* Feel free to change this code in any way that you find useful, * or to ignore it completely and roll your own code generator from * scratch. *
* This code assumes that your top-level AST node is called * Program. You may need to change this to match your own AST * hierarchy. Usage: * *
* val cg = new CodeGenerator("file.ic", program);
* cg.generate();
*
*/
class CodeGenerator64(icFileName : String, val program : Program) {
val asmFile = icFileName.substring(0, icFileName.lastIndexOf('.')) + ".s";
val out = new PrintWriter(new FileWriter(asmFile));
/**
* The main method to call when you wish to perform the
* translation.
*/
def generate() = {
out.println("# File " + asmFile);
out.println();
out.println();
generateVTables();
generateCode();
generateErrorHandlers();
// TODO: Provide the real information for main.
val classForMain = "Simple";
val sizeOfMainObject = 8;
val offsetOfMainInDV = 0;
generateMain(classForMain, sizeOfMainObject, offsetOfMainInDV);
generateStringConstants();
out.close();
}
/**
* Print the VTable for all the classes. You'll need to change this.
*
*/
protected def generateVTables() = {
// TODO: You must implement this method
out.println("# ----------------------------");
out.println("# VTables");
out.println();
out.println(".data");
out.println(".align 8");
out.println();
out.println("_Simple_DV:");
out.println(" .quad _Simple_main");
out.println("");
out.println("");
out.println("");
}
/**
* Generate Simple.main method. You'll need to change this.
*/
protected def generateCode() = {
// TODO: You must implement this method
out.println("# ----------------------------");
out.println("# Code. Just the Simple main method for now...");
out.println("");
out.println(".text");
out.println(".align 8");
out.println("_Simple_main:");
out.println("");
out.println(" # prologue");
out.println(" pushq %rbp ");
out.println(" movq %rsp, %rbp ");
out.println(" subq $8, %rsp ");
out.println("");
out.println(" # store 1234 into a local variable.");
out.println(" movq $1234, %rcx ");
out.println(" movq %rcx, -8(%rbp)");
out.println("");
out.println(" # print that local var...");
out.println(" movq -8(%rbp), %rdi");
out.println(" call __LIB_printi");
out.println("");
out.println(" # ... and a new line");
val lab = labelForStringConstant("\na string \n containing \t\t quotes and escape characters: \"moo\"\n");
out.println(s" movq ${lab}(%rip), %rdi\n");
out.println(" call __LIB_println");
out.println(" ");
out.println(" # epilogue");
out.println(" movq %rbp, %rsp ");
out.println(" popq %rbp ");
out.println(" ret ");
out.println("");
out.println("");
out.println("");
}
/**
* Print out the assembly code to print run-time errors and
* exit gracefully. You should jump to these labels on
* run-time check failure. You should not need to change this
* method.
*/
protected def generateErrorHandlers() = {
out.println("# ----------------------------");
out.println("# Error handling. Jump to these procedures when a run-time check fails.");
out.println("");
out.println(".data");
out.println(".align 8");
out.println("");
out.println(".quad 23");
out.println(" strNullPtrErrorChars: .ascii \"Null pointer violation.\"");
out.println("strNullPtrError: .quad strNullPtrErrorChars");
out.println("");
out.println(".quad 23");
out.println(" strArrayBoundsErrorChars: .ascii \"Array bounds violation.\"");
out.println("strArrayBoundsError: .quad strArrayBoundsErrorChars");
out.println("");
out.println(".quad 21");
out.println(" strArraySizeErrorChars: .ascii \"Array size violation.\"");
out.println("strArraySizeError: .quad strArraySizeErrorChars");
out.println("");
out.println(".quad 22");
out.println(" divByZeroErrorChars: .ascii \"Divide by 0 violation.\"");
out.println("divByZeroError: .quad divByZeroErrorChars");
out.println("");
out.println(".text");
out.println(".align 8");
out.println("labelNullPtrError:");
out.println(" movq strNullPtrError(%rip), %rdi");
out.println(" call __LIB_println");
out.println(" movq $1, %rdi");
out.println(" call __LIB_exit");
out.println("");
out.println(".align 8");
out.println("labelArrayBoundsError:");
out.println(" movq strArrayBoundsError(%rip), %rdi");
out.println(" call __LIB_println");
out.println(" movq $1, %rdi");
out.println(" call __LIB_exit");
out.println("");
out.println(".align 8");
out.println("labelArraySizeError:");
out.println(" movq strArraySizeError(%rip), %rdi");
out.println(" call __LIB_println");
out.println(" movq $1, %rdi");
out.println(" call __LIB_exit");
out.println("");
out.println(".align 8");
out.println("labelDivByZeroError:");
out.println(" movq divByZeroError(%rip), %rdi");
out.println(" call __LIB_println");
out.println(" movq $1, %rdi");
out.println(" call __LIB_exit");
out.println("");
out.println("");
out.println("");
}
/**
* Generate the __ic_main stub that creates and calls main on
* the right object. You should not need to change this
* method.
