rodata truncated by two

[Jason W Larsen <Jason dot Larsen at inl dot gov>]

I'm not sure this is the correct mailing list, but here goes.  I was 
trying to debug a program 
and finally got down to the raw object file.  Under certain circumstances, 
constants in the .rodata 
section of an object file are getting truncated.  Here's the data:


Smallest C program that has the bug:

int ObjectLoad(void* vars,void* Object){
        int x = (int)Object;
 
        switch (x){
        case 0:
                printf("X is %i\n",x);
                break;
        case 1:
                printf("X is %i\n",x);
                break;
        case 2:
                printf("X is %i\n",x);
                break;
        case 3:
                printf("X is %i\n",x);
                break;
        case 4:
                printf("X is %i\n",x);
                break; 
        case 5:
                printf("X is %i\n",x);
                break; 
        case 6:
                printf("X is %i\n",x);
                break; 
        case 7:
                printf("X is %i\n",x);
                break; 
        case 8:
                printf("X is %i\n",x);
                break; 
        case 9:
                printf("X is %i\n",x);
                break; 
        default:
                printf("Some other x\n"); 
        }
}

int main(int artc, char**argv){
}


Compiler Info and command line

gcc -c -o testobject.o testobject.c -g -Wall
gcc --version
->gcc (GCC) 4.1.1 (Gentoo 4.1.1-r1)


hex dump of the truncated part

00000ce0  2f 5a 08 2f 5a 08 2f 5a  08 2f 30 08 2f 30 08 2f 
|/Z./Z./Z./0./0./|
00000cf0  30 08 2f 30 08 2f 30 08  2f 30 bc 30 d7 02 06 00 
|0./0./0./0.0....|
00000d00  01 01 00 00 58 20 69 73  20 25 69 0a 00 53 6f 6d  |....X is 
%i..Som|
00000d10  65 20 6f 74 68 65 72 20  78 00 00 00 24 00 00 00  |e other 
x...$...|
00000d20  3c 00 00 00 54 00 00 00  6c 00 00 00 84 00 00 00 
|<...T...l.......|
00000d30  99 00 00 00 ae 00 00 00  c3 00 00 00 d8 00 00 00 
|................|
00000d40  ed 00 00 00 10 00 00 00  ff ff ff ff 01 00 01 7c 
|...............||
00000d50  08 0c 04 04 88 01 00 00  14 00 00 00 00 00 00 00 
|................|
00000d60  00 00 00 00 10 01 00 00  41 0e 08 85 02 42 0d 05 
|........A....B..|
00000d70  24 00 00 00 00 00 00 00  10 01 00 00 14 00 00 00 
|$...............|


Are you can see the constant strings fall before the jump table later 
filled in by the
the linker for use by the case statement.  The jump table entries are 
intact, but the 
string "Some other x\n" is missing the trailing <cr> as well as the 
terminating NULL.

Let me know if you need more data.

Jason Larsen
larsj@inel.gov