocMgr,
 
   if (Options.Verbose) {
     DIDumpOptions DumpOpts;
-    DumpOpts.RecurseDepth = 0;
+    DumpOpts.ChildRecurseDepth = 0;
     DumpOpts.Verbose = Options.Verbose;
     DIE.dump(outs(), 8 /* Indent */, DumpOpts);
   }
@@ -685,7 +685,7 @@ unsigned DwarfLinker::shouldKeepSubprogramDIE(
 
   if (Options.Verbose) {
     DIDumpOptions DumpOpts;
-    DumpOpts.RecurseDepth = 0;
+    DumpOpts.ChildRecurseDepth = 0;
     DumpOpts.Verbose = Options.Verbose;
     DIE.dump(outs(), 8 /* Indent */, DumpOpts);
   }
@@ -2096,8 +2096,10 @@ void DwarfLinker::DIECloner::copyAbbrev(
   Linker.AssignAbbrev(Copy);
 }
 
-uint32_t DwarfLinker::DIECloner::hashFullyQualifiedName(
-    DWARFDie DIE, CompileUnit &U, const DebugMapObject &DMO, int RecurseDepth) {
+uint32_t
+DwarfLinker::DIECloner::hashFullyQualifiedName(DWARFDie DIE, CompileUnit &U,
+                                               const DebugMapObject &DMO,
+                                               int ChildRecurseDepth) {
   const char *Name = nullptr;
   DWARFUnit *OrigUnit = &U.getOrigUnit();
   CompileUnit *CU = &U;
@@ -2131,13 +2133,13 @@ uint32_t DwarfLinker::DIECloner::hashFullyQualifiedName(
       // FIXME: dsymutil-classic compatibility. Ignore modules.
       CU->getOrigUnit().getDIEAtIndex(CU->getInfo(Idx).ParentIdx).getTag() ==
           dwarf::DW_TAG_module)
-    return djbHash(Name ? Name : "", djbHash(RecurseDepth ? "" : "::"));
+    return djbHash(Name ? Name : "", djbHash(ChildRecurseDepth ? "" : "::"));
 
   DWARFDie Die = OrigUnit->getDIEAtIndex(CU->getInfo(Idx).ParentIdx);
   return djbHash(
       (Name ? Name : ""),
       djbHash((Name ? "::" : ""),
-              hashFullyQualifiedName(Die, *CU, DMO, ++RecurseDepth)));
+              hashFullyQualifiedName(Die, *CU, DMO, ++ChildRecurseDepth)));
 }
 
 static uint64_t getDwoId(const DWARFDie &CUDie, const DWARFUnit &Unit) {
@@ -2656,7 +2658,7 @@ bool DwarfLinker::link(const DebugMap &Map) {
       if (Options.Verbose) {
         outs() << "Input compilation unit:";
         DIDumpOptions DumpOpts;
-        DumpOpts.RecurseDepth = 0;
+        DumpOpts.ChildRecurseDepth = 0;
         DumpOpts.Verbose = Options.Verbose;
         CUDie.dump(outs(), 0, DumpOpts);
       }

llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp

@@ -192,13 +192,18 @@ static opt<bool>
              cat(DwarfDumpCategory));
 static alias ShowFormAlias("F", desc("Alias for -show-form."),
                            aliasopt(ShowForm), cat(DwarfDumpCategory));
-static opt<unsigned> RecurseDepth(
-    "recurse-depth",
-    desc("Only recurse to a depth of N when displaying debug info entries."),
-    cat(DwarfDumpCategory), init(-1U), value_desc("N"));
-static alias RecurseDepthAlias("r", desc("Alias for -recurse-depth."),
-                               aliasopt(RecurseDepth));
-
+static opt<unsigned>
+    ChildRecurseDepth("recurse-depth",
+                      desc("Only recurse to a depth of N when displaying "
+                           "children of debug info entries."),
+                      cat(DwarfDumpCategory), init(-1U), value_desc("N"));
+static alias ChildRecurseDepthAlias("r", desc("Alias for -recurse-depth."),
+                                    aliasopt(ChildRecurseDepth));
+static opt<unsigned>
+    ParentRecurseDepth("parent-recurse-depth",
+                       desc("Only recurse to a depth of N when displaying "
+                            "parents of debug info entries."),
+                       cat(DwarfDumpCategory), init(-1U), value_desc("N"));
 static opt<bool>
     SummarizeTypes("summarize-types",
                    desc("Abbreviate the description of type unit entries."),
@@ -233,7 +238,8 @@ static void error(StringRef Prefix, std::error_code EC) {
 static DIDumpOptions getDumpOpts() {
   DIDumpOptions DumpOpts;
   DumpOpts.DumpType = DumpType;
-  DumpOpts.RecurseDepth = RecurseDepth;
+  DumpOpts.ChildRecurseDepth = ChildRecurseDepth;
+  DumpOpts.ParentRecurseDepth = ParentRecurseDepth;
   DumpOpts.ShowAddresses = !Diff;
   DumpOpts.ShowChildren = ShowChildren;
   DumpOpts.ShowParents = ShowParents;
@@ -389,7 +395,7 @@ static bool lookup(ObjectFile &Obj, DWARFContext &DICtx, uint64_t Address,
     return false;
 
   DIDumpOptions DumpOpts = getDumpOpts();
-  DumpOpts.RecurseDepth = 0;
+  DumpOpts.ChildRecurseDepth = 0;
   DIEsForAddr.CompileUnit->dump(OS, DumpOpts);
   if (DIEsForAddr.FunctionDIE) {
     DIEsForAddr.FunctionDIE.dump(OS, 2, DumpOpts);