* @param className name of the class containing main
* @param objectSize size of objects of that class
* @param indexOfMainInVTable index on that class's vtable for main
*/
protected def generateMain(className : String, objectSize : Int, indexOfMainInVTable : Int) = {
out.println("# The main entry point. Allocate object and invoke main on it.");
out.println("");
out.println(".text");
out.println(".align 8");
out.println(".globl __ic_main");
out.println("__ic_main:");
out.println(" pushq %rbp # prologue");
out.println(" movq %rsp,%rbp ");
out.println(" pushq %rdi # o.main(args) -> push args");
out.println("");
out.println(s" movq $$${objectSize}, %rdi # o = new $className\n");
out.println(" call __LIB_allocateObject ");
out.println(s" leaq _${className}_DV(%rip), %rdi \n");
out.println(" movq %rdi, (%rax)");
out.println(" pushq %rax # o.main(args) -> push o");
out.println(" movq (%rax), %rax ");
out.println(s" call *${indexOfMainInVTable * 8}(%rax) # main is at offset $indexOfMainInVTable in vtable\n");
out.println(" addq $16, %rsp ");
out.println(" movq $0, %rax # __ic_main always returns 0");
out.println("");
out.println(" movq %rbp,%rsp # epilogue");
out.println(" popq %rbp ");
out.println(" ret ");
out.println("");
out.println("");
out.println("");
}
/********************** String Constants *********************/
/** A map from string constant to the assembly code label in
* the data segment where that constant is stored. See the
* labelForStringConstant method.
*/
protected val stringConstantsToLabel : HashMap[String,String] = new HashMap[String,String]();
/**
* Return a unique label for a string constant. After
* translating all code and getting labels for all string
* constants, the code generator will print out a data segment
* containing the labels and string constants. The string may
* contain only the following escape characters: \n, \r, \t.
*/
protected def labelForStringConstant(stringConstant : String) : String = {
stringConstantsToLabel.get(stringConstant) match {
case None => {
val label = "_str" + stringConstantsToLabel.size;
stringConstantsToLabel.put(stringConstant, label);
label;
}
case Some(label) => {
label;
}
}
}
/**
* Iterate over all used string constants and print them into
* a data segment. You should not need to change this method.
*/
protected def generateStringConstants() = {
out.println("# ----------------------------");
out.println("# String Constants");
out.println();
out.println(".data");
out.println(".align 8");
out.println();
for ((str, label) <- stringConstantsToLabel) {
val len = str.length();
out.println(s".quad $len");
val escapedString =
"\"" + str.replace("\n", "\\n").replace("\t", "\\t").replace("\"", "\\\"").replace("\r", "\\r") + "\"";
out.println(s" ${label}Chars:\t.ascii ${escapedString}");
out.println(s"${label}:\t.quad ${label}Chars");
}
out.println("");
out.println("");
out.println("");
}
}