Assembly 在0x004000a8处继续获取运行时异常：地址超出范围0x10400004
*我似乎找不到解决方案来修复我的chkvar（lb$t3，tokArray+0（$s5））中的代码并不断得到错误：第77行：0x004000a8处的运行时异常：地址超出范围0x10400004 Go：执行因错误而终止*Assembly 在0x004000a8处继续获取运行时异常：地址超出范围0x10400004,assembly,mips,mars-simulator,Assembly,Mips,Mars Simulator,*我似乎找不到解决方案来修复我的chkvar（lb$t3，tokArray+0（$s5））中的代码并不断得到错误：第77行：0x004000a8处的运行时异常：地址超出范围0x10400004 Go：执行因错误而终止* .data saveReg: .word 0:10 # extra register space! #NULL or 0 in tokArray prematurely terminates dumping #tokArray.Use bl
.data
saveReg: .word 0:10 # extra register space!
#NULL or 0 in tokArray prematurely terminates dumping
#tokArray.Use blanks instead.
TOKEN: .word 0x20202020:3 # 2-word TOKEN & its TYPE
tokArray: .word 0x20202020:60 # initializing with blanks
inBuf: .space 80
space: .asciiz " "
st_prompt: .asciiz "Enter a new input line. \n"
st_error: .asciiz "An error has occurred. \n"
tableHead: .asciiz " TOKEN TYPE\n"
error: .asciiz "Double Definition Error"
hex: .asciiz "0x"
symTab: .word 0:40
tableHeader: .asciiz "Token Value Status \n"
dash: .asciiz "---------------------------------------------\n"
tempNewLine: .asciiz "\n"
.text
#######################################################################
#
#Main
#
#read an input line
#call scanner driver
#clear buffers
#
#Global Registers
#$t5 : index to inBuf in bytes
#$s0 : char type, T
#$s1 : next state Qx
#$s3 : index to the new char space in TOKEN
#$a3 : index to tokArray in 12 bytes per entry
#
######################################################################
li $s4, 0x400 # LOC in $s4
li $t7, 0 # symTab index
newline:
jal getline # get a new input string
li $t5,0 # $t5: index to inBuf
li $a3,0 # $a3: index to tokArray
#State table driver
la $s1, Q0 # initial state Q0
driver: lw $s2, 0($s1) # get the action routine
jalr $v1, $s2 # execute the action
sll $s0, $s0, 2 # compute byte offset of T
add $s1, $s1, $s0 # locate the next state
la $s1, ($s1)
lw $s1, ($s1) # next State in $s1
sra $s0, $s0, 2 # reset $s0 for T
b driver # go to the next state
dump:
lb $t3, tokArray # if the first token is # exit
beq $t3, 0x23, exit
li $s5, 0 # index to tokArray[][]
nextTok:
lb $t3, tokArray+12($s5)
bne $t3, ':', operator # check if next token is colon
lw $t4, tokArray+0($s5) # get current token
sw $t4, TOKEN
lw $t4, tokArray+4($s5)
sw $t4, TOKEN+4
li $s6, 1 # DEFN = $s6 = 1
jal VARIABLE
addi $s5, $s5, 24 # skip next token: �:�
operator:
addi $s5, $s5, 12 # get next token index
li $s7, 1 # $s7 = isComma = true
chkVar:
#lw $t3, tokArray + 8($s5)
#beq $t3, 6, realDump #type is 6 �#� then dump
lb $t3, tokArray+0($s5)
beq $t3, '#', realDump
bne $s7, 1, nextVar # not comma or type is not 2
lb $t3, tokArray+10($s5) # TESTESSTDSERS
subi $t3, $t3, 0x30
bne $t3, 2, nextVar
lw $t4, tokArray+0($s5) # get current token
sw $t4, TOKEN
lw $t4, tokArray+4($s5)
sw $t4, TOKEN+4
li $s6, 0 # DEFN = $s6 = 0
jal VARIABLE # call VARIABLE function
nextVar:
lb $t3, tokArray+0($s5) # check if token is �,�
beq $t3, 0x2C, yes
bne $t3, 0x2C, no
yes:
li $s7, 1
j after
no:
li $s7, 0
j after
after:
addi $s5, $s5, 12 # get next token index
