DWARF: Don't compute address ranges for type units

[labath]

Summary

Type units don't describe any code, so they should never be the result
of any address lookup queries.

Previously, we would compute the address ranges for the type units for
via the line tables they reference because the type units looked a lot
like line-tables-only compile units. However, this is not correct, as
the line tables are only referenced from type units so that other
declarations can use the file names contained in them.

In this patch I make the BuildAddressRangeTable function virtual, and
implement it only for compile units.

Testing this was a bit tricky, because the behavior depends on the order
in which we add things to the address range map. This rarely caused a
problem with DWARF v4 type units, as they are always added after all
CUs. It happened more frequently with DWARF v5, as there clang emits the
type units first. However, this is still not something that it is
required to do, so for testing I've created an assembly file where I've
deliberately sandwiched a compile unit between two type units, which
should isolate us from both changes in how the compiler emits the units
and changes in the order we process them.

[JDevlieghere]

LGTM with a few small nits, even though I know you just moved the code.

source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp

77 ↗

(On Diff #200420)

nullptr

80 ↗

(On Diff #200420)

if (LineTable* line_table = )

105 ↗

(On Diff #200420)

Same here

[labath]

• rebase and modernize the code as suggested

lldb/trunk/lit/SymbolFile/DWARF/debug-types-address-ranges.s

+# Check address lookup works correctly in the presence of type units.
+# Specifically check that we don't use the line table pointed to by the
+# DW_AT_stmt_list of the type unit (which used only for the file names) to
+# compute address range for the type unit as type units don't describe any
+# addresses. The addresses should always resolve to the relevant compile units.
+
+# RUN: llvm-mc -dwarf-version=5 -triple x86_64-pc-linux %s -filetype=obj >%t.o
+# RUN: ld.lld %t.o -o %t -image-base=0x47000
+# RUN: %lldb %t -o "image lookup -a 0x48000 -v" -o exit | FileCheck %s
+
+# CHECK:   CompileUnit: id = {0x00000001}, file = "/tmp/a.cc", language = "c++"
+# CHECK:      Function: id = {0x7fffffff0000006a}, name = "::_start({{.*}})", range = [0x0000000000048000-0x000000000004800c)
+# CHECK:     LineEntry: [0x0000000000048000-0x000000000004800a): /tmp/a.cc:4
+# CHECK:        Symbol: id = {0x00000002}, range = [0x0000000000048000-0x000000000004800c), name="_start"
+# CHECK:      Variable: id = {0x7fffffff00000075}, name = "v1", {{.*}} decl = a.cc:4
+# CHECK:      Variable: id = {0x7fffffff00000080}, name = "v2", {{.*}} decl = a.cc:4
+
+
+# Output generated via
+# clang -g -fdebug-types-section -gdwarf-5 -S
+# from
+# enum E1 { e1 };
+# enum E2 { e2 };
+# extern "C" void _start(E1 v1, E2 v2) {}
+# The output was modified to place the compile unit in between the two type
+# units.
+
+        .text
+        .file   "a.cc"
+        .file   0 "/tmp" "a.cc"
+
+        .text
+        .globl  _start                  # -- Begin function _start
+        .p2align        4, 0x90
+        .type   _start,@function
+_start:                                 # @_start
+.Lfunc_begin0:
+        .loc    0 4 0                   # /tmp/a.cc:4:0
+        .cfi_startproc
+# %bb.0:                                # %entry
+        pushq   %rbp
+        .cfi_def_cfa_offset 16
+        .cfi_offset %rbp, -16
+        movq    %rsp, %rbp
+        .cfi_def_cfa_register %rbp
+        movl    %edi, -4(%rbp)
+        movl    %esi, -8(%rbp)
+.Ltmp0:
+        .loc    0 4 23 prologue_end     # /tmp/a.cc:4:23
+        popq    %rbp
+        .cfi_def_cfa %rsp, 8
+        retq
+.Ltmp1:
+.Lfunc_end0:
+        .size   _start, .Lfunc_end0-_start
+        .cfi_endproc
+                                        # -- End function
+        .section        .debug_str_offsets,"",@progbits
+        .long   52
+        .short  5
+        .short  0
+.Lstr_offsets_base0:
+        .section        .debug_str,"MS",@progbits,1
+.Linfo_string0:
+        .asciz  "clang version 9.0.0 (trunk 360907) (llvm/trunk 360908)"
