Question

# Given a number, this program compute the square of a given function
# For Example the 2*2 is 4

#This program showa how to call a function recursively
.section .data
#This program has no global data

.section .text

.globl _start
.globl square #this is unneeded unless we need to share this program 
        #among others
_start:
pushl $4    #The function takes one argument_ the number we want 
        # square of . So it get pushed of.
call square     #run the square function
addl $4, %esp   # Scrubs the paramter that was pushed on the stack

movl %eax, %ebx #factorial returns the answer in %eax, but we want it           #in %ebx to send it as the exit status
movl $1, %eax   #call the kernel's next function
int $0x80 

#This is a function that test square of a function
# It takes one argument and then return the square

 .type square, @square
square:

pushl %ebp  #standard function stuff -we have to
        #restore %ebp to its prior state before 
        #returning, so we have to push it.
movl %esp,%ebp  #This is because we don't want to modify
        #the stack pointer, so we use %ebp
movl 8(%ebp), %eax #This moves the first argument to %eax
        #4(%ebp) holds the return address, and 
        #8(%ebp) holds the first parameter.
cmpl $1,%eax    #If the number is 1, that is our base
        #case, and we simply return(1 is
        #already in %eax as the return value.)
je end_square
pushl %eax  #Push it for call to square
call square     #call square
movl 8(%ebp),%ebx #%eax has the return value, so we
        #reload or parameter into %ebx
imull %ebx,%eax #multiply that by the result of the last call
        #to square(in %eax) the answer is stored in %eax,
        #which is good since that's where return values go.
end_square:
movl %ebp, %esp # standard function stuff-we have to restore %ebp and
popl %ebp   # %esp to where they were were before the function started
ret # return from the function (this pops the # return value, too)

Answer 1

尝试使用：.type square, @square

替换.type square, @function（这没有意义）

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编译无法识别的符号类型square时出现Linux汇编语言错误

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