Rewrite the parser for better structure, Add DPI parsing

src/parser.c

@@ -5,18 +5,159 @@
 #include <stdbool.h>
 #include "parser.h"
 #include "a64instruction/a64instruction.h"
+#include "tokeniser.c"
 
-//takes input string, read from asm file and returns
+/** Prototypes */
-//input as an a64 instruction
+void parse_instruction(char asmLine[], a64inst_instruction *instr);
+static char *duplicateString(char *str);
+void parseSingleTransfer(a64inst_instruction *instr, char *opcode, char *operandList[], int numOperands);
+void parseBranch(a64inst_instruction *instr, char* opcode, char *operandList[]);
+void calcluateAddressFormat(a64inst_instruction *instr,  char *operandList[], int numOperands);
+void parseDPImmediate(a64inst_instruction *inst, 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"};
+
+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;
+}
+
+static char *duplicateString(char *str) {
+    char *newStr = malloc(strlen(str) + 1);
+    strcpy(newStr, str);
+    return newStr;
+}
+
+static bool isStringIn(char *str, const char *arr[], int arrSize) {
+    for (int i = 0; i < arrSize; i++) {
+        if (strcmp(str, arr[i]) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+// If more than one occurance, return the last index
+static int indexStringIn(char *str, const char *arr[], int arrSize) {
+    for (int i = arrSize - 1; i >= 0; i--) {
+        if (strcmp(str, arr[i]) == 0) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int isOperandRegister(char regStartChar) {
+    return((regStartChar == 'x') || (regStartChar == 'w'));
+}
+
+int classifyDPInst(char *operandList[]){
+    return(isOperandRegister(operandList[1][0]) &&
+    isOperandRegister(operandList[2][0]) &&
+    isOperandRegister(operandList[3][0]));
+}
+
+void classifyOpcode(char* opcode, a64inst_instruction *instr, char *tokens[], int tokensCount){
+
+    if (isStringIn(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 (isStringIn(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;
+        }
+    } else if (classifyDPInst(tokens)) {
+        instr->type = a64inst_DPREGISTER;
+    } else {
+        instr->type = a64inst_DPIMMEDIATE;
+    }
+
+}
+
+
+void parse_instruction(char asmLine[], a64inst_instruction *instr) {
+    if (instr == NULL){
+        exit(EXIT_FAILURE);
+    }
+
+    if(strcmp(asmLine, HALT_ASM_CMD) == 0){
+        instr->type = a64inst_HALT;
+        return;
+    }
+
+    char *asmLineCopy = duplicateString(asmLine);
+    int tokensCount = 0;
+    char **tokens = tokenise(asmLineCopy, &tokensCount);
+    char *opcode = tokens[0];
+
+    if(strcmp(opcode, ".int") == 0){
+        // Directive
+        instr->type = a64inst_DIRECTIVE;
+        
+    } 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
+        classifyOpcode(opcode, instr, tokens, tokensCount);
+
+        switch(instr->type){
+            case a64inst_BRANCH:
+                parseBranch(instr, opcode, tokens);
+                break;
+
+            case a64inst_SINGLETRANSFER:
+                parseSingleTransfer(instr, opcode, tokens, tokensCount);
+                calcluateAddressFormat(instr, tokens, tokensCount);
+                break;
+            case a64inst_LOADLITERAL:
+                parseSingleTransfer(instr, opcode, tokens, tokensCount);
+                break;
+            case a64inst_DPREGISTER:
+                //generate DP operands;
+                break;
+            case a64inst_DPIMMEDIATE:
+                parseDPImmediate(instr, tokens, tokensCount);
+                break;
+            default:   
+                printf("Error: Invalid Instruction\n");
+                break;
+        }
+        
+    }
+
+    /* TODO: FREE MEMORY! */
+
+}
 
-//TODO: 
-// - use string matching to get opcode, and operands (DONE)
-// - check operand count (DONE)
-// - match opcode to a64 struct types (DONE)
-// - count operands and match type/values (DONE)
-// - generate final a64inst and return (TODO: DP instrs)
-// - ASK ABOUT OFFSET CALCULATION
-// - CREATE FUNC TO TIDY UP OPERANDS IN DP
 
 //takes inputted char array and returns the integer of the operand, skipping the first character
 //e.g. for a passed "R32", it skips the 'R' and returns 32
@@ -28,64 +169,61 @@ int getOperandNumber(char *operand){
     return number;
 }
 
-int isOperandRegister(char regStartChar){
-    return((regStartChar == 'x') || (regStartChar == 'w'));
-}
 
