LCOV - code coverage report
Current view: top level - include/llvm/DebugInfo/DWARF - DWARFDie.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 21 21 100.0 %
Date: 2018-07-13 00:08:38 Functions: 2 2 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- DWARFDie.h -----------------------------------------------*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : 
      10             : #ifndef LLVM_DEBUGINFO_DWARFDIE_H
      11             : #define LLVM_DEBUGINFO_DWARFDIE_H
      12             : 
      13             : #include "llvm/ADT/ArrayRef.h"
      14             : #include "llvm/ADT/Optional.h"
      15             : #include "llvm/ADT/iterator.h"
      16             : #include "llvm/ADT/iterator_range.h"
      17             : #include "llvm/BinaryFormat/Dwarf.h"
      18             : #include "llvm/DebugInfo/DIContext.h"
      19             : #include "llvm/DebugInfo/DWARF/DWARFAddressRange.h"
      20             : #include "llvm/DebugInfo/DWARF/DWARFAttribute.h"
      21             : #include "llvm/DebugInfo/DWARF/DWARFDebugInfoEntry.h"
      22             : #include <cassert>
      23             : #include <cstdint>
      24             : #include <iterator>
      25             : 
      26             : namespace llvm {
      27             : 
      28             : class DWARFUnit;
      29             : class raw_ostream;
      30             : 
      31             : //===----------------------------------------------------------------------===//
      32             : /// Utility class that carries the DWARF compile/type unit and the debug info
      33             : /// entry in an object.
      34             : ///
      35             : /// When accessing information from a debug info entry we always need to DWARF
      36             : /// compile/type unit in order to extract the info correctly as some information
      37             : /// is relative to the compile/type unit. Prior to this class the DWARFUnit and
      38             : /// the DWARFDebugInfoEntry was passed around separately and there was the
      39             : /// possibility for error if the wrong DWARFUnit was used to extract a unit
      40             : /// relative offset. This class helps to ensure that this doesn't happen and
      41             : /// also simplifies the attribute extraction calls by not having to specify the
      42             : /// DWARFUnit for each call.
      43             : class DWARFDie {
      44             :   DWARFUnit *U = nullptr;
      45             :   const DWARFDebugInfoEntry *Die = nullptr;
      46             : 
      47             : public:
      48         208 :   DWARFDie() = default;
      49        1220 :   DWARFDie(DWARFUnit *Unit, const DWARFDebugInfoEntry * D) : U(Unit), Die(D) {}
      50             : 
      51      319458 :   bool isValid() const { return U && Die; }
      52             :   explicit operator bool() const { return isValid(); }
      53             :   const DWARFDebugInfoEntry *getDebugInfoEntry() const { return Die; }
      54             :   DWARFUnit *getDwarfUnit() const { return U; }
      55             : 
      56             :   /// Get the abbreviation declaration for this DIE.
      57             :   ///
      58             :   /// \returns the abbreviation declaration or NULL for null tags.
      59             :   const DWARFAbbreviationDeclaration *getAbbreviationDeclarationPtr() const {
      60             :     assert(isValid() && "must check validity prior to calling");
      61      163192 :     return Die->getAbbreviationDeclarationPtr();
      62             :   }
      63             : 
      64             :   /// Get the absolute offset into the debug info or types section.
      65             :   ///
      66             :   /// \returns the DIE offset or -1U if invalid.
      67             :   uint32_t getOffset() const {
      68             :     assert(isValid() && "must check validity prior to calling");
      69      105713 :     return Die->getOffset();
      70             :   }
      71             : 
      72             :   dwarf::Tag getTag() const {
      73       43112 :     auto AbbrevDecl = getAbbreviationDeclarationPtr();
      74       49056 :     if (AbbrevDecl)
      75       44586 :       return AbbrevDecl->getTag();
      76             :     return dwarf::DW_TAG_null;
      77             :   }
      78             : 
      79             :   bool hasChildren() const {
      80             :     assert(isValid() && "must check validity prior to calling");
      81        1865 :     return Die->hasChildren();
      82             :   }
      83             : 
      84             :   /// Returns true for a valid DIE that terminates a sibling chain.
      85             :   bool isNULL() const {
      86        7488 :     return getAbbreviationDeclarationPtr() == nullptr;
      87             :   }
      88             : 
      89             :   /// Returns true if DIE represents a subprogram (not inlined).
      90             :   bool isSubprogramDIE() const;
      91             : 
      92             :   /// Returns true if DIE represents a subprogram or an inlined subroutine.
