[llvm] r290274 - Add the ability for DWARFDie objects to get the parent DWARFDie.
Greg Clayton via llvm-commits
llvm-commits at lists.llvm.org
Wed Dec 21 13:37:06 PST 2016
Author: gclayton
Date: Wed Dec 21 15:37:06 2016
New Revision: 290274
URL: http://llvm.org/viewvc/llvm-project?rev=290274&view=rev
Log:
Add the ability for DWARFDie objects to get the parent DWARFDie.
In order for the llvm DWARF parser to be used in LLDB we will need to be able to get the parent of a DIE. This patch adds that functionality by changing the DWARFDebugInfoEntry class to store a depth field instead of a sibling index. Using a depth field allows us to easily calculate the sibling and the parent without increasing the size of DWARFDebugInfoEntry.
I tested llvm-dsymutil on a debug version of clang where this fully parses DWARF in over 1200 .o files to verify there was no serious regression in performance.
Added a full suite of unit tests to test this functionality.
Differential Revision: https://reviews.llvm.org/D27995
Modified:
llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h
llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDie.h
llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h
llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp
llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp
llvm/trunk/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h Wed Dec 21 15:37:06 2016
@@ -31,13 +31,14 @@ class DWARFDebugInfoEntry {
/// Offset within the .debug_info of the start of this entry.
uint32_t Offset;
- /// How many to add to "this" to get the sibling.
- uint32_t SiblingIdx;
+ /// The integer depth of this DIE within the compile unit DIEs where the
+ /// compile/type unit DIE has a depth of zero.
+ uint32_t Depth;
const DWARFAbbreviationDeclaration *AbbrevDecl;
public:
DWARFDebugInfoEntry()
- : Offset(0), SiblingIdx(0), AbbrevDecl(nullptr) {}
+ : Offset(0), Depth(0), AbbrevDecl(nullptr) {}
/// Extracts a debug info entry, which is a child of a given unit,
/// starting at a given offset. If DIE can't be extracted, returns false and
@@ -45,33 +46,16 @@ public:
bool extractFast(const DWARFUnit &U, uint32_t *OffsetPtr);
/// High performance extraction should use this call.
bool extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
- const DataExtractor &DebugInfoData, uint32_t UEndOffset);
+ const DataExtractor &DebugInfoData,
+ uint32_t UEndOffset,
+ uint32_t Depth);
uint32_t getOffset() const { return Offset; }
- bool hasChildren() const { return AbbrevDecl && AbbrevDecl->hasChildren(); }
-
- // We know we are kept in a vector of contiguous entries, so we know
- // our sibling will be some index after "this".
- const DWARFDebugInfoEntry *getSibling() const {
- return SiblingIdx > 0 ? this + SiblingIdx : nullptr;
- }
-
- // We know we are kept in a vector of contiguous entries, so we know
- // we don't need to store our child pointer, if we have a child it will
- // be the next entry in the list...
- const DWARFDebugInfoEntry *getFirstChild() const {
- return hasChildren() ? this + 1 : nullptr;
+ uint32_t getDepth() const { return Depth; }
+ dwarf::Tag getTag() const {
+ return AbbrevDecl ? AbbrevDecl->getTag() : dwarf::DW_TAG_null;
}
-
- void setSibling(const DWARFDebugInfoEntry *Sibling) {
- if (Sibling) {
- // We know we are kept in a vector of contiguous entries, so we know
- // our sibling will be some index after "this".
- SiblingIdx = Sibling - this;
- } else
- SiblingIdx = 0;
- }
-
+ bool hasChildren() const { return AbbrevDecl && AbbrevDecl->hasChildren(); }
const DWARFAbbreviationDeclaration *getAbbreviationDeclarationPtr() const {
return AbbrevDecl;
}
Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDie.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDie.h?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDie.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFDie.h Wed Dec 21 15:37:06 2016
@@ -40,6 +40,9 @@ public:
bool isValid() const { return U && Die; }
explicit operator bool() const { return isValid(); }
+ bool operator ==(const DWARFDie &RHS) const {
+ return Die == RHS.Die && U == RHS.U;
+ }
const DWARFDebugInfoEntry *getDebugInfoEntry() const { return Die; }
DWARFUnit *getDwarfUnit() const { return U; }
@@ -82,23 +85,26 @@ public:
/// Returns true if DIE represents a subprogram or an inlined subroutine.
bool isSubroutineDIE() const;
-
- /// Get the silbing of this DIE object.
+ /// Get the parent of this DIE object.
+ ///
+ /// \returns a valid DWARFDie instance if this object has a parent or an
+ /// invalid DWARFDie instance if it doesn't.
+ DWARFDie getParent() const;
+
+ /// Get the sibling of this DIE object.