-//calculate offsets from string
+void calcluateAddressFormat(a64inst_instruction *instr,  char *tokens[], int tokenCount) {
-void calcluateAddressFormat(a64inst_instruction *instr,  char *operandList[], int numOperands){
+    assert(*tokens[2] == '[');
-    char baseRegParam[strlen(operandList[1])];
-    strcpy(baseRegParam, operandList[1]);
-    char *startptr = &baseRegParam[1];
-    int base = getOperandNumber(startptr);
-    instr->data.SingleTransferData.processOpData.singleDataTransferData.base = base;
 
-    if(operandList[2][strlen(operandList[2])-2] == '!'){
+    int operandCount = 0;
+    char **operands = tokeniseOperands(tokens[2], &operandCount);
+
+    int baseRegister = getOperandNumber(operands[0]);
+    
+    instr->data.SingleTransferData.processOpData.singleDataTransferData.base = baseRegister;
+
+    if(operands[1][strlen(operands[1])-1] == '!') {
         instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_PRE_INDEXED;
-        instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getOperandNumber(operandList[2]);
+        instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getOperandNumber(operands[1]);
-    } else if(operandList[1][strlen(operandList[1])-2] == ']') {
+    
-        //post-indexed
+    } else if(operands[1][strlen(operands[1])-1] == ']') {
-        char immOffset[strlen(operandList[2])+1];
+        // POST_INDEXED
-        strcpy(immOffset, operandList[2]);
         instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_POST_INDEXED;
-        instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getOperandNumber(immOffset);
+        instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.indexedOffset = getOperandNumber(tokens[3]);
-    } else if( (isOperandRegister(operandList[1][0]) == 1)
+   
-                || (isOperandRegister(operandList[2][0]) == 1)){
+    } else if( (isOperandRegister(*operands[0]) == 1)
+                && (isOperandRegister(*operands[1]) == 1)){
                     //register
                     instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_REGISTER_OFFSET;
-                    instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg = getOperandNumber(operandList[2]);
+                    instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.offsetReg = getOperandNumber(operands[1]);
+    
     } else {
         instr->data.SingleTransferData.processOpData.singleDataTransferData.addressingMode = a64inst_UNSIGNED_OFFSET;
-        if(numOperands==3){
+        if(operandCount > 1){
-            int offset = getOperandNumber(operandList[2]);
+            int offset = getOperandNumber(operands[1]);
             instr->data.SingleTransferData.processOpData.singleDataTransferData.a64inst_addressingModeData.unsignedOffset = offset/8;
             //NEED TO SCALE IMMEDIATE VALUE BASED ON REGISTER TYPE IN ASSEMBLER
         }
     } 
 }
 
-void generateLoadStoreOperands(a64inst_instruction *instr, char *opcode, char *operandList[], int numOperands){
+static int parseRegisterType(char *operand) {
+    return operand[0] == 'x';
+}
+
+void parseSingleTransfer(a64inst_instruction *instr, char *opcode, char *tokens[], int tokensCount) {
+
     switch(instr->type){
-        case a64inst_SINGLETRANSFER: {
+        case a64inst_SINGLETRANSFER:
-            if(operandList[0][0] == 'x'){
+            instr->data.SingleTransferData.regType = parseRegisterType(tokens[1]);
-                //x-register
+            instr->data.SingleTransferData.target = getOperandNumber(tokens[1]);
-                instr->data.SingleTransferData.regType = 1;
-            } else {
-                instr->data.SingleTransferData.regType = 0;
-            }
-            instr->data.SingleTransferData.target = getOperandNumber(operandList[0]);
             break;
-        }
+
         case a64inst_LOADLITERAL:
-            if(operandList[0][0] == 'x') {
+            instr->data.SingleTransferData.regType = parseRegisterType(tokens[1]);
-                instr->data.SingleTransferData.regType = 1;
+            instr->data.SingleTransferData.target = getOperandNumber(tokens[1]);
-            } else {
+
-                instr->data.SingleTransferData.regType = 0;
+            if(*tokens[2] =='#'){
-            }
-            instr->data.SingleTransferData.target = getOperandNumber(operandList[0]);
-            if(operandList[1][0] =='#'){
                 //offset is immediate
-                int offset = getOperandNumber(operandList[1]);
+                int offset = getOperandNumber(tokens[1]);
                 instr->data.SingleTransferData.processOpData.loadLiteralData.offset = offset;
             } else {
                 //offset is literal, use symbol table and calculate difference
@@ -97,7 +235,7 @@ void generateLoadStoreOperands(a64inst_instruction *instr, char *opcode, char *o
     }
 }
 
