test.c :
	__attribute__((target("arm"))) int foo(void)
	{
    	return 0;
	}

	int main(void)
	{
    	return foo();
	}

Disassembly :

00000000 <foo>:
   0:	2000      	movs	r0, #0
   2:	4770      	bx	lr

00000004 <main>:
   4:	b580      	push	{r7, lr}
   6:	af00      	add	r7, sp, #0
   8:	b082      	sub	sp, #8
   a:	2000      	movs	r0, #0
   c:	9001      	str	r0, [sp, #4]
   e:	f7ff fffe 	bl	0 <foo>
			e: R_ARM_THM_CALL	foo
  12:	b002      	add	sp, #8
  14:	bc80      	pop	{r7}
  16:	bc02      	pop	{r1}
  18:	468e      	mov	lr, r1
  1a:	4770      	bx	lr

Command :
	clang -nostdlib -target armv4t-none-eabi -mthumb -c test.c -o first.clang.o

Command output :
	'+arm' is not a recognized feature for this target (ignoring feature)
	'+soft-float-abi' is not a recognized feature for this target (ignoring feature)
	'+arm' is not a recognized feature for this target (ignoring feature)
	'+soft-float-abi' is not a recognized feature for this target (ignoring feature)