///
/// \returns a valid DWARFDie instance if this object has a sibling or an
/// invalid DWARFDie instance if it doesn't.
- DWARFDie getSibling() const {
- assert(isValid() && "must check validity prior to calling");
- return DWARFDie(U, Die->getSibling());
- }
+ DWARFDie getSibling() const;
/// Get the first child of this DIE object.
///
/// \returns a valid DWARFDie instance if this object has children or an
/// invalid DWARFDie instance if it doesn't.
DWARFDie getFirstChild() const {
- assert(isValid() && "must check validity prior to calling");
- return DWARFDie(U, Die->getFirstChild());
+ if (isValid() && Die->hasChildren())
+ return DWARFDie(U, Die + 1);
+ return DWARFDie();
}
/// Dump the DIE and all of its attributes to the supplied stream.
Modified: llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h (original)
+++ llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h Wed Dec 21 15:37:06 2016
@@ -140,6 +140,12 @@ class DWARFUnit {
const DWARFUnitIndex::Entry *IndexEntry;
+ uint32_t getDIEIndex(const DWARFDebugInfoEntry *Die) {
+ auto First = DieArray.data();
+ assert(Die >= First && Die < First + DieArray.size());
+ return Die - First;
+ }
+
protected:
virtual bool extractImpl(DataExtractor debug_info, uint32_t *offset_ptr);
/// Size in bytes of the unit header.
@@ -251,19 +257,18 @@ public:
/// method on a DIE that isn't accessible by following
/// children/sibling links starting from this unit's getUnitDIE().
uint32_t getDIEIndex(const DWARFDie &D) {
- auto DIE = D.getDebugInfoEntry();
- assert(!DieArray.empty() && DIE >= &DieArray[0] &&
- DIE < &DieArray[0] + DieArray.size());
- return DIE - &DieArray[0];
+ return getDIEIndex(D.getDebugInfoEntry());
}
/// \brief Return the DIE object at the given index.
DWARFDie getDIEAtIndex(unsigned Index) {
- if (Index < DieArray.size())
- return DWARFDie(this, &DieArray[Index]);
- return DWARFDie();
+ assert(Index < DieArray.size());
+ return DWARFDie(this, &DieArray[Index]);
}
+ DWARFDie getParent(const DWARFDebugInfoEntry *Die);
+ DWARFDie getSibling(const DWARFDebugInfoEntry *Die);
+
/// \brief Return the DIE object for a given offset inside the
/// unit's DIE vector.
///
@@ -298,10 +303,6 @@ private:
/// extractDIEsToVector - Appends all parsed DIEs to a vector.
void extractDIEsToVector(bool AppendCUDie, bool AppendNonCUDIEs,
std::vector<DWARFDebugInfoEntry> &DIEs) const;
- /// setDIERelations - We read in all of the DIE entries into our flat list
- /// of DIE entries and now we need to go back through all of them and set the
- /// parent, sibling and child pointers for quick DIE navigation.
- void setDIERelations();
/// clearDIEs - Clear parsed DIEs to keep memory usage low.
void clearDIEs(bool KeepCUDie);
Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFDebugInfoEntry.cpp Wed Dec 21 15:37:06 2016
@@ -26,13 +26,13 @@ bool DWARFDebugInfoEntry::extractFast(co
uint32_t *OffsetPtr) {
DataExtractor DebugInfoData = U.getDebugInfoExtractor();
const uint32_t UEndOffset = U.getNextUnitOffset();
- return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset);
+ return extractFast(U, OffsetPtr, DebugInfoData, UEndOffset, 0);
}
-bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U,
- uint32_t *OffsetPtr,
- const DataExtractor &DebugInfoData,
- uint32_t UEndOffset) {
+bool DWARFDebugInfoEntry::extractFast(const DWARFUnit &U, uint32_t *OffsetPtr,
+ const DataExtractor &DebugInfoData,
+ uint32_t UEndOffset, uint32_t D) {
Offset = *OffsetPtr;
+ Depth = D;
if (Offset >= UEndOffset || !DebugInfoData.isValidOffset(Offset))
return false;
uint64_t AbbrCode = DebugInfoData.getULEB128(OffsetPtr);
Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFDie.cpp Wed Dec 21 15:37:06 2016
@@ -428,3 +428,14 @@ void DWARFDie::getInlinedChainForAddress
std::reverse(InlinedChain.begin(), InlinedChain.end());
}
+DWARFDie DWARFDie::getParent() const {
+ if (isValid())
+ return U->getParent(Die);
+ return DWARFDie();
+}
+
+DWARFDie DWARFDie::getSibling() const {
+ if (isValid())
+ return U->getSibling(Die);
+ return DWARFDie();
+}
Modified: llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp (original)
+++ llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp Wed Dec 21 15:37:06 2016
@@ -158,35 +158,6 @@ Optional<uint64_t> DWARFUnit::getDWOId()
return getUnitDIE().getAttributeValueAsUnsignedConstant(DW_AT_GNU_dwo_id);
}
-void DWARFUnit::setDIERelations() {
- if (DieArray.size() <= 1)
- return;
-
- std::vector<DWARFDebugInfoEntry *> ParentChain;
- DWARFDebugInfoEntry *SiblingChain = nullptr;
- for (auto &DIE : DieArray) {
- if (SiblingChain) {
- SiblingChain->setSibling(&DIE);
- }
- if (const DWARFAbbreviationDeclaration *AbbrDecl =
- DIE.getAbbreviationDeclarationPtr()) {
- // Normal DIE.