-void generateBranchOperands(a64inst_instruction *instr, char* opcode, char *operandList[]){
+void parseBranch(a64inst_instruction *instr, char* opcode, char *operandList[]) {
     switch(instr->data.BranchData.BranchType){
         case a64inst_UNCONDITIONAL:
             //define and sign extend immediate offset
@@ -132,155 +270,62 @@ void generateBranchOperands(a64inst_instruction *instr, char* opcode, char *oper
     }
 }
 
-int classifyDPInst(char *operandList[]){
+void parseDPImmediate(a64inst_instruction *inst, char *tokens[], int tokensCount) {
-    return(isOperandRegister(operandList[0][0]) &&
+    a64inst_DPImmediateData *data = &inst->data.DPImmediateData;
-    isOperandRegister(operandList[1][0]) &&
+    data->dest = getOperandNumber(tokens[1]);
-    isOperandRegister(operandList[2][0]));
+    data->regType = parseRegisterType(tokens[1]);
-}
 
-void classifyOpcode(char* opcode, a64inst_instruction *instr, char *operandList[], int numOperands){
+    if (isStringIn(tokens[0], WIDE_MOV_OPCODES, 3)) {
-    int isUnconditional = strcmp(opcode, "b");
+        data->DPIOpType = a64inst_DPI_WIDEMOV;
-    int isRegister = strcmp(opcode, "br");
+        data->processOp = indexStringIn(tokens[0], WIDE_MOV_OPCODES, 3); 
-    int isLoad = strcmp(opcode, "ldr");
+        data->processOpData.wideMovData.immediate = getOperandNumber(tokens[2]);
-    int isStore = strcmp(opcode, "str");
+        if (tokensCount >= 3) {
-
+            data->processOpData.wideMovData.shiftScalar = getOperandNumber(tokens[3]);
-    if(isUnconditional == 0 || 
-        isRegister == 0 || 
-        strncmp(opcode, "b.", 2) == 0){
-            instr->type = a64inst_BRANCH;
-            if(isRegister == 0){
-                instr->data.BranchData.BranchType = a64inst_REGISTER;
-            } else if (isUnconditional == 0){
-                instr->data.BranchData.BranchType = a64inst_UNCONDITIONAL;
-            } else {
-                instr->data.BranchData.BranchType = a64inst_CONDITIONAL;
-            }
-    } else if(isLoad == 0 || isStore == 0){
-        //loading/storing instruction; classify operands
-        if( operandList[1][0] == '['){
-            //type is register
-            instr->type = a64inst_SINGLETRANSFER;
-            instr->data.SingleTransferData.SingleTransferOpType = a64inst_SINGLE_TRANSFER_SINGLE_DATA_TRANSFER;
-            if(isLoad == 0){
-                instr->data.SingleTransferData.processOpData.singleDataTransferData.transferType = a64inst_LOAD;
-            } else {
-                instr->data.SingleTransferData.processOpData.singleDataTransferData.transferType = a64inst_STORE;
-            }
-        } else {
-            instr->type = a64inst_LOADLITERAL;
         }
 
     } else {
-        if(classifyDPInst(operandList)){
+        data->DPIOpType = a64inst_DPI_ARITHM;
-            instr->type = a64inst_DPREGISTER;
+        data->processOp = indexStringIn(tokens[0], ARITHMETIC_OPCODES, 4);
-        } else {
+        data->processOpData.arithmData.src = getOperandNumber(tokens[2]);
-            instr->type = a64inst_DPIMMEDIATE;
+        data->processOpData.arithmData.immediate = getOperandNumber(tokens[3]);
+        
+        if (tokensCount >= 5) {
+            int shiftAmount = getOperandNumber(tokens[4]);
+            if (shiftAmount > 0) {
+                data->processOpData.arithmData.shiftImmediate = true;
+            }
         }
 
     }
 }
 
-void tokeniseOperands(char* str, int *operandCount, char *operands[], int *numOperands){
+void parseDPRegister(a64inst_instruction *inst, char *tokens[], int tokensCount) {
-    assert(str != NULL);
+    a64inst_DPRegisterData *data = &inst->data.DPRegisterData;
-    char *operandsDupe = malloc(strlen(str)+1);
+    data->dest = getOperandNumber(tokens[1]);
-    assert(operandsDupe != NULL);
+    data->regType = parseRegisterType(tokens[1]);
-    strcpy(operandsDupe, str);
+    data->src1 = getOperandNumber(tokens[2]);
-    char *operand = strtok(operandsDupe, OPERAND_DELIMITER);
+    data->src2 = getOperandNumber(tokens[3]);
-    operands[0] = operand;
 
