//===- DWARFDie.h -----------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_DEBUGINFO_DWARF_DWARFDIE_H
#define LLVM_DEBUGINFO_DWARF_DWARFDIE_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DIContext.h"
#include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
#include "llvm/DebugInfo/DWARF/DWARFAttribute.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
#include "llvm/DebugInfo/DWARF/DWARFLocationExpression.h"
#include <cassert>
#include <cstdint>
#include <iterator>
namespace llvm {
class DWARFUnit;
class raw_ostream;
//===----------------------------------------------------------------------===//
/// Utility class that carries the DWARF compile/type unit and the debug info
/// entry in an object.
///
/// When accessing information from a debug info entry we always need to DWARF
/// compile/type unit in order to extract the info correctly as some information
/// is relative to the compile/type unit. Prior to this class the DWARFUnit and
/// the DWARFDebugInfoEntry was passed around separately and there was the
/// possibility for error if the wrong DWARFUnit was used to extract a unit
/// relative offset. This class helps to ensure that this doesn't happen and
/// also simplifies the attribute extraction calls by not having to specify the
/// DWARFUnit for each call.
class DWARFDie {
DWARFUnit *U = nullptr;
const DWARFDebugInfoEntry *Die = nullptr;
public:
DWARFDie() = default;
DWARFDie(DWARFUnit *Unit, const DWARFDebugInfoEntry *D) : U(Unit), Die(D) {}
bool isValid() const { return U && Die; }
explicit operator bool() const { return isValid(); }
const DWARFDebugInfoEntry *getDebugInfoEntry() const { return Die; }
DWARFUnit *getDwarfUnit() const { return U; }
/// Get the abbreviation declaration for this DIE.
///
/// \returns the abbreviation declaration or NULL for null tags.
const DWARFAbbreviationDeclaration *getAbbreviationDeclarationPtr() const {
assert(isValid() && "must check validity prior to calling");
return Die->getAbbreviationDeclarationPtr();
}
/// Get the absolute offset into the debug info or types section.
///
/// \returns the DIE offset or -1U if invalid.
uint64_t getOffset() const {
assert(isValid() && "must check validity prior to calling");
return Die->getOffset();
}
dwarf::Tag getTag() const {
auto AbbrevDecl = getAbbreviationDeclarationPtr();
if (AbbrevDecl)
return AbbrevDecl->getTag();
return dwarf::DW_TAG_null;
}
bool hasChildren() const {
assert(isValid() && "must check validity prior to calling");
return Die->hasChildren();
}
/// Returns true for a valid DIE that terminates a sibling chain.
bool isNULL() const { return getAbbreviationDeclarationPtr() == nullptr; }
/// Returns true if DIE represents a subprogram (not inlined).
bool isSubprogramDIE() const;
/// Returns true if DIE represents a subprogram or an inlined subroutine.
bool isSubroutineDIE() const;
/// 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;
/// Get the previous 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 getPreviousSibling() 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;
/// Get the last child of this DIE object.
///
/// \returns a valid null DWARFDie instance if this object has children or an
/// invalid DWARFDie instance if it doesn't.
DWARFDie getLastChild() const;
/// Dump the DIE and all of its attributes to the supplied stream.
///
/// \param OS the stream to use for output.
/// \param indent the number of characters to indent each line that is output.
void dump(raw_ostream &OS, unsigned indent = 0,
DIDumpOptions DumpOpts = DIDumpOptions()) const;
/// Convenience zero-argument overload for debugging.
LLVM_DUMP_METHOD void dump() const;
/// Extract the specified attribute from this DIE.
///
/// Extract an attribute value from this DIE only. This call doesn't look
/// for the attribute value in any DW_AT_specification or
/// DW_AT_abstract_origin referenced DIEs.
///
/// \param Attr the attribute to extract.
/// \returns an optional DWARFFormValue that will have the form value if the
/// attribute was successfully extracted.
std::optional<DWARFFormValue> find(dwarf::Attribute Attr) const;
/// Extract the first value of any attribute in Attrs from this DIE.