+.Linfo_string1:
+        .asciz  "a.cc"
+.Linfo_string2:
+        .asciz  "/tmp"
+.Linfo_string3:
+        .asciz  "unsigned int"
+.Linfo_string4:
+        .asciz  "e1"
+.Linfo_string5:
+        .asciz  "E1"
+.Linfo_string6:
+        .asciz  "e2"
+.Linfo_string7:
+        .asciz  "E2"
+.Linfo_string8:
+        .asciz  "_start"
+.Linfo_string9:
+        .asciz  "f"
+.Linfo_string10:
+        .asciz  "v1"
+.Linfo_string11:
+        .asciz  "v2"
+        .section        .debug_str_offsets,"",@progbits
+        .long   .Linfo_string0
+        .long   .Linfo_string1
+        .long   .Linfo_string2
+        .long   .Linfo_string3
+        .long   .Linfo_string4
+        .long   .Linfo_string5
+        .long   .Linfo_string6
+        .long   .Linfo_string7
+        .long   .Linfo_string8
+        .long   .Linfo_string9
+        .long   .Linfo_string10
+        .long   .Linfo_string11
+        .section        .debug_abbrev,"",@progbits
+        .byte   1                       # Abbreviation Code
+        .byte   65                      # DW_TAG_type_unit
+        .byte   1                       # DW_CHILDREN_yes
+        .byte   19                      # DW_AT_language
+        .byte   5                       # DW_FORM_data2
+        .byte   16                      # DW_AT_stmt_list
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   114                     # DW_AT_str_offsets_base
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   2                       # Abbreviation Code
+        .byte   4                       # DW_TAG_enumeration_type
+        .byte   1                       # DW_CHILDREN_yes
+        .byte   73                      # DW_AT_type
+        .byte   19                      # DW_FORM_ref4
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .byte   11                      # DW_AT_byte_size
+        .byte   11                      # DW_FORM_data1
+        .byte   58                      # DW_AT_decl_file
+        .byte   11                      # DW_FORM_data1
+        .byte   59                      # DW_AT_decl_line
+        .byte   11                      # DW_FORM_data1
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   3                       # Abbreviation Code
+        .byte   40                      # DW_TAG_enumerator
+        .byte   0                       # DW_CHILDREN_no
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .byte   28                      # DW_AT_const_value
+        .byte   15                      # DW_FORM_udata
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   4                       # Abbreviation Code
+        .byte   36                      # DW_TAG_base_type
+        .byte   0                       # DW_CHILDREN_no
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .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   5                       # Abbreviation Code
+        .byte   17                      # DW_TAG_compile_unit
+        .byte   1                       # DW_CHILDREN_yes
+        .byte   37                      # DW_AT_producer
+        .byte   37                      # DW_FORM_strx1
+        .byte   19                      # DW_AT_language
+        .byte   5                       # DW_FORM_data2
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .byte   114                     # DW_AT_str_offsets_base
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   16                      # DW_AT_stmt_list
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   27                      # DW_AT_comp_dir
+        .byte   37                      # DW_FORM_strx1
+        .byte   17                      # DW_AT_low_pc
+        .byte   27                      # DW_FORM_addrx
+        .byte   18                      # DW_AT_high_pc
+        .byte   6                       # DW_FORM_data4
+        .byte   115                     # DW_AT_addr_base
+        .byte   23                      # DW_FORM_sec_offset
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   6                       # Abbreviation Code
+        .byte   4                       # DW_TAG_enumeration_type
+        .byte   0                       # DW_CHILDREN_no
