ARMv8/src/parser.c

433 lines
16 KiB
C

/** @file parser.c
* @brief Functions to parse ARMv8 assembly lines into an array of a special
* internal representation of instructions, a64inst_instruction.
* @author Ethan Dias Alberto
* @author George Niedringhaus
* @author Saleh Bubshait
*/
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdbool.h>
#include "parser.h"
#include "a64instruction/a64instruction.h"
#include "global.h"
#include "tokeniser.h"
#include "string_util.h"
/************************************
* STRUCTS
************************************/
typedef struct {
int type;
int immediate;
} ShiftData;
/************************************
* PROTOTYPES
************************************/
static void parse_instruction(char asmLine[], a64inst_instruction *instr);
static void parseSingleTransfer(a64inst_instruction *instr, char *opcode, char *operandList[], int numOperands);
static void parseBranch(a64inst_instruction *instr, char* opcode, char *operandList[]);
static void parseAddressingMode(a64inst_instruction *instr, char *operandList[], int numOperands);
static void parseDPImmediate(a64inst_instruction *inst, char *tokens[], int tokensCount);
static void parseDPRegister(a64inst_instruction *inst, char *tokens[], int tokensCount);
static void parseDirective(a64inst_instruction *inst, char *tokens[]);
static ShiftData *parseShift(char *shift);
static void classifyOpcode(char* opcode, a64inst_instruction *instr, char *tokens[], int *tokensCount);
/************************************
* CONSTANTS
************************************/
static const char *BRANCH_OPCODES[] = {"b", "br", "b.eq", "b.ne", "b.ge", "b.lt", "b.gt", "b.le", "b.al"};
static const char *SINGLE_TRANSFER_OPCODES[] = {"ldr", "str"};
static const char *WIDE_MOV_OPCODES[] = {"movn", "movz", "movz", "movk"};
static const char *ARITHMETIC_OPCODES[] = {"add", "adds", "sub", "subs"};
static const char *MULTIPLY_OPCODES[] = {"mul", "madd", "msub", "mneg"};
static const char *SHIFT_TYPE_OPCODES[] = {"lsl", "lsr", "asr", "ror"};
static const char *LOGIC_OPCODES[] = {"and", "ands", "bic", "bics", "eor", "eon", "orr", "orn"};
/************************************
* FUNCTIONS
************************************/
a64inst_instruction *parse(char **asmLines, int lineCount) {
a64inst_instruction *instructions = malloc(sizeof(a64inst_instruction) * lineCount);
int i = 0;
while (asmLines[i] != NULL) {
parse_instruction(asmLines[i], &instructions[i]);
i++;
}
return instructions;
}
/** Parses a single ARMv8 assembly line into an a64inst_instruction.
*/
static void parse_instruction(char asmLine[], a64inst_instruction *instr) {
if (instr == NULL){
exit(EXIT_FAILURE);
}
char *asmLineCopy = duplicateString(asmLine);
int tokensCount = 0;
char **tokens = tokenise(asmLineCopy, &tokensCount);
char *opcode = tokens[0];
// Check if the instruction is the halt instruction, "and x0, x0, x0".
if (tokensCount == 4 && strcmp(opcode, "and") == 0
&& getRegister(tokens[1]) == 0
&& getRegister(tokens[2]) == 0
&& getRegister(tokens[3]) == 0) {
instr->type = a64inst_HALT;
return;
}
if(strcmp(opcode, ".int") == 0){
// Directive
instr->type = a64inst_DIRECTIVE;
parseDirective(instr, tokens);
} else if(opcode[strlen(opcode)-1]== ':') {
// Label
instr->type = a64inst_LABEL;
opcode[strlen(opcode) - 1] = '\0'; // Remove the colon
instr->data.LabelData.label = opcode;
} else {
// Instruction
// Classify the opcode into the correct instruction type.