b chkVar # check next token
realDump:
jal clearInBuf # clear input buffer
jal clearTokArray # clear token array
jal clearTok
jal printsymTab
addi $s4, $s4, 4 # LOC +=4
b newline # ask for next input line
exit:
li $v0, 10
syscall
VARIABLE:
sw $ra, saveReg # +0 = $ra
jal srchSymTab # symIndex = $t8
bge $t8, $zero, else
li $s0, 0x4
or $t9, $s0, $s6 # newStatus = $t9
jal saveSymTab
b varEnd
else:
sw $t2, saveReg+4 # $t2 = oldStatus
lw $t2, symTab+12($t8)
and $t9, $t2, 0x2
and $t2, $t2, 0x1
sll $t2, $t2, 1
or $t9, $t9, $t2
or $t9, $t9, $s6
sw $t9, symTab+12($t8)
lw $t2, saveReg+4
varEnd:
b realEnd
varRealEnd:
lw $ra, saveReg
jr $ra
saveSymTab:
sw $t9, symTab+12($t7)
sw $t2, saveReg+4
lw $t2, TOKEN
sw $t2, symTab+0($t7)
lw $t2, TOKEN+4
sw $t2, symTab+4($t7)
add $t8, $zero, $t7
addi $t7, $t7, 16
lw $t2, saveReg+4
jr $ra
printsymTab:
sw $t2, saveReg+8
sw $t3, saveReg+12
sw $t4, saveReg+16
sw $t5, saveReg+20
li $t2, 0
li $v0, 4
la $a0, tableHeader # load header
syscall
la $a0, dash # load dashes
syscall
repeat:
beq $t2, $t7, ret
la $t3, symTab($t2)
lb $t4, symTab+8($t2)
li $t5, '\0'
sb $t5, symTab+8($t2)
move $a0, $t3
syscall
sb $t4, symTab+8($t2)
addi $t2, $t2, 8
la $a0, space
syscall
li $v0, 1
lw $a0, symTab($t2)
addi $t2, $t2, 4
syscall
li $v0, 4
la $a0, space
syscall
la $a0, hex
syscall
li $v0, 1
lw $a0, symTab($t2)
addi $t2, $t2, 4
syscall
li $v0, 4
la $a0, tempNewLine
syscall
bc1f repeat
ret:
lw $t2, saveReg+8
lw $t3, saveReg+12
lw $t4, saveReg+16
lw $t5, saveReg+20
jr $ra
realEnd:
la $s0, symACTS # load address of symACTS to access the first line
sll $t9, $t9, 2 # newStatus * 8
add $s0, $s0, $t9 # calculate the address of the correct symACT
sra $t9, $t9, 2
jr $s0
symACTS:
b symACT0
b symACT1
b symACT2
b symACT3
b symACT4
b symACT5
symACT0:
lw $t1, symTab+8($t8)
sw $s4, symTab+8($t8)
b varRealEnd
symACT1:
lw $t1, symTab+8($t8)
sw $s4, symTab+8($t8)
b varRealEnd
symACT2:
lw $t1, symTab+8($t8)
b varRealEnd
symACT3:
la $a0, error
li $v0, 4
syscall
li $t1, -1
b varRealEnd
symACT4:
sw $s4, symTab+8($t8)
li $t1, -1
b varRealEnd
symACT5:
sw $s4, symTab+8($t8)
li $t1, 0
b varRealEnd
srchSymTab:
sw $t2, saveReg+4
sw $t3, saveReg+8
sw $t4, saveReg+12
li $t2, 0 # i index
li $t8, -1
startSearch:
bge $t2, $t7, srchEnd
lw $t3, TOKEN
lw $t4, symTab($t2)
bne $t3, $t4, update
lw $t3, TOKEN+4
lw $t4, symTab+4($t2)
bne $t3, $t4, update
add $t8, $zero, $t2
j srchEnd
update:
addi $t2, $t2, 16
b startSearch
srchEnd:
lw $t2, saveReg+4
lw $t3, saveReg+8
lw $t4, saveReg+12
jr $ra
####################### STATE ACTION ROUTINES #####################
###################################################################
#
#ACT1:
#$t5 : Get next char
#T = char type
#
##############################################
ACT1:
lb $a0, inBuf($t5) # $a0: next char
jal lin_search # $s0: T (char type)
addi $t5, $t5, 1 # $t5++
jr $v1
###############################################
#
#ACT2:
#save char to TOKEN for the first time
#save char type as Token type
#set remaining token space
#
##############################################
ACT2:
li $s3, 0 # initialize index to TOKEN char
sb $a0, TOKEN($s3) # save 1st char to TOKEN
addi $t0, $s0, 0x30 # T in ASCII
sb $t0, TOKEN+10($s3) # save T as Token type
li $t0, '\n'
sb $t0, TOKEN+11($s3) # NULL to terminate an entry
addi $s3, $s3, 1
jr $v1
#############################################
#
#ACT3:
#collect char to TOKEN
#update remaining token space
#
#############################################
ACT3:
bgt $s3, 7, lenError # TOKEN length error
sb $a0, TOKEN($s3) # save char to TOKEN
addi $s3, $s3, 1 # $s3: index to TOKEN
jr $v1
lenError:
li $s0, 7 # T=7 for token length error
jr $v1
#############################################
#
#ACT4:
#move TOKEN to tokArray
#
############################################
ACT4:
lw $t0, TOKEN($0) # get 1st word of TOKEN
sw $t0, tokArray($a3) # save 1st word to tokArray
lw $t0, TOKEN+4($0) # get 2nd word of TOKEN
sw $t0, tokArray+4($a3) # save 2nd word to tokArray
lw $t0, TOKEN+8($0) # get Token Type
sw $t0, tokArray+8($a3) # save Token Type to tokArray
addi $a3, $a3, 12 # update index to tokArray
jal clearTok # clear 3-word TOKEN
jr $v1
############################################
#
#RETURN:
#End of the input string
#
############################################
RETURN:
sw $zero, tokArray($a3) # force NULL into tokArray
b dump # leave the state table
#############################################
#
#ERROR:
#Error statement and quit
#
############################################
ERROR:
la $a0, st_error # print error occurrence
li $v0, 4
syscall
b dump
############################### BOOK-KEEPING FUNCTIONS #########################
#############################################
#
#clearTok:
#clear 3 - word TOKEN after copying it to tokArray
#
#############################################
clearTok:
li $t1, 0x20202020
sw $t1, TOKEN($0)
sw $t1, TOKEN+4($0)
sw $t1, TOKEN+8($0)
jr $ra
#############################################
#
#printline:
#Echo print input string
#
#############################################
printline:
la $a0, inBuf # input Buffer address
li $v0,4
syscall
jr $ra
#############################################
#
#printTokArray:
#print Token array header
#print each token entry
#
#############################################
printTokArray:
la $a0, tableHead # table heading
li $v0, 4
syscall
la $a0, tokArray # print tokArray
li $v0, 4
syscall
jr $ra
############################################
#
#clearInBuf:
#clear inbox
#
############################################
clearInBuf:
li $t0,0
loopInB:
bge $t0, 80, doneInB
sw $zero, inBuf($t0) # clear inBuf to 0x0
addi $t0, $t0, 4
b loopInB
doneInB:
jr $ra
###########################################
#
#clearTokArray:
#clear Token Array
#
###########################################
clearTokArray:
li $t0, 0
li $t1, 0x20202020 # intialized with blanks
loopCTok:
bge $t0, $a3, doneCTok
sw $t1, tokArray($t0) # clear
sw $t1, tokArray+4($t0) # 3-word entry
sw $t1, tokArray+8($t0) # in tokArray
addi $t0, $t0, 12
b loopCTok
doneCTok:
jr $ra
###################################################################
#
#getline:
#get input string into inbox
