BUG: Extra lines are generated in assembly code when you Use #line directive in Visual C++ (240626)

MORE INFORMATION

Steps to reproduce the behavior

Compile Main.cpp:

/*******************************************
   Main.cpp file
   Uses #line directives. 
   
  ******************************************/ 

#include <stdio.h>
#line 1 "thetestfile"
void main() {
#line 1 "thetestfile"
int xx = 1;
#line 1 "thetestfile"

#line 1 "thetestfile"
if (xx == 1) {
#line 1 "thetestfile"
	printf("hello1\n");
#line 1 "thetestfile"
	++xx;
#line 1 "thetestfile"
}
#line 1 "thetestfile"


if (xx == 2) {
#line 2 "thetestfile"	
	int r = 0;
#line 2 "thetestfile"
	printf("hello2\n");
#line 2 "thetestfile"
}
#line 2 "thetestfile"

#line 3 "thetestfile"
if (xx == 2) {
#line 3 "thetestfile"	
	int r = 0;
#line 3 "thetestfile"
	printf("hello3\n");
#line 3 "thetestfile"
}
#line 3 "thetestfile"

}
				

Create a text file named thetestfile, and add the following lines to the file:

line 1 : Write hello1 on console
line 2 : Write hello2 on console
line 3 : Write hello3 on console
				

The following is the generated assembly code:

1:    line 1 : Write hello1 on console
00401010   push        ebp
00401011   mov         ebp,esp
00401013   sub         esp,4Ch
00401016   push        ebx
00401017   push        esi
00401018   push        edi
00401019   lea         edi,[ebp-4Ch]
0040101C   mov         ecx,13h
00401021   mov         eax,0CCCCCCCCh
00401026   rep stos    dword ptr [edi]
00401028   mov         dword ptr [ebp-4],1
0040102F   cmp         dword ptr [ebp-4],1
00401033   jne         main+3Bh (0040104b)
00401035   push        offset string "hello1\n" (00420034)
0040103A   call        printf (004010b0)
0040103F   add         esp,4
00401042   mov         eax,dword ptr [ebp-4]
00401045   add         eax,1
00401048   mov         dword ptr [ebp-4],eax
3:    line 3 : Write hello3 on console
0040104B   cmp         dword ptr [ebp-4],2
0040104F   jne         main+55h (00401065)
2:    line 2 : Write hello2 on console
00401051   mov         dword ptr [r],0
2:    line 2 : Write hello2 on console
00401058   push        offset string "hello2\n" (00420028)
0040105D   call        printf (004010b0)
00401062   add         esp,4
3:    line 3 : Write hello3 on console
00401065   cmp         dword ptr [ebp-4],2
00401069   jne         main+6Fh (0040107f)
3:    line 3 : Write hello3 on console
0040106B   mov         dword ptr [r],0
3:    line 3 : Write hello3 on console
00401072   push        offset string "hello3\n" (0042001c)
00401077   call        printf (004010b0)
0040107C   add         esp,4
4:
0040107F   pop         edi
00401080   pop         esi
00401081   pop         ebx
00401082   add         esp,4Ch
00401085   cmp         ebp,esp
00401087   call        __chkesp (00401130)
0040108C   mov         esp,ebp
0040108E   pop         ebp
0040108F   ret
				

Extra lines are generated for line 2 and line 3 directives. As a result, you need to press F10 multiple times for line 2 and line 3 while debugging.