| ; The assembly below corresponds to this program: | |
| ; __attribute__((nodebug)) | |
| ; int foo() { | |
| ; return 10; | |
| ; } | |
| ; int main(int argc, char **argv) { | |
| ; foo(); | |
| ; return 0; | |
| ; } | |
| ; | |
| ; The assembly was edited in two places (search for "EDIT"): | |
| ; 1. A "orr x29, x29, #0x1000000000000000" instruction was added in foo. This | |
| ; effectively changes the CFA value of the frame above foo (i.e. main). | |
| ; 2. In main, the DWARF location of `argv` was changed to DW_AT_call_frame_cfa. | |
| ; | |
| ; This allows us to stop in foo, go to frame 1 (main) and do `v &argv`, | |
| ; obtaining the result of evaluating DW_AT_call_frame_cfa. | |
| .section __TEXT,__text,regular,pure_instructions | |
| .globl _foo ; -- Begin function foo | |
| .p2align 2 | |
| _foo: ; @foo | |
| Lfunc_begin0: | |
| .cfi_startproc | |
| orr x29, x29, #0x1000000000000000 ; EDIT: Set top byte of fp. | |
| stp x29, x30, [sp, #-16]! ; 16-byte Folded Spill | |
| mov x29, sp | |
| .cfi_def_cfa w29, 16 | |
| .cfi_offset w30, -8 | |
| .cfi_offset w29, -16 | |
| mov w0, #10 ; =0xa | |
| ldp x29, x30, [sp], #16 ; 16-byte Folded Reload | |
| ret | |
| Lfunc_end0: | |
| .cfi_endproc | |
| ; -- End function | |
| .globl _main ; -- Begin function main | |
| .p2align 2 | |
| _main: ; @main | |
| Lfunc_begin1: | |
| .file 1 "/test" "test.c" | |
| .loc 1 6 0 ; test.c:6:0 | |
| .cfi_startproc | |
| sub sp, sp, #48 | |
| stp x29, x30, [sp, #32] ; 16-byte Folded Spill | |
| add x29, sp, #32 | |
| .cfi_def_cfa w29, 16 | |
| .cfi_offset w30, -8 | |
| .cfi_offset w29, -16 | |
| mov w8, #0 ; =0x0 | |
| str w8, [sp, #12] ; 4-byte Folded Spill | |
| stur wzr, [x29, #-4] | |
| stur w0, [x29, #-8] | |
| str x1, [sp, #16] | |
| Ltmp0: | |
| bl _foo | |
| ldr w0, [sp, #12] ; 4-byte Folded Reload | |
| ldp x29, x30, [sp, #32] ; 16-byte Folded Reload | |
| add sp, sp, #48 | |
| ret | |
| Ltmp1: | |
| Lfunc_end1: | |
| .cfi_endproc | |
| ; -- End function | |
| .section __DWARF,__debug_abbrev,regular,debug | |
| Lsection_abbrev: | |
| .byte 1 ; Abbreviation Code | |
| .byte 17 ; DW_TAG_compile_unit | |
| .byte 1 ; DW_CHILDREN_yes | |
| .byte 37 ; DW_AT_producer | |
| .byte 14 ; DW_FORM_strp | |
| .byte 19 ; DW_AT_language | |
| .byte 5 ; DW_FORM_data2 | |
| .byte 3 ; DW_AT_name | |
| .byte 14 ; DW_FORM_strp | |
| .ascii "\202|" ; DW_AT_LLVM_sysroot | |
| .byte 14 ; DW_FORM_strp | |
| .ascii "\357\177" ; DW_AT_APPLE_sdk | |
| .byte 14 ; DW_FORM_strp | |
| .byte 16 ; DW_AT_stmt_list | |
| .byte 23 ; DW_FORM_sec_offset | |
| .byte 27 ; DW_AT_comp_dir | |
| .byte 14 ; DW_FORM_strp | |
| .byte 17 ; DW_AT_low_pc | |
| .byte 1 ; DW_FORM_addr | |
| .byte 18 ; DW_AT_high_pc | |
| .byte 6 ; DW_FORM_data4 | |
| .byte 0 ; EOM(1) | |
| .byte 0 ; EOM(2) | |
| .byte 2 ; Abbreviation Code | |
| .byte 46 ; DW_TAG_subprogram | |
| .byte 1 ; DW_CHILDREN_yes | |
| .byte 17 ; DW_AT_low_pc | |
| .byte 1 ; DW_FORM_addr | |
| .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 14 ; DW_FORM_strp | |
| .byte 58 ; DW_AT_decl_file | |
| .byte 11 ; DW_FORM_data1 | |
| .byte 59 ; DW_AT_decl_line | |
| .byte 11 ; DW_FORM_data1 | |
| .byte 39 ; DW_AT_prototyped | |
| .byte 25 ; DW_FORM_flag_present | |
| .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 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 14 ; DW_FORM_strp | |