classifyOpcode(opcode, instr, tokens, &tokensCount);
switch(instr->type){
case a64inst_BRANCH:
parseBranch(instr, opcode, tokens);
break;
case a64inst_SINGLETRANSFER:
parseSingleTransfer(instr, opcode, tokens, tokensCount);
parseAddressingMode(instr, tokens, tokensCount);
break;
case a64inst_LOADLITERAL:
parseSingleTransfer(instr, opcode, tokens, tokensCount);
break;
case a64inst_DPREGISTER:
//generate DP operands;
parseDPRegister(instr, tokens, tokensCount);
break;
case a64inst_DPIMMEDIATE:
parseDPImmediate(instr, tokens, tokensCount);
break;
default:
printf("Error: Invalid Instruction, '%s'\n", opcode);
break;
}
}
}
static void parseDirective(a64inst_instruction *instr, char *tokens[]) {
char *intValue = tokens[1];
char *endptr;
if(strncmp(intValue, "0x", 2) == 0) {
intValue += 2;
instr->data.DirectiveData.value = strtol(intValue, &endptr, 16);
} else {
instr->data.DirectiveData.value = strtol(tokens[1], &endptr, 10);
}
}
static void parseSingleTransfer(a64inst_instruction *instr, char *opcode, char *tokens[], int tokensCount) {
switch(instr->type){
case a64inst_SINGLETRANSFER:
instr->data.SingleTransferData.regType = getRegisterType(tokens[1]);
instr->data.SingleTransferData.target = getRegister(tokens[1]);
break;
case a64inst_LOADLITERAL:
instr->data.SingleTransferData.regType = getRegisterType(tokens[1]);
instr->data.SingleTransferData.target = getRegister(tokens[1]);
if(*tokens[2] =='#'){
//offset is immediate
instr->data.SingleTransferData.processOpData.loadLiteralData.offset = getImmediate(tokens[2]);;
} else {
//offset is label
instr->data.SingleTransferData.processOpData.loadLiteralData.label = tokens[2];
}
break;
default:
break;
}
}
void parseBranch(a64inst_instruction *instr, char* opcode, char *operandList[]) {
switch(instr->data.BranchData.BranchType){
case a64inst_UNCONDITIONAL:
//define and sign extend immediate offset
//use symbol table
printf("unconditional");
instr->data.BranchData.processOpData.unconditionalData.label = operandList[1];
break;
case a64inst_REGISTER:
instr->data.BranchData.processOpData.registerData.src = getRegister(operandList[1]);
break;
case a64inst_CONDITIONAL:
{
char condition[strlen(opcode)+1];
strcpy(condition, opcode+2);
if(strcmp(condition, "eq")==0){
instr->data.BranchData.processOpData.conditionalData.cond = EQ;
} else if (strcmp(condition, "ne")==0){
instr->data.BranchData.processOpData.conditionalData.cond = NE;
} else if (strcmp(condition, "ge")==0){
instr->data.BranchData.processOpData.conditionalData.cond = GE;
} else if (strcmp(condition, "lt")==0){
instr->data.BranchData.processOpData.conditionalData.cond = LT;
} else if (strcmp(condition, "gt")==0){
instr->data.BranchData.processOpData.conditionalData.cond = GT;
} else if (strcmp(condition, "le")==0){
instr->data.BranchData.processOpData.conditionalData.cond = LE;
} else if (strcmp(condition, "al")==0){
instr->data.BranchData.processOpData.conditionalData.cond = AL;
}
instr->data.BranchData.processOpData.unconditionalData.label = operandList[1];
break;
}
}
}
void parseDPImmediate(a64inst_instruction *inst, char *tokens[], int tokensCount) {
a64inst_DPImmediateData *data = &inst->data.DPImmediateData;
data->dest = getRegister(tokens[1]);
data->regType = getRegisterType(tokens[1]);
if (containsString(tokens[0], WIDE_MOV_OPCODES, 4)) {
data->DPIOpType = a64inst_DPI_WIDEMOV;
data->processOp = lastIndexOfString(tokens[0], WIDE_MOV_OPCODES, 4);
data->processOpData.wideMovData.immediate = getImmediate(tokens[2]);
if (tokensCount >= 4) {
ShiftData shData = *parseShift(tokens[3]);
data->processOpData.wideMovData.shiftScalar = shData.immediate;
}
} else {
data->DPIOpType = a64inst_DPI_ARITHM;
data->processOp = lastIndexOfString(tokens[0], ARITHMETIC_OPCODES, 4);
data->processOpData.arithmData.src = getRegister(tokens[2]);
data->processOpData.arithmData.immediate = getImmediate(tokens[3]);
if (tokensCount >= 5) {
ShiftData shData = *parseShift(tokens[4]);
if (shData.immediate > 0) {
data->processOpData.arithmData.shiftImmediate = true;
}
}
}
}
void parseDPRegister(a64inst_instruction *inst, char *tokens[], int tokensCount) {
a64inst_DPRegisterData *data = &inst->data.DPRegisterData;
data->dest = getRegister(tokens[1]);
data->regType = getRegisterType(tokens[1]);
data->src1 = getRegister(tokens[2]);
data->src2 = getRegister(tokens[3]);
if (containsString(tokens[0], MULTIPLY_OPCODES, 4)) {
// Multiply
data->DPROpType = a64inst_DPR_MULTIPLY;
if (tokensCount >= 5) {
data->processOpData.multiplydata.summand = getRegister(tokens[4]);
data->processOpData.multiplydata.negProd = strcmp(tokens[0], "msub") == 0;
}
else {
data->processOpData.multiplydata.summand = ZERO_REGISTER;
data->processOpData.multiplydata.negProd = strcmp(tokens[0], "mneg") == 0;
}
} else {
// Arithmetic/Logic
