Commit 78d41a12 authored by David Blaikie's avatar David Blaikie
Browse files

lldb: Add support for printing variables with DW_AT_ranges on DW_TAG_subprograms 

Finishing out the support (to the best of my knowledge/based on current
testing running the whole check-lldb with a clang forcibly using
DW_AT_ranges on all DW_TAG_subprograms) for this feature.

Differential Revision: https://reviews.llvm.org/D94064
parent b3fcc72e

lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp

+7 −2
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include "lldb/Interpreter/OptionValueProperties.h"



#include "Plugins/ExpressionParser/Clang/ClangUtil.h"

#include "Plugins/SymbolFile/DWARF/DWARFDebugInfoEntry.h"

#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"

#include "lldb/Symbol/Block.h"

#include "lldb/Symbol/CompileUnit.h"
@@ -3040,8 +3041,12 @@ size_t SymbolFileDWARF::ParseVariablesForContext(const SymbolContext &sc) { 
    if (sc.function) {

      DWARFDIE function_die = GetDIE(sc.function->GetID());



      const dw_addr_t func_lo_pc = function_die.GetAttributeValueAsAddress(

          DW_AT_low_pc, LLDB_INVALID_ADDRESS);

      dw_addr_t func_lo_pc = LLDB_INVALID_ADDRESS;

      DWARFRangeList ranges;

      if (function_die.GetDIE()->GetAttributeAddressRanges(

              function_die.GetCU(), ranges,

              /*check_hi_lo_pc=*/true))

        func_lo_pc = ranges.GetMinRangeBase(0);

      if (func_lo_pc != LLDB_INVALID_ADDRESS) {

        const size_t num_variables = ParseVariables(

            sc, function_die.GetFirstChild(), func_lo_pc, true, true);

lldb/test/Shell/SymbolFile/DWARF/Inputs/subprogram_ranges.s

+57 −35
Original line number Diff line number Diff line 
	.text

	.file	"main.c"

	.file	"subprogram_ranges.c"

	.globl	main                            # -- Begin function main

	.p2align	4, 0x90

	.type	main,@function

main:                                   # @main

.Lfunc_begin0:

	.file	1 "/usr/local/google/home/blaikie/dev/scratch" "main.c"

	.loc	1 1 0                           # main.c:1:0

	.file	1 "/usr/local/google/home/blaikie/dev/scratch" "subprogram_ranges.c"

	.loc	1 2 0                           # subprogram_ranges.c:2:0

	.cfi_startproc

# %bb.0:                                # %entry

	pushq	%rbp

	.cfi_def_cfa_offset 16

	.cfi_offset %rbp, -16

	movq	%rsp, %rbp

	.cfi_def_cfa_register %rbp

	xorl	%eax, %eax

	#DEBUG_VALUE: main:var <- 3

	.loc	1 4 5 prologue_end              # subprogram_ranges.c:4:5

	movl	$1, i(%rip)

.Ltmp0:

	.loc	1 2 7 prologue_end              # main.c:2:7

	movl	$3, -4(%rbp)

	.loc	1 3 1                           # main.c:3:1

	popq	%rbp

	.cfi_def_cfa %rsp, 8

	#DEBUG_VALUE: main:var <- 5

	.loc	1 6 5                           # subprogram_ranges.c:6:5

	movl	$2, i(%rip)

	.loc	1 7 1                           # subprogram_ranges.c:7:1

	xorl	%eax, %eax

	retq

.Ltmp1:

.Lfunc_end0:

	.size	main, .Lfunc_end0-main

	.cfi_endproc

                                        # -- End function

	.type	i,@object                       # @i

	.bss

	.globl	i

	.p2align	2

i:

	.long	0                               # 0x0

	.size	i, 4



	.section	.debug_loc,"",@progbits

.Ldebug_loc0:

	.quad	.Lfunc_begin0-.Lfunc_begin0

	.quad	.Ltmp0-.Lfunc_begin0

	.short	3                               # Loc expr size

	.byte	17                              # DW_OP_consts

	.byte	3                               # 3

	.byte	159                             # DW_OP_stack_value

	.quad	.Ltmp0-.Lfunc_begin0

	.quad	.Lfunc_end0-.Lfunc_begin0

	.short	3                               # Loc expr size

	.byte	17                              # DW_OP_consts

	.byte	5                               # 5

	.byte	159                             # DW_OP_stack_value

	.quad	0

	.quad	0

	.section	.debug_abbrev,"",@progbits

	.byte	1                               # Abbreviation Code

	.byte	17                              # DW_TAG_compile_unit
@@ -54,6 +75,8 @@ main: # @main 
	.byte	23                              # DW_FORM_sec_offset

	.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	3                               # DW_AT_name

	.byte	14                              # DW_FORM_strp

	.byte	58                              # DW_AT_decl_file
@@ -70,7 +93,7 @@ main: # @main 
	.byte	52                              # DW_TAG_variable

	.byte	0                               # DW_CHILDREN_no

	.byte	2                               # DW_AT_location

	.byte	24                              # DW_FORM_exprloc

	.byte	23                              # DW_FORM_sec_offset

	.byte	3                               # DW_AT_name

	.byte	14                              # DW_FORM_strp

	.byte	58                              # DW_AT_decl_file
@@ -100,7 +123,7 @@ main: # @main 
	.short	4                               # DWARF version number

