[Lldb-commits] [lldb] [lldb] Skip declaration DIEs in the debug_names index (PR #94744)
Pavel Labath via lldb-commits
lldb-commits at lists.llvm.org
Fri Jun 7 03:54:15 PDT 2024
https://github.com/labath created https://github.com/llvm/llvm-project/pull/94744
This makes sure we try to process declaration DIEs that are erroneously present in the index. Until bd5c6367bd7, clang was emitting index entries for declaration DIEs with DW_AT_signature attributes. This makes sure to avoid returning those DIEs as the definitions of a type, but also makes sure to pass through DIEs referring to static constexpr member variables, which is a (probably nonconforming) extension used by dsymutil.
It adds test cases for both of the scenarios. It is essentially a recommit of #91808.
>From 506eeb483a81146aa4e7798ad6d325da3b83a8de Mon Sep 17 00:00:00 2001
From: Pavel Labath <pavel at labath.sk>
Date: Fri, 7 Jun 2024 12:32:37 +0200
Subject: [PATCH] [lldb] Skip declaration DIEs in the debug_names index
This makes sure we try to process declaration DIEs that are erroneously
present in the index. Until bd5c6367bd7, clang was emitting index
entries for declaration DIEs with DW_AT_signature attributes. This makes
sure to avoid returning those DIEs as the definitions of a type, but
also makes sure to pass through DIEs referring to static constexpr
member variables, which is a (probably nonconforming) extension used by
dsymutil.
It adds test cases for both of the scenarios. It is essentially a
recommit of #91808.
---
.../SymbolFile/DWARF/DebugNamesDWARFIndex.cpp | 5 +
.../DWARF/x86/debug-names-signature.s | 265 ++++++++++++++++++
.../x86/debug-names-static-constexpr-member.s | 169 +++++++++++
3 files changed, 439 insertions(+)
create mode 100644 lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-signature.s
create mode 100644 lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-static-constexpr-member.s
diff --git a/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp b/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
index 90e42be7202d8..1d17f20670eed 100644
--- a/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
+++ b/lldb/source/Plugins/SymbolFile/DWARF/DebugNamesDWARFIndex.cpp
@@ -85,6 +85,11 @@ bool DebugNamesDWARFIndex::ProcessEntry(
DWARFDIE die = GetDIE(entry);
if (!die)
return true;
+ // Clang used to erroneously emit index entries for declaration DIEs in case
+ // when the definition is in a type unit (llvm.org/pr77696).
+ if (die.IsStructUnionOrClass() &&
+ die.GetAttributeValueAsUnsigned(DW_AT_declaration, 0))
+ return true;
return callback(die);
}
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-signature.s b/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-signature.s
new file mode 100644
index 0000000000000..7b845a72bbed4
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-signature.s
@@ -0,0 +1,265 @@
+## Test that we can correctly complete types even if the debug_names index
+## contains entries referring to declaration dies (clang emitted entries like
+## that until bd5c6367bd7).
+##
+## This test consists of two compile units and one type unit. CU1 has the
+## definition of a variable, but only a forward-declaration of its type. When
+## attempting to find a definition, the debug_names lookup will return the DIE
+## in CU0, which is also a forward-declaration (with a reference to a type
+## unit). LLDB needs to find the definition of the type within the type unit.