| .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 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 15 ; DW_TAG_pointer_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 0 ; EOM(3) | |
| .section __DWARF,__debug_info,regular,debug | |
| Lsection_info: | |
| Lcu_begin0: | |
| .set Lset0, Ldebug_info_end0-Ldebug_info_start0 ; Length of Unit | |
| .long Lset0 | |
| Ldebug_info_start0: | |
| .short 4 ; DWARF version number | |
| .set Lset1, Lsection_abbrev-Lsection_abbrev ; Offset Into Abbrev. Section | |
| .long Lset1 | |
| .byte 8 ; Address Size (in bytes) | |
| .byte 1 ; Abbrev [1] 0xb:0x76 DW_TAG_compile_unit | |
| .long 0 ; DW_AT_producer | |
| .short 12 ; DW_AT_language | |
| .long 47 ; DW_AT_name | |
| .long 54 ; DW_AT_LLVM_sysroot | |
| .long 165 ; DW_AT_APPLE_sdk | |
| .set Lset2, Lline_table_start0-Lsection_line ; DW_AT_stmt_list | |
| .long Lset2 | |
| .long 180 ; DW_AT_comp_dir | |
| .quad Lfunc_begin1 ; DW_AT_low_pc | |
| .set Lset3, Lfunc_end1-Lfunc_begin1 ; DW_AT_high_pc | |
| .long Lset3 | |
| .byte 2 ; Abbrev [2] 0x32:0x36 DW_TAG_subprogram | |
| .quad Lfunc_begin1 ; DW_AT_low_pc | |
| .set Lset4, Lfunc_end1-Lfunc_begin1 ; DW_AT_high_pc | |
| .long Lset4 | |
| .byte 1 ; DW_AT_frame_base | |
| .byte 109 | |
| .long 247 ; DW_AT_name | |
| .byte 1 ; DW_AT_decl_file | |
| .byte 6 ; DW_AT_decl_line | |
| ; DW_AT_prototyped | |
| .long 107 ; DW_AT_type | |
| ; DW_AT_external | |
| .byte 3 ; Abbrev [3] 0x4b:0xe DW_TAG_formal_parameter | |
| .byte 2 ; DW_AT_location | |
| .byte 145 | |
| .byte 120 | |
| .long 256 ; DW_AT_name | |
| .byte 1 ; DW_AT_decl_file | |
| .byte 6 ; DW_AT_decl_line | |
| .long 103 ; DW_AT_type | |
| .byte 3 ; Abbrev [3] 0x59:0xe DW_TAG_formal_parameter | |
| .byte 1 ; DW_AT_location | |
| .byte 0x9c ; EDIT: DW_AT_call_frame_cfa | |
| .long 261 ; DW_AT_name | |
| .byte 1 ; DW_AT_decl_file | |
| .byte 6 ; DW_AT_decl_line | |
| .long 110 ; DW_AT_type | |
| .byte 0 ; End Of Children Mark | |
| .byte 4 ; Abbrev [4] 0x68:0x7 DW_TAG_base_type | |
| .long 252 ; DW_AT_name | |
| .byte 5 ; DW_AT_encoding | |
| .byte 4 ; DW_AT_byte_size | |
| .byte 5 ; Abbrev [5] 0x6f:0x5 DW_TAG_pointer_type | |
| .long 115 ; DW_AT_type | |
| .byte 5 ; Abbrev [5] 0x74:0x5 DW_TAG_pointer_type | |
| .long 120 ; DW_AT_type | |
| .byte 4 ; Abbrev [4] 0x79:0x7 DW_TAG_base_type | |
| .long 266 ; DW_AT_name | |
| .byte 6 ; DW_AT_encoding | |
| .byte 1 ; DW_AT_byte_size | |
| .byte 0 ; End Of Children Mark | |
| Ldebug_info_end0: | |
| .section __DWARF,__debug_str,regular,debug | |
| Linfo_string: | |
| .asciz "Apple clang " ; string offset=0 | |
| .asciz "test.c" ; string offset=47 | |
| .asciz "/Applications/Xcode..........................................................................................." ; string offset=54 | |
| .asciz ".............." ; string offset=165 | |
| .asciz "......................................................../llvm_src1" ; string offset=180 | |
| .asciz "main" ; string offset=247 | |
| .asciz "int" ; string offset=252 | |
| .asciz "argc" ; string offset=256 | |
| .asciz "argv" ; string offset=261 | |
| .asciz "char" ; string offset=266 | |
| .subsections_via_symbols | |
| .section __DWARF,__debug_line,regular,debug | |
| Lsection_line: | |
| Lline_table_start0: |