Looking at disassembly with interleaved source code I detected a mismatch. Trying with the following simple program app.d
1 import std.stdio;
2
3 void main()
4 {
5 int a = 10;
6
7 a += 3;
8
9 ++a;
10
11 writefln("Value: %d", a);
12
13 writeln("Helloworld!");
14
15 }
I get this output with '$ objdump -d -S app' for the function _Dmain
000000000043aae8 <_Dmain>:
import std.stdio;
void main()
43aae8: 55 push %rbp
43aae9: 48 8b ec mov %rsp,%rbp
43aaec: 48 83 ec 10 sub $0x10,%rsp
{
int a = 10;
43aaf0: c7 45 f8 0a 00 00 00 movl $0xa,-0x8(%rbp)
a += 3;
43aaf7: 83 45 f8 03 addl $0x3,-0x8(%rbp)
++a;
43aafb: ff 45 f8 incl -0x8(%rbp)
writefln("Value: %d", a);
43aafe: ba 60 e5 46 00 mov $0x46e560,%edx
43ab03: be 09 00 00 00 mov $0x9,%esi
{
int a = 10;
a += 3;
++a;
43ab08: 8b 7d f8 mov -0x8(%rbp),%edi
43ab0b: e8 18 00 00 00 callq 43ab28 <_D3std5stdio19__T8writeflnTAyaTiZ8writeflnFNfAyaiZv>
writefln("Value: %d", a);
writeln("Helloworld!");
43ab10: ba 6a e5 46 00 mov $0x46e56a,%edx
43ab15: bf 0b 00 00 00 mov $0xb,%edi
43ab1a: 48 89 d6 mov %rdx,%rsi
43ab1d: e8 e6 9b 00 00 callq 444708 <_D3std5stdio16__T7writelnTAyaZ7writelnFNfAyaZv>
43ab22: 31 c0 xor %eax,%eax
}
43ab24: c9 leaveq
43ab25: c3 retq
43ab26: 66 90 xchg %ax,%ax
000000000043ab28 <_D3std5stdio19__T8writeflnTAyaTiZ8writeflnFNfAyaiZv>:
}
Looking at the debug line table for the main function with the command '$ objdump --dwarf=decodedline app | less' I get this
./app.d:[++]
app.d 3 0x43aae8
app.d 5 0x43aaf0
app.d 7 0x43aaf7
app.d 9 0x43aafb
app.d 11 0x43aafe
app.d 9 0x43ab08
app.d 13 0x43ab10
app.d 15 0x43ab24
After closer inspection of the disassembly code it appears that the second line with 9 should not be present. Removing it should provide a correct debug table.
I didn't check the possible frequency of occurrence in a more complex program.
Comment #1 by robert.schadek — 2024-12-13T18:47:59Z