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Homework B (benchmarks)

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This commit is contained in:
Carlos Galindo 2020-01-15 22:38:07 +01:00
commit 76fbabdf53
Signed by: kauron
GPG key ID: 83E68706DEE119A3
64 changed files with 7477 additions and 1969 deletions
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285
src/cd/Config.java
View file

@ -3,137 +3,160 @@ package cd;
import java.io.File;
public class Config {
public static enum SystemKind {
LINUX,
WINDOWS,
MACOSX
}
/**
* Defines the extension used for assembler files on this platform.
* Currently always {@code .s}.
*/
public static final String ASMEXT = ".s";
/** Defines the extension used for binary files on this platform. */
public static final String BINARYEXT;
/** Defines the name of the main function to be used in .s file */
public static final String MAIN;
/** Defines the name of the printf function to be used in .s file */
public static final String PRINTF;
/** Defines the name of the scanf function to be used in .s file */
public static final String SCANF;
/** Defines the name of the calloc function to be used in .s file */
public static final String CALLOC;
/** Defines the name of the exit function to be used in .s file */
public static final String EXIT;
/** The assembler directive used to define a constant string */
public static final String DOT_STRING;
/** The assembler directive used to define a constant int */
public static final String DOT_INT;
/** The assembler directive used to start the text section */
public static final String TEXT_SECTION;
/** The assembler directive used to start the section for integer data */
public static final String DATA_INT_SECTION;
/**
* The assembler directive used to start the section for string data (if
* different from {@link #DATA_INT_SECTION}
*/
public static final String DATA_STR_SECTION;
/** Comment separator used in assembly files */
public static final String COMMENT_SEP;
/**
* Defines the assembler command to use. Should be a string array where each
* entry is one argument. Use the special string "$0" to refer to the output
* file, and $1 to refer to the ".s" file.
*/
public static final String[] ASM;
/**
* The directory from which to run the assembler. In a CYGWIN installation,
* this can make a big difference!
*/
public static final File ASM_DIR;
/**
* sizeof a pointer in bytes in the target platform.
*/
public static final int SIZEOF_PTR = 4;
/**
* Name of java executable in JRE path
*/
public static enum SystemKind {
LINUX,
WINDOWS,
MACOSX
}
public static final int TRUE = 1;
public static final int FALSE = 0;
/**
* Defines the extension used for assembler files on this platform.
* Currently always {@code .s}.
*/
public static final String ASMEXT = ".s";
/**
* Defines the extension used for binary files on this platform.
*/
public static final String BINARYEXT;
/**
* Defines the name of the main function to be used in .s file
*/
public static final String MAIN;
/**
* Defines the name of the printf function to be used in .s file
*/
public static final String PRINTF;
/**
* Defines the name of the scanf function to be used in .s file
*/
public static final String SCANF;
/**
* Defines the name of the calloc function to be used in .s file
*/
public static final String CALLOC;
/**
* Defines the name of the exit function to be used in .s file
*/
public static final String EXIT;
/**
* The assembler directive used to define a constant string
*/
public static final String DOT_STRING;
/**
* The assembler directive used to define a constant int
*/
public static final String DOT_INT;
/**
* The assembler directive used to start the text section
*/
public static final String TEXT_SECTION;
/**
* The assembler directive used to start the section for integer data
*/
public static final String DATA_INT_SECTION;
/**
* The assembler directive used to start the section for string data (if
* different from {@link #DATA_INT_SECTION}
*/
public static final String DATA_STR_SECTION;
/**
* Comment separator used in assembly files
*/
public static final String COMMENT_SEP;
/**
* Defines the assembler command to use. Should be a string array where each
* entry is one argument. Use the special string "$0" to refer to the output
* file, and $1 to refer to the ".s" file.
*/
public static final String[] ASM;
/**
* The directory from which to run the assembler. In a CYGWIN installation,
* this can make a big difference!
*/
public static final File ASM_DIR;
/**
* sizeof a pointer in bytes in the target platform.
*/
public static final int SIZEOF_PTR = 4;
/**
* Name of java executable in JRE path
*/
public static final String JAVA_EXE;
static {
final String os = System.getProperty("os.name").toLowerCase();
if(os.contains("windows") || os.contains("nt")) {
BINARYEXT = ".exe";
MAIN = "_main";
PRINTF = "_printf";
SCANF = "_scanf";
CALLOC = "_calloc";
EXIT = "_exit";
// These are set up for a Cygwin installation on C:,
// you can change as needed.
ASM = new String[]{"gcc", "-o", "$0", "$1"};
ASM_DIR = new File("C:\\CYGWIN\\BIN");
JAVA_EXE = "javaw.exe";
DOT_STRING = ".string";
DOT_INT = ".int";
TEXT_SECTION = ".section .text";
DATA_INT_SECTION = ".section .data";
DATA_STR_SECTION = ".section .data";
COMMENT_SEP = "#";
}
else if(os.contains("mac os x") || os.contains("darwin")) {
BINARYEXT = ".bin";
MAIN = "_main";
PRINTF = "_printf";
SCANF = "_scanf";
CALLOC = "_calloc";
EXIT = "_exit";
ASM = new String[]{"gcc", "-m32", "-o", "$0", "$1"};
ASM_DIR = new File(".");
JAVA_EXE = "java";
DOT_STRING = ".asciz";
DOT_INT = ".long";
TEXT_SECTION = ".text";
DATA_INT_SECTION = ".data";
DATA_STR_SECTION = ".cstring";
COMMENT_SEP = "#";
}
else {
BINARYEXT = ".bin";
MAIN = "main";
PRINTF = "printf";
SCANF = "scanf";
CALLOC = "calloc";
EXIT = "exit";
ASM = new String[]{"gcc", "-m32", "-o", "$0", "$1"};
ASM_DIR = new File(".");
JAVA_EXE = "java";
DOT_STRING = ".string";
DOT_INT = ".int";
TEXT_SECTION = ".section .text";
DATA_INT_SECTION = ".section .data";
DATA_STR_SECTION = ".section .data";
COMMENT_SEP = "#";
}
}
static {
final String os = System.getProperty("os.name").toLowerCase();
if (os.contains("windows") || os.contains("nt")) {
BINARYEXT = ".exe";
MAIN = "_main";
PRINTF = "_printf";
SCANF = "_scanf";
CALLOC = "_calloc";
EXIT = "_exit";
// These are set up for a Cygwin installation on C:,
// you can change as needed.
ASM = new String[]{"gcc", "-o", "$0", "$1"};
ASM_DIR = new File("C:\\CYGWIN\\BIN");
JAVA_EXE = "javaw.exe";
DOT_STRING = ".string";
DOT_INT = ".int";
TEXT_SECTION = ".section .text";
DATA_INT_SECTION = ".section .data";
DATA_STR_SECTION = ".section .data";
COMMENT_SEP = "#";
} else if (os.contains("mac os x") || os.contains("darwin")) {
BINARYEXT = ".bin";
MAIN = "_main";
PRINTF = "_printf";
SCANF = "_scanf";
CALLOC = "_calloc";
EXIT = "_exit";
ASM = new String[]{"gcc", "-m32", "-o", "$0", "$1"};
ASM_DIR = new File(".");
JAVA_EXE = "java";
DOT_STRING = ".asciz";
DOT_INT = ".long";
TEXT_SECTION = ".text";
DATA_INT_SECTION = ".data";
DATA_STR_SECTION = ".cstring";
COMMENT_SEP = "#";
} else {
BINARYEXT = ".bin";
MAIN = "main";
PRINTF = "printf";
SCANF = "scanf";
CALLOC = "calloc";
EXIT = "exit";
ASM = new String[]{"gcc", "-m32", "-o", "$0", "$1"};
ASM_DIR = new File(".");
JAVA_EXE = "java";
DOT_STRING = ".string";
DOT_INT = ".int";
TEXT_SECTION = ".section .text";
DATA_INT_SECTION = ".section .data";
DATA_STR_SECTION = ".section .data";
COMMENT_SEP = "#";
}
}
}

114
src/cd/Main.java
View file

@ -1,6 +1,6 @@
package cd;
import cd.backend.codegen.AstCodeGenerator;
import cd.backend.codegen.CfgCodeGenerator;
import cd.frontend.parser.JavaliAstVisitor;
import cd.frontend.parser.JavaliLexer;
import cd.frontend.parser.JavaliParser;
@ -8,9 +8,13 @@ import cd.frontend.parser.JavaliParser.UnitContext;
import cd.frontend.parser.ParseFailure;
import cd.frontend.semantic.SemanticAnalyzer;
import cd.ir.Ast.ClassDecl;
import cd.ir.Symbol;
import cd.ir.Ast.MethodDecl;
import cd.ir.Symbol.ClassSymbol;
import cd.ir.Symbol.TypeSymbol;
import cd.transform.AstOptimizer;
import cd.transform.CfgBuilder;
import cd.util.debug.AstDump;
import cd.util.debug.CfgDump;
import org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.BailErrorStrategy;
import org.antlr.v4.runtime.CommonTokenStream;
@ -20,26 +24,29 @@ import java.io.*;
import java.util.ArrayList;
import java.util.List;
/**
* The main entrypoint for the compiler. Consists of a series
* of routines which must be invoked in order. The main()
* routine here invokes these routines, as does the unit testing
* code. This is not the <b>best</b> programming practice, as the
* series of calls to be invoked is duplicated in two places in the
* code, but it will do for now. */
/**
* The main entrypoint for the compiler. Consists of a series of routines which must be invoked in
* order. The main() routine here invokes these routines, as does the unit testing code. This is not
* the <b>best</b> programming practice, as the series of calls to be invoked is duplicated in two
* places in the code, but it will do for now.
*/
public class Main {
// Set to non-null to write debug info out
public Writer debug = null;
// Set to non-null to write dump of control flow graph
public File cfgdumpbase;
/** Symbol for the Main type */
public Symbol.ClassSymbol mainType;
/** List of all type symbols, used by code generator. */
public List<TypeSymbol> allTypeSymbols;
/**
* Symbol for the Main type
*/
public ClassSymbol mainType;
/**
* List of all type symbols, used by code generator.
*/
public List<TypeSymbol> allTypeSymbols;
public void debug(String format, Object... args) {
if (debug != null) {
@ -53,23 +60,28 @@ public class Main {
}
}
}
/** Parse command line, invoke compile() routine */
/**
* Parse command line, invoke compile() routine
*/
public static void main(String args[]) throws IOException {
Main m = new Main();
for (String arg : args) {
if (arg.equals("-d"))
m.debug = new OutputStreamWriter(System.err);
else {
if (m.debug != null)
m.cfgdumpbase = new File(arg);
FileReader fin = new FileReader(arg);
// Parse:
List<ClassDecl> astRoots = m.parse(fin);
// Run the semantic check:
m.semanticCheck(astRoots);
// Generate code:
String sFile = arg + Config.ASMEXT;
try (FileWriter fout = new FileWriter(sFile)) {
@ -78,51 +90,63 @@ public class Main {
}
}
}
/** Parses an input stream into an AST
* @throws IOException */
/**
* Parses an input stream into an AST
*
* @throws IOException
*/
public List<ClassDecl> parse(Reader reader) throws IOException {
List<ClassDecl> result = new ArrayList<ClassDecl>();
try {
JavaliLexer lexer = new JavaliLexer(new ANTLRInputStream(reader));
JavaliParser parser = new JavaliParser(new CommonTokenStream(lexer));
parser.setErrorHandler(new BailErrorStrategy());
UnitContext unit = parser.unit();
JavaliAstVisitor visitor = new JavaliAstVisitor();
visitor.visit(unit);
result = visitor.classDecls;
result = visitor.classDecls;
} catch (ParseCancellationException e) {
ParseFailure pf = new ParseFailure(0, "?");
pf.initCause(e);
throw pf;
}
debug("AST Resulting From Parsing Stage:");
dumpAst(result);
return result;
}
// TODO: decide how to do/call optimization
public void semanticCheck(List<ClassDecl> astRoots) {
{
new SemanticAnalyzer(this).check(astRoots);
}
}
public void generateCode(List<ClassDecl> astRoots, Writer out) {
{
AstCodeGenerator cg = AstCodeGenerator.createCodeGenerator(this, out);
cg.go(astRoots);
}
new SemanticAnalyzer(this).check(astRoots);
// Build control flow graph:
for (ClassDecl cd : astRoots)
for (MethodDecl md : cd.methods()) {
new CfgBuilder().build(md);
}
CfgDump.toString(astRoots, ".cfg", cfgdumpbase, false);
// Optimize
new AstOptimizer().go(astRoots, allTypeSymbols);
CfgDump.toString(astRoots, ".cfgOPT", cfgdumpbase, false);
}
/** Dumps the AST to the debug stream */
public void generateCode(List<ClassDecl> astRoots, Writer out) {
CfgCodeGenerator cg = new CfgCodeGenerator(this, out);
cg.go(astRoots);
}
/**
* Dumps the AST to the debug stream
*/
private void dumpAst(List<ClassDecl> astRoots) throws IOException {
if (this.debug == null) return;
if (this.debug == null)
return;
this.debug.write(AstDump.toString(astRoots));
}
}