+
+# RUN: llvm-mc -triple=x86_64-pc-linux -filetype=obj %s > %t
+# RUN: %lldb %t -o "target variable s" -o exit | FileCheck %s
+
+# CHECK: (lldb) target variable s
+# CHECK-NEXT: (Struct) s = (member = 47)
+
+ .data
+ .p2align 2, 0x0
+ .long 0
+s:
+ .long 47 # 0x2f
+
+ .section .debug_abbrev,"", at 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 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 2 # Abbreviation Code
+ .byte 19 # DW_TAG_structure_type
+ .byte 1 # DW_CHILDREN_yes
+ .byte 54 # DW_AT_calling_convention
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 11 # DW_AT_byte_size
+ .byte 11 # DW_FORM_data1
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 3 # Abbreviation Code
+ .byte 13 # DW_TAG_member
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 56 # DW_AT_data_member_location
+ .byte 11 # DW_FORM_data1
+ .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 14 # DW_FORM_strp
+ .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 8 # DW_FORM_string
+ .byte 19 # DW_AT_language
+ .byte 5 # DW_FORM_data2
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 6 # Abbreviation Code
+ .byte 52 # DW_TAG_variable
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 2 # DW_AT_location
+ .byte 24 # DW_FORM_exprloc
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 7 # Abbreviation Code
+ .byte 19 # DW_TAG_structure_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 8 # Abbreviation Code
+ .byte 19 # DW_TAG_structure_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 60 # DW_AT_declaration
+ .byte 25 # DW_FORM_flag_present
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 0 # EOM(3)
+
+ .section .debug_info,"", at progbits
+.Ltu_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 4878254330033667422 # Type Signature
+ .long .LStruct_def-.Ltu_begin0 # Type DIE Offset
+ .byte 1 # Abbrev [1] 0x18:0x20 DW_TAG_type_unit
+ .short 33 # DW_AT_language
+.LStruct_def:
+ .byte 2 # Abbrev [2] 0x23:0x10 DW_TAG_structure_type
+ .byte 5 # DW_AT_calling_convention
+ .long .Linfo_string6 # DW_AT_name
+ .byte 4 # DW_AT_byte_size
+ .byte 3 # Abbrev [3] 0x29:0x9 DW_TAG_member
+ .long .Linfo_string4 # DW_AT_name
+ .long .Lint-.Ltu_begin0 # DW_AT_type
+ .byte 0 # DW_AT_data_member_location
+ .byte 0 # End Of Children Mark
+.Lint:
+ .byte 4 # Abbrev [4] 0x33:0x4 DW_TAG_base_type
+ .long .Linfo_string5 # DW_AT_name
+ .byte 5 # DW_AT_encoding
+ .byte 4 # DW_AT_byte_size
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end0:
+
+.Lcu_begin0:
+ .long .Ldebug_info_end1-.Ldebug_info_start1 # Length of Unit
+.Ldebug_info_start1:
+ .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:0x27 DW_TAG_compile_unit
+ .asciz "Hand-written DWARF" # DW_AT_producer
+ .short 33 # DW_AT_language
+.Ls:
+ .byte 6 # Abbrev [6] 0x1e:0xb DW_TAG_variable
+ .long .Linfo_string3 # DW_AT_name
+ .long .LStruct_decl2-.Lcu_begin0 # DW_AT_type
+ .byte 9 # DW_AT_location
+ .byte 3
+ .quad s
+.LStruct_decl2:
+ .byte 8 # Abbrev [8] 0x29:0x9 DW_TAG_structure_type
+ .long .Linfo_string6 # DW_AT_name
+ # DW_AT_declaration
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end1:
+
+.Lcu_begin1:
+ .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:0x27 DW_TAG_compile_unit
+ .asciz "Hand-written DWARF" # DW_AT_producer
+ .short 33 # DW_AT_language
+.LStruct_decl:
+ .byte 7 # Abbrev [7] 0x29:0x9 DW_TAG_structure_type
+ # DW_AT_declaration
+ .quad 4878254330033667422 # DW_AT_signature
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end2:
+
+ .section .debug_str,"MS", at progbits,1
+.Linfo_string3:
+ .asciz "s" # string offset=60
+.Linfo_string4:
+ .asciz "member" # string offset=62
+.Linfo_string5:
+ .asciz "int" # string offset=69
+.Linfo_string6:
