use proper dwarf parsing in disassembler #495
Description
currently we are just parsing the output of objdump which in case of inlined functions is not useable. See #490
If I comple test.c
#include <stdio.h>
inline int square(int i) {
return i * i;
}
int main() {
for (int i = 0; i < 10000; i++) {
int sum = 0;
for (int j = 0; j < i; j++) {
sum += square(j);
}
printf("Sum: %d\n", sum);
}
}with -O3 -g I end up with the following in objdump:
0000000000001040 <main>:
main():
/tmp/test.c:7
1040: 55 push %rbp
/tmp/test.c:13
1041: 48 8d 2d bc 0f 00 00 lea 0xfbc(%rip),%rbp # 2004 <_IO_stdin_used+0x4>
....
square():
/tmp/test.c:4
109b: 66 0f 6f d0 movdqa %xmm0,%xmm2
109f: 66 0f f4 d0 pmuludq %xmm0,%xmm2
10a3: 66 0f 73 d0 20 psrlq $0x20,%xmm0
10a8: 66 0f f4 c0 pmuludq %xmm0,%xmm0
10ac: 66 0f 70 d2 08 pshufd $0x8,%xmm2,%xmm2
10b1: 66 0f 70 c0 08 pshufd $0x8,%xmm0,%xmm0
10b6: 66 0f 62 d0 punpckldq %xmm0,%xmm2
main():
/tmp/test.c:11 (discriminator 1)
10ba: 66 0f fe ca paddd %xmm2,%xmm1
...dwarfdump gives me:
0x000000f6: DW_TAG_inlined_subroutine
DW_AT_abstract_origin (0x00000166 "square")
DW_AT_entry_pc (0x000000000000109b)
DW_AT_GNU_entry_view (0x01)
DW_AT_ranges (0x0000006f
[0x000000000000109b, 0x00000000000010ba)
[0x00000000000010f0, 0x00000000000010f5))
DW_AT_call_file ("/tmp/test.c")
DW_AT_call_line (11)
DW_AT_call_column (0x20)
0x00000166: DW_TAG_subprogram
DW_AT_external (true)
DW_AT_name ("square")
DW_AT_decl_file ("/tmp/test.c")
DW_AT_decl_line (3)
DW_AT_decl_column (0x0c)
DW_AT_prototyped (true)
DW_AT_type (0x00000054 "int")
DW_AT_inline (DW_INL_declared_inlined)so it may be worth investing some time into proper dwarf parsing.