+        .byte   60                      # DW_AT_declaration
+        .byte   25                      # DW_FORM_flag_present
+        .byte   105                     # DW_AT_signature
+        .byte   32                      # DW_FORM_ref_sig8
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   7                       # Abbreviation Code
+        .byte   46                      # DW_TAG_subprogram
+        .byte   1                       # DW_CHILDREN_yes
+        .byte   17                      # DW_AT_low_pc
+        .byte   27                      # DW_FORM_addrx
+        .byte   18                      # DW_AT_high_pc
+        .byte   6                       # DW_FORM_data4
+        .byte   64                      # DW_AT_frame_base
+        .byte   24                      # DW_FORM_exprloc
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .byte   58                      # DW_AT_decl_file
+        .byte   11                      # DW_FORM_data1
+        .byte   59                      # DW_AT_decl_line
+        .byte   11                      # DW_FORM_data1
+        .byte   63                      # DW_AT_external
+        .byte   25                      # DW_FORM_flag_present
+        .byte   0                       # EOM(1)
+        .byte   0                       # EOM(2)
+        .byte   8                       # Abbreviation Code
+        .byte   5                       # DW_TAG_formal_parameter
+        .byte   0                       # DW_CHILDREN_no
+        .byte   2                       # DW_AT_location
+        .byte   24                      # DW_FORM_exprloc
+        .byte   3                       # DW_AT_name
+        .byte   37                      # DW_FORM_strx1
+        .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   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  5                       # DWARF version number
+        .byte   2                       # DWARF Unit Type
+        .byte   8                       # Address Size (in bytes)
+        .long   .debug_abbrev           # Offset Into Abbrev. Section
+        .quad   -6180787752776176174    # Type Signature
+        .long   35                      # Type DIE Offset
+        .byte   1                       # Abbrev [1] 0x18:0x1d DW_TAG_type_unit
+        .short  4                       # DW_AT_language
+        .long   .Lline_table_start0     # DW_AT_stmt_list
+        .long   .Lstr_offsets_base0     # DW_AT_str_offsets_base
+        .byte   2                       # Abbrev [2] 0x23:0xd DW_TAG_enumeration_type
+        .long   48                      # DW_AT_type
+        .byte   5                       # DW_AT_name
+        .byte   4                       # DW_AT_byte_size
+        .byte   0                       # DW_AT_decl_file
+        .byte   1                       # DW_AT_decl_line
+        .byte   3                       # Abbrev [3] 0x2c:0x3 DW_TAG_enumerator
+        .byte   4                       # DW_AT_name
+        .byte   0                       # DW_AT_const_value
+        .byte   0                       # End Of Children Mark
+        .byte   4                       # Abbrev [4] 0x30:0x4 DW_TAG_base_type
+        .byte   3                       # DW_AT_name
+        .byte   7                       # DW_AT_encoding
+        .byte   4                       # DW_AT_byte_size
+        .byte   0                       # End Of Children Mark
+.Ldebug_info_end0:
+
+        .long   .Ldebug_info_end2-.Ldebug_info_start2 # Length of Unit
+.Ldebug_info_start2:
+        .short  5                       # DWARF version number
+        .byte   1                       # DWARF Unit Type
+        .byte   8                       # Address Size (in bytes)
+        .long   .debug_abbrev           # Offset Into Abbrev. Section
+        .byte   5                       # Abbrev [5] 0xc:0x4d DW_TAG_compile_unit
+        .byte   0                       # DW_AT_producer
+        .short  4                       # DW_AT_language
+        .byte   1                       # DW_AT_name
+        .long   .Lstr_offsets_base0     # DW_AT_str_offsets_base
+        .long   .Lline_table_start0     # DW_AT_stmt_list
+        .byte   2                       # DW_AT_comp_dir