+ .asciz "Struct" # string offset=73
+
+ .section .debug_names,"", at progbits
+ .long .Lnames_end0-.Lnames_start0 # Header: unit length
+.Lnames_start0:
+ .short 5 # Header: version
+ .short 0 # Header: padding
+ .long 2 # Header: compilation unit count
+ .long 1 # Header: local type unit count
+ .long 0 # Header: foreign type unit count
+ .long 0 # Header: bucket count
+ .long 3 # Header: name count
+ .long .Lnames_abbrev_end0-.Lnames_abbrev_start0 # Header: abbreviation table size
+ .long 8 # Header: augmentation string size
+ .ascii "LLVM0700" # Header: augmentation string
+ .long .Lcu_begin0 # Compilation unit 0
+ .long .Lcu_begin1 # Compilation unit 1
+ .long .Ltu_begin0 # Type unit 0
+ .long .Linfo_string6 # String in Bucket 0: Struct
+ .long .Linfo_string3 # String in Bucket 1: s
+ .long .Linfo_string5 # String in Bucket 2: int
+ .long .Lnames1-.Lnames_entries0 # Offset in Bucket 0
+ .long .Lnames2-.Lnames_entries0 # Offset in Bucket 1
+ .long .Lnames0-.Lnames_entries0 # Offset in Bucket 2
+.Lnames_abbrev_start0:
+ .byte 1 # Abbrev code
+ .byte 19 # DW_TAG_structure_type
+ .byte 2 # DW_IDX_type_unit
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 2 # Abbrev code
+ .byte 52 # DW_TAG_variable
+ .byte 1 # DW_IDX_compile_unit
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 3 # Abbrev code
+ .byte 36 # DW_TAG_base_type
+ .byte 2 # DW_IDX_type_unit
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 4 # Abbrev code
+ .byte 19 # DW_TAG_structure_type
+ .byte 1 # DW_IDX_compile_unit
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev list
+.Lnames_abbrev_end0:
+.Lnames_entries0:
+.Lnames1:
+ .byte 4 # Abbreviation code
+ .byte 1 # DW_IDX_compile_unit
+ .long .LStruct_decl-.Lcu_begin1 # DW_IDX_die_offset
+ .byte 1 # Abbreviation code
+ .byte 0 # DW_IDX_type_unit
+ .long .LStruct_def-.Ltu_begin0 # DW_IDX_die_offset
+ .byte 0
+ # End of list: Struct
+.Lnames2:
+ .byte 2 # Abbreviation code
+ .byte 0 # DW_IDX_compile_unit
+ .long .Ls-.Lcu_begin0 # DW_IDX_die_offset
+ .byte 0
+ # End of list: s
+.Lnames0:
+ .byte 3 # Abbreviation code
+ .byte 0 # DW_IDX_type_unit
+ .long .Lint-.Ltu_begin0 # DW_IDX_die_offset
+ .byte 0
+ # End of list: int
+ .p2align 2, 0x0
+.Lnames_end0:
diff --git a/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-static-constexpr-member.s b/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-static-constexpr-member.s
new file mode 100644
index 0000000000000..9cb534207c3d1
--- /dev/null
+++ b/lldb/test/Shell/SymbolFile/DWARF/x86/debug-names-static-constexpr-member.s
@@ -0,0 +1,169 @@
+## Check that lldb can locate a static constant variable when its declaration is
+## referenced by a debug_names index. This is a non-conforming extension used by
+## dsymutil.
+
+# RUN: llvm-mc -triple=x86_64-pc-linux -filetype=obj %s > %t
+# RUN: %lldb %t -o "target variable Class::constant" \
+# RUN: -o "expr -l c++ -- Class::constant" -o exit | FileCheck %s
+
+# CHECK: (lldb) target variable Class::constant
+# CHECK-NEXT: (const int) Class::constant = 47
+# CHECK: (lldb) expr -l c++ -- Class::constant
+# CHECK-NEXT: (const int) $0 = 47
+
+ .section .debug_abbrev,"", at progbits
+ .byte 1 # Abbreviation Code
+ .byte 17 # DW_TAG_compile_unit
+ .byte 1 # DW_CHILDREN_yes
+ .byte 37 # DW_AT_producer
+ .byte 8 # DW_FORM_string
+ .byte 19 # DW_AT_language
+ .byte 5 # DW_FORM_data2
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 3 # Abbreviation Code
+ .byte 2 # DW_TAG_class_type
+ .byte 1 # DW_CHILDREN_yes
+ .byte 54 # DW_AT_calling_convention
+ .byte 11 # DW_FORM_data1
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 11 # DW_AT_byte_size
+ .byte 11 # DW_FORM_data1
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 4 # Abbreviation Code