#
###################################################################
getline:
la $a0, st_prompt # Prompt to enter a new line
li $v0, 4
syscall
la $a0, inBuf # read a new line
li $a1, 80
li $v0, 8
syscall
jr $ra
##################################################################
#
#lin_search:
#Linear search of Tabchar
#
#$a0 : char key
#$s0 : char type, T
#
#################################################################
lin_search:
li $t0,0 # index to Tabchar
li $s0, 7 # return value, type T
loopSrch:
lb $t1, Tabchar($t0)
beq $t1, 0x7F, charFail
beq $t1, $a0, charFound
addi $t0, $t0, 8
b loopSrch
charFound:
lw $s0, Tabchar+4($t0) # return char type
charFail:
jr $ra
.data
STAB:
Q0: .word ACT1
.word Q1 # T1
.word Q1 # T2
.word Q1 # T3
.word Q1 # T4
.word Q1 # T5
.word Q1 # T6
.word Q11 # T7
Q1: .word ACT2
.word Q2 # T1
.word Q5 # T2
.word Q3 # T3
.word Q3 # T4
.word Q0 # T5
.word Q4 # T6
.word Q11 # T7
Q2: .word ACT1
.word Q6 # T1
.word Q7 # T2
.word Q7 # T3
.word Q7 # T4
.word Q7 # T5
.word Q7 # T6
.word Q11 # T7
Q3: .word ACT4
.word Q0 # T1
.word Q0 # T2
.word Q0 # T3
.word Q0 # T4
.word Q0 # T5
.word Q0 # T6
.word Q11 # T7
Q4: .word ACT4
.word Q10 # T1
.word Q10 # T2
.word Q10 # T3
.word Q10 # T4
.word Q10 # T5
.word Q10 # T6
.word Q11 # T7
Q5: .word ACT1
.word Q8 # T1
.word Q8 # T2
.word Q9 # T3
.word Q9 # T4
.word Q9 # T5
.word Q9 # T6
.word Q11 # T7
Q6: .word ACT3
.word Q2 # T1
.word Q2 # T2
.word Q2 # T3
.word Q2 # T4
.word Q2 # T5
.word Q2 # T6
.word Q11 # T7
Q7: .word ACT4
.word Q1 # T1
.word Q1 # T2
.word Q1 # T3
.word Q1 # T4
.word Q1 # T5
.word Q1 # T6
.word Q11 # T7
Q8: .word ACT3
.word Q5 # T1
.word Q5 # T2
.word Q5 # T3
.word Q5 # T4
.word Q5 # T5
.word Q5 # T6
.word Q11 # T7
Q9: .word ACT4
.word Q1 # T1
.word Q1 # T2
.word Q1 # T3
.word Q1 # T4
.word Q1 # T5
.word Q1 # T6
.word Q11 # T7
Q10: .word RETURN
.word Q10 # T1
.word Q10 # T2
.word Q10 # T3
.word Q10 # T4
.word Q10 # T5
.word Q10 # T6
.word Q11 # T7
Q11: .word ERROR
.word Q4 # T1
.word Q4 # T2
.word Q4 # T3
.word Q4 # T4
.word Q4 # T5
.word Q4 # T6
.word Q4 # T7
Tabchar:
.word ' ', 5
.word '#', 6
.word '$', 4
.word '(', 4
.word ')', 4
.word '*', 3
.word '+', 3
.word ',', 4
.word '-', 3
.word '.', 4
.word '/', 3
.word '0', 1
.word '1', 1
.word '2', 1
.word '3', 1
.word '4', 1
.word '5', 1
.word '6', 1
.word '7', 1
.word '8', 1
.word '9', 1
.word ':', 4
.word 'A', 2
.word 'B', 2
.word 'C', 2
.word 'D', 2
.word 'E', 2
.word 'F', 2
.word 'G', 2
.word 'H', 2
.word 'I', 2
.word 'J', 2
.word 'K', 2
.word 'L', 2
.word 'M', 2
.word 'N', 2
.word 'O', 2
.word 'P', 2
.word 'Q', 2
.word 'R', 2
.word 'S', 2
.word 'T', 2
.word 'U', 2
.word 'V', 2
.word 'W', 2
.word 'X', 2
.word 'Y', 2
.word 'Z', 2
.word 'a', 2
.word 'b', 2
.word 'c', 2
.word 'd', 2
.word 'e', 2
.word 'f', 2
.word 'g', 2
.word 'h', 2
.word 'i', 2
.word 'j', 2
.word 'k', 2
.word 'l', 2
.word 'm', 2
.word 'n', 2
.word 'o', 2
.word 'p', 2
.word 'q', 2
.word 'r', 2
.word 's', 2
.word 't', 2
.word 'u', 2
.word 'v', 2
.word 'w', 2
.word 'x', 2
.word 'y', 2
.word 'z', 2
.word 0x7F, 0
那么，当崩溃发生时，
$s5$s5