add support for ctors/dtors on arm with modern gcc

a while back, gcc switched from using the old _init/_fini fragments
method for calling ctors and dtors on arm to the __init_array and
__fini_array method. unfortunately, on glibc this depends on ugly
hacks involving making libc.so a linker script and pulling parts of
libc into the main program binary. so I cheat a little bit, and just
write asm to iterate over the init/fini arrays from the _init/_fini
asm. the same approach could be used on any arch it's needed on, but
for now arm is the only one.
This commit is contained in:
Rich Felker 2012-12-07 23:04:49 -05:00
parent b8ccf8e46b
commit 34aa169dcf
2 changed files with 40 additions and 4 deletions

View File

@ -1,9 +1,27 @@
.section .init
.global _init
_init:
push {lr}
push {r0,r1,r2,r4,r5,lr}
.weak __fini_array_start
.weak __fini_array_end
.section .fini
.global _fini
_fini:
push {lr}
push {r4,r5,r6,lr}
adr lr, 1f
ldr r4, 2f
ldr r5, 2f+4
add r4, r4, lr
add r5, r5, lr
1: adr lr, 1b
cmp r4, r5
beq 3f
ldmia r4!, {r3}
tst r3,#1
moveq pc,r3
bx r3
2: .word __fini_array_start-1b
.word __fini_array_end-1b
3:

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@ -1,11 +1,29 @@
.weak __init_array_start
.weak __init_array_end
.section .init
pop {lr}
adr lr, 1f
ldr r4, 2f
ldr r5, 2f+4
add r4, r4, lr
add r5, r5, lr
1: adr lr, 1b
cmp r4, r5
beq 3f
ldmia r4!, {r3}
ldm sp, {r0,r1,r2}
tst r3,#1
moveq pc,r3
bx r3
3: pop {r0,r1,r2,r4,r5,lr}
tst lr,#1
moveq pc,lr
bx lr
2: .word __init_array_start-1b
.word __init_array_end-1b
.section .fini
pop {lr}
pop {r4,r5,r6,lr}
tst lr,#1
moveq pc,lr
bx lr