-    while (operand != NULL){
+    if (isStringIn(tokens[0], MULTIPLY_OPCODES, 4)) {
-        *operandCount = *(operandCount)+1;
+        // Multiply
-        operand = strtok(NULL, OPERAND_DELIMITER);
+        data->DPROpType = a64inst_DPR_MULTIPLY;
-        operands[*(operandCount)] = operand;
+        if (tokensCount >= 5) {
-    }
+            data->processOpData.multiplydata.summand = getOperandNumber(tokens[4]);
-    *(numOperands) = *(operandCount);
+            data->processOpData.multiplydata.negProd = strcmp(tokens[4], "mneg") == 0;
-}
+        }
 
-//takes inputted assembly line and returns a 
-//pointer to an abstract representation of the instruction
-void parser_instruction(char asmLine[], a64inst_instruction *instr) {
-    printf("%s", asmLine);
-    int numOperands = 0;
-    if (instr == NULL){
-        exit(EXIT_FAILURE);
-    }
-
-    if(strcmp(asmLine, HALT_ASM_CMD) == 0){
-        instr->type = a64inst_HALT;
-        return;
-    }
-
-    //"opcode operand1, {operand2}, ..."
-    //duplicated as strtok modifies the input string
-    
-    char stringptr[strlen(asmLine) + 1];
-    strcpy(stringptr, asmLine);
-    char *token;
-    token = strtok(stringptr, " ");
-    char opcode[strlen(token)+1]; 
-    strcpy(opcode, token);
-    token = strtok(NULL, "");
-    char operands[strlen(token)+1];
-    strcpy(operands, token);
-
-    if(strcmp(opcode, ".int") == 0){
-        //type is directive
-        instr->type = a64inst_DIRECTIVE;
-        
-    } else if(opcode[strlen(opcode)-1]== ':') {
-        //type is label
-        //add to symbol table
-        instr->type = a64inst_LABEL;
-        char opcodeCpy[strlen(opcode)+1];
-        strcpy(opcodeCpy, opcode);
-        char *labelData = strtok(opcodeCpy, ":");
-        instr->data.LabelData.label = labelData;
     } else {
-        //type is instruction
+        // Arithmetic/Logic
-        int operandCount = 0;
+        data->DPROpType = a64inst_DPR_ARITHMLOGIC;
-        char *operandList[5];
+        
-        //generate list of operands
+        if (isStringIn(tokens[0], ARITHMETIC_OPCODES, 4)) {
-        tokeniseOperands(operands, &operandCount, operandList, &numOperands);
+            // Arithmetic
-        //categorise instruction type from opcode and operands
+            data->processOp = indexStringIn(tokens[0], ARITHMETIC_OPCODES, 4);
-        classifyOpcode(opcode, instr, operandList, operandCount);
+            data->processOpData.arithmLogicData.type = 1;
-        //define struct values according to operands and type
+
-        printf("got to here");
+        } else {
-        switch(instr->type){
+            // Logic
-            case a64inst_BRANCH:
+            
-                generateBranchOperands(instr, opcode, operandList);
-                break;
-            case a64inst_SINGLETRANSFER:
-                generateLoadStoreOperands(instr, opcode, operandList, numOperands);
-                calcluateAddressFormat(instr, operandList, numOperands);
-                break;
-            case a64inst_LOADLITERAL:
-                generateLoadStoreOperands(instr, opcode, operandList, numOperands);
-                break;
-            case a64inst_DPREGISTER:
-                //generate DP operands;
-                break;
-            case a64inst_DPIMMEDIATE:
-                //generate DP operands;
-                break;
-            default:   
-                printf("INVALID INSTRUCTION");
-                break;
         }
-        
     }
-
-}
-
-// Takes an array of strings, each string representing an assembly instruction.
-// Returns an array of a64inst_instruction pointers, each representing an instruction.
-a64inst_instruction *parse(char **asmLines, int lineCount) {
-    a64inst_instruction *instructions = malloc(sizeof(a64inst_instruction) * lineCount);
-
-    int i = 0;
-    while (asmLines[i] != NULL) {
-        parser_instruction(asmLines[i], &instructions[i]);
-        i++;
-    }
-
-    return instructions;
 }