data->DPROpType = a64inst_DPR_ARITHMLOGIC;
if (containsString(tokens[0], ARITHMETIC_OPCODES, 4)) {
// Arithmetic
data->processOp = lastIndexOfString(tokens[0], ARITHMETIC_OPCODES, 4);
data->processOpData.arithmLogicData.type = 1;
if(tokensCount == 5) {
//has a shift
int numTokens = 0;
char **shiftOperands = tokenise(tokens[4], &numTokens);
data->processOpData.arithmLogicData.shiftType = lastIndexOfString(shiftOperands[0], SHIFT_TYPE_OPCODES, 4);
data->processOpData.arithmLogicData.shiftAmount = getImmediate(shiftOperands[1]);
}
} else {
// Logic
int opcodeCategory = lastIndexOfString(tokens[0], LOGIC_OPCODES, 8);
switch(opcodeCategory/2){
case 0:
//and
if((tokens[0][strlen(tokens[0])-1]) == 's'){
data->processOp = 3;
} else {
data->processOp = 0;
}
data->processOpData.arithmLogicData.negShiftedSrc2 = 0;
break;
case 1:
//negated AND
if((tokens[0][strlen(tokens[0])-1]) == 's'){
data->processOp = 3;
} else {
data->processOp = 0;
}
data->processOpData.arithmLogicData.negShiftedSrc2 = 1;
break;
case 2:
//XOR
data->processOp = 2;
if(opcodeCategory==4){
data->processOpData.arithmLogicData.negShiftedSrc2 = 0;
} else {
data->processOpData.arithmLogicData.negShiftedSrc2 = 1;
}
break;
case 3:
//OR
data->processOp = 1;
if(opcodeCategory==6){
data->processOpData.arithmLogicData.negShiftedSrc2 = 0;
} else {
data->processOpData.arithmLogicData.negShiftedSrc2 = 1;
}
break;
}
if(tokensCount == 5) {
//has a shift
int numTokens = 0;
char **shiftOperands = tokenise(tokens[4], &numTokens);
data->processOpData.arithmLogicData.shiftType = lastIndexOfString(shiftOperands[0], SHIFT_TYPE_OPCODES, 4);
data->processOpData.arithmLogicData.shiftAmount = getImmediate(shiftOperands[1]);
}
}
}
}
/** Classifies the given opcode into the correct instruction type.
* Modifies instr to reflect the classification.
*/
static void classifyOpcode(char* opcode, a64inst_instruction *instr, char *tokens[], int *tokensCount) {
// First, if the opcode is an alias, convert it to the target instruction.
translateAlias(opcode, tokens, tokensCount);
if (containsString(opcode, BRANCH_OPCODES, 9)) {
instr->type = a64inst_BRANCH;
if (strcmp(opcode, "br") == 0) {
instr->data.BranchData.BranchType = a64inst_REGISTER;
} else if (strcmp(opcode, "b") == 0) {
instr->data.BranchData.BranchType = a64inst_UNCONDITIONAL;
} else {
instr->data.BranchData.BranchType = a64inst_CONDITIONAL;
}
} else if (containsString(opcode, SINGLE_TRANSFER_OPCODES, 2)) {
instr->type = a64inst_SINGLETRANSFER;
if (*tokens[2] == '[') {
instr->data.SingleTransferData.SingleTransferOpType = a64inst_SINGLE_TRANSFER_SINGLE_DATA_TRANSFER;
instr->data.SingleTransferData.processOpData.singleDataTransferData.transferType = strcmp(opcode, "ldr") == 0;
} else {
instr->type = a64inst_LOADLITERAL;
}
// DP Instruction.
// DP Register if the third operand is a register.
} else if (*tokensCount >= 4 && isRegister(tokens[3])) {
instr->type = a64inst_DPREGISTER;
} else {
instr->type = a64inst_DPIMMEDIATE;
}
}
/** Parses a shift string into a ShiftData struct.
*/
static ShiftData *parseShift(char *shift) {
char buffer[20];
strcpy(buffer, shift);
char *shiftType = strtok(buffer, " ");
char *shiftAmount = strtok(NULL, " ");
ShiftData *data = malloc(sizeof(ShiftData));
data->type = lastIndexOfString(shiftType, SHIFT_TYPE_OPCODES, 4);
SKIP_WHITESPACE(shiftAmount);
data->immediate = getImmediate(shiftAmount);
return data;
}
/** Parses the addressing mode of a single transfer instruction. (Not load literal)
*/
static void parseAddressingMode(a64inst_instruction *instr, char *tokens[], int tokenCount) {
assert(*tokens[2] == '[');
int operandCount = 0;
char *unsplitString = duplicateString(tokens[2]);
char **operands = tokeniseOperands(tokens[2], &operandCount);
int baseRegister = getRegister(operands[0]);
instr->data.SingleTransferData.processOpData.singleDataTransferData.base = baseRegister;
if (tokenCount >= 4) {
instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_POST_INDEXED;
instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getImmediate(tokens[3]);
} else if(unsplitString[strlen(unsplitString)-1] == '!') {
instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_PRE_INDEXED;
instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getImmediate(operands[1]);
} else if (operandCount == 1 || (!isRegister(operands[1]))) {
instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_UNSIGNED_OFFSET;
if(operandCount > 1){
int offset = getImmediate(operands[1]);
instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.unsignedOffset = offset/8;
}
} else {
if((isRegister(operands[0]) == 1)
&& (isRegister(operands[1]) == 1)){
instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_REGISTER_OFFSET;
instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg = getRegister(operands[1]);
}
}
}