14
src/cd/ToDoException.java
View file

@ -1,14 +0,0 @@
package cd;
/** TAs insert this to mark code that students need to write */
public class ToDoException extends RuntimeException {
private static final long serialVersionUID = 4054810321239901944L;
public ToDoException() {
}
public ToDoException(String message) {
super(message);
}
}

6
src/cd/backend/ExitCode.java
View file

@ -10,10 +10,10 @@ public enum ExitCode {
INFINITE_LOOP(6),
DIVISION_BY_ZERO(7),
INTERNAL_ERROR(22);
public final int value;
private ExitCode(int value) {
this.value = value;
private ExitCode(int value) {
this.value = value;
}
}

34
src/cd/backend/codegen/AssemblyEmitter.java
View file

@ -15,25 +15,33 @@ public class AssemblyEmitter {
this.out = out;
}
/** Creates an constant operand. */
/**
* Creates an constant operand.
*/
static String constant(int i) {
return "$" + i;
}
/** Creates an constant operand with the address of a label. */
/**
* Creates an constant operand with the address of a label.
*/
static String labelAddress(String lbl) {
return "$" + lbl;
}
/** Creates an operand relative to another operand. */
/**
* Creates an operand relative to another operand.
*/
static String registerOffset(int offset, Register reg) {
return String.format("%d(%s)", offset, reg);
}
/** Creates an operand addressing an item in an array */
/**
* Creates an operand addressing an item in an array
*/
static String arrayAddress(Register arrReg, Register idxReg) {
final int offset = Config.SIZEOF_PTR * 2; // one word each in front for
// vptr and length
// vptr and length
final int mul = Config.SIZEOF_PTR; // assume all arrays of 4-byte elem
return String.format("%d(%s,%s,%d)", offset, arrReg, idxReg, mul);
}
@ -90,10 +98,6 @@ public class AssemblyEmitter {
emit(op, constant(src), dest);
}
void emit(String op, int src, String dest) {
emit(op, constant(src), dest);
}
void emit(String op, String dest) {
emitRaw(op + " " + dest);
}
@ -106,10 +110,6 @@ public class AssemblyEmitter {
emit(op, constant(dest));
}
void emit(String op, int src, int dest) {
emit(op, constant(src), constant(dest));
}
void emitMove(Register src, String dest) {
emitMove(src.repr, dest);
}
@ -127,10 +127,6 @@ public class AssemblyEmitter {
emit("movl", src, dest);
}
void emitMove(int src, Register dest) {
emitMove(constant(src), dest);
}
void emitLoad(int srcOffset, Register src, Register dest) {
emitMove(registerOffset(srcOffset, src), dest.repr);
}
@ -143,10 +139,6 @@ public class AssemblyEmitter {
emitMove(src, registerOffset(destOffset, dest));
}
void emitStore(int src, int destOffset, Register dest) {
emitStore(constant(src), destOffset, dest);
}
void emitConstantData(String data) {
emitRaw(String.format("%s %s", Config.DOT_INT, data));
}

5
src/cd/backend/codegen/AssemblyFailedException.java
View file

@ -2,13 +2,14 @@ package cd.backend.codegen;
public class AssemblyFailedException extends RuntimeException {
private static final long serialVersionUID = -5658502514441032016L;
public final String assemblerOutput;
public AssemblyFailedException(
String assemblerOutput) {
super("Executing assembler failed.\n"
+ "Output:\n"
+ assemblerOutput);
this.assemblerOutput = assemblerOutput;
}
}
}

776
src/cd/backend/codegen/AstCodeGenerator.java
View file

@ -2,43 +2,42 @@ package cd.backend.codegen;
import cd.Config;
import cd.Main;
import cd.backend.ExitCode;
import cd.backend.codegen.RegisterManager.Register;
import cd.ir.Ast;
import cd.ir.Ast.ClassDecl;
import cd.ir.Ast.Expr;
import cd.ir.Ast.MethodDecl;
import cd.ir.Symbol.*;
import java.io.Writer;
import java.util.*;
import java.util.Collections;
import java.util.List;
import static cd.Config.MAIN;
import static cd.Config.*;
import static cd.backend.codegen.AssemblyEmitter.constant;
import static cd.backend.codegen.AssemblyEmitter.registerOffset;
import static cd.backend.codegen.RegisterManager.BASE_REG;
import static cd.backend.codegen.RegisterManager.STACK_REG;
public class AstCodeGenerator {
/** Constant representing the boolean TRUE as integer */
static final int TRUE = 1;
/** Constant representing the boolean FALSE as integer */
static final int FALSE = 0;
/** Size of any variable in assembly
* Primitive variables take up 4 bytes (booleans are integers)
* Reference variables are a 4 byte pointer
*/
static final int VAR_SIZE = 4;
RegsNeededVisitor rnv;
ExprGenerator eg;
StmtGenerator sg;
protected RegsNeededVisitor rnv;
protected ExprGenerator eg;
protected StmtGenerator sg;
protected final Main main;
final AssemblyEmitter emit;
final RegisterManager rm = new RegisterManager();
protected final AssemblyEmitter emit;
protected final RegisterManager rm = new RegisterManager();
protected ExprGeneratorRef egRef;
protected StmtGeneratorRef sgRef;
AstCodeGenerator(Main main, Writer out) {
initMethodData();
main.allTypeSymbols = new ArrayList<>();
this.emit = new AssemblyEmitter(out);
this.main = main;
this.rnv = new RegsNeededVisitor();
@ -52,14 +51,15 @@ public class AstCodeGenerator {
}
public static AstCodeGenerator createCodeGenerator(Main main, Writer out) {
return new AstCodeGenerator(main, out);
return new AstCodeGeneratorRef(main, out);
}
/**
* Main method. Causes us to emit x86 assembly corresponding to {@code ast}
* into {@code file}. Throws a {@link RuntimeException} should any I/O error
* occur.
*
*
* <p>
* The generated file will be divided into two sections:
* <ol>
@ -70,103 +70,693 @@ public class AstCodeGenerator {
* </ol>
*/
public void go(List<? extends ClassDecl> astRoots) {
// Find main type and assign to main.mainType
// Add array types to the types list to lookup later
for (ClassDecl decl : astRoots) {
if (decl.name.equals("Main")) {
main.mainType = decl.sym;
}
main.allTypeSymbols.add(new ArrayTypeSymbol(decl.sym));
}
main.allTypeSymbols.add(new ArrayTypeSymbol(PrimitiveTypeSymbol.intType));
main.allTypeSymbols.add(new ArrayTypeSymbol(PrimitiveTypeSymbol.booleanType));
main.allTypeSymbols.add(new ArrayTypeSymbol(ClassSymbol.objectType));
emitPrefix();
for (ClassDecl ast : astRoots) {
sg.gen(ast);
}
}
private void emitPrefix() {
// Emit some useful string constants (copied from old HW1 method declaration)
protected void initMethodData() {
rm.initRegisters();
}
protected void emitMethodSuffix(boolean returnNull) {
if (returnNull)
emit.emit("movl", "$0", Register.EAX);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
}
class AstCodeGeneratorRef extends AstCodeGenerator {
/**
* The address of the this ptr relative to the BP. Note that the this ptr is
* always the first argument. Default offset value is 8 but this can change
* depending on the number of parameters pushed on the stack.
*/
protected int THIS_OFFSET = 8;
/**
* Name of the internal Javali$CheckCast() helper function we generate.
*/
static final String CHECK_CAST = "Javali$CheckCast";
/**
* Name of the internal Javali$CheckNull() helper function we generate.
*/
static final String CHECK_NULL = "Javali$CheckNull";
/**
* Name of the internal Javali$CheckNonZero() helper function we generate.
*/
static final String CHECK_NON_ZERO = "Javali$CheckNonZero";
/**
* Name of the internal Javali$CheckArraySize() helper function we generate.
*/
static final String CHECK_ARRAY_SIZE = "Javali$CheckArraySize";
/**
* Name of the internal Javali$CheckArrayBounds() helper function we
* generate.
*/
static final String CHECK_ARRAY_BOUNDS = "Javali$CheckArrayBounds";
/**
* Name of the internal Javali$Alloc() helper function we generate.
*/
static final String ALLOC = "Javali$Alloc";
/**
* Name of the internal Javali$PrintNewLine() helper function we generate.
*/
static final String PRINT_NEW_LINE = "Javali$PrintNewLine";
/**
* Name of the internal Javali$PrintInteger() helper function we generate.
*/
static final String PRINT_INTEGER = "Javali$PrintInteger";
/**
* Name of the internal Javali$ReadInteger() helper function we generate.
*/
static final String READ_INTEGER = "Javali$ReadInteger";
public AstCodeGeneratorRef(Main main, Writer out) {
super(main, out);
this.egRef = new ExprGeneratorRef(this);
this.eg = this.egRef;
this.sgRef = new StmtGeneratorRef(this);
this.sg = this.sgRef;
}
protected void emitPrefix(List<? extends ClassDecl> astRoots) {
// compute method and field offsets
for (ClassDecl ast : astRoots) {
computeFieldOffsets(ast.sym);
computeVtableOffsets(ast.sym);
}
// emit vtables
for (TypeSymbol ts : main.allTypeSymbols)
emitVtable(ts);
// Emit some useful string constants and static data:
emit.emitRaw(Config.DATA_STR_SECTION);
emit.emitLabel("STR_NL");
emit.emitRaw(Config.DOT_STRING + " \"\\n\"");
emit.emitLabel("STR_D");
emit.emitRaw(Config.DOT_STRING + " \"%d\"");
// Define Object, Object[], int, int[], boolean and boolean[]
List<TypeSymbol> elementTypes = new ArrayList<>();
elementTypes.add(ClassSymbol.objectType);
elementTypes.add(PrimitiveTypeSymbol.intType);
elementTypes.add(PrimitiveTypeSymbol.booleanType);
emit.emitLabel("STR_F");
emit.emitRaw(Config.DOT_STRING + " \"%.5f\"");
emit.emitLabel("SCANF_STR_F");
emit.emitRaw(Config.DOT_STRING + " \"%f\"");
emit.emitRaw(Config.DATA_INT_SECTION);
for (TypeSymbol type : elementTypes) {
// type vtable
emit.emitLabel(Label.type(type));
emit.emitConstantData("0"); // Supertype (null)
// array vtable
emit.emitLabel(Label.type(new ArrayTypeSymbol(type)));
emit.emitConstantData(Label.type(ClassSymbol.objectType)); // Supertype
emit.emitConstantData(Label.type(type)); // Element type
emit.emitRaw(Config.TEXT_SECTION);
// Generate a helper method for checking casts:
// It takes first a vtable and second an object ptr.
{
Register obj = RegisterManager.CALLER_SAVE[0];
Register cls = RegisterManager.CALLER_SAVE[1];
String looplbl = emit.uniqueLabel();
String donelbl = emit.uniqueLabel();
String faillbl = emit.uniqueLabel();
emit.emitCommentSection(CHECK_CAST + " function");
emit.emitLabel(CHECK_CAST);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emitLoad(SIZEOF_PTR * 2, BASE_REG, cls);
emit.emitLoad(SIZEOF_PTR * 3, BASE_REG, obj);
emit.emit("cmpl", constant(0), obj);
emit.emit("je", donelbl); // allow null objects to pass
emit.emitLoad(0, obj, obj); // load vtbl of object
emit.emitLabel(looplbl);
emit.emit("cmpl", obj, cls);
emit.emit("je", donelbl);
emit.emit("cmpl", constant(0), obj);
emit.emit("je", faillbl);
emit.emitLoad(0, obj, obj); // load parent vtable
emit.emit("jmp", looplbl);
emit.emitLabel(faillbl);
emit.emitStore(constant(ExitCode.INVALID_DOWNCAST.value), 0, STACK_REG);
emit.emit("call", Config.EXIT);
emit.emitLabel(donelbl);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Emit the new Main().main() code to start the program:
// Generate a helper method for checking for null ptrs:
{
String oknulllbl = emit.uniqueLabel();
emit.emitCommentSection(CHECK_NULL + " function");
emit.emitLabel(CHECK_NULL);
// 1. Enter TEXT and start the program
emit.emitRaw(Config.TEXT_SECTION);
emit.emit(".globl", MAIN);
emit.emitLabel(MAIN);
// 1.1. Prepare first frame
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
// 2. Create main variable
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emit("cmpl", constant(0), registerOffset(SIZEOF_PTR * 2, BASE_REG));
emit.emit("jne", oknulllbl);
emit.emitStore(constant(ExitCode.NULL_POINTER.value), 0, STACK_REG);
emit.emit("call", Config.EXIT);
emit.emitLabel(oknulllbl);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for checking that we don't divide by zero:
{
String oknzlbl = emit.uniqueLabel();
emit.emitCommentSection(CHECK_NON_ZERO + " function");
emit.emitLabel(CHECK_NON_ZERO);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emit("cmpl", constant(0), registerOffset(SIZEOF_PTR * 2, BASE_REG));
emit.emit("jne", oknzlbl);
emit.emitStore(constant(ExitCode.DIVISION_BY_ZERO.value), 0, STACK_REG);
emit.emit("call", Config.EXIT);
emit.emitLabel(oknzlbl);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for checking array size:
{
String okunqlbl = emit.uniqueLabel();
emit.emitCommentSection(CHECK_ARRAY_SIZE + " function");
emit.emitLabel(CHECK_ARRAY_SIZE);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emit("cmpl", constant(0), registerOffset(SIZEOF_PTR * 2, BASE_REG));
emit.emit("jge", okunqlbl);
emit.emitStore(constant(ExitCode.INVALID_ARRAY_SIZE.value), 0, STACK_REG);
emit.emit("call", Config.EXIT);
emit.emitLabel(okunqlbl);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for checking array bounds:
{
Register arr = RegisterManager.CALLER_SAVE[0];
Register idx = RegisterManager.CALLER_SAVE[1];
String faillbl = emit.uniqueLabel();
emit.emitCommentSection(CHECK_ARRAY_BOUNDS + " function");
emit.emitLabel(CHECK_ARRAY_BOUNDS);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emitLoad(SIZEOF_PTR * 3, BASE_REG, idx);
emit.emitLoad(SIZEOF_PTR * 2, BASE_REG, arr);
emit.emit("cmpl", constant(0), idx); // idx < 0
emit.emit("jl", faillbl);
emit.emit("cmpl", registerOffset(Config.SIZEOF_PTR, arr), idx); // idx >= len
emit.emit("jge", faillbl);
// done
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
// fail
emit.emitLabel(faillbl);
emit.emitStore(constant(ExitCode.INVALID_ARRAY_BOUNDS.value), 0, STACK_REG);
emit.emit("call", Config.EXIT);
}
// Generate a helper method for allocating objects/arrays
{
Register size = RegisterManager.CALLER_SAVE[0];
emit.emitCommentSection(ALLOC + " function");
emit.emitLabel(ALLOC);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emitLoad(8, BASE_REG, size);
emit.emitStore(size, 0, STACK_REG);
emit.emitStore(constant(1), 4, STACK_REG);
emit.emit("call", Config.CALLOC);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for printing a new line
{
emit.emitCommentSection(PRINT_NEW_LINE + " function");
emit.emitLabel(PRINT_NEW_LINE);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emitStore("$STR_NL", 0, STACK_REG);
emit.emit("call", Config.PRINTF);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for printing an integer
{
Register temp = RegisterManager.CALLER_SAVE[0];
emit.emitCommentSection(PRINT_INTEGER + " function");
emit.emitLabel(PRINT_INTEGER);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emitLoad(8, BASE_REG, temp);
emit.emitStore(temp, 4, STACK_REG);
emit.emitStore("$STR_D", 0, STACK_REG);
emit.emit("call", Config.PRINTF);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate a helper method for reading an integer
{
Register number = RegisterManager.CALLER_SAVE[0];
emit.emitCommentSection(READ_INTEGER + " function");
emit.emitLabel(READ_INTEGER);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", constant(-16), STACK_REG);
emit.emit("sub", constant(16), STACK_REG);
emit.emit("leal", registerOffset(8, STACK_REG), number);
emit.emitStore(number, 4, STACK_REG);
emit.emitStore("$STR_D", 0, STACK_REG);
emit.emit("call", SCANF);
emit.emitLoad(8, STACK_REG, Register.EAX);
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
// Generate AST for main() method:
// new Main().main()
Ast.NewObject newMain = new Ast.NewObject("Main");
newMain.type = main.mainType;
Register mainLocation = eg.visit(newMain, null);
// 3. Call main()
emit.emit("push", mainLocation);
for (ClassSymbol sym = main.mainType; sym != ClassSymbol.objectType; sym = sym.superClass)
if (sym.methods.getOrDefault("main", null) != null) {
emit.emit("call", Label.method(sym, sym.methods.get("main")));
break;
}
emitMethodSuffix(true);
Ast.MethodCallExpr mce = new Ast.MethodCallExpr(newMain, "main", Collections.<Expr>emptyList());
Ast.MethodCall callMain = new Ast.MethodCall(mce);
mce.sym = main.mainType.getMethod("main");
// Emit the main() method:
// new Main().main();
emit.emitCommentSection("main() function");
emit.emitRaw(".globl " + MAIN);
emit.emitLabel(MAIN);
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(8), STACK_REG);
emit.emit("and", -16, STACK_REG);
sg.gen(callMain);
emit.emit("movl", constant(ExitCode.OK.value), Register.EAX); // normal termination:
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
void initMethodData() {
rm.initRegisters();
@Override
public void go(List<? extends ClassDecl> astRoots) {
emitPrefix(astRoots);
super.go(astRoots);
}
/**
* Computes the vtable offset for each method defined in the class
* {@code sym}.
*/
protected int computeVtableOffsets(ClassSymbol sym) {
if (sym == null)
return 0;
if (sym.totalMethods != -1)
return sym.totalMethods;
int index = computeVtableOffsets(sym.superClass);
for (MethodSymbol ms : sym.methods.values()) {
assert ms.vtableIndex == -1;
if (ms.overrides != null)
ms.vtableIndex = ms.overrides.vtableIndex;
else
ms.vtableIndex = index++;
}
sym.totalMethods = index;
return index;
}
/**
* Computes the offset for each field.
*/
protected int computeFieldOffsets(ClassSymbol sym) {
if (sym == null)
return 0;
if (sym.totalFields != -1)
return sym.totalFields;
int index = computeFieldOffsets(sym.superClass);
for (VariableSymbol fs : sym.fields.values()) {
assert fs.offset == -1;
// compute offset in bytes; note that 0 is the vtable
fs.offset = (index * SIZEOF_PTR) + SIZEOF_PTR;
index++;
}
sym.totalFields = index;
sym.sizeof = (sym.totalFields + 1) * Config.SIZEOF_PTR;
return index;
}
private void collectVtable(MethodSymbol[] vtable, ClassSymbol sym) {
if (sym.superClass != null)
collectVtable(vtable, sym.superClass);
for (MethodSymbol ms : sym.methods.values())
vtable[ms.vtableIndex] = ms;
}
protected void emitVtable(TypeSymbol ts) {
if (ts instanceof ClassSymbol) {
ClassSymbol cs = (ClassSymbol) ts;
// Collect the vtable:
MethodSymbol[] vtable = new MethodSymbol[cs.totalMethods];
collectVtable(vtable, cs);
// Emit vtable for this class:
emit.emitLabel(vtable(cs));
if (cs.superClass != null)
emit.emitConstantData(vtable(cs.superClass));
else
emit.emitConstantData("0");
for (int i = 0; i < cs.totalMethods; i++)
emit.emitConstantData(methodLabel(vtable[i]));
} else if (ts instanceof ArrayTypeSymbol) {
ArrayTypeSymbol as = (ArrayTypeSymbol) ts;
emit.emitLabel(vtable(as));
emit.emitConstantData(vtable(ClassSymbol.objectType));
}
}
protected String vtable(TypeSymbol ts) {
if (ts instanceof ClassSymbol) {
return "vtable_" + ((ClassSymbol) ts).name;
} else if (ts instanceof ArrayTypeSymbol) {
return "vtablearr_" + ((ArrayTypeSymbol) ts).elementType.name;
} else {
throw new RuntimeException("No vtable for " + ts.name);
}
}
void emitMethodSuffix(boolean returnNull) {
@Override
protected void initMethodData() {
THIS_OFFSET = 8;
bytes = 0;
super.initMethodData();
}
protected int padding(int numberOfParameters) {
int padding = (bytes + numberOfParameters * Config.SIZEOF_PTR + 15) & 0xFFFFFFF0;
return padding - bytes - numberOfParameters * Config.SIZEOF_PTR;
}
protected void push(int padding) {
if (padding > 0) {
emit.emit("sub", padding, STACK_REG);
bytes += padding;
}
}
protected void pop(int padding) {
if (padding > 0) {
emit.emit("add", padding, STACK_REG);
bytes -= padding;
}
assert bytes >= 0;
}
protected void push(String reg) {
emit.emit("push", reg);
bytes += Config.SIZEOF_PTR;
}
protected void pop(String reg) {
emit.emit("pop", reg);
bytes -= Config.SIZEOF_PTR;
assert bytes >= 0;
}
protected void restoreCalleeSaveRegs() {
for (int reg = RegisterManager.CALLEE_SAVE.length - 1; reg >= 0; reg--) {
emit.emit("pop", RegisterManager.CALLEE_SAVE[reg]);
}
}
protected void storeCalleeSaveRegs() {
bytes = 0;
for (int reg = 0; reg < RegisterManager.CALLEE_SAVE.length; reg++) {
emit.emit("push", RegisterManager.CALLEE_SAVE[reg]);
bytes += Config.SIZEOF_PTR;
}
}
protected void restoreCallerSaveRegs(Register res) {
for (int reg = RegisterManager.CALLER_SAVE.length - 1; reg >= 0; reg--) {
if (!rm.isInUse(RegisterManager.CALLER_SAVE[reg]))
continue; // not in use
if (RegisterManager.CALLER_SAVE[reg].equals(res))
continue; // contains our result
pop(RegisterManager.CALLER_SAVE[reg].repr);
}
}
protected void storeCallerSaveRegs(Register res) {
for (int reg = 0; reg < RegisterManager.CALLER_SAVE.length; reg++) {
if (!rm.isInUse(RegisterManager.CALLER_SAVE[reg]))
continue; // not in use
if (RegisterManager.CALLER_SAVE[reg].equals(res))
continue; // will contain our result
push(RegisterManager.CALLER_SAVE[reg].repr);
}
}
protected int emitCallPrefix(Register res, int numberOfParameters) {
storeCallerSaveRegs(res);
int padding = padding(numberOfParameters);
push(padding);
return padding;
}
protected void emitCallSuffix(Register res, int numberOfParameters,
int padding) {
pop(numberOfParameters * Config.SIZEOF_PTR + padding);
if (res != null) {
emit.emitMove(Register.EAX, res);
}
restoreCallerSaveRegs(res);
}
/**
* Generates code which evaluates {@code ast} and branches to {@code lbl} if
* the value generated for {@code ast} is false.
*/
protected void genJumpIfFalse(Expr ast, String lbl) {
// A better way to implement this would be with a separate
// visitor.
Register reg = eg.gen(ast);
emit.emit("cmpl", "$0", reg);
emit.emit("je", lbl);
rm.releaseRegister(reg);
}
/**
* Used to store the temporaries. We grow our stack dynamically, we allocate
* "temporary" values on this stack during method execution. Values can be
* stored and retrieved using {@link #push(String)} and {@link #pop(String)}
* , which use the program stack.
*/
protected int bytes = 0;
protected String methodLabel(MethodSymbol msym) {
return "meth_" + msym.owner.name + "_" + msym.name;
}
protected void emitMethodPrefix(MethodDecl ast) {
// Emit the label for the method:
emit.emitRaw(Config.TEXT_SECTION);
emit.emitCommentSection(String.format("Method %s.%s", ast.sym.owner.name,
ast.name));
emit.emitRaw(".globl " + methodLabel(ast.sym));
emit.emitLabel(methodLabel(ast.sym));
// Compute the size and layout of the stack frame. Our
// frame looks like (the numbers are relative to our ebp):
//
// (caller's locals)
// (padding)
// arg 0 (this ptr)
// ...
// 12 arg N - 1
// 8 arg N
// 4 linkage ptr (return address)
// 0 saved ebp
// -4 locals
// (callee's arguments + temporaries)
//
// We allocate on the stack during the course of
// a function call using push(...) and pop(...) instructions.
//
// Stack slots fall into several
// categories:
// - "Linkage": overhead for function calls.
// This includes the return address and saved ebp.
// - locals: these store the value of user-declared local
// variables.
// - temporaries: these are stack slots used to store
// values during expression evaluation when we run out
// of registers, saving caller-saved registers, and
// other miscellaneous purposes.
// - padding: only there to ensure the stack size is a multiple
// of 16.
// - arguments: values we will pass to functions being
// invoked.
//
// We calculate all address relative to the base pointer.
// Initialize method-specific data
initMethodData();
// Assign parameter offsets:
// As shown above, these start from 8.
// Being able to evaluate parameters like in Java
// with left-to-right evaluation order they result
// on the stack in reversed order.
// The "this" parameter is the first pushed on the stack
// thus receiving higher offset.
int paramOffset = Config.SIZEOF_PTR * 2;
for (int i = ast.sym.parameters.size() - 1; i >= 0; i--) {
final VariableSymbol param = ast.sym.parameters.get(i);
assert param.offset == -1;
param.offset = paramOffset;
paramOffset += Config.SIZEOF_PTR;
}
THIS_OFFSET = paramOffset;
paramOffset += Config.SIZEOF_PTR;
// First few slots are reserved for caller save regs:
int localSlot = RegisterManager.CALLER_SAVE.length * RegisterManager.SIZEOF_REG;
// Assign local variable offsets:
emit.emitComment(String.format("%-10s Offset", "Variable"));
for (VariableSymbol local : ast.sym.locals.values()) {
assert local.offset == -1;
local.offset = -localSlot;
localSlot += Config.SIZEOF_PTR;
emit.emitComment(String.format("%-10s %d", local, local.offset));
}
// Round up stack size to make it a multiple of 16.
// The actual amount passed to the enter instruction is 8
// less, however, because it wants to know the amount
// in addition to the linkage ptr and saved ebp.
int implicit = Config.SIZEOF_PTR * 2;
int stackSize = (implicit + localSlot + 15) & 0xFFFFFFF0;
stackSize -= implicit;
emit.emitComment(String.format("implicit=%d localSlot=%d sum=%d", implicit,
localSlot, implicit + localSlot));
// emit.emitRaw(String.format("enter $%d, $0", stackSize));
emit.emit("push", BASE_REG);
emit.emitMove(STACK_REG, BASE_REG);
emit.emit("sub", constant(stackSize), STACK_REG);
emit.emit("and", -16, STACK_REG);
storeCalleeSaveRegs();
// zero-initialize locals
for (VariableSymbol local : ast.sym.locals.values()) {
emit.emitMove(constant(0), registerOffset(local.offset, BASE_REG));
}
}
@Override
protected void emitMethodSuffix(boolean returnNull) {
if (returnNull)
emit.emit("movl", 0, Register.EAX);
emit.emitRaw("leave");
emit.emit("movl", "$0", Register.EAX);
restoreCalleeSaveRegs();
emit.emitMove(BASE_REG, STACK_REG);
emit.emit("pop", BASE_REG);
emit.emitRaw("ret");
}
}
static class Label {
static String type(TypeSymbol symbol) {
if (symbol instanceof ClassSymbol)
return String.format("type_%s", symbol);
else if (symbol instanceof ArrayTypeSymbol)
return String.format("array_%s", ((ArrayTypeSymbol) symbol).elementType);
else if (symbol instanceof PrimitiveTypeSymbol)
return String.format("primive_%s", symbol);
throw new RuntimeException("Unimplemented type symbol");
}
class AstCodeGeneratorNop90 extends AstCodeGeneratorRef {
public AstCodeGeneratorNop90(Main main, Writer out, CfgCodeGenerator cfgCg) {
super(main, out);
this.egRef = new ExprGeneratorNop90(this, cfgCg);
this.eg = this.egRef;
this.sgRef = new StmtGeneratorNop90(this, cfgCg);
this.sg = this.sgRef;
}
static String method(ClassSymbol classSymbol, MethodSymbol methodSymbol) {
return String.format("method_%s_%s", classSymbol.name, methodSymbol.name);
}
static String returnMethod(ClassSymbol classSymbol, MethodSymbol methodSymbol) {
return String.format("return_%s", method(classSymbol, methodSymbol));
}
}
}

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src/cd/backend/codegen/CfgCodeGenerator.java Normal file
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package cd.backend.codegen;
import cd.Main;
import cd.ir.Ast.ClassDecl;
import cd.ir.Ast.MethodDecl;
import cd.ir.Ast.Stmt;
import cd.ir.Ast;
import cd.ir.AstVisitor;
import cd.ir.BasicBlock;
import cd.ir.ControlFlowGraph;
import cd.ir.Symbol.PrimitiveTypeSymbol;
import cd.ir.Symbol.TypeSymbol;
import cd.ir.Symbol.VariableSymbol;
import cd.transform.analysis.ArraySizeAnalysis;
import cd.transform.analysis.AssignmentAnalysis;
import cd.transform.analysis.DynamicTypeAnalysis;
import cd.transform.analysis.MaybeC;
import cd.transform.analysis.NullAnalysis;
import java.io.Writer;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class CfgCodeGenerator {
public final Main main;
private final AstCodeGeneratorRef cg;
public final CompileTimeChecks check;
protected Map<VariableSymbol, MaybeC<Integer>> arraySizeState;
protected Map<VariableSymbol, MaybeC<Boolean>> nullState;
protected Map<VariableSymbol, MaybeC<TypeSymbol>> dynamicTypeState;
//protected Map<VariableSymbol, MaybeC<List<Ast.Assign>>> unusedAssignmentsState;
public CfgCodeGenerator(Main main, Writer out) {
this.main = main;
cg = new AstCodeGeneratorNop90(main, out, this);
check = new CompileTimeChecks(cg, this);
}
public void go(List<? extends ClassDecl> astRoots) {
cg.emitPrefix(astRoots);
for (ClassDecl cdecl : astRoots)
new CfgStmtVisitor().visit(cdecl, null);
}
private class CfgStmtVisitor extends AstVisitor<Void, Void> {
@Override
public Void classDecl(ClassDecl ast, Void arg) {
cg.emit.emitCommentSection("Class " + ast.name);
cg.emit.increaseIndent("");
super.classDecl(ast, arg);
cg.emit.decreaseIndent();
return null;
}
@Override
public Void methodDecl(MethodDecl ast, Void arg) {
cg.emitMethodPrefix(ast);
ControlFlowGraph cfg = ast.cfg;
assert cfg != null;
Map<BasicBlock, String> labels = new HashMap<BasicBlock, String>();
for (BasicBlock blk : cfg.allBlocks)
labels.put(blk, cg.emit.uniqueLabel());
String exitLabel = cg.emit.uniqueLabel();
cg.emit.emit("jmp", labels.get(cfg.start));
// Run analysis here to have the relevant results to this cfg object
ArraySizeAnalysis arraySizeAnalysis = new ArraySizeAnalysis(cfg);
NullAnalysis nullAnalysis = new NullAnalysis(cfg);
DynamicTypeAnalysis dynamicTypeAnalysis = new DynamicTypeAnalysis(cfg);
//AssignmentAnalysis assignmentAnalysis = new AssignmentAnalysis(cfg);
for (BasicBlock blk : cfg.allBlocks) {
arraySizeState = arraySizeAnalysis.inStateOf(blk);
nullState = nullAnalysis.inStateOf(blk);
dynamicTypeState = dynamicTypeAnalysis.inStateOf(blk);
//unusedAssignmentsState = assignmentAnalysis.inStateOf(blk);
assert nullState != null;
assert arraySizeState != null;
assert dynamicTypeState != null;
//assert unusedAssignmentsState != null;
cg.emit.emitCommentSection("Basic block " + blk.index);
cg.emit.emitLabel(labels.get(blk));
for (Stmt stmt : blk.stmts) {
cg.sg.gen(stmt);
//assignmentAnalysis.transferStmt(stmt, unusedAssignmentsState);
arraySizeAnalysis.transferStmt(stmt, arraySizeState);
nullAnalysis.transferStmt(stmt, nullState);
dynamicTypeAnalysis.transferStmt(stmt, dynamicTypeState);
}
if (blk == cfg.end) {
cg.emit.emitComment(String.format("Return"));
assert blk.successors.size() == 0;
cg.emit.emit("jmp", exitLabel);
} else if (blk.condition != null) {
assert blk.successors.size() == 2;
cg.emit.emitComment(String.format(
"Exit to block %d if true, block %d if false",
blk.trueSuccessor().index, blk.falseSuccessor().index));
cg.genJumpIfFalse(blk.condition, labels.get(blk.falseSuccessor()));
cg.emit.emit("jmp", labels.get(blk.trueSuccessor()));
} else {
cg.emit.emitComment(String.format(
"Exit to block %d", blk.successors.get(0).index));
assert blk.successors.size() == 1;
cg.emit.emit("jmp", labels.get(blk.successors.get(0)));
}
}
cg.emit.emitLabel(exitLabel);
if (ast.sym.returnType.equals(PrimitiveTypeSymbol.voidType))
cg.emitMethodSuffix(true);
else
cg.emitMethodSuffix(true);
return null;
}
}
}

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src/cd/backend/codegen/CompileTimeChecks.java Executable file
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package cd.backend.codegen;
import cd.Config;
import cd.backend.ExitCode;
import cd.ir.Ast;
import cd.ir.Ast.*;
import cd.ir.CompileTimeEvaluator;
import cd.ir.Symbol.VariableSymbol;
import cd.transform.analysis.MaybeC;
import java.util.Optional;
import static cd.backend.codegen.AssemblyEmitter.constant;
import static cd.backend.codegen.RegisterManager.STACK_REG;
/**
* Class with simple static checks mimicking the runtime system with the functions to check
* possible errors at runtime. The purpose is to skip unnecessary calls to those functions
*/
public class CompileTimeChecks {
protected final CfgCodeGenerator cfgCg;
protected final AstCodeGeneratorRef cgRef;
protected CompileTimeEvaluator cte;
public CompileTimeChecks(AstCodeGeneratorRef cg, CfgCodeGenerator cfgCodeGenerator) {
this.cfgCg = cfgCodeGenerator;
this.cgRef = cg;
cte = new CompileTimeEvaluator();
}
/**
* Convenience method that extracts the VariableSymbol from a Var or Field node.
* <br/> If the node is not one of those, the node must be a Index
*/
private VariableSymbol symbolOf(Expr expr) {
if (expr instanceof Var)
return ((Var) expr).sym;
if (expr instanceof Field)
return ((Field) expr).sym;
// assert expr instanceof Index // only for local checks
return null;
}
/** Returns whether a NewArray expression needs to check dynamically for the
* validity of the index (>=0). In case that it is known but invalid, a call
* to exit is done with the appropriate error code.
*/
public boolean checkArraySize(Ast.NewArray expr) {
Optional<Integer> arraySize = cte.calc(expr.arg());
if (!arraySize.isPresent()) {
return true;
}
int arraySizeValue = arraySize.get();
if (arraySizeValue < 0) {
cgRef.emit.emitStore(constant(ExitCode.INVALID_ARRAY_SIZE.value), 0, STACK_REG);
cgRef.emit.emit("call", Config.EXIT);
return false;
}
return false;
}
/** Returns whether a run-time check for the bounds of an array index is necessary.
* <br/> A check is only necessary if the index expression cannot be evaluated in
* compile time or the size of the array is unknown.
* <br/> If the value is known and it is invalid, an unconditional call to exit is
* performed with the appropriate exit code
*/
public boolean checkArrayBound(Index expr) {
Optional<Integer> index = cte.calc(expr.right());
if (!index.isPresent()) {
return true;
}
VariableSymbol symbol = symbolOf(expr.left());
if (!cfgCg.arraySizeState.containsKey(symbol)) {
return true;
}
int indexValue = index.get();
MaybeC<Integer> bound = cfgCg.arraySizeState.get(symbol);
if (bound.isNotConstant()) {
return true;
}
int boundValue = bound.getValue();
if (indexValue < 0 || indexValue > (boundValue - 1)) {
cgRef.emit.emitStore(constant(ExitCode.INVALID_ARRAY_BOUNDS.value), 0, STACK_REG);
cgRef.emit.emit("call", Config.EXIT);
}
return false;
}
/**
* Returns true only when it is impossible for the expression (Field or Var) to be null.
* <br/> Currently doesn't check indexes.
*/
public boolean isNotNull(Expr expr) {
if (expr instanceof ThisRef) {
return false;
} else {
VariableSymbol symbol = symbolOf(expr);
MaybeC<Boolean> isNull = cfgCg.nullState.get(symbol);
return isNull != null && isNull.isConstant() && !isNull.getValue();
}
}
}

1407
src/cd/backend/codegen/ExprGenerator.java
View file

File diff suppressed because it is too large Load diff

19
src/cd/backend/codegen/Interrupts.java
View file

@ -1,19 +0,0 @@
package cd.backend.codegen;
import cd.backend.ExitCode;
import cd.backend.codegen.RegisterManager.Register;
public class Interrupts {
protected static final int INTERRUPT_EXIT = 1;
/**
* Generates a exit interrupt with the code provided
* @param cg AstCodeGenerator to print instructions
* @param exitCode Number to use as exit code (can use constants in this class)
*/
protected static void exit(AstCodeGenerator cg, ExitCode exitCode) {
cg.emit.emitMove(AssemblyEmitter.constant(INTERRUPT_EXIT), Register.EAX);
cg.emit.emitMove(AssemblyEmitter.constant(exitCode.value), Register.EBX);
cg.emit.emit("int", 0x80);
}
}

42
src/cd/backend/codegen/Location.java
View file

@ -1,42 +0,0 @@
package cd.backend.codegen;
import cd.ir.Symbol.ClassSymbol;
import cd.ir.Symbol.MethodSymbol;
public class Location {
private ClassSymbol classSymbol;
private MethodSymbol methodSymbol = null;
private boolean obtainReference = false;
public Location (ClassSymbol sym) {
classSymbol = sym;
}
public ClassSymbol classSym() {
return classSymbol;
}
public MethodSymbol methodSym() {
assert methodSymbol != null;
return methodSymbol;
}
public void enterMethod(MethodSymbol sym) {
methodSymbol = sym;
}
public void leaveMethod() {
methodSymbol = null;
}
public boolean isObtainReference() {
boolean aux = obtainReference;
obtainReference = false;
return aux;
}
public Location obtainReference() {
obtainReference = true;
return this;
}
}

13
src/cd/backend/codegen/RegisterManager.java
View file

@ -16,10 +16,10 @@ public class RegisterManager {
Register.EDI, Register.EBX};
public static final Register CALLER_SAVE[] = new Register[]{Register.EAX,
Register.ECX, Register.EDX};
// list of general purpose registers
public static final Register GPR[] = new Register[]{Register.EAX, Register.EBX,
Register.ECX, Register.EDX, Register.ESI, Register.EDI};
Register.ECX, Register.EDX, Register.ESI, Register.EDI};
// special purpose registers
public static final Register BASE_REG = Register.EBP;
@ -27,7 +27,7 @@ public class RegisterManager {
public static final int SIZEOF_REG = 4;
public enum Register {
EAX("%eax", ByteRegister.EAX), EBX("%ebx", ByteRegister.EBX), ECX(
"%ecx", ByteRegister.ECX), EDX("%edx", ByteRegister.EDX), ESI(
@ -99,18 +99,11 @@ public class RegisterManager {
return registers.remove(last);
}
public void useRegister(Register reg) {
assert registers.contains(reg);
assert reg != null;
registers.remove(reg);
}
/**
* marks a currently used register as free
*/
public void releaseRegister(Register reg) {
assert !registers.contains(reg);
assert reg != null;
registers.add(reg);
}

35
src/cd/backend/codegen/RegsNeededVisitor.java
View file

@ -10,18 +10,19 @@ import java.util.Map;
import static java.lang.Math.max;
import static java.lang.Math.min;
/**
* Determines the maximum number of registers
* required to execute one subtree. */
/**
* Determines the maximum number of registers
* required to execute one subtree.
*/
public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public int calc(Ast ast) {
return visit(ast, null);
}
private Map<Ast,Integer> memo = new HashMap<Ast, Integer>();
/**
private Map<Ast, Integer> memo = new HashMap<Ast, Integer>();
/**
* Override visit() so as to memorize the results and avoid
* unnecessary computation
*/
@ -31,9 +32,9 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
return memo.get(ast);
Integer res = ast.accept(this, null);
memo.put(ast, res);
return res;
return res;
}
@Override
protected Integer dflt(Ast ast, Void arg) {
// For a non-expression, it suffices to find the
@ -54,8 +55,8 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public Integer binaryOp(BinaryOp ast, Void arg) {
int left = calc(ast.left());
int right = calc(ast.right());
int ifLeftFirst = max(left, right+1);
int ifRightFirst = max(left+1, right);
int ifLeftFirst = max(left, right + 1);
int ifRightFirst = max(left + 1, right);
int overall = min(ifLeftFirst, ifRightFirst);
return overall;
}
@ -64,7 +65,7 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public Integer assign(Assign ast, Void arg) {
return max(calc(ast.left()) + 1, calc(ast.right()));
}
@Override
public Integer booleanConst(BooleanConst ast, Void arg) {
return 1;
@ -74,7 +75,7 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public Integer builtInRead(BuiltInRead ast, Void arg) {
return 1;
}
@Override
public Integer cast(Cast ast, Void arg) {
return calc(ast.arg());
@ -84,7 +85,7 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public Integer index(Index ast, Void arg) {
return max(calc(ast.left()), calc(ast.right()) + 1);
}
@Override
public Integer field(Field ast, Void arg) {
return calc(ast.arg());
@ -114,7 +115,7 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
public Integer thisRef(ThisRef ast, Void arg) {
return 1;
}
@Override
public Integer methodCall(MethodCallExpr ast, Void arg) {
int max = 1;
@ -134,5 +135,5 @@ public class RegsNeededVisitor extends AstVisitor<Integer, Void> {
@Override
public Integer var(Var ast, Void arg) {
return 1;
}
}
}

541
src/cd/backend/codegen/StmtGenerator.java
View file

@ -1,34 +1,31 @@
package cd.backend.codegen;
import cd.Config;
import cd.backend.ExitCode;
import cd.backend.codegen.AstCodeGenerator.Label;
import cd.backend.codegen.RegisterManager.Register;
import cd.frontend.semantic.ReturnCheckerVisitor;
import cd.ir.Ast;
import cd.ir.Ast.*;
import cd.ir.AstVisitor;
import cd.ir.Symbol;
import cd.ir.Symbol.ClassSymbol;
import cd.ir.CompileTimeEvaluator;
import cd.ir.ExprVisitor;
import cd.ir.Symbol.MethodSymbol;
import cd.ir.Symbol.PrimitiveTypeSymbol;
import cd.util.Pair;
import cd.util.debug.AstOneLine;
import java.util.*;
import java.util.List;
import static cd.backend.codegen.AstCodeGenerator.VAR_SIZE;
import static cd.backend.codegen.AstCodeGenerator.TRUE;
import static cd.backend.codegen.AssemblyEmitter.arrayAddress;
import static cd.backend.codegen.RegisterManager.BASE_REG;
import static cd.backend.codegen.RegisterManager.STACK_REG;
/**
* Generates code to process statements and declarations.
*/
class StmtGenerator extends AstVisitor<Register,Location> {
class StmtGenerator extends AstVisitor<Register, Void> {
protected final AstCodeGenerator cg;
StmtGenerator(AstCodeGenerator astCodeGenerator) {
cg = astCodeGenerator;
}
public void gen(Ast ast) {
@ -36,253 +33,337 @@ class StmtGenerator extends AstVisitor<Register,Location> {
}
@Override
public Register visit(Ast ast, Location arg) {
public Register visit(Ast ast, Void arg) {
try {
cg.emit.increaseIndent("Emitting " + AstOneLine.toString(ast));
if (cg.rnv.calc(ast) > cg.rm.availableRegisters()) {
Deque<Register> pushed = new ArrayDeque<>();
for (Register r : RegisterManager.GPR) {
if (cg.rm.isInUse(r)) {
cg.emit.emit("push", r);
pushed.push(r);
cg.rm.releaseRegister(r);
}
}
Register result = super.visit(ast, arg);
for (Register r : pushed)
cg.rm.useRegister(r);
Register finalResult = cg.rm.getRegister();
cg.emit.emitMove(result, finalResult);
for (Register r = pushed.pop(); !pushed.isEmpty(); r = pushed.pop())
cg.emit.emit("pop", r);
return finalResult;
} else return super.visit(ast, arg);
return super.visit(ast, arg);
} finally {
cg.emit.decreaseIndent();
}
}
@Override
public Register methodCall(MethodCall ast, Location arg) {
Register result = cg.eg.visit(ast.getMethodCallExpr(), arg);
if (result != null)
cg.rm.releaseRegister(result);
return null;
}
public Register methodCall(MethodSymbol sym, List<Expr> allArguments) {
throw new RuntimeException("Not required");
}
/**
* vtable structure for a class type: pointer to superclass, and methods, each with 2 entries, name's hashCode and
* pointer to method execution
*/
}
/*
* StmtGenerator with the reference solution
*/
class StmtGeneratorRef extends StmtGenerator {
/* cg and cgRef are the same instance. cgRef simply
* provides a wider interface */
protected final AstCodeGeneratorRef cgRef;
StmtGeneratorRef(AstCodeGeneratorRef astCodeGenerator) {
super(astCodeGenerator);
this.cgRef = astCodeGenerator;
}
@Override
public Register classDecl(ClassDecl ast, Location arg) {
cg.emit.emitRaw(Config.DATA_INT_SECTION);
// Emit vtable for class
cg.emit.emitLabel(Label.type(ast.sym)); // Label
cg.emit.emitConstantData(Label.type(ast.sym.superClass)); // Superclass
// Methods (don't write those that are overridden twice)
Set<String> generated = new HashSet<>();
ClassSymbol currSym = ast.sym;
while (currSym != ClassSymbol.objectType) {
ClassSymbol finalCurrSym = currSym;
currSym.methods.values().forEach(o -> {
if (!generated.add(o.name)) return;
cg.emit.emitConstantData(String.valueOf(o.name.hashCode()));
cg.emit.emitConstantData(Label.method(finalCurrSym, o));
});
currSym = currSym.superClass;
public Register methodCall(MethodSymbol mthSymbol, List<Expr> allArgs) {
// Push the arguments and the method prefix (caller save register,
// and padding) onto the stack.
// Note that the space for the arguments is not already reserved,
// so we just push them in the Java left-to-right order.
//
// After each iteration of the following loop, reg holds the
// register used for the previous argument.
int padding = cgRef.emitCallPrefix(null, allArgs.size());
Register reg = null;
for (int i = 0; i < allArgs.size(); i++) {
if (reg != null) {
cgRef.rm.releaseRegister(reg);
}
reg = cgRef.eg.gen(allArgs.get(i));
cgRef.push(reg.repr);
}
// End of class vtable
// Array vtable
boolean found = false;
for (Symbol.TypeSymbol type : cg.main.allTypeSymbols) {
if (type instanceof Symbol.ArrayTypeSymbol) {
Symbol.ArrayTypeSymbol aType = (Symbol.ArrayTypeSymbol) type;
if (aType.elementType == ast.sym) {
cg.emit.emitLabel(Label.type(aType)); // Label
found = true;
break;
}
// Since "this" is the first parameter that push
// we have to get it back to resolve the method call
cgRef.emit.emitComment("Load \"this\" pointer");
cgRef.emit.emitLoad((allArgs.size() - 1) * Config.SIZEOF_PTR, STACK_REG, reg);
// Check for a null receiver
int cnPadding = cgRef.emitCallPrefix(null, 1);
cgRef.push(reg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_NULL);
cgRef.emitCallSuffix(null, 1, cnPadding);
// Load the address of the method to call into "reg"
// and call it indirectly.
cgRef.emit.emitLoad(0, reg, reg);
int mthdoffset = 4 + mthSymbol.vtableIndex * Config.SIZEOF_PTR;
cgRef.emit.emitLoad(mthdoffset, reg, reg);
cgRef.emit.emit("call", "*" + reg);
cgRef.emitCallSuffix(reg, allArgs.size(), padding);
if (mthSymbol.returnType == PrimitiveTypeSymbol.voidType) {
cgRef.rm.releaseRegister(reg);
return null;
}
return reg;
}
@Override
public Register methodCall(MethodCall ast, Void dummy) {
Register reg = cgRef.eg.gen(ast.getMethodCallExpr());
if (reg != null)
cgRef.rm.releaseRegister(reg);
return reg;
}
@Override
public Register classDecl(ClassDecl ast, Void arg) {
// Emit each method:
cgRef.emit.emitCommentSection("Class " + ast.name);
return visitChildren(ast, arg);
}
@Override
public Register methodDecl(MethodDecl ast, Void arg) {
cgRef.emitMethodPrefix(ast);
gen(ast.body());
cgRef.emitMethodSuffix(false);
return null;
}
@Override
public Register ifElse(IfElse ast, Void arg) {
String falseLbl = cgRef.emit.uniqueLabel();
String doneLbl = cgRef.emit.uniqueLabel();
cgRef.genJumpIfFalse(ast.condition(), falseLbl);
gen(ast.then());
cgRef.emit.emit("jmp", doneLbl);
cgRef.emit.emitLabel(falseLbl);
gen(ast.otherwise());
cgRef.emit.emitLabel(doneLbl);
return null;
}
@Override
public Register whileLoop(WhileLoop ast, Void arg) {
String nextLbl = cgRef.emit.uniqueLabel();
String doneLbl = cgRef.emit.uniqueLabel();
cgRef.emit.emitLabel(nextLbl);
cgRef.genJumpIfFalse(ast.condition(), doneLbl);
gen(ast.body());
cgRef.emit.emit("jmp", nextLbl);
cgRef.emit.emitLabel(doneLbl);
return null;
}
@Override
public Register assign(Assign ast, Void arg) {
class AssignVisitor extends ExprVisitor<Void, Expr> {
@Override
public Void var(Var ast, Expr right) {
final Register rhsReg = cgRef.eg.gen(right);
cgRef.emit.emitStore(rhsReg, ast.sym.offset, BASE_REG);
cgRef.rm.releaseRegister(rhsReg);
return null;
}
@Override
public Void field(Field ast, Expr right) {
final Register rhsReg = cgRef.eg.gen(right);
Pair<Register> regs = cgRef.egRef.genPushing(rhsReg, ast.arg());
int padding = cgRef.emitCallPrefix(null, 1);
cgRef.push(regs.b.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_NULL);
cgRef.emitCallSuffix(null, 1, padding);
cgRef.emit.emitStore(regs.a, ast.sym.offset, regs.b);
cgRef.rm.releaseRegister(regs.b);
cgRef.rm.releaseRegister(regs.a);
return null;
}
@Override
public Void index(Index ast, Expr right) {
Register rhsReg = cgRef.egRef.gen(right);
Pair<Register> regs = cgRef.egRef.genPushing(rhsReg, ast.left());
rhsReg = regs.a;
Register arrReg = regs.b;
int padding = cgRef.emitCallPrefix(null, 1);
cgRef.push(arrReg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_NULL);
cgRef.emitCallSuffix(null, 1, padding);
regs = cgRef.egRef.genPushing(arrReg, ast.right());
arrReg = regs.a;
Register idxReg = regs.b;
// Check array bounds
padding = cgRef.emitCallPrefix(null, 2);
cgRef.push(idxReg.repr);
cgRef.push(arrReg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_ARRAY_BOUNDS);
cgRef.emitCallSuffix(null, 2, padding);
cgRef.emit.emitMove(rhsReg, arrayAddress(arrReg, idxReg));
cgRef.rm.releaseRegister(arrReg);
cgRef.rm.releaseRegister(idxReg);
cgRef.rm.releaseRegister(rhsReg);
return null;
}
@Override
protected Void dfltExpr(Expr ast, Expr arg) {
throw new RuntimeException("Store to unexpected lvalue " + ast);
}
}
new AssignVisitor().visit(ast.left(), ast.right());
return null;
}
@Override
public Register builtInWrite(BuiltInWrite ast, Void arg) {
Register reg = cgRef.eg.gen(ast.arg());
int padding = cgRef.emitCallPrefix(null, 1);
cgRef.push(reg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.PRINT_INTEGER);
cgRef.emitCallSuffix(null, 1, padding);
cgRef.rm.releaseRegister(reg);
return null;
}
@Override
public Register builtInWriteln(BuiltInWriteln ast, Void arg) {
int padding = cgRef.emitCallPrefix(null, 0);
cgRef.emit.emit("call", AstCodeGeneratorRef.PRINT_NEW_LINE);
cgRef.emitCallSuffix(null, 0, padding);
return null;
}
@Override
public Register returnStmt(ReturnStmt ast, Void arg) {
if (ast.arg() != null) {
Register reg = cgRef.eg.gen(ast.arg());
cgRef.emit.emitMove(reg, "%eax");
cgRef.emitMethodSuffix(false);
cgRef.rm.releaseRegister(reg);
} else {
cgRef.emitMethodSuffix(true); // no return value -- return NULL as
// a default (required for main())
}
return null;
}
}
class StmtGeneratorNop90 extends StmtGeneratorRef {
protected final CfgCodeGenerator cfgCg;
protected CompileTimeEvaluator cte;
StmtGeneratorNop90(AstCodeGeneratorNop90 astCodeGenerator, CfgCodeGenerator cfgCodeGenerator) {
super(astCodeGenerator);
this.cfgCg = cfgCodeGenerator;
cte = new CompileTimeEvaluator();
}
@Override
public Register assign(Assign ast, Void arg) {
/*
if (ast.left() instanceof Ast.Var) {
Ast.Var var = (Ast.Var) ast.left();
VariableSymbol sym = var.sym;
MaybeC<List<Assign>> maybeStateList = cfgCg.unusedAssignmentsState.get(sym);
List<Ast.Assign> stateList = maybeStateList.getValue();
if (stateList.contains(ast)) {
return null;
}
}
if (!found)
throw new RuntimeException("The array type could not be found");
cg.emit.emitConstantData(Label.type(ClassSymbol.objectType)); // Supertype
cg.emit.emitConstantData(Label.type(ast.sym)); // Type of elements
// End of array vtable
cg.emit.emitRaw(Config.TEXT_SECTION);
// Method bodies
for (Ast method : ast.methods())
visit(method, new Location(ast.sym));
return null;
}
*/
class AssignVisitor extends ExprVisitor<Void, Expr> {
@Override
public Register methodDecl(MethodDecl ast, Location arg) {
// Bookkeeping for framework
arg.enterMethod(ast.sym);
cg.initMethodData();
@Override
public Void var(Var ast, Expr right) {
final Register rhsReg = cgRef.eg.gen(right);
cgRef.emit.emitStore(rhsReg, ast.sym.offset, BASE_REG);
cgRef.rm.releaseRegister(rhsReg);
return null;
}
// Begin method
cg.emit.emitLabel(Label.method(arg.classSym(), ast.sym));
@Override
public Void field(Field ast, Expr right) {
final Register rhsReg = cgRef.eg.gen(right);
Pair<Register> regs = cgRef.egRef.genPushing(rhsReg, ast.arg());
if (!cfgCg.check.isNotNull(ast.arg())) {
int padding = cgRef.emitCallPrefix(null, 1);
cgRef.push(regs.b.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_NULL);
cgRef.emitCallSuffix(null, 1, padding);
}
cgRef.emit.emitStore(regs.a, ast.sym.offset, regs.b);
cgRef.rm.releaseRegister(regs.b);
cgRef.rm.releaseRegister(regs.a);
return null;
}
// 1. Save and update the base register, reserve space for local variables
cg.emit.emit("enter", ast.sym.locals.size() * VAR_SIZE, 0);
for (int i = 0; i < ast.sym.locals.size(); i++)
cg.emit.emitStore(0, -(i + 1) * VAR_SIZE, BASE_REG);
@Override
public Void index(Index ast, Expr right) {
boolean isNotNull = cfgCg.check.isNotNull(ast.left());
boolean emitBoundCheck = cfgCg.check.checkArrayBound(ast);
Register rhsReg = cgRef.egRef.gen(right);
// 2. Save CPU registers
Register[] regs = RegisterManager.CALLEE_SAVE;
for (int i = 0; i < regs.length; i++)
cg.emit.emit("push", regs[i]);
Pair<Register> regs = cgRef.egRef.genPushing(rhsReg, ast.left());
rhsReg = regs.a;
Register arrReg = regs.b;
if (!isNotNull) {
int padding = cgRef.emitCallPrefix(null, 1);
cgRef.push(arrReg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_NULL);
cgRef.emitCallSuffix(null, 1, padding);
}
// 3. Run the code contained in the function
Register returnReg = visit(ast.body(), arg);
cg.emit.emitLabel(Label.returnMethod(arg.classSym(), ast.sym));
regs = cgRef.egRef.genPushing(arrReg, ast.right());
arrReg = regs.a;
Register idxReg = regs.b;
// 4. Restore saved registers (if there is a mismatch, the stack will be corrupted)
for (int i = regs.length - 1; i >= 0; i--)
cg.emit.emit("pop", regs[i]);
// Check array bounds
if (emitBoundCheck) {
int padding = cgRef.emitCallPrefix(null, 2);
cgRef.push(idxReg.repr);
cgRef.push(arrReg.repr);
cgRef.emit.emit("call", AstCodeGeneratorRef.CHECK_ARRAY_BOUNDS);
cgRef.emitCallSuffix(null, 2, padding);
}
// 5 and 6: Restore the old base pointer and return from the function
cg.emitMethodSuffix(returnReg == null);
cgRef.emit.emitMove(rhsReg, arrayAddress(arrReg, idxReg));
cgRef.rm.releaseRegister(arrReg);
cgRef.rm.releaseRegister(idxReg);
cgRef.rm.releaseRegister(rhsReg);
// Framework bookkeeping
arg.leaveMethod();
return null;
}
return null;
}
@Override
public Register ifElse(IfElse ast, Location arg) {
// Emit condition check
Register conditionRegister = cg.eg.visit(ast.condition(), arg);
// If both blocks are empty, no more code need be generated, and the condition can be ignored
if (ast.then().children().isEmpty() && ast.otherwise().children().isEmpty()) {
// Generate the condition and ignore the result
cg.rm.releaseRegister(conditionRegister);
return null;
}
String notIfLabel = cg.emit.uniqueLabel();
String endLabel = cg.emit.uniqueLabel();
@Override
protected Void dfltExpr(Expr ast, Expr arg) {
throw new RuntimeException("Store to unexpected lvalue " + ast);
}
cg.emit.emit("cmp", TRUE, conditionRegister);
cg.rm.releaseRegister(conditionRegister);
if (!ast.then().children().isEmpty()) {
cg.emit.emit("jne", notIfLabel);
visit(ast.then(), arg);
// If there is no otherwise, the jump instruction makes no sense
// as the next code executed will be the next instruction
if (!ast.otherwise().children().isEmpty())
cg.emit.emit("jmp", endLabel);
} else {
// No if, therefore the else follows the condition immediately
cg.emit.emit("je", endLabel);
}
cg.emit.emitLabel(notIfLabel);
// Emit otherwise
visit(ast.otherwise(), arg);
cg.emit.emitLabel(endLabel);
// Check if the ifElse ast node contains a return statement
ReturnCheckerVisitor rc = new ReturnCheckerVisitor();
if (rc.ifElse(ast, null)) {
return Register.EAX;
} else {
return null;
}
}
@Override
public Register whileLoop(WhileLoop ast, Location arg) {
String conditionLabel = cg.emit.uniqueLabel();
cg.emit.emitLabel(conditionLabel);
Register conditionRegister = cg.eg.visit(ast.condition(), arg);
cg.emit.emit("cmp", TRUE, conditionRegister);
cg.rm.releaseRegister(conditionRegister);
if (ast.body().children().isEmpty()) {
// Jump structure can be easier if there is no body
cg.emit.emit("je", conditionLabel);
} else {
String endLabel = cg.emit.uniqueLabel();
// Emit jumps, labels and body
cg.emit.emit("jne", endLabel);
visit(ast.body(), arg);
cg.emit.emit("jmp", conditionLabel);
cg.emit.emitLabel(endLabel);
}
return null;
}
@Override
public Register assign(Assign ast, Location arg) {
Register value = cg.eg.visit(ast.right(), arg);
// If the type is a reference, visiting the lhs will yield its address
// else, the lhs will yield the current value. We need a visitor that
// returns a pointer to the position of the variable/field in memory
// for primitive types.
Register pointer = cg.eg.visit(ast.left(), arg.obtainReference());
if (ast.left().type.isReferenceType()) {
// Check null pointer
String validPointerLabel = cg.emit.uniqueLabel();
cg.emit.emit("cmp", 0, pointer);
cg.emit.emit("jne", validPointerLabel);
Interrupts.exit(cg, ExitCode.NULL_POINTER);
cg.emit.emitLabel(validPointerLabel);
}
cg.emit.emitStore(value, 0, pointer);
cg.rm.releaseRegister(pointer);
cg.rm.releaseRegister(value);
return null;
}
@Override
public Register builtInWrite(BuiltInWrite ast, Location arg) {
Register reg = cg.eg.visit(ast.arg(), arg);
cg.emit.emit("sub", 16, STACK_REG);
cg.emit.emitStore(reg, 4, STACK_REG);
cg.emit.emitStore("$STR_D", 0, STACK_REG);
cg.emit.emit("call", Config.PRINTF);
cg.emit.emit("add", 16, STACK_REG);
cg.rm.releaseRegister(reg);
return null;
}
@Override
public Register builtInWriteln(BuiltInWriteln ast, Location arg) {
cg.emit.emit("sub", 16, STACK_REG);
cg.emit.emitStore("$STR_NL", 0, STACK_REG);
cg.emit.emit("call", Config.PRINTF);
cg.emit.emit("add", 16, STACK_REG);
return null;
}
@Override
public Register returnStmt(ReturnStmt ast, Location arg) {
if (ast.arg() != null) {
Register retReg = cg.eg.visit(ast.arg(), arg);
cg.emit.emitMove(retReg, Register.EAX);
cg.rm.releaseRegister(retReg);
}
cg.emit.emit("jmp", Label.returnMethod(arg.classSym(), arg.methodSym()));
return Register.EAX;
}
@Override
public Register seq(Seq ast, Location arg) {
for (Ast instruction : ast.children()) {
Register res = visit(instruction, arg);
if (res != null)
return res; // don't generate instructions after a return
}
new AssignVisitor().visit(ast.left(), ast.right());
return null;
}
}

40
src/cd/frontend/semantic/FieldQualifier.java Normal file
View file

@ -0,0 +1,40 @@
package cd.frontend.semantic;
import cd.ir.Ast;
import cd.ir.Ast.ClassDecl;
import cd.ir.Ast.Var;
import cd.ir.AstRewriteVisitor;
import cd.ir.Symbol.ClassSymbol;
/**
* Runs after the semantic check and rewrites expressions to be more normalized.
* References to a field {@code foo} are rewritten to always use
* {@link Ast.Field} objects (i.e., {@code this.foo}.
*/
public class FieldQualifier {
public void rewrite(ClassDecl cd) {
AstRewriteVisitor<ClassSymbol> rewriter = new AstRewriteVisitor<ClassSymbol>() {
@Override
public Ast var(Var ast, ClassSymbol cs) {
switch (ast.sym.kind) {
case PARAM:
case LOCAL:
// Leave params or local variables alone
return ast;
case FIELD:
// Convert an implicit field reference to "this.foo"
Ast.Field f = new Ast.Field(new Ast.ThisRef(), ast.name);
f.arg().type = cs;
f.sym = ast.sym;
f.type = ast.type;
return f;
}
throw new RuntimeException("Unknown kind of var");
}
};
cd.accept(rewriter, cd.sym);
}
}

23
src/cd/frontend/semantic/InheritanceChecker.java
View file

@ -13,13 +13,13 @@ import java.util.HashSet;
import java.util.Set;
public class InheritanceChecker extends AstVisitor<Void, Void> {
ClassSymbol classSym;
@Override
public Void classDecl(ClassDecl ast, Void arg) {
classSym = ast.sym;
// check for cycles in the inheritance hierarchy:
Set<ClassSymbol> supers = new HashSet<ClassSymbol>();
ClassSymbol sc = classSym.superClass;
@ -28,30 +28,31 @@ public class InheritanceChecker extends AstVisitor<Void, Void> {
if (supers.contains(sc))
throw new SemanticFailure(
Cause.CIRCULAR_INHERITANCE,
"Class %s has %s as a superclass twice",
"Class %s has %s as a superclass twice",
ast.name, sc.name);
supers.add(sc);
sc = sc.superClass;
}
this.visitChildren(ast, null);
return null;
}
@Override
public Void methodDecl(MethodDecl ast, Void arg) {
// check that methods overridden from a parent class agree
// on number/type of parameters
MethodSymbol sym = ast.sym;
MethodSymbol superSym = classSym.superClass.getMethod(ast.name);
sym.overrides = superSym;
if (superSym != null) {
if (superSym.parameters.size() != sym.parameters.size())
throw new SemanticFailure(
Cause.INVALID_OVERRIDE,
"Overridden method %s has %d parameters, " +
"but original has %d",
"but original has %d",
ast.name, sym.parameters.size(),
superSym.parameters.size());
for (Pair<VariableSymbol> pair : Pair.zip(sym.parameters, superSym.parameters))
@ -59,17 +60,17 @@ public class InheritanceChecker extends AstVisitor<Void, Void> {
throw new SemanticFailure(
Cause.INVALID_OVERRIDE,
"Method parameter %s has type %s, but " +
"corresponding base class parameter %s has type %s",
"corresponding base class parameter %s has type %s",
pair.a.name, pair.a.type, pair.b.name, pair.b.type);
if (superSym.returnType != sym.returnType)
throw new SemanticFailure(
Cause.INVALID_OVERRIDE,
"Overridden method %s has return type %s," +
"but its superclass has %s",
"but its superclass has %s",
ast.name, sym.returnType, superSym.returnType);
}
return null;
}
}
}

21
src/cd/frontend/semantic/ReturnCheckerVisitor.java
View file

@ -5,22 +5,21 @@ import cd.ir.Ast.*;
import cd.ir.AstVisitor;
/**
* Visitor that checks if all paths of a given sequence have a
* return statement.
*
* <p>
* This visitor only needs to be used if are not using the Control Flow Graph.
*
*
* @author Leo Buttiker
*/
public class ReturnCheckerVisitor extends AstVisitor<Boolean, Void> {
public class ReturnCheckerVisitor extends AstVisitor<Boolean, Void> {
@Override
protected Boolean dfltStmt(Stmt ast, Void arg) {
return false;
}
@Override
public Boolean returnStmt(ReturnStmt ast, Void arg) {
return true;
@ -28,7 +27,7 @@ public class ReturnCheckerVisitor extends AstVisitor<Boolean, Void> {
@Override
public Boolean ifElse(IfElse ast, Void arg) {
boolean allPathHaveAReturnStmt = true;
boolean allPathHaveAReturnStmt = true;
allPathHaveAReturnStmt &= visit(ast.then(), null);
allPathHaveAReturnStmt &= visit(ast.otherwise(), null);
return allPathHaveAReturnStmt;
@ -36,17 +35,17 @@ public class ReturnCheckerVisitor extends AstVisitor<Boolean, Void> {
@Override
public Boolean seq(Seq ast, Void arg) {
boolean allPathHaveAReturnStmt = false;
boolean allPathHaveAReturnStmt = false;
for (Ast child : ast.children()) {
allPathHaveAReturnStmt |= this.visit(child, null);
}
return allPathHaveAReturnStmt;
}
@Override
public Boolean whileLoop(WhileLoop ast, Void arg) {
return false;
return false;
}
}

86
src/cd/frontend/semantic/SemanticAnalyzer.java
View file

@ -11,70 +11,76 @@ import java.util.ArrayList;
import java.util.List;
public class SemanticAnalyzer {
public final Main main;
public SemanticAnalyzer(Main main) {
this.main = main;
}
public void check(List<ClassDecl> classDecls)
throws SemanticFailure {
public void check(List<ClassDecl> classDecls)
throws SemanticFailure {
{
SymTable<TypeSymbol> typeSymbols = createSymbols(classDecls);
checkInheritance(classDecls);
checkStartPoint(typeSymbols);
checkMethodBodies(typeSymbols, classDecls);
{
rewriteMethodBodies(classDecls);
main.allTypeSymbols = typeSymbols.allSymbols();
}
}
}
/**
* Creates a symbol table with symbols for all built-in types,
* Creates a symbol table with symbols for all built-in types,
* as well as all classes and their fields and methods. Also
* creates a corresponding array symbol for every type
* creates a corresponding array symbol for every type
* (named {@code type[]}).
*
* @see SymbolCreator
*/
private SymTable<TypeSymbol> createSymbols(List<ClassDecl> classDecls) {
// Start by creating a symbol for all built-in types.
SymTable<TypeSymbol> typeSymbols = new SymTable<TypeSymbol>(null);
typeSymbols.add(PrimitiveTypeSymbol.intType);
typeSymbols.add(PrimitiveTypeSymbol.booleanType);
typeSymbols.add(PrimitiveTypeSymbol.voidType);
typeSymbols.add(ClassSymbol.objectType);
// Add symbols for all declared classes.
for (ClassDecl ast : classDecls) {
// Check for classes named Object
if (ast.name.equals(ClassSymbol.objectType.name))
throw new SemanticFailure(Cause.OBJECT_CLASS_DEFINED);
ast.sym = new ClassSymbol(ast);
typeSymbols.add(ast.sym);
typeSymbols.add(ast.sym);
}
// Create symbols for arrays of each type.
for (Symbol sym : new ArrayList<Symbol>(typeSymbols.localSymbols())) {
Symbol.ArrayTypeSymbol array =
new Symbol.ArrayTypeSymbol((TypeSymbol) sym);
Symbol.ArrayTypeSymbol array =
new Symbol.ArrayTypeSymbol((TypeSymbol) sym);
typeSymbols.add(array);
}
// For each class, create symbols for each method and field
SymbolCreator sc = new SymbolCreator(main, typeSymbols);
for (ClassDecl ast : classDecls)
sc.createSymbols(ast);
return typeSymbols;
}
/**
* Check for errors related to inheritance:
* Check for errors related to inheritance:
* circular inheritance, invalid super
* classes, methods with different types, etc.
* Note that this must be run early because other code assumes
* that the inheritance is correct, for type checking etc.
*
* @see InheritanceChecker
*/
private void checkInheritance(List<ClassDecl> classDecls) {
@ -93,25 +99,26 @@ public class SemanticAnalyzer {
MethodSymbol mainMethod = cs.getMethod("main");
if (mainMethod != null && mainMethod.parameters.size() == 0 &&
mainMethod.returnType == PrimitiveTypeSymbol.voidType) {
main.mainType = cs;
return; // found the main() method!
}
}
throw new SemanticFailure(Cause.INVALID_START_POINT, "No Main class with method 'void main()' found");
}
/**
* Check the bodies of methods for errors, particularly type errors
* but also undefined identifiers and the like.
*
* @see TypeChecker
*/
private void checkMethodBodies(
SymTable<TypeSymbol> typeSymbols,
List<ClassDecl> classDecls)
{
List<ClassDecl> classDecls) {
TypeChecker tc = new TypeChecker(typeSymbols);
for (ClassDecl classd : classDecls) {
SymTable<VariableSymbol> fldTable = new SymTable<VariableSymbol>(null);
// add all fields of this class, or any of its super classes
@ -119,37 +126,42 @@ public class SemanticAnalyzer {
for (VariableSymbol s : p.fields.values())
if (!fldTable.contains(s.name))
fldTable.add(s);
// type check any method bodies and final locals
for (MethodDecl md : classd.methods()) {
boolean hasReturn = new ReturnCheckerVisitor().visit(md.body(), null);
if (!md.returnType.equals("void") && !hasReturn) {
throw new SemanticFailure(Cause.MISSING_RETURN,
"Method %s.%s is missing a return statement",
classd.name,
throw new SemanticFailure(Cause.MISSING_RETURN,
"Method %s.%s is missing a return statement",
classd.name,
md.name);
}
SymTable<VariableSymbol> mthdTable = new SymTable<VariableSymbol>(fldTable);
mthdTable.add(classd.sym.thisSymbol);
for (VariableSymbol p : md.sym.parameters) {
mthdTable.add(p);
}
for (VariableSymbol l : md.sym.locals.values()) {
mthdTable.add(l);
}
tc.checkMethodDecl(md, mthdTable);
}
}
}
private void rewriteMethodBodies(List<ClassDecl> classDecls) {
for (ClassDecl cd : classDecls)
new FieldQualifier().rewrite(cd);
}
}

78
src/cd/frontend/semantic/SemanticFailure.java
View file

@ -1,40 +1,50 @@
package cd.frontend.semantic;
/**
/**
* Thrown by the semantic checker when a semantic error is detected
* in the user's program. */
* in the user's program.
*/
public class SemanticFailure extends RuntimeException {
private static final long serialVersionUID = 5375946759285719123L;
public enum Cause {
/**
/**
* Caused by an assignment to either a final field, {@code this},
* or some other kind of expression which cannot be assigned to.
* <b>Not</b> used for type errors in assignments, which fall
* under {@link #TYPE_ERROR}. */
* under {@link #TYPE_ERROR}.
*/
NOT_ASSIGNABLE,
/** Two variables, fields, methods, or classes with the same name
* were declared in the same scope */
/**
* Two variables, fields, methods, or classes with the same name
* were declared in the same scope
*/
DOUBLE_DECLARATION,
/** A field was accessed that does not exist */
/**
* A field was accessed that does not exist
*/
NO_SUCH_FIELD,
/** A method was called that does not exist */
/**
* A method was called that does not exist
*/
NO_SUCH_METHOD,
/**
/**
* A variable or other identifier was used in a method
* body which has no corresponding declaration */
* body which has no corresponding declaration
*/
NO_SUCH_VARIABLE,
/**
* A method with a return type is missing a return statement among one of its paths */
/**
* A method with a return type is missing a return statement among one of its paths
*/
MISSING_RETURN,
/**
/**
* Can occur in many contents:
* <ul>
* <li> Assignment to a variable from an expression of wrong type
@ -53,12 +63,12 @@ public class SemanticFailure extends RuntimeException {
* </ul>
*/
TYPE_ERROR,
/**
* A class is its own super class
*/
CIRCULAR_INHERITANCE,
/**
* One of the following:
* <ul>
@ -69,13 +79,13 @@ public class SemanticFailure extends RuntimeException {
* </ul>
*/
INVALID_START_POINT,
/**
* A class {@code Object} was defined. This class is implicitly
* defined and cannot be defined explicitly.
*/
OBJECT_CLASS_DEFINED,
/**
* A type name was found for which no class declaration exists.
* This can occur in many contexts:
@ -86,34 +96,36 @@ public class SemanticFailure extends RuntimeException {
* </ul>
*/
NO_SUCH_TYPE,
/**
* The parameters of an overridden method have different types
* from the base method, there is a different
* from the base method, there is a different
* number of parameters, or the return value is different.
*/
INVALID_OVERRIDE,
/** A method was called with the wrong number of arguments */
/**
* A method was called with the wrong number of arguments
*/
WRONG_NUMBER_OF_ARGUMENTS,
/**
/**
* Indicates the use of a local variable that may not have been
* initialized (ACD only).
*/
POSSIBLY_UNINITIALIZED,
}
public final Cause cause;
public SemanticFailure(Cause cause) {
super(cause.name());
this.cause = cause;
}
public SemanticFailure(Cause cause, String format, Object... args) {
super(String.format(format, args));
this.cause = cause;
}
}

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