+ .byte 52 # DW_TAG_variable
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 63 # DW_AT_external
+ .byte 25 # DW_FORM_flag_present
+ .byte 60 # DW_AT_declaration
+ .byte 25 # DW_FORM_flag_present
+ .byte 28 # DW_AT_const_value
+ .byte 13 # DW_FORM_sdata
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 5 # Abbreviation Code
+ .byte 38 # DW_TAG_const_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 73 # DW_AT_type
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # EOM(1)
+ .byte 0 # EOM(2)
+ .byte 6 # Abbreviation Code
+ .byte 36 # DW_TAG_base_type
+ .byte 0 # DW_CHILDREN_no
+ .byte 3 # DW_AT_name
+ .byte 14 # DW_FORM_strp
+ .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_info,"", at progbits
+.Lcu_begin0:
+ .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+ .short 5 # DWARF version number
+ .byte 1 # DWARF Unit Type
+ .byte 8 # Address Size (in bytes)
+ .long .debug_abbrev # Offset Into Abbrev. Section
+ .byte 1 # Abbrev [1] 0xc:0x40 DW_TAG_compile_unit
+ .asciz "Hand-written DWARF" # DW_AT_producer
+ .short 33 # DW_AT_language
+.LClass:
+ .byte 3 # Abbrev [3] 0x29:0x10 DW_TAG_class_type
+ .byte 5 # DW_AT_calling_convention
+ .long .Linfo_string4 # DW_AT_name
+ .byte 1 # DW_AT_byte_size
+.Lvariable:
+ .byte 4 # Abbrev [4] 0x2f:0x9 DW_TAG_variable
+ .long .Linfo_string5 # DW_AT_name
+ .long .Lconst_int-.Lcu_begin0 # DW_AT_type
+ # DW_AT_external
+ # DW_AT_declaration
+ .byte 47 # DW_AT_const_value
+ .byte 0 # End Of Children Mark
+.Lconst_int:
+ .byte 5 # Abbrev [5] 0x39:0x5 DW_TAG_const_type
+ .long .Lint-.Lcu_begin0 # DW_AT_type
+.Lint:
+ .byte 6 # Abbrev [6] 0x3e:0x4 DW_TAG_base_type
+ .long .Linfo_string6 # DW_AT_name
+ .byte 5 # DW_AT_encoding
+ .byte 4 # DW_AT_byte_size
+ .byte 0 # End Of Children Mark
+.Ldebug_info_end0:
+
+ .section .debug_str,"MS", at progbits,1
+.Linfo_string4:
+ .asciz "Class"
+.Linfo_string5:
+ .asciz "constant"
+.Linfo_string6:
+ .asciz "int"
+
+ .section .debug_names,"", at progbits
+ .long .Lnames_end0-.Lnames_start0 # Header: unit length
+.Lnames_start0:
+ .short 5 # Header: version
+ .short 0 # Header: padding
+ .long 1 # Header: compilation unit count
+ .long 0 # Header: local type unit count
+ .long 0 # Header: foreign type unit count
+ .long 0 # Header: bucket count
+ .long 3 # Header: name count
+ .long .Lnames_abbrev_end0-.Lnames_abbrev_start0 # Header: abbreviation table size
+ .long 8 # Header: augmentation string size
+ .ascii "LLVM0700" # Header: augmentation string
+ .long .Lcu_begin0 # Compilation unit 0
+ .long .Linfo_string4 # String: Class
+ .long .Linfo_string5 # String: constant
+ .long .Linfo_string6 # String: int
+ .long .Lnames0-.Lnames_entries0
+ .long .Lnames3-.Lnames_entries0
+ .long .Lnames1-.Lnames_entries0
+.Lnames_abbrev_start0:
+ .byte 1 # Abbrev code
+ .byte 2 # DW_TAG_class_type
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 2 # Abbrev code
+ .byte 52 # DW_TAG_variable
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 3 # Abbrev code
+ .byte 36 # DW_TAG_base_type
+ .byte 3 # DW_IDX_die_offset
+ .byte 19 # DW_FORM_ref4
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev
+ .byte 0 # End of abbrev list
+.Lnames_abbrev_end0:
+.Lnames_entries0:
+.Lnames0:
+ .byte 1 # Abbreviation code
+ .long .LClass-.Lcu_begin0 # DW_IDX_die_offset
+ .byte 0 # DW_IDX_parent
+ # End of list: Class
+.Lnames3:
+ .byte 2 # Abbreviation code
+ .long .Lvariable-.Lcu_begin0 # DW_IDX_die_offset
+ .byte 0 # DW_IDX_parent
+ # End of list: constant
+.Lnames1:
+ .byte 3 # Abbreviation code
+ .long .Lint-.Lcu_begin0 # DW_IDX_die_offset
+ .byte 0 # DW_IDX_parent
+ # End of list: int
+.Lnames_end0:
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