///
/// Extract the first attribute that matches from this DIE only. This call
/// doesn't look for the attribute value in any DW_AT_specification or
/// DW_AT_abstract_origin referenced DIEs. The attributes will be searched
/// linearly in the order they are specified within Attrs.
///
/// \param Attrs an array of DWARF attribute to look for.
/// \returns an optional that has a valid DWARFFormValue for the first
/// matching attribute in Attrs, or std::nullopt if none of the attributes in
/// Attrs exist in this DIE.
std::optional<DWARFFormValue> find(ArrayRef<dwarf::Attribute> Attrs) const;
/// Extract the first value of any attribute in Attrs from this DIE and
/// recurse into any DW_AT_specification or DW_AT_abstract_origin referenced
/// DIEs.
///
/// \param Attrs an array of DWARF attribute to look for.
/// \returns an optional that has a valid DWARFFormValue for the first
/// matching attribute in Attrs, or std::nullopt if none of the attributes in
/// Attrs exist in this DIE or in any DW_AT_specification or
/// DW_AT_abstract_origin DIEs.
std::optional<DWARFFormValue>
findRecursively(ArrayRef<dwarf::Attribute> Attrs) const;
/// Extract the specified attribute from this DIE as the referenced DIE.
///
/// Regardless of the reference type, return the correct DWARFDie instance if
/// the attribute exists. The returned DWARFDie object might be from another
/// DWARFUnit, but that is all encapsulated in the new DWARFDie object.
///
/// Extract an attribute value from this DIE only. This call doesn't look
/// for the attribute value in any DW_AT_specification or
/// DW_AT_abstract_origin referenced DIEs.
///
/// \param Attr the attribute to extract.
/// \returns a valid DWARFDie instance if the attribute exists, or an invalid
/// DWARFDie object if it doesn't.
DWARFDie getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const;
DWARFDie getAttributeValueAsReferencedDie(const DWARFFormValue &V) const;
DWARFDie resolveTypeUnitReference() const;
/// Extract the range base attribute from this DIE as absolute section offset.
///
/// This is a utility function that checks for either the DW_AT_rnglists_base
/// or DW_AT_GNU_ranges_base attribute.
///
/// \returns anm optional absolute section offset value for the attribute.
std::optional<uint64_t> getRangesBaseAttribute() const;
std::optional<uint64_t> getLocBaseAttribute() const;
/// Get the DW_AT_high_pc attribute value as an address.
///
/// In DWARF version 4 and later the high PC can be encoded as an offset from
/// the DW_AT_low_pc. This function takes care of extracting the value as an
/// address or offset and adds it to the low PC if needed and returns the
/// value as an optional in case the DIE doesn't have a DW_AT_high_pc
/// attribute.
///
/// \param LowPC the low PC that might be needed to calculate the high PC.
/// \returns an optional address value for the attribute.
std::optional<uint64_t> getHighPC(uint64_t LowPC) const;
/// Retrieves DW_AT_low_pc and DW_AT_high_pc from CU.
/// Returns true if both attributes are present.
bool getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
uint64_t &SectionIndex) const;
/// Get the address ranges for this DIE.
///
/// Get the hi/low PC range if both attributes are available or exrtracts the
/// non-contiguous address ranges from the DW_AT_ranges attribute.
///
/// Extracts the range information from this DIE only. This call doesn't look
/// for the range in any DW_AT_specification or DW_AT_abstract_origin DIEs.
///
/// \returns a address range vector that might be empty if no address range
/// information is available.
Expected<DWARFAddressRangesVector> getAddressRanges() const;
bool addressRangeContainsAddress(const uint64_t Address) const;
Expected<DWARFLocationExpressionsVector>
getLocations(dwarf::Attribute Attr) const;
/// If a DIE represents a subprogram (or inlined subroutine), returns its
/// mangled name (or short name, if mangled is missing). This name may be
/// fetched from specification or abstract origin for this subprogram.
/// Returns null if no name is found.
const char *getSubroutineName(DINameKind Kind) const;
/// Return the DIE name resolving DW_AT_specification or DW_AT_abstract_origin
/// references if necessary. For the LinkageName case it additionaly searches
/// for ShortName if LinkageName is not found.
/// Returns null if no name is found.
const char *getName(DINameKind Kind) const;
void getFullName(raw_string_ostream &,
std::string *OriginalFullName = nullptr) const;
/// Return the DIE short name resolving DW_AT_specification or
/// DW_AT_abstract_origin references if necessary. Returns null if no name
/// is found.
const char *getShortName() const;
/// Return the DIE linkage name resolving DW_AT_specification or
/// DW_AT_abstract_origin references if necessary. Returns null if no name
/// is found.
const char *getLinkageName() const;
/// Returns the declaration line (start line) for a DIE, assuming it specifies
/// a subprogram. This may be fetched from specification or abstract origin
/// for this subprogram by resolving DW_AT_sepcification or
/// DW_AT_abstract_origin references if necessary.
uint64_t getDeclLine() const;
std::string getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const;
/// Retrieves values of DW_AT_call_file, DW_AT_call_line and DW_AT_call_column
/// from DIE (or zeroes if they are missing). This function looks for
/// DW_AT_call attributes in this DIE only, it will not resolve the attribute
/// values in any DW_AT_specification or DW_AT_abstract_origin DIEs.
/// \param CallFile filled in with non-zero if successful, zero if there is no
/// DW_AT_call_file attribute in this DIE.
/// \param CallLine filled in with non-zero if successful, zero if there is no
/// DW_AT_call_line attribute in this DIE.
/// \param CallColumn filled in with non-zero if successful, zero if there is
/// no DW_AT_call_column attribute in this DIE.
/// \param CallDiscriminator filled in with non-zero if successful, zero if
/// there is no DW_AT_GNU_discriminator attribute in this DIE.
void getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
uint32_t &CallColumn, uint32_t &CallDiscriminator) const;
class attribute_iterator;
/// Get an iterator range to all attributes in the current DIE only.
///
/// \returns an iterator range for the attributes of the current DIE.
iterator_range<attribute_iterator> attributes() const;
/// Gets the type size (in bytes) for this DIE.
///
/// \param PointerSize the pointer size of the containing CU.
/// \returns if this is a type DIE, or this DIE contains a DW_AT_type, returns
/// the size of the type.
std::optional<uint64_t> getTypeSize(uint64_t PointerSize);
class iterator;
iterator begin() const;
iterator end() const;
std::reverse_iterator<iterator> rbegin() const;
std::reverse_iterator<iterator> rend() const;
iterator_range<iterator> children() const;
};
class DWARFDie::attribute_iterator
: public iterator_facade_base<attribute_iterator, std::forward_iterator_tag,
const DWARFAttribute> {
/// The DWARF DIE we are extracting attributes from.
DWARFDie Die;
/// The value vended to clients via the operator*() or operator->().
DWARFAttribute AttrValue;
/// The attribute index within the abbreviation declaration in Die.
uint32_t Index;
friend bool operator==(const attribute_iterator &LHS,
const attribute_iterator &RHS);
/// Update the attribute index and attempt to read the attribute value. If the
/// attribute is able to be read, update AttrValue and the Index member
/// variable. If the attribute value is not able to be read, an appropriate
/// error will be set if the Err member variable is non-NULL and the iterator
/// will be set to the end value so iteration stops.
void updateForIndex(const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I);
public:
attribute_iterator() = delete;
explicit attribute_iterator(DWARFDie D, bool End);
attribute_iterator &operator++();
attribute_iterator &operator--();
explicit operator bool() const { return AttrValue.isValid(); }
const DWARFAttribute &operator*() const { return AttrValue; }
};
inline bool operator==(const DWARFDie::attribute_iterator &LHS,
const DWARFDie::attribute_iterator &RHS) {
return LHS.Index == RHS.Index;
}
inline bool operator!=(const DWARFDie::attribute_iterator &LHS,
const DWARFDie::attribute_iterator &RHS) {
return !(LHS == RHS);
}
inline bool operator==(const DWARFDie &LHS, const DWARFDie &RHS) {
return LHS.getDebugInfoEntry() == RHS.getDebugInfoEntry() &&
LHS.getDwarfUnit() == RHS.getDwarfUnit();
}
inline bool operator!=(const DWARFDie &LHS, const DWARFDie &RHS) {
return !(LHS == RHS);
}
inline bool operator<(const DWARFDie &LHS, const DWARFDie &RHS) {
return LHS.getOffset() < RHS.getOffset();
}
class DWARFDie::iterator
: public iterator_facade_base<iterator, std::bidirectional_iterator_tag,
const DWARFDie> {
DWARFDie Die;
friend std::reverse_iterator<llvm::DWARFDie::iterator>;
friend bool operator==(const DWARFDie::iterator &LHS,
const DWARFDie::iterator &RHS);
public:
iterator() = default;
explicit iterator(DWARFDie D) : Die(D) {}
iterator &operator++() {
Die = Die.getSibling();
return *this;
}
iterator &operator--() {
Die = Die.getPreviousSibling();
return *this;
}
const DWARFDie &operator*() const { return Die; }
};
inline bool operator==(const DWARFDie::iterator &LHS,
const DWARFDie::iterator &RHS) {
return LHS.Die == RHS.Die;
}
// These inline functions must follow the DWARFDie::iterator definition above
// as they use functions from that class.
inline DWARFDie::iterator DWARFDie::begin() const {
return iterator(getFirstChild());
}
inline DWARFDie::iterator DWARFDie::end() const {
return iterator(getLastChild());
}
inline iterator_range<DWARFDie::iterator> DWARFDie::children() const {
return make_range(begin(), end());
}
} // end namespace llvm
namespace std {
template <>
class reverse_iterator<llvm::DWARFDie::iterator>
: public llvm::iterator_facade_base<
reverse_iterator<llvm::DWARFDie::iterator>,
bidirectional_iterator_tag, const llvm::DWARFDie> {
private:
llvm::DWARFDie Die;
bool AtEnd;
public:
reverse_iterator(llvm::DWARFDie::iterator It)
: Die(It.Die), AtEnd(!It.Die.getPreviousSibling()) {
if (!AtEnd)
Die = Die.getPreviousSibling();
}
llvm::DWARFDie::iterator base() const {
return llvm::DWARFDie::iterator(AtEnd ? Die : Die.getSibling());
}
reverse_iterator<llvm::DWARFDie::iterator> &operator++() {
assert(!AtEnd && "Incrementing rend");
llvm::DWARFDie D = Die.getPreviousSibling();
if (D)
Die = D;
else
AtEnd = true;
return *this;
}
reverse_iterator<llvm::DWARFDie::iterator> &operator--() {
if (AtEnd) {
AtEnd = false;
return *this;
}
Die = Die.getSibling();
assert(!Die.isNULL() && "Decrementing rbegin");
return *this;
}
const llvm::DWARFDie &operator*() const {
assert(Die.isValid());
return Die;
}
// FIXME: We should be able to specify the equals operator as a friend, but
// that causes the compiler to think the operator overload is ambiguous
// with the friend declaration and the actual definition as candidates.
bool equals(const reverse_iterator<llvm::DWARFDie::iterator> &RHS) const {
return Die == RHS.Die && AtEnd == RHS.AtEnd;
}
};
} // namespace std
namespace llvm {
inline bool operator==(const std::reverse_iterator<DWARFDie::iterator> &LHS,
const std::reverse_iterator<DWARFDie::iterator> &RHS) {
return LHS.equals(RHS);
}
inline bool operator!=(const std::reverse_iterator<DWARFDie::iterator> &LHS,
const std::reverse_iterator<DWARFDie::iterator> &RHS) {
return !(LHS == RHS);
}
inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rbegin() const {
return std::make_reverse_iterator(end());
}
inline std::reverse_iterator<DWARFDie::iterator> DWARFDie::rend() const {
return std::make_reverse_iterator(begin());
}
void dumpTypeQualifiedName(const DWARFDie &DIE, raw_ostream &OS);
void dumpTypeUnqualifiedName(const DWARFDie &DIE, raw_ostream &OS,
std::string *OriginalFullName = nullptr);
} // end namespace llvm
#endif // LLVM_DEBUGINFO_DWARF_DWARFDIE_H