+        .byte   0                       # DW_AT_low_pc
+        .long   .Lfunc_end0-.Lfunc_begin0 # DW_AT_high_pc
+        .long   .Laddr_table_base0      # DW_AT_addr_base
+        .byte   6                       # Abbrev [6] 0x23:0x9 DW_TAG_enumeration_type
+                                        # DW_AT_declaration
+        .quad   -6180787752776176174    # DW_AT_signature
+        .byte   6                       # Abbrev [6] 0x2c:0x9 DW_TAG_enumeration_type
+                                        # DW_AT_declaration
+        .quad   7818257750321376053     # DW_AT_signature
+        .byte   7                       # Abbrev [7] 0x35:0x23 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   86
+        .byte   8                       # DW_AT_name
+        .byte   0                       # DW_AT_decl_file
+        .byte   4                       # DW_AT_decl_line
+                                        # DW_AT_external
+        .byte   8                       # Abbrev [8] 0x41:0xb DW_TAG_formal_parameter
+        .byte   2                       # DW_AT_location
+        .byte   145
+        .byte   124
+        .byte   10                      # DW_AT_name
+        .byte   0                       # DW_AT_decl_file
+        .byte   4                       # DW_AT_decl_line
+        .long   35                      # DW_AT_type
+        .byte   8                       # Abbrev [8] 0x4c:0xb DW_TAG_formal_parameter
+        .byte   2                       # DW_AT_location
+        .byte   145
+        .byte   120
+        .byte   11                      # DW_AT_name
+        .byte   0                       # DW_AT_decl_file
+        .byte   4                       # DW_AT_decl_line
+        .long   44                      # DW_AT_type
+        .byte   0                       # End Of Children Mark
+        .byte   0                       # End Of Children Mark
+.Ldebug_info_end2:
+
+        .long   .Ldebug_info_end1-.Ldebug_info_start1 # Length of Unit
+.Ldebug_info_start1:
+        .short  5                       # DWARF version number
+        .byte   2                       # DWARF Unit Type
+        .byte   8                       # Address Size (in bytes)
+        .long   .debug_abbrev           # Offset Into Abbrev. Section
+        .quad   7818257750321376053     # Type Signature
+        .long   35                      # Type DIE Offset
+        .byte   1                       # Abbrev [1] 0x18:0x1d DW_TAG_type_unit
+        .short  4                       # DW_AT_language
+        .long   .Lline_table_start0     # DW_AT_stmt_list
+        .long   .Lstr_offsets_base0     # DW_AT_str_offsets_base
+        .byte   2                       # Abbrev [2] 0x23:0xd DW_TAG_enumeration_type
+        .long   48                      # DW_AT_type
+        .byte   7                       # DW_AT_name
+        .byte   4                       # DW_AT_byte_size
+        .byte   0                       # DW_AT_decl_file
+        .byte   2                       # DW_AT_decl_line
+        .byte   3                       # Abbrev [3] 0x2c:0x3 DW_TAG_enumerator
+        .byte   6                       # DW_AT_name
+        .byte   0                       # DW_AT_const_value
+        .byte   0                       # End Of Children Mark
+        .byte   4                       # Abbrev [4] 0x30:0x4 DW_TAG_base_type
+        .byte   3                       # DW_AT_name
+        .byte   7                       # DW_AT_encoding
+        .byte   4                       # DW_AT_byte_size
+        .byte   0                       # End Of Children Mark
+.Ldebug_info_end1:
+        .section        .debug_macinfo,"",@progbits
+        .byte   0                       # End Of Macro List Mark
+        .section        .debug_addr,"",@progbits
+        .long   .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+        .short  5                       # DWARF version number
+        .byte   8                       # Address size
+        .byte   0                       # Segment selector size
+.Laddr_table_base0:
+        .quad   .Lfunc_begin0
+.Ldebug_addr_end0:
+
+        .section        .debug_line,"",@progbits
+.Lline_table_start0:

lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.h

 //===-- DWARFCompileUnit.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 SymbolFileDWARF_DWARFCompileUnit_h_
 #define SymbolFileDWARF_DWARFCompileUnit_h_
 
 #include "DWARFUnit.h"
 #include "llvm/Support/Error.h"
 
 class DWARFCompileUnit : public DWARFUnit {
 public:
+  void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) override;
+
   void Dump(lldb_private::Stream *s) const override;
 
 private:
   DWARFCompileUnit(SymbolFileDWARF *dwarf, lldb::user_id_t uid,
                    const DWARFUnitHeader &header,
                    const DWARFAbbreviationDeclarationSet &abbrevs,
                    DIERef::Section section)
       : DWARFUnit(dwarf, uid, header, abbrevs, section) {}
 
   DISALLOW_COPY_AND_ASSIGN(DWARFCompileUnit);
 
   friend class DWARFUnit;
 };
 
 #endif // SymbolFileDWARF_DWARFCompileUnit_h_

lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFCompileUnit.cpp

 //===-- DWARFCompileUnit.cpp ------------------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "DWARFCompileUnit.h"
+#include "DWARFDebugAranges.h"
+#include "SymbolFileDWARFDebugMap.h"
 
+#include "lldb/Symbol/CompileUnit.h"
+#include "lldb/Symbol/LineTable.h"
 #include "lldb/Utility/Stream.h"
 
 using namespace lldb;
 using namespace lldb_private;
 
 void DWARFCompileUnit::Dump(Stream *s) const {
   s->Printf("0x%8.8x: Compile Unit: length = 0x%8.8x, version = 0x%4.4x, "
             "abbr_offset = 0x%8.8x, addr_size = 0x%2.2x (next CU at "
             "{0x%8.8x})\n",
             GetOffset(), GetLength(), GetVersion(), GetAbbrevOffset(),
             GetAddressByteSize(), GetNextUnitOffset());
 }
+
+void DWARFCompileUnit::BuildAddressRangeTable(
+    DWARFDebugAranges *debug_aranges) {
+  // This function is usually called if there in no .debug_aranges section in
+  // order to produce a compile unit level set of address ranges that is
+  // accurate.
+
+  size_t num_debug_aranges = debug_aranges->GetNumRanges();
+
+  // First get the compile unit DIE only and check if it has a DW_AT_ranges
+  const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
+
+  const dw_offset_t cu_offset = GetOffset();
+  if (die) {
+    DWARFRangeList ranges;
+    const size_t num_ranges =
+        die->GetAttributeAddressRanges(this, ranges, false);
+    if (num_ranges > 0) {
+      // This compile unit has DW_AT_ranges, assume this is correct if it is
+      // present since clang no longer makes .debug_aranges by default and it
+      // emits DW_AT_ranges for DW_TAG_compile_units. GCC also does this with
+      // recent GCC builds.
+      for (size_t i = 0; i < num_ranges; ++i) {
+        const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
+        debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
+                                   range.GetRangeEnd());
+      }
+
+      return; // We got all of our ranges from the DW_AT_ranges attribute
+    }
+  }
+  // We don't have a DW_AT_ranges attribute, so we need to parse the DWARF
+
+  // If the DIEs weren't parsed, then we don't want all dies for all compile
+  // units to stay loaded when they weren't needed. So we can end up parsing
+  // the DWARF and then throwing them all away to keep memory usage down.
+  ScopedExtractDIEs clear_dies(ExtractDIEsScoped());
+
+  die = DIEPtr();
+  if (die)
+    die->BuildAddressRangeTable(this, debug_aranges);
+
+  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
+    // We got nothing from the functions, maybe we have a line tables only
+    // situation. Check the line tables and build the arange table from this.
+    SymbolContext sc;
+    sc.comp_unit = m_dwarf->GetCompUnitForDWARFCompUnit(this);
+    if (sc.comp_unit) {
+      SymbolFileDWARFDebugMap *debug_map_sym_file =
+          m_dwarf->GetDebugMapSymfile();
+      if (debug_map_sym_file == nullptr) {
+        if (LineTable *line_table = sc.comp_unit->GetLineTable()) {
+          LineTable::FileAddressRanges file_ranges;
+          const bool append = true;
+          const size_t num_ranges =
+              line_table->GetContiguousFileAddressRanges(file_ranges, append);
+          for (uint32_t idx = 0; idx < num_ranges; ++idx) {
+            const LineTable::FileAddressRanges::Entry &range =
+                file_ranges.GetEntryRef(idx);
+            debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
+                                       range.GetRangeEnd());
+          }
+        }
+      } else
+        debug_map_sym_file->AddOSOARanges(m_dwarf, debug_aranges);
+    }
+  }
+
+  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
+    // We got nothing from the functions, maybe we have a line tables only
+    // situation. Check the line tables and build the arange table from this.
+    SymbolContext sc;
+    sc.comp_unit = m_dwarf->GetCompUnitForDWARFCompUnit(this);
+    if (sc.comp_unit) {
+      if (LineTable *line_table = sc.comp_unit->GetLineTable()) {
+        LineTable::FileAddressRanges file_ranges;
+        const bool append = true;
+        const size_t num_ranges =
+            line_table->GetContiguousFileAddressRanges(file_ranges, append);
+        for (uint32_t idx = 0; idx < num_ranges; ++idx) {
+          const LineTable::FileAddressRanges::Entry &range =
+              file_ranges.GetEntryRef(idx);
+          debug_aranges->AppendRange(GetOffset(), range.GetRangeBase(),
+                                     range.GetRangeEnd());
+        }
+      }
+    }
+  }
+}

lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFTypeUnit.h

 //===-- DWARFTypeUnit.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 SymbolFileDWARF_DWARFTypeUnit_h_
 #define SymbolFileDWARF_DWARFTypeUnit_h_
 
 #include "DWARFUnit.h"
 #include "llvm/Support/Error.h"
 
 class DWARFTypeUnit : public DWARFUnit {
 public:
+  void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) override {}
+
   void Dump(lldb_private::Stream *s) const override;
 
 private:
   DWARFTypeUnit(SymbolFileDWARF *dwarf, lldb::user_id_t uid,
                 const DWARFUnitHeader &header,
                 const DWARFAbbreviationDeclarationSet &abbrevs,
                 DIERef::Section section)
       : DWARFUnit(dwarf, uid, header, abbrevs, section) {}
 
   friend class DWARFUnit;
 };
 
 #endif // SymbolFileDWARF_DWARFTypeUnit_h_

lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFUnit.h

public:
   dw_addr_t GetBaseAddress() const { return m_base_addr; }
   dw_addr_t GetAddrBase() const { return m_addr_base; }
   dw_addr_t GetRangesBase() const { return m_ranges_base; }
   dw_addr_t GetStrOffsetsBase() const { return m_str_offsets_base; }
   void SetAddrBase(dw_addr_t addr_base);
   void SetRangesBase(dw_addr_t ranges_base);
   void SetBaseObjOffset(dw_offset_t base_obj_offset);
   void SetStrOffsetsBase(dw_offset_t str_offsets_base);
-  void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges);
+  virtual void BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) = 0;
 
   lldb::ByteOrder GetByteOrder() const;
 
   lldb_private::TypeSystem *GetTypeSystem();
 
   const DWARFDebugAranges &GetFunctionAranges();
 
   DWARFFormValue::FixedFormSizes GetFixedFormSizes();
DWARFUnit(SymbolFileDWARF *dwarf, lldb::user_id_t uid,
             const DWARFUnitHeader &header,
             const DWARFAbbreviationDeclarationSet &abbrevs,
             DIERef::Section section);
 
   llvm::Error ExtractHeader(SymbolFileDWARF *dwarf,
                             const lldb_private::DWARFDataExtractor &data,
                             lldb::offset_t *offset_ptr);
 
+  // Get the DWARF unit DWARF debug information entry. Parse the single DIE
+  // if needed.
+  const DWARFDebugInfoEntry *GetUnitDIEPtrOnly() {
+    ExtractUnitDIEIfNeeded();
+    // m_first_die_mutex is not required as m_first_die is never cleared.
+    if (!m_first_die)
+      return NULL;
+    return &m_first_die;
+  }
+
+  // Get all DWARF debug informration entries. Parse all DIEs if needed.
+  const DWARFDebugInfoEntry *DIEPtr() {
+    ExtractDIEsIfNeeded();
+    if (m_die_array.empty())
+      return NULL;
+    return &m_die_array[0];
+  }
+
   SymbolFileDWARF *m_dwarf = nullptr;
   std::unique_ptr<SymbolFileDWARFDwo> m_dwo_symbol_file;
   DWARFUnitHeader m_header;
   const DWARFAbbreviationDeclarationSet *m_abbrevs = nullptr;
   void *m_user_data = nullptr;
   // The compile unit debug information entry item
   DWARFDebugInfoEntry::collection m_die_array;
   mutable llvm::sys::RWMutex m_die_array_mutex;
protected:
   dw_offset_t m_str_offsets_base = 0; // Value of DW_AT_str_offsets_base.
   const DIERef::Section m_section;
 
 private:
   void ParseProducerInfo();
   void ExtractDIEsRWLocked();
   void ClearDIEsRWLocked();
 