      93             :   bool isSubroutineDIE() const;
      94             : 
      95             :   /// Get the parent of this DIE object.
      96             :   ///
      97             :   /// \returns a valid DWARFDie instance if this object has a parent or an
      98             :   /// invalid DWARFDie instance if it doesn't.
      99             :   DWARFDie getParent() const;
     100             : 
     101             :   /// Get the sibling of this DIE object.
     102             :   ///
     103             :   /// \returns a valid DWARFDie instance if this object has a sibling or an
     104             :   /// invalid DWARFDie instance if it doesn't.
     105             :   DWARFDie getSibling() const;
     106             : 
     107             :   /// Get the first child of this DIE object.
     108             :   ///
     109             :   /// \returns a valid DWARFDie instance if this object has children or an
     110             :   /// invalid DWARFDie instance if it doesn't.
     111             :   DWARFDie getFirstChild() const;
     112             : 
     113             :   /// Dump the DIE and all of its attributes to the supplied stream.
     114             :   ///
     115             :   /// \param OS the stream to use for output.
     116             :   /// \param indent the number of characters to indent each line that is output.
     117             :   void dump(raw_ostream &OS, unsigned indent = 0,
     118             :             DIDumpOptions DumpOpts = DIDumpOptions()) const;
     119             : 
     120             : 
     121             :   /// Convenience zero-argument overload for debugging.
     122             :   LLVM_DUMP_METHOD void dump() const;
     123             : 
     124             :   /// Extract the specified attribute from this DIE.
     125             :   ///
     126             :   /// Extract an attribute value from this DIE only. This call doesn't look
     127             :   /// for the attribute value in any DW_AT_specification or
     128             :   /// DW_AT_abstract_origin referenced DIEs.
     129             :   ///
     130             :   /// \param Attr the attribute to extract.
     131             :   /// \returns an optional DWARFFormValue that will have the form value if the
     132             :   /// attribute was successfully extracted.
     133             :   Optional<DWARFFormValue> find(dwarf::Attribute Attr) const;
     134             : 
     135             :   /// Extract the first value of any attribute in Attrs from this DIE.
     136             :   ///
     137             :   /// Extract the first attribute that matches from this DIE only. This call
     138             :   /// doesn't look for the attribute value in any DW_AT_specification or
     139             :   /// DW_AT_abstract_origin referenced DIEs. The attributes will be searched
     140             :   /// linearly in the order they are specified within Attrs.
     141             :   ///
     142             :   /// \param Attrs an array of DWARF attribute to look for.
     143             :   /// \returns an optional that has a valid DWARFFormValue for the first
     144             :   /// matching attribute in Attrs, or None if none of the attributes in Attrs
     145             :   /// exist in this DIE.
     146             :   Optional<DWARFFormValue> find(ArrayRef<dwarf::Attribute> Attrs) const;
     147             : 
     148             :   /// Extract the first value of any attribute in Attrs from this DIE and
     149             :   /// recurse into any DW_AT_specification or DW_AT_abstract_origin referenced
     150             :   /// DIEs.
     151             :   ///
     152             :   /// \param Attrs an array of DWARF attribute to look for.
     153             :   /// \returns an optional that has a valid DWARFFormValue for the first
     154             :   /// matching attribute in Attrs, or None if none of the attributes in Attrs
     155             :   /// exist in this DIE or in any DW_AT_specification or DW_AT_abstract_origin
     156             :   /// DIEs.
     157             :   Optional<DWARFFormValue>
     158             :   findRecursively(ArrayRef<dwarf::Attribute> Attrs) const;
     159             : 
     160             :   /// Extract the specified attribute from this DIE as the referenced DIE.
     161             :   ///
     162             :   /// Regardless of the reference type, return the correct DWARFDie instance if
     163             :   /// the attribute exists. The returned DWARFDie object might be from another
     164             :   /// DWARFUnit, but that is all encapsulated in the new DWARFDie object.
     165             :   ///
     166             :   /// Extract an attribute value from this DIE only. This call doesn't look
     167             :   /// for the attribute value in any DW_AT_specification or
     168             :   /// DW_AT_abstract_origin referenced DIEs.
     169             :   ///
     170             :   /// \param Attr the attribute to extract.
     171             :   /// \returns a valid DWARFDie instance if the attribute exists, or an invalid
     172             :   /// DWARFDie object if it doesn't.
     173             :   DWARFDie getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const;
     174             : 
     175             :   /// Extract the range base attribute from this DIE as absolute section offset.
     176             :   ///
     177             :   /// This is a utility function that checks for either the DW_AT_rnglists_base
     178             :   /// or DW_AT_GNU_ranges_base attribute.
