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# An example of a function which has been split into two parts. Roughly
# corresponds to this C code.
# int baz() { return 47; }
# int bar() { return foo(0); }
# int foo(int flag) { return flag ? bar() : baz(); }
# int main() { return foo(1); }
# The function bar has been placed "in the middle" of foo. The functions are not
# using the frame pointer register and the are deliberately adjusting the stack
# pointer to test that we're using the correct unwind row.
.att_syntax
.text
.type baz,@function
baz:
.cfi_startproc
movl $47, %eax
retq
.cfi_endproc
.Lbaz_end:
.size baz, .Lbaz_end-baz
foo.__part.3:
.cfi_startproc
.cfi_def_cfa_offset 32
.cfi_offset %rbx, -16
addq $24, %rsp
.cfi_def_cfa %rsp, 8
retq
.Lfoo.__part.3_end:
.size foo.__part.3, .Lfoo.__part.3_end-foo.__part.3
.cfi_endproc
# NB: Deliberately inserting padding to separate the two parts of the function
# as we're currently only parsing a single FDE entry from a (coalesced) address
# range.
nop
foo.__part.1:
.cfi_startproc
.cfi_def_cfa_offset 32
.cfi_offset %rbx, -16
subq $16, %rsp
.cfi_def_cfa_offset 48
callq bar
addq $16, %rsp
.cfi_def_cfa_offset 32
jmp foo.__part.3
.Lfoo.__part.1_end:
.size foo.__part.1, .Lfoo.__part.1_end-foo.__part.1
.cfi_endproc
bar:
.cfi_startproc
subq $88, %rsp
.cfi_def_cfa_offset 96
xorl %edi, %edi
callq foo
addq $88, %rsp
.cfi_def_cfa %rsp, 8
retq
.cfi_endproc
.Lbar_end:
.size bar, .Lbar_end-bar
.type foo,@function
foo:
.cfi_startproc
pushq %rbx
.cfi_def_cfa_offset 16
.cfi_offset %rbx, -16
movl %edi, %ebx
cmpl $0, %ebx
je foo.__part.2
subq $16, %rsp
.cfi_def_cfa_offset 32
jmp foo.__part.1
.cfi_endproc
.Lfoo_end:
.size foo, .Lfoo_end-foo
# NB: Deliberately inserting padding to separate the two parts of the function
# as we're currently only parsing a single FDE entry from a (coalesced) address
# range.
nop
foo.__part.2:
.cfi_startproc
.cfi_def_cfa_offset 16
.cfi_offset %rbx, -16
subq $16, %rsp
.cfi_def_cfa_offset 32
callq baz
jmp foo.__part.3
.Lfoo.__part.2_end:
.size foo.__part.2, .Lfoo.__part.2_end-foo.__part.2
.cfi_endproc
.globl main
.type main,@function
main:
.cfi_startproc
movl $1, %edi
callq foo
retq
.cfi_endproc
.Lmain_end:
.size main, .Lmain_end-main
.section .debug_abbrev,"",@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 17 # DW_AT_low_pc
.byte 1 # DW_FORM_addr
.byte 85 # DW_AT_ranges
.byte 35 # DW_FORM_rnglistx
.byte 116 # DW_AT_rnglists_base
.byte 23 # DW_FORM_sec_offset
.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
.byte 1 # DW_FORM_addr
.byte 18 # DW_AT_high_pc
.byte 1 # DW_FORM_addr
.byte 3 # DW_AT_name
.byte 8 # DW_FORM_string
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 3 # Abbreviation Code
.byte 46 # DW_TAG_subprogram
.byte 1 # DW_CHILDREN_yes
.byte 85 # DW_AT_ranges
.byte 35 # DW_FORM_rnglistx
.byte 64 # DW_AT_frame_base
.byte 24 # DW_FORM_exprloc
.byte 3 # DW_AT_name
.byte 8 # DW_FORM_string
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 4 # 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 8 # DW_FORM_string
.byte 73 # DW_AT_type
.byte 19 # DW_FORM_ref4
.byte 0 # EOM(1)
.byte 0 # EOM(2)
.byte 5 # Abbreviation Code
.byte 36 # DW_TAG_base_type
.byte 0 # DW_CHILDREN_no
.byte 3 # DW_AT_name
.byte 8 # DW_FORM_string
.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,"",@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] DW_TAG_compile_unit
.asciz "Hand-written DWARF" # DW_AT_producer
.short 29 # DW_AT_language
.quad 0 # DW_AT_low_pc
.byte 1 # DW_AT_ranges
.long .Lrnglists_table_base0 # DW_AT_rnglists_base
.byte 2 # Abbrev [2] DW_TAG_subprogram
.quad baz # DW_AT_low_pc
.quad .Lbaz_end # DW_AT_high_pc
.asciz "baz" # DW_AT_name
.byte 2 # Abbrev [2] DW_TAG_subprogram
.quad bar # DW_AT_low_pc
.quad .Lbar_end # DW_AT_high_pc
.asciz "bar" # DW_AT_name
.byte 3 # Abbrev [3] DW_TAG_subprogram
.byte 0 # DW_AT_ranges
.byte 1 # DW_AT_frame_base
.byte 86
.asciz "foo" # DW_AT_name
.byte 4 # Abbrev [4] DW_TAG_formal_parameter
.byte 1 # DW_AT_location
.byte 0x53 # DW_OP_reg3
.asciz "flag" # DW_AT_name
.long .Lint-.Lcu_begin0 # DW_AT_type
.byte 0 # End Of Children Mark
.byte 2 # Abbrev [2] DW_TAG_subprogram
.quad main # DW_AT_low_pc
.quad .Lmain_end # DW_AT_high_pc
.asciz "main" # DW_AT_name
.Lint:
.byte 5 # Abbrev [5] DW_TAG_base_type
.asciz "int" # 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_rnglists,"",@progbits
.long .Ldebug_list_header_end0-.Ldebug_list_header_start0 # Length
.Ldebug_list_header_start0:
.short 5 # Version
.byte 8 # Address size
.byte 0 # Segment selector size
.long 2 # Offset entry count
.Lrnglists_table_base0:
.long .Ldebug_ranges0-.Lrnglists_table_base0
.long .Ldebug_ranges1-.Lrnglists_table_base0
.Ldebug_ranges0:
.byte 6 # DW_RLE_start_end
.quad foo
.quad .Lfoo_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.1
.quad .Lfoo.__part.1_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.2
.quad .Lfoo.__part.2_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.3
.quad .Lfoo.__part.3_end
.byte 0 # DW_RLE_end_of_list
.Ldebug_ranges1:
.byte 6 # DW_RLE_start_end
.quad baz
.quad .Lbaz_end
.byte 6 # DW_RLE_start_end
.quad bar
.quad .Lbar_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.1
.quad .Lfoo.__part.1_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.2
.quad .Lfoo.__part.2_end
.byte 6 # DW_RLE_start_end
.quad foo.__part.3
.quad .Lfoo.__part.3_end
.byte 6 # DW_RLE_start_end
.quad foo
.quad .Lfoo_end
.byte 6 # DW_RLE_start_end
.quad main
.quad .Lmain_end
.byte 0 # DW_RLE_end_of_list
.Ldebug_list_header_end0:
.section ".note.GNU-stack","",@progbits
|