-  // Get the DWARF unit DWARF debug informration entry. Parse the single DIE
-  // if needed.
-  const DWARFDebugInfoEntry *GetUnitDIEPtrOnly() {
-    ExtractUnitDIEIfNeeded();
-    // m_first_die_mutex is not required as m_first_die is never cleared.
-    if (!m_first_die)
-      return NULL;
-    return &m_first_die;
-  }
-
-  // Get all DWARF debug informration entries. Parse all DIEs if needed.
-  const DWARFDebugInfoEntry *DIEPtr() {
-    ExtractDIEsIfNeeded();
-    if (m_die_array.empty())
-      return NULL;
-    return &m_die_array[0];
-  }
-
   void AddUnitDIE(const DWARFDebugInfoEntry &cu_die);
 
   void ComputeCompDirAndGuessPathStyle();
 
   DISALLOW_COPY_AND_ASSIGN(DWARFUnit);
 };
 
 #endif // SymbolFileDWARF_DWARFUnit_h_

lldb/trunk/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp

 //===-- DWARFUnit.cpp -------------------------------------------*- 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "DWARFUnit.h"
 
 #include "lldb/Core/Module.h"
 #include "lldb/Host/StringConvert.h"
-#include "lldb/Symbol/CompileUnit.h"
-#include "lldb/Symbol/LineTable.h"
 #include "lldb/Symbol/ObjectFile.h"
 #include "lldb/Utility/LLDBAssert.h"
 #include "lldb/Utility/StreamString.h"
 #include "lldb/Utility/Timer.h"
 #include "llvm/Object/Error.h"
 
 #include "DWARFCompileUnit.h"
 #include "DWARFDebugAranges.h"
 #include "DWARFDebugInfo.h"
 #include "DWARFTypeUnit.h"
 #include "LogChannelDWARF.h"
-#include "SymbolFileDWARFDebugMap.h"
 #include "SymbolFileDWARFDwo.h"
 
 using namespace lldb;
 using namespace lldb_private;
 using namespace std;
 
 extern int g_verbose;
 

 void DWARFUnit::ClearDIEsRWLocked() {
   m_die_array.clear();
   m_die_array.shrink_to_fit();
 
   if (m_dwo_symbol_file)
     m_dwo_symbol_file->GetCompileUnit()->ClearDIEsRWLocked();
 }
 