- if (AbbrDecl->hasChildren()) {
- ParentChain.push_back(&DIE);
- SiblingChain = nullptr;
- } else {
- SiblingChain = &DIE;
- }
- } else {
- // NULL entry terminates the sibling chain.
- SiblingChain = ParentChain.back();
- ParentChain.pop_back();
- }
- }
- assert(SiblingChain == nullptr || SiblingChain == &DieArray[0]);
- assert(ParentChain.empty());
-}
-
void DWARFUnit::extractDIEsToVector(
bool AppendCUDie, bool AppendNonCUDies,
std::vector<DWARFDebugInfoEntry> &Dies) const {
@@ -202,7 +173,8 @@ void DWARFUnit::extractDIEsToVector(
uint32_t Depth = 0;
bool IsCUDie = true;
- while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset)) {
+ while (DIE.extractFast(*this, &DIEOffset, DebugInfoData, NextCUOffset,
+ Depth)) {
if (IsCUDie) {
if (AppendCUDie)
Dies.push_back(DIE);
@@ -266,7 +238,6 @@ size_t DWARFUnit::extractDIEsIfNeeded(bo
// skeleton CU DIE, so that DWARF users not aware of it are not broken.
}
- setDIERelations();
return DieArray.size();
}
@@ -409,4 +380,42 @@ const DWARFUnitIndex &getDWARFUnitIndex(
return Context.getTUIndex();
}
+DWARFDie DWARFUnit::getParent(const DWARFDebugInfoEntry *Die) {
+ if (!Die)
+ return DWARFDie();
+ const uint32_t Depth = Die->getDepth();
+ // Unit DIEs always have a depth of zero and never have parents.
+ if (Depth == 0)
+ return DWARFDie();
+ // Depth of 1 always means parent is the compile/type unit.
+ if (Depth == 1)
+ return getUnitDIE();
+ // Look for previous DIE with a depth that is one less than the Die's depth.
+ const uint32_t ParentDepth = Depth - 1;
+ for (uint32_t I = getDIEIndex(Die) - 1; I > 0; --I) {
+ if (DieArray[I].getDepth() == ParentDepth)
+ return DWARFDie(this, &DieArray[I]);
+ }
+ return DWARFDie();
+}
+
+DWARFDie DWARFUnit::getSibling(const DWARFDebugInfoEntry *Die) {
+ if (!Die)
+ return DWARFDie();
+ uint32_t Depth = Die->getDepth();
+ // Unit DIEs always have a depth of zero and never have siblings.
+ if (Depth == 0)
+ return DWARFDie();
+ // NULL DIEs don't have siblings.
+ if (Die->getAbbreviationDeclarationPtr() == nullptr)
+ return DWARFDie();
+
+ // Find the next DIE whose depth is the same as the Die's depth.
+ for (size_t I=getDIEIndex(Die)+1, EndIdx = DieArray.size(); I<EndIdx; ++I) {
+ if (DieArray[I].getDepth() == Depth)
+ return DWARFDie(this, &DieArray[I]);
+ }
+ return DWARFDie();
+}
+
} // end namespace llvm
Modified: llvm/trunk/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp?rev=290274&r1=290273&r2=290274&view=diff
==============================================================================
--- llvm/trunk/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp (original)
+++ llvm/trunk/unittests/DebugInfo/DWARF/DWARFDebugInfoTest.cpp Wed Dec 21 15:37:06 2016
@@ -967,5 +967,121 @@ TEST(DWARFDebugInfo, TestDWARF32Version4
TestAddresses<4, AddrType>();
}
+TEST(DWARFDebugInfo, TestRelations) {
+ // Test the DWARF APIs related to accessing the DW_AT_low_pc and
+ // DW_AT_high_pc.
+ uint16_t Version = 4;
+
+ const uint8_t AddrSize = sizeof(void *);
+ initLLVMIfNeeded();
+ Triple Triple = getHostTripleForAddrSize(AddrSize);
+ auto ExpectedDG = dwarfgen::Generator::create(Triple, Version);
+ if (HandleExpectedError(ExpectedDG))
+ return;
+ dwarfgen::Generator *DG = ExpectedDG.get().get();
+ dwarfgen::CompileUnit &CU = DG->addCompileUnit();
+
+ enum class Tag: uint16_t {
+ A = dwarf::DW_TAG_lo_user,
+ B,
+ B1,
+ B2,
+ C,
+ C1
+ };
+
+ // Scope to allow us to re-use the same DIE names
+ {
+ // Create DWARF tree that looks like:
+ //
+ // CU
+ // A
+ // B
+ // B1
+ // B2
+ // C
+ // C1
+ dwarfgen::DIE CUDie = CU.getUnitDIE();
+ CUDie.addChild((dwarf::Tag)Tag::A);
+ dwarfgen::DIE B = CUDie.addChild((dwarf::Tag)Tag::B);
+ dwarfgen::DIE C = CUDie.addChild((dwarf::Tag)Tag::C);
+ B.addChild((dwarf::Tag)Tag::B1);
+ B.addChild((dwarf::Tag)Tag::B2);
+ C.addChild((dwarf::Tag)Tag::C1);
+ }
+
+ MemoryBufferRef FileBuffer(DG->generate(), "dwarf");
+ auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
+ EXPECT_TRUE((bool)Obj);
+ DWARFContextInMemory DwarfContext(*Obj.get());
+
+ // Verify the number of compile units is correct.
+ uint32_t NumCUs = DwarfContext.getNumCompileUnits();
+ EXPECT_EQ(NumCUs, 1u);
+ DWARFCompileUnit *U = DwarfContext.getCompileUnitAtIndex(0);
+
+ // Get the compile unit DIE is valid.
+ auto CUDie = U->getUnitDIE(false);
+ EXPECT_TRUE(CUDie.isValid());
+ // DieDG.dump(llvm::outs(), U, UINT32_MAX);
+
+ // The compile unit doesn't have a parent or a sibling.
+ auto ParentDie = CUDie.getParent();
+ EXPECT_FALSE(ParentDie.isValid());
+ auto SiblingDie = CUDie.getSibling();
+ EXPECT_FALSE(SiblingDie.isValid());
+
+ // Get the children of the compile unit
+ auto A = CUDie.getFirstChild();
+ auto B = A.getSibling();
+ auto C = B.getSibling();
+ auto Null = C.getSibling();
+
+ // Verify NULL Die is NULL and has no children or siblings
+ EXPECT_TRUE(Null.isNULL());
+ EXPECT_FALSE(Null.getSibling().isValid());
+ EXPECT_FALSE(Null.getFirstChild().isValid());
+
+ // Verify all children of the compile unit DIE are correct.
+ EXPECT_EQ(A.getTag(), (dwarf::Tag)Tag::A);
+ EXPECT_EQ(B.getTag(), (dwarf::Tag)Tag::B);
+ EXPECT_EQ(C.getTag(), (dwarf::Tag)Tag::C);
+
+ // Verify who has children
+ EXPECT_FALSE(A.hasChildren());
+ EXPECT_TRUE(B.hasChildren());
+
+ // Make sure the parent of all the children of the compile unit are the
+ // compile unit.
+ EXPECT_EQ(A.getParent(), CUDie);
+ EXPECT_EQ(B.getParent(), CUDie);
+ EXPECT_EQ(Null.getParent(), CUDie);
+
+ EXPECT_FALSE(A.getFirstChild().isValid());
+
+ // Verify the children of the B DIE
+ auto B1 = B.getFirstChild();
+ auto B2 = B1.getSibling();
+ EXPECT_TRUE(B2.getSibling().isNULL());
+
+ // Verify all children of the B DIE correctly valid or invalid.
+ EXPECT_EQ(B1.getTag(), (dwarf::Tag)Tag::B1);
+ EXPECT_EQ(B2.getTag(), (dwarf::Tag)Tag::B2);
+
+ // Make sure the parent of all the children of the B are the B.
+ EXPECT_EQ(B1.getParent(), B);
+ EXPECT_EQ(B2.getParent(), B);
+}
+
+TEST(DWARFDebugInfo, TestDWARFDie) {
+
+ // Make sure a default constructed DWARFDie doesn't have any parent, sibling
+ // or child;
+ DWARFDie DefaultDie;
+ EXPECT_FALSE(DefaultDie.getParent().isValid());
+ EXPECT_FALSE(DefaultDie.getFirstChild().isValid());
+ EXPECT_FALSE(DefaultDie.getSibling().isValid());
+}
+
} // end anonymous namespace
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