On 10/28/2009 11:43 PM, Helge Deller wrote:
On 10/28/2009 11:18 PM, John David Anglin wrote:
and whether it follows inb in its .o. From my understanding of things,
it shouldn't be necessary to remove the unwind info for unused weak
symbols if they aren't garbage collected. A simple testcase would
be helpful.
Attached is a testcase (t1.c and t2.c):
t1.c contains weak function f().
t2.c contains non-weak function f().
hppa-linux-gcc -c t1.c t2.c
hppa-linux-ld -r -o all.o t1.o t2.o
hppa-linux-readelf -s t1.o gives:
Symbol table '.symtab' contains 10 entries:
Num: Value Size Type Bind Vis Ndx Name
6: 00000000 28 FUNC GLOBAL DEFAULT 1 a
7: 0000001c 32 FUNC WEAK DEFAULT 1 f
8: 0000003c 28 FUNC GLOBAL DEFAULT 1 z
9: 00000058 80 FUNC GLOBAL DEFAULT 1 main
hppa-linux-readelf -s t2.o gives:
Symbol table '.symtab' contains 7 entries:
Num: Value Size Type Bind Vis Ndx Name
6: 00000000 32 FUNC GLOBAL DEFAULT 1 f
hppa-linux-readelf -s all.o gives:
Symbol table '.symtab' contains 11 entries:
Num: Value Size Type Bind Vis Ndx Name
7: 00000000 32 FUNC GLOBAL DEFAULT 3 f
8: 0000003c 28 FUNC GLOBAL DEFAULT 1 z
9: 00000058 80 FUNC GLOBAL DEFAULT 1 main
10: 00000000 28 FUNC GLOBAL DEFAULT 1 a
hppa-linux-readelf -u all.o gives:
Unwind section '.PARISC.unwind' at offset 0xfc contains 5 entries:
<a>: [0x0-0x30]
Entry_GR=1 Save_SP Total_frame_size=8
<f>: [0x0-0x70]
Entry_GR=1 Save_SP Total_frame_size=8
<z>: [0x3c-0xa8]
Entry_GR=1 Save_SP Total_frame_size=8
<main>: [0x58-0x148]
Entry_GR=2 Save_SP Save_RP Total_frame_size=8
<f>: [0x0-0x38]
Entry_GR=1 Save_SP Total_frame_size=8
Function f() is listed twice and with different lengths.
Sadly in this example f() starts at offset 0. I think if you tweak
the example, try to see what you get when the start of f() is not zero.
Helge
/who has to run now...
int a(void)
{
return 1;
}
int __attribute__((weak)) f(int x)
{
return 0;
}
int z(void)
{
return 2;
}
int main(void)
{
return a() + f(0) + z();
}
int f(int x)
{
return 500;
}