-void DWARFUnit::BuildAddressRangeTable(DWARFDebugAranges *debug_aranges) {
-  // This function is usually called if there in no .debug_aranges section in
-  // order to produce a compile unit level set of address ranges that is
-  // accurate.
-
-  size_t num_debug_aranges = debug_aranges->GetNumRanges();
-
-  // First get the compile unit DIE only and check if it has a DW_AT_ranges
-  const DWARFDebugInfoEntry *die = GetUnitDIEPtrOnly();
-
-  const dw_offset_t cu_offset = GetOffset();
-  if (die) {
-    DWARFRangeList ranges;
-    const size_t num_ranges =
-        die->GetAttributeAddressRanges(this, ranges, false);
-    if (num_ranges > 0) {
-      // This compile unit has DW_AT_ranges, assume this is correct if it is
-      // present since clang no longer makes .debug_aranges by default and it
-      // emits DW_AT_ranges for DW_TAG_compile_units. GCC also does this with
-      // recent GCC builds.
-      for (size_t i = 0; i < num_ranges; ++i) {
-        const DWARFRangeList::Entry &range = ranges.GetEntryRef(i);
-        debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
-                                   range.GetRangeEnd());
-      }
-
-      return; // We got all of our ranges from the DW_AT_ranges attribute
-    }
-  }
-  // We don't have a DW_AT_ranges attribute, so we need to parse the DWARF
-
-  // If the DIEs weren't parsed, then we don't want all dies for all compile
-  // units to stay loaded when they weren't needed. So we can end up parsing
-  // the DWARF and then throwing them all away to keep memory usage down.
-  ScopedExtractDIEs clear_dies(ExtractDIEsScoped());
-
-  die = DIEPtr();
-  if (die)
-    die->BuildAddressRangeTable(this, debug_aranges);
-
-  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
-    // We got nothing from the functions, maybe we have a line tables only
-    // situation. Check the line tables and build the arange table from this.
-    SymbolContext sc;
-    sc.comp_unit = m_dwarf->GetCompUnitForDWARFCompUnit(this);
-    if (sc.comp_unit) {
-      SymbolFileDWARFDebugMap *debug_map_sym_file =
-          m_dwarf->GetDebugMapSymfile();
-      if (debug_map_sym_file == NULL) {
-        LineTable *line_table = sc.comp_unit->GetLineTable();
-
-        if (line_table) {
-          LineTable::FileAddressRanges file_ranges;
-          const bool append = true;
-          const size_t num_ranges =
-              line_table->GetContiguousFileAddressRanges(file_ranges, append);
-          for (uint32_t idx = 0; idx < num_ranges; ++idx) {
-            const LineTable::FileAddressRanges::Entry &range =
-                file_ranges.GetEntryRef(idx);
-            debug_aranges->AppendRange(cu_offset, range.GetRangeBase(),
-                                       range.GetRangeEnd());
-          }
-        }
-      } else
-        debug_map_sym_file->AddOSOARanges(m_dwarf, debug_aranges);
-    }
-  }
-
-  if (debug_aranges->GetNumRanges() == num_debug_aranges) {
-    // We got nothing from the functions, maybe we have a line tables only
-    // situation. Check the line tables and build the arange table from this.
-    SymbolContext sc;
-    sc.comp_unit = m_dwarf->GetCompUnitForDWARFCompUnit(this);
-    if (sc.comp_unit) {
-      LineTable *line_table = sc.comp_unit->GetLineTable();
-
-      if (line_table) {
-        LineTable::FileAddressRanges file_ranges;
-        const bool append = true;
-        const size_t num_ranges =
-            line_table->GetContiguousFileAddressRanges(file_ranges, append);
-        for (uint32_t idx = 0; idx < num_ranges; ++idx) {
-          const LineTable::FileAddressRanges::Entry &range =
-              file_ranges.GetEntryRef(idx);
-          debug_aranges->AppendRange(GetOffset(), range.GetRangeBase(),
-                                     range.GetRangeEnd());
-        }
-      }
-    }
-  }
-}
-
 lldb::ByteOrder DWARFUnit::GetByteOrder() const {
   return m_dwarf->GetObjectFile()->GetByteOrder();
 }
 
 TypeSystem *DWARFUnit::GetTypeSystem() {
   if (m_dwarf)
     return m_dwarf->GetTypeSystemForLanguage(GetLanguageType());
   else

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.h

 
 class SymbolFileDWARF : public lldb_private::SymbolFile,
                         public lldb_private::UserID {
 public:
   friend class SymbolFileDWARFDebugMap;
   friend class SymbolFileDWARFDwo;
   friend class DebugMapModule;
   friend struct DIERef;
-  friend class DWARFUnit;
+  friend class DWARFCompileUnit;
   friend class DWARFDIE;
   friend class DWARFASTParserClang;
 
   // Static Functions
   static void Initialize();
 
   static void Terminate();
 

lldb/trunk/source/Plugins/SymbolFile/DWARF/SymbolFileDWARFDebugMap.h

public:
   uint32_t GetPluginVersion() override;
 
 protected:
   enum { kHaveInitializedOSOs = (1 << 0), kNumFlags };
 
   friend class DebugMapModule;
   friend struct DIERef;
   friend class DWARFASTParserClang;
-  friend class DWARFUnit;
+  friend class DWARFCompileUnit;
   friend class SymbolFileDWARF;
   struct OSOInfo {
     lldb::ModuleSP module_sp;
 
     OSOInfo() : module_sp() {}
   };
 
   typedef std::shared_ptr<OSOInfo> OSOInfoSP;