     179             :   ///
     180             :   /// \returns anm optional absolute section offset value for the attribute.
     181             :   Optional<uint64_t> getRangesBaseAttribute() const;
     182             : 
     183             :   /// Get the DW_AT_high_pc attribute value as an address.
     184             :   ///
     185             :   /// In DWARF version 4 and later the high PC can be encoded as an offset from
     186             :   /// the DW_AT_low_pc. This function takes care of extracting the value as an
     187             :   /// address or offset and adds it to the low PC if needed and returns the
     188             :   /// value as an optional in case the DIE doesn't have a DW_AT_high_pc
     189             :   /// attribute.
     190             :   ///
     191             :   /// \param LowPC the low PC that might be needed to calculate the high PC.
     192             :   /// \returns an optional address value for the attribute.
     193             :   Optional<uint64_t> getHighPC(uint64_t LowPC) const;
     194             : 
     195             :   /// Retrieves DW_AT_low_pc and DW_AT_high_pc from CU.
     196             :   /// Returns true if both attributes are present.
     197             :   bool getLowAndHighPC(uint64_t &LowPC, uint64_t &HighPC,
     198             :                        uint64_t &SectionIndex) const;
     199             : 
     200             :   /// Get the address ranges for this DIE.
     201             :   ///
     202             :   /// Get the hi/low PC range if both attributes are available or exrtracts the
     203             :   /// non-contiguous address ranges from the DW_AT_ranges attribute.
     204             :   ///
     205             :   /// Extracts the range information from this DIE only. This call doesn't look
     206             :   /// for the range in any DW_AT_specification or DW_AT_abstract_origin DIEs.
     207             :   ///
     208             :   /// \returns a address range vector that might be empty if no address range
     209             :   /// information is available.
     210             :   Expected<DWARFAddressRangesVector> getAddressRanges() const;
     211             : 
     212             :   /// Get all address ranges for any DW_TAG_subprogram DIEs in this DIE or any
     213             :   /// of its children.
     214             :   ///
     215             :   /// Get the hi/low PC range if both attributes are available or exrtracts the
     216             :   /// non-contiguous address ranges from the DW_AT_ranges attribute for this DIE
     217             :   /// and all children.
     218             :   ///
     219             :   /// \param Ranges the addres range vector to fill in.
     220             :   void collectChildrenAddressRanges(DWARFAddressRangesVector &Ranges) const;
     221             : 
     222             :   bool addressRangeContainsAddress(const uint64_t Address) const;
     223             : 
     224             :   /// If a DIE represents a subprogram (or inlined subroutine), returns its
     225             :   /// mangled name (or short name, if mangled is missing). This name may be
     226             :   /// fetched from specification or abstract origin for this subprogram.
     227             :   /// Returns null if no name is found.
     228             :   const char *getSubroutineName(DINameKind Kind) const;
     229             : 
     230             :   /// Return the DIE name resolving DW_AT_sepcification or DW_AT_abstract_origin
     231             :   /// references if necessary. Returns null if no name is found.
     232             :   const char *getName(DINameKind Kind) const;
     233             : 
     234             :   /// Returns the declaration line (start line) for a DIE, assuming it specifies
     235             :   /// a subprogram. This may be fetched from specification or abstract origin
     236             :   /// for this subprogram by resolving DW_AT_sepcification or
     237             :   /// DW_AT_abstract_origin references if necessary.
     238             :   uint64_t getDeclLine() const;
     239             : 
     240             :   /// Retrieves values of DW_AT_call_file, DW_AT_call_line and DW_AT_call_column
     241             :   /// from DIE (or zeroes if they are missing). This function looks for
     242             :   /// DW_AT_call attributes in this DIE only, it will not resolve the attribute
     243             :   /// values in any DW_AT_specification or DW_AT_abstract_origin DIEs.
     244             :   /// \param CallFile filled in with non-zero if successful, zero if there is no
     245             :   /// DW_AT_call_file attribute in this DIE.
     246             :   /// \param CallLine filled in with non-zero if successful, zero if there is no
     247             :   /// DW_AT_call_line attribute in this DIE.
     248             :   /// \param CallColumn filled in with non-zero if successful, zero if there is
     249             :   /// no DW_AT_call_column attribute in this DIE.
     250             :   /// \param CallDiscriminator filled in with non-zero if successful, zero if
     251             :   /// there is no DW_AT_GNU_discriminator attribute in this DIE.
     252             :   void getCallerFrame(uint32_t &CallFile, uint32_t &CallLine,
     253             :                       uint32_t &CallColumn, uint32_t &CallDiscriminator) const;
     254             : 
     255             :   class attribute_iterator;
     256             : 
     257             :   /// Get an iterator range to all attributes in the current DIE only.
     258             :   ///
     259             :   /// \returns an iterator range for the attributes of the current DIE.
     260             :   iterator_range<attribute_iterator> attributes() const;
     261             : 
     262             :   class iterator;
     263             : 
     264             :   iterator begin() const;
     265             :   iterator end() const;
     266             :   iterator_range<iterator> children() const;
     267             : };
     268             : 
     269             : class DWARFDie::attribute_iterator :
     270             :     public iterator_facade_base<attribute_iterator, std::forward_iterator_tag,
     271             :                                 const DWARFAttribute> {
     272             :   /// The DWARF DIE we are extracting attributes from.
     273             :   DWARFDie Die;
     274             :   /// The value vended to clients via the operator*() or operator->().
     275             :   DWARFAttribute AttrValue;
     276             :   /// The attribute index within the abbreviation declaration in Die.
     277             :   uint32_t Index;
     278             : 
     279             :   /// Update the attribute index and attempt to read the attribute value. If the
     280             :   /// attribute is able to be read, update AttrValue and the Index member
     281             :   /// variable. If the attribute value is not able to be read, an appropriate
     282             :   /// error will be set if the Err member variable is non-NULL and the iterator
     283             :   /// will be set to the end value so iteration stops.
     284             :   void updateForIndex(const DWARFAbbreviationDeclaration &AbbrDecl, uint32_t I);
     285             : 
     286             : public:
     287             :   attribute_iterator() = delete;
     288             :   explicit attribute_iterator(DWARFDie D, bool End);
     289             : 
     290             :   attribute_iterator &operator++();
     291             :   explicit operator bool() const { return AttrValue.isValid(); }
     292             :   const DWARFAttribute &operator*() const { return AttrValue; }
     293             :   bool operator==(const attribute_iterator &X) const { return Index == X.Index; }
     294             : };
     295             : 
     296             : inline bool operator==(const DWARFDie &LHS, const DWARFDie &RHS) {
     297       14301 :   return LHS.getDebugInfoEntry() == RHS.getDebugInfoEntry() &&
     298        3867 :       LHS.getDwarfUnit() == RHS.getDwarfUnit();
     299             : }
     300             : 
     301             : inline bool operator!=(const DWARFDie &LHS, const DWARFDie &RHS) {
     302             :   return !(LHS == RHS);
     303             : }
     304             : 
     305             : inline bool operator<(const DWARFDie &LHS, const DWARFDie &RHS) {
     306        1190 :   return LHS.getOffset() < RHS.getOffset();
     307             : }
     308             : 
     309             : class DWARFDie::iterator : public iterator_facade_base<iterator,
     310             :                                                       std::forward_iterator_tag,
     311             :                                                       const DWARFDie> {
     312             :   DWARFDie Die;
     313             :   void skipNull() {
     314        7538 :     if (Die && Die.isNULL())
     315        1613 :       Die = DWARFDie();
     316             :   }
     317             : public:
     318             :   iterator() = default;
     319             : 
     320             :   explicit iterator(DWARFDie D) : Die(D) {
     321             :     // If we start out with only a Null DIE then invalidate.
     322             :     skipNull();
     323             :   }
     324             : 
     325        5491 :   iterator &operator++() {
     326        5491 :     Die = Die.getSibling();
     327             :     // Don't include the NULL die when iterating.
     328             :     skipNull();
     329        5491 :     return *this;
     330             :   }
     331             : 
     332             :   explicit operator bool() const { return Die.isValid(); }
     333             :   const DWARFDie &operator*() const { return Die; }
     334             :   bool operator==(const iterator &X) const { return Die == X.Die; }
     335             : };
     336             : 
     337             : // These inline functions must follow the DWARFDie::iterator definition above
     338             : // as they use functions from that class.
     339        4280 : inline DWARFDie::iterator DWARFDie::begin() const {
     340        8560 :   return iterator(getFirstChild());
     341             : }
     342             : 
     343             : inline DWARFDie::iterator DWARFDie::end() const {
     344             :   return iterator();
     345             : }
     346             : 
     347             : inline iterator_range<DWARFDie::iterator> DWARFDie::children() const {
     348        3871 :   return make_range(begin(), end());
     349             : }
     350             : 
     351             : } // end namespace llvm
     352             : 
     353             : #endif // LLVM_DEBUGINFO_DWARFDIE_H

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