Commit 04c203e3 authored by David Blaikie's avatar David Blaikie
Browse files

llvm-symbolizer: Fix "start file" to work with Split DWARF 

A followup to the feature added in
69da27c7 that added the optional "start
file name" to match "start line" - but this didn't work with Split DWARF
because of the need for the decl file number resolution code to refer
back to the skeleton unit to find its .debug_line contribution. So this
patch adds the necessary infrastructure to track the skeleton unit
corresponding to a split full unit for the purpose of this lookup.
parent 882ee7fb

llvm/include/llvm/DebugInfo/DWARF/DWARFUnit.h

+7 −0
Original line number Diff line number Diff line
@@ -218,6 +218,7 @@ class DWARFUnit { 
  StringRef StringSection;

  const DWARFSection &StringOffsetSection;

  const DWARFSection *AddrOffsetSection;

  DWARFUnit *SU;

  Optional<uint64_t> AddrOffsetSectionBase;

  bool isLittleEndian;

  bool IsDWO;
@@ -301,6 +302,12 @@ public: 
    return StringOffsetSection;

  }



  void setSkeletonUnit(DWARFUnit *SU) { this->SU = SU; }

  // Returns itself if not using Split DWARF, or if the unit is a skeleton unit

  // - otherwise returns the split full unit's corresponding skeleton, if

  // available.

  DWARFUnit *getLinkedUnit() { return IsDWO ? SU : this; }



  void setAddrOffsetSection(const DWARFSection *AOS, uint64_t Base) {

    AddrOffsetSection = AOS;

    AddrOffsetSectionBase = Base;

llvm/lib/DebugInfo/DWARF/DWARFDie.cpp

+9 −4
Original line number Diff line number Diff line
@@ -571,11 +571,16 @@ uint64_t DWARFDie::getDeclLine() const { 


std::string

DWARFDie::getDeclFile(DILineInfoSpecifier::FileLineInfoKind Kind) const {

  auto D = getAttributeValueAsReferencedDie(DW_AT_abstract_origin);

  if (!D)

    D = *this;

  std::string FileName;

  if (auto DeclFile = toUnsigned(findRecursively(DW_AT_decl_file))) {

    if (const auto *LT = U->getContext().getLineTableForUnit(U)) {

      LT->getFileNameByIndex(*DeclFile, U->getCompilationDir(), Kind, FileName);

    }

  if (auto DeclFile = toUnsigned(D.find(DW_AT_decl_file))) {

    if (const auto *LineTable =

            getDwarfUnit()->getContext().getLineTableForUnit(

                D.getDwarfUnit()->getLinkedUnit()))

      LineTable->getFileNameByIndex(

          *DeclFile, D.getDwarfUnit()->getCompilationDir(), Kind, FileName);

  }

  return FileName;

}

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

+2 −0
Original line number Diff line number Diff line
@@ -388,6 +388,7 @@ void DWARFUnit::clear() { 
  RangeSectionBase = 0;

  LocSectionBase = 0;

  AddrOffsetSectionBase = None;

  SU = nullptr;

  clearDIEs(false);

  DWO.reset();

}
@@ -586,6 +587,7 @@ bool DWARFUnit::parseDWO() { 
  if (!DWOCU)

    return false;

  DWO = std::shared_ptr<DWARFCompileUnit>(std::move(DWOContext), DWOCU);

  DWO->setSkeletonUnit(this);

  // Share .debug_addr and .debug_ranges section with compile unit in .dwo

  if (AddrOffsetSectionBase)

    DWO->setAddrOffsetSection(AddrOffsetSection, *AddrOffsetSectionBase);

llvm/test/DebugInfo/X86/symbolize_function_start.s

0 → 100644
+211 −0
Original line number Diff line number Diff line 
# RUN: rm -rf %t

# RUN: mkdir %t

# RUN: llvm-mc -filetype=obj -triple=x86_64 -dwarf-version=4 %s -o %t/test.o

# RUN: cd %t

# RUN: llvm-symbolizer -verbose 0x0 -obj=test.o | FileCheck --check-prefix=SYM %s

# RUN: llvm-dwarfdump -lookup=0x1 test.o | FileCheck --check-prefix=LOOKUP %s



# SYM: Filename: ./././test.h

# SYM: Function start filename: ./test.cpp



# LOOKUP: Line info: line 0, column 0, start file 'test.cpp', start line 1





	.text

	.file	"test.cpp"

	.globl	_Z2f1v                          # -- Begin function _Z2f1v

	.p2align	4, 0x90

	.type	_Z2f1v,@function

_Z2f1v:                                 # @_Z2f1v

.Lfunc_begin0:

	.file	1 "." "test.cpp"

	.loc	1 1 0                           # test.cpp:1:0

	.cfi_startproc

# %bb.0:                                # %entry

	.file	2 "." "./test.h"

	.loc	2 1 1 prologue_end              # ./test.h:1:1

	xorl	%eax, %eax

	retq

.Ltmp0:

.Lfunc_end0:

	.size	_Z2f1v, .Lfunc_end0-_Z2f1v

	.cfi_endproc

                                        # -- End function

	.section	.debug_abbrev,"",@progbits

	.byte	1                               # Abbreviation Code

	.byte	17                              # DW_TAG_compile_unit

	.byte	0                               # DW_CHILDREN_no

	.byte	16                              # DW_AT_stmt_list

	.byte	23                              # DW_FORM_sec_offset

	.byte	27                              # DW_AT_comp_dir

	.byte	14                              # DW_FORM_strp

	.ascii	"\264B"                         # DW_AT_GNU_pubnames

	.byte	25                              # DW_FORM_flag_present

	.ascii	"\260B"                         # DW_AT_GNU_dwo_name

	.byte	14                              # DW_FORM_strp

	.ascii	"\261B"                         # DW_AT_GNU_dwo_id

	.byte	7                               # DW_FORM_data8

	.byte	17                              # DW_AT_low_pc

	.byte	1                               # DW_FORM_addr

	.byte	18                              # DW_AT_high_pc

	.byte	6                               # DW_FORM_data4

	.ascii	"\263B"                         # DW_AT_GNU_addr_base

	.byte	23                              # DW_FORM_sec_offset

	.byte	0                               # EOM(1)

	.byte	0                               # EOM(2)

	.byte	0                               # EOM(3)

	.section	.debug_info,"",@progbits

.Lcu_begin0:

	.long	.Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit

.Ldebug_info_start0:

	.short	4                               # DWARF version number

	.long	.debug_abbrev                   # Offset Into Abbrev. Section

	.byte	8                               # Address Size (in bytes)

	.byte	1                               # Abbrev [1] 0xb:0x25 DW_TAG_compile_unit

	.long	.Lline_table_start0             # DW_AT_stmt_list

	.long	.Lskel_string0                  # DW_AT_comp_dir

                                        # DW_AT_GNU_pubnames

	.long	.Lskel_string1                  # DW_AT_GNU_dwo_name

	.quad	7198491773836599109             # DW_AT_GNU_dwo_id

	.quad	.Lfunc_begin0                   # DW_AT_low_pc

	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc

	.long	.Laddr_table_base0              # DW_AT_GNU_addr_base

.Ldebug_info_end0:

	.section	.debug_str,"MS",@progbits,1

.Lskel_string0:

	.asciz	"."                             # string offset=0

.Lskel_string1:

	.asciz	"test.o"                        # string offset=2

	.section	.debug_str.dwo,"eMS",@progbits,1

.Linfo_string0:

	.asciz	"_Z2f1v"                        # string offset=0

.Linfo_string1:

	.asciz	"f1"                            # string offset=7

.Linfo_string2:

	.asciz	"int"                           # string offset=10

.Linfo_string3:

	.asciz	"clang version 13.0.0 (git@github.com:llvm/llvm-project.git 882ee7fbd6fc989fba53f3d9672440771feb80f5)" # string offset=14

.Linfo_string4:

	.asciz	"test.cpp"                      # string offset=115

.Linfo_string5:

	.asciz	"test.o"                        # string offset=124

	.section	.debug_str_offsets.dwo,"e",@progbits

	.long	0

	.long	7

	.long	10

	.long	14

	.long	115

	.long	124

	.section	.debug_info.dwo,"e",@progbits

	.long	.Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit

.Ldebug_info_dwo_start0:

	.short	4                               # DWARF version number

	.long	0                               # Offset Into Abbrev. Section

	.byte	8                               # Address Size (in bytes)