	.long	.debug_abbrev                   # Offset Into Abbrev. Section

	.byte	8                               # Address Size (in bytes)

	.byte	1                               # Abbrev [1] 0xb:0x47 DW_TAG_compile_unit

	.byte	1                               # Abbrev [1] 0xb:0x48 DW_TAG_compile_unit

	.long	.Linfo_string0                  # DW_AT_producer

	.short	12                              # DW_AT_language

	.long	.Linfo_string1                  # DW_AT_name
@@ -108,25 +131,24 @@ main: # @main 
	.long	.Linfo_string2                  # DW_AT_comp_dir

	.quad	.Lfunc_begin0                   # DW_AT_low_pc

	.long	.Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc

	.byte	2                               # Abbrev [2] 0x2a:0x20 DW_TAG_subprogram

	.byte	2                               # Abbrev [2] 0x2a:0x21 DW_TAG_subprogram

	.long	.Ldebug_ranges0                 # DW_AT_ranges

	.byte	1                               # DW_AT_frame_base

	.byte	86

	.byte	87

                                        # DW_AT_GNU_all_call_sites

	.long	.Linfo_string3                  # DW_AT_name

	.byte	1                               # DW_AT_decl_file

	.byte	1                               # DW_AT_decl_line

	.long	74                              # DW_AT_type

	.byte	2                               # DW_AT_decl_line

	.long	75                              # DW_AT_type

                                        # DW_AT_external

	.byte	3                               # Abbrev [3] 0x3b:0xe DW_TAG_variable

	.byte	2                               # DW_AT_location

	.byte	145

	.byte	124

	.byte	3                               # Abbrev [3] 0x3b:0xf DW_TAG_variable

	.long	.Ldebug_loc0                    # DW_AT_location

	.long	.Linfo_string5                  # DW_AT_name

	.byte	1                               # DW_AT_decl_file

	.byte	2                               # DW_AT_decl_line

	.long	74                              # DW_AT_type

	.byte	3                               # DW_AT_decl_line

	.long	75                              # DW_AT_type

	.byte	0                               # End Of Children Mark

	.byte	4                               # Abbrev [4] 0x4a:0x7 DW_TAG_base_type

	.byte	4                               # Abbrev [4] 0x4b:0x7 DW_TAG_base_type

	.long	.Linfo_string4                  # DW_AT_name

	.byte	5                               # DW_AT_encoding

	.byte	4                               # DW_AT_byte_size
@@ -140,20 +162,20 @@ main: # @main 
	.quad	0

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

.Linfo_string0:

	.asciz	"clang version 12.0.0 (git@github.com:llvm/llvm-project.git 1c15aa171b2f67d9198a8498945cbdb936c0cd3b)" # string offset=0

	.asciz	"clang version 12.0.0 (git@github.com:llvm/llvm-project.git 439e8f6c05584c36ea3f79d9b83a78098d40e629)" # string offset=0

.Linfo_string1:

	.asciz	"main.c"                        # string offset=101

	.asciz	"subprogram_ranges.c"           # string offset=101

.Linfo_string2:

	.asciz	"/usr/local/google/home/blaikie/dev/scratch" # string offset=108

	.asciz	"/usr/local/google/home/blaikie/dev/scratch" # string offset=121

.Linfo_string3:

	.asciz	"main"                          # string offset=151

	.asciz	"main"                          # string offset=164

.Linfo_string4:

	.asciz	"int"                           # string offset=156

	.asciz	"int"                           # string offset=169

.Linfo_string5:

	.asciz	"var"                           # string offset=160

	.ident	"clang version 12.0.0 (git@github.com:llvm/llvm-project.git 1c15aa171b2f67d9198a8498945cbdb936c0cd3b)"

	.asciz	"var"                           # string offset=173

	.ident	"clang version 12.0.0 (git@github.com:llvm/llvm-project.git 439e8f6c05584c36ea3f79d9b83a78098d40e629)"

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

	.addrsig

	.addrsig_sym i

	.section	.debug_line,"",@progbits

.Lline_table_start0:

lldb/test/Shell/SymbolFile/DWARF/subprogram_ranges.test

+21 −1
Original line number Diff line number Diff line
@@ -14,6 +14,26 @@ 
# especially useful, but don't dismiss it as pointless just because it's a bit

# weird.



# * Using volatile writes to create instructions the location may be valid over

# * Using two values for the variable so it is described by a location list,

#   not a single location description

# * Not using function calls, so that the function has no frame pointer

#   initialization/no prologue instructions, so the location of "var" is valid

#   at the start of the function, so 'image lookup -v -s main' will include it.

#

# Source:

# __attribute__((nodebug)) volatile int i;

# int main() {

#   int var = 3;

#   i = 1;

#   var = 5;

#   i = 2;

# }



b main

# CHECK: (lldb) b main

# CHECK-NEXT: Breakpoint 1: where = {{.*}}`main + 6 at main.c:2:7
 
# CHECK-NEXT: Breakpoint 1: where = {{.*}}`main at subprogram_ranges.c:4:5



image lookup -v -s main

# CHECK: 1 symbols match 'main'

# CHECK:  Variable: {{.*}}, name = "var", type = "int", {{.*}}, decl = subprogram_ranges.c:3