	.byte	1                               # Abbrev [1] 0xb:0x23 DW_TAG_compile_unit

	.byte	3                               # DW_AT_producer

	.short	33                              # DW_AT_language

	.byte	4                               # DW_AT_name

	.byte	5                               # DW_AT_GNU_dwo_name

	.quad	7198491773836599109             # DW_AT_GNU_dwo_id

	.byte	2                               # Abbrev [2] 0x19:0x10 DW_TAG_subprogram

	.byte	0                               # DW_AT_low_pc

	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc

	.byte	1                               # DW_AT_frame_base

	.byte	87

                                        # DW_AT_GNU_all_call_sites

	.byte	0                               # DW_AT_linkage_name

	.byte	1                               # DW_AT_name

	.byte	1                               # DW_AT_decl_file

	.byte	1                               # DW_AT_decl_line

	.long	41                              # DW_AT_type

                                        # DW_AT_external

	.byte	3                               # Abbrev [3] 0x29:0x4 DW_TAG_base_type

	.byte	2                               # DW_AT_name

	.byte	5                               # DW_AT_encoding

	.byte	4                               # DW_AT_byte_size

	.byte	0                               # End Of Children Mark

.Ldebug_info_dwo_end0:

	.section	.debug_abbrev.dwo,"e",@progbits

	.byte	1                               # Abbreviation Code

	.byte	17                              # DW_TAG_compile_unit

	.byte	1                               # DW_CHILDREN_yes

	.byte	37                              # DW_AT_producer

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.byte	19                              # DW_AT_language

	.byte	5                               # DW_FORM_data2

	.byte	3                               # DW_AT_name

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.ascii	"\260B"                         # DW_AT_GNU_dwo_name

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.ascii	"\261B"                         # DW_AT_GNU_dwo_id

	.byte	7                               # DW_FORM_data8

	.byte	0                               # EOM(1)

	.byte	0                               # EOM(2)

	.byte	2                               # Abbreviation Code

	.byte	46                              # DW_TAG_subprogram

	.byte	0                               # DW_CHILDREN_no

	.byte	17                              # DW_AT_low_pc

	.ascii	"\201>"                         # DW_FORM_GNU_addr_index

	.byte	18                              # DW_AT_high_pc

	.byte	6                               # DW_FORM_data4

	.byte	64                              # DW_AT_frame_base

	.byte	24                              # DW_FORM_exprloc

	.ascii	"\227B"                         # DW_AT_GNU_all_call_sites

	.byte	25                              # DW_FORM_flag_present

	.byte	110                             # DW_AT_linkage_name

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.byte	3                               # DW_AT_name

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.byte	58                              # DW_AT_decl_file

	.byte	11                              # DW_FORM_data1

	.byte	59                              # DW_AT_decl_line

	.byte	11                              # DW_FORM_data1

	.byte	73                              # DW_AT_type

	.byte	19                              # DW_FORM_ref4

	.byte	63                              # DW_AT_external

	.byte	25                              # DW_FORM_flag_present

	.byte	0                               # EOM(1)

	.byte	0                               # EOM(2)

	.byte	3                               # Abbreviation Code

	.byte	36                              # DW_TAG_base_type

	.byte	0                               # DW_CHILDREN_no

	.byte	3                               # DW_AT_name

	.ascii	"\202>"                         # DW_FORM_GNU_str_index

	.byte	62                              # DW_AT_encoding

	.byte	11                              # DW_FORM_data1

	.byte	11                              # DW_AT_byte_size

	.byte	11                              # DW_FORM_data1

	.byte	0                               # EOM(1)

	.byte	0                               # EOM(2)

	.byte	0                               # EOM(3)

	.section	.debug_addr,"",@progbits

.Laddr_table_base0:

	.quad	.Lfunc_begin0

	.section	.debug_gnu_pubnames,"",@progbits

	.long	.LpubNames_end0-.LpubNames_start0 # Length of Public Names Info

.LpubNames_start0:

	.short	2                               # DWARF Version

	.long	.Lcu_begin0                     # Offset of Compilation Unit Info

	.long	48                              # Compilation Unit Length

	.long	25                              # DIE offset

	.byte	48                              # Attributes: FUNCTION, EXTERNAL

	.asciz	"f1"                            # External Name

	.long	0                               # End Mark

.LpubNames_end0:

	.section	.debug_gnu_pubtypes,"",@progbits

	.long	.LpubTypes_end0-.LpubTypes_start0 # Length of Public Types Info

.LpubTypes_start0:

	.short	2                               # DWARF Version

	.long	.Lcu_begin0                     # Offset of Compilation Unit Info

	.long	48                              # Compilation Unit Length

	.long	41                              # DIE offset

	.byte	144                             # Attributes: TYPE, STATIC

	.asciz	"int"                           # External Name

	.long	0                               # End Mark

.LpubTypes_end0:

	.ident	"clang version 13.0.0 (git@github.com:llvm/llvm-project.git 882ee7fbd6fc989fba53f3d9672440771feb80f5)"

	.section	".note.GNU-stack","",@progbits

	.addrsig

	.section	.debug_line,"",@progbits

.Lline_table_start0: