Merge branch 'arrays'

Including updated support for ArrayLiterals. User can now write array literals in code. ArrayLiterals are now constructed slightly more efficiently using temps.
Additionally INT_MIN and INT_MAX limitations are now respected by IntLiterals.

Author: crzysdrs

src/Compiler.java

@@ -92,34 +92,27 @@ public static void main(String[] args) {
      */
     static void compile(String inputFile, CommandLine cmd) {
         String [] input_files = {inputFile, "src/Runtime.j"};
-        ArrayList<ClassType> class_list = new ArrayList<ClassType>();
         Source fake = new JavaSource(null, "<MJCInternal>", null);
         Position fake_pos = new SourcePosition(fake, 0, 0);
-        for (Type p : Type.getArrayPrimitives()) {
-            class_list.add(
-                new ArrayType(new Modifiers(fake_pos), new Id(fake_pos, p.toString()), p));
-        }
         Handler handler = new SimpleHandler();
+        Context context = new Context(fake_pos, handler);
+
         for (String i : input_files) {
             try {
                 Reader  reader = new FileReader(i);
                 Source      source  = new JavaSource(handler, i, reader);
                 MjcLexer    lexer   = new MjcLexer(handler, source);
                 syntax.Parser parser  = new syntax.Parser(handler, lexer);
-                if (parser.getClasses() != null) {
-                    class_list.addAll(Arrays.asList(parser.getClasses()));
-                }
+                parser.setContext(context);
+                parser.parseNow();
             } catch (FileNotFoundException e) {
                 handler.report(new Failure("Cannot open input file " +
                                            i));
             }
         }
-
-        ClassType [] classes = class_list.toArray(new ClassType[0]);
         MethEnv main = null;
-        Context context = new Context(fake_pos, handler, classes);
         if ((main = context.check()) != null) {
-            classes = context.getClasses();
+            ClassType [] classes = context.getClasses();
             if (cmd.hasOption("x")) {
                 String assemblyFile = cmd.getOptionValue("x");
                 Assembly assembly = Assembly.assembleToFile(assemblyFile);

src/Runtime.j

@@ -12,10 +12,11 @@ class Exception {
         MJC.die();
     }
     public static void throwLoc(String file, int lineno, String message) {
-        String [] items = new String[3];
-        items[0] = file;
-        items[1] = Integer.toString(lineno);
-        items[2] = message;
+        String [] items = new String[] {
+            file,
+            Integer.toString(lineno),
+            message
+        };
         Exception.throw(String.format("%:% %", items));
     }
 }
@@ -99,9 +100,10 @@ class ClassPool {
         System.out.println(Integer.toString(used));
 
         while (x < used) {
-            String [] items = new String[2];
-            items[0] = pool[x].getName();
-            items[1] = Integer.toString(pool[x].getClassRefId());
+            String [] items = new String[] {
+                pool[x].getName(),
+                Integer.toString(pool[x].getClassRefId())
+            };
             System.out.println(String.format("Name: % Id: %", items));
             x = x + 1;
         }
@@ -137,9 +139,10 @@ class Array {
             return true;
         } else {
             String msg = "";
-            String [] items = new String[2];
-            items[0] = Integer.toString(index);
-            items[1] = Integer.toString(length);
+            String [] items = new String[] {
+                Integer.toString(index),
+                Integer.toString(length)
+            };
             Exception.throwLoc(filename, lineno,
                                String.format("Array access out of bounds (index %, length %).", items));
             return false;
@@ -252,28 +255,11 @@ class Boolean {
 
 class Integer {
     public static char digitToChar(int x) {
-        if (x == 0) {
-            return '0';
-        } else if (x == 1) {
-            return '1';
-        } else if (x == 2) {
-            return '2';
-        } else if (x == 3) {
-            return '3';
-        } else if (x == 4) {
-            return '4';
-        } else if (x == 5) {
-            return '5';
-        } else if (x == 6) {
-            return '6';
-        } else if (x == 7) {
-            return '7';
-        } else if (x == 8) {
-            return '8';
-        } else if (x == 9) {
-            return '9';
+        String digits = "0123456789";
+        if (x < digits.length()) {
+            return digits.charAt(x);
         } else {
-            System.out.println("Digit not between 0-9");
+            Exception.throw("Digit not between 0-9");
         }
         return 'X';
     }

src/checker/Checker.java

@@ -56,12 +56,15 @@ public static void main(String[] args) {
      */
     static void check(Handler handler, Reader reader, String inputFile) {
         Source fake = new JavaSource(null, "<MJCInternal>", null);
+        ClassType [] classes = new ClassType[] {};
         Position fake_pos = new SourcePosition(fake, 0, 0);
+        Context context = new Context(fake_pos, handler);
         Source      source  = new JavaSource(handler, inputFile, reader);
         MjcLexer    lexer   = new MjcLexer(handler, source);
         Parser      parser  = new Parser(handler, lexer);
-        ClassType[] classes = parser.getClasses();
-        if (new Context(fake_pos, handler, classes).check() != null) {
+        parser.setContext(context);
+        parser.parseNow();
+        if (context.check() != null) {
             System.out.println(
                 "No static errors found in \"" + inputFile + "\"");
         }

src/checker/Context.java

@@ -30,7 +30,7 @@
 /** Provides a representation for contexts used during type checking.
  */
 public final class Context extends Phase {
-    private ClassType[] classes;
+    private ArrayList<ClassType> classes;
     private ClassType   currClass;
     private MethEnv     currMethod;
     private int         localBytes;
@@ -40,13 +40,16 @@ public final class Context extends Phase {
     private int staticStringCount;
     private Id static_class_id;
 
-    public Context(Position pos, Handler handler, ClassType[] classes) {
+    public Context(Position pos, Handler handler) {
         super(handler);
-        this.classes = classes;
         this.pos = pos;
         this.uniqueStrings = new Hashtable<String, StringLiteral>();
         this.staticStringCount = 0;
         this.static_class_id = new Id(pos, "MJCStatic");
+        this.classes = new ArrayList<ClassType>();
+    }
+    public void addClass(ClassType cls) {
+        classes.add(cls);
     }
     public StringLiteral [] getUniqueStrings() {
         return uniqueStrings.values().toArray(new StringLiteral[0]);
@@ -62,14 +65,14 @@ public StringLiteral addStringLiteral(StringLiteral s) {
     }
 
     public ClassType [] getClasses() {
-        return classes;
+        return classes.toArray(new ClassType[0]);
     }
     /** Look for the definition of a class by its name.
      */
     public ClassType findClass(String name) {
-        for (int i = 0; i < classes.length; i++) {
-            if (name.equals(classes[i].getId().getName())) {
-                return classes[i];
+        for (ClassType c : classes) {
+            if (name.equals(c.getId().getName())) {
+                return c;
             }
         }
         return null;
@@ -126,18 +129,19 @@ && checkClasses()
      *  in the input program.
      */
     private boolean checkClasses() {
-        ClassType[] classes = this.classes;
-        for (int i = classes.length - 1; i >= 0; i--) {
+        for (int i = classes.size() - 1; i >= 0; i--) {
+            ClassType c_i = classes.get(i);
             for (int j = 0; j < i; j++) {
-                if (classes[i].getId().sameId(classes[j].getId())) {
-                    report(new Failure(classes[i].getPos(),
+                ClassType c_j = classes.get(j);
+                if (c_i.getId().sameId(c_j.getId())) {
+                    report(new Failure(c_i.getPos(),
                                        "Multiple definitions for class " +
-                                       classes[i].getId()));
+                                       c_i.getId()));
                     break;
                 }
             }
             try {
-                classes[i].checkClass(this);
+                c_i.checkClass(this);
             } catch (Diagnostic d) {
                 report(d);
                 return noFailures();
@@ -203,14 +207,7 @@ private boolean checkClasses() {
                                  null, new Block(pos, static_body.toArray(new Statement[0]))).link(decls);
 
             staticClass = new ClassType(m, static_class_id, null, new Type[0], decls);
-            ClassType [] new_classes = new ClassType[classes.length + 1];
-            int x = 0;
-            for (ClassType c : classes) {
-                new_classes[x] = c;
-                x++;
-            }
-            new_classes[classes.length] = staticClass;
-            this.classes = new_classes;
+            classes.add(staticClass);
             try {
                 staticClass.checkClass(this);
             } catch (Diagnostic d) {
@@ -226,10 +223,9 @@ private boolean checkClasses() {
      *  methods) of the classes in this program.
      */
     private boolean checkMembers() {
-        ClassType[] classes = this.classes;
-        for (int i = 0; i < classes.length; i++) {
-            setCurrClass(classes[i]);
-            classes[i].checkMembers(this);
+        for (ClassType c : classes) {
+            setCurrClass(c);
+            c.checkMembers(this);
         }
         setCurrClass(null);
         return noFailures();

src/checker/MethEnv.java

@@ -342,6 +342,7 @@ public void compileInvocation(Assembly a, Args args, int free) {
         if (isStatic()) {
             a.call(methName(a), free, size);
         } else {
+            a.unspill(0);
             a.call(a.aindirect(a.reg(0)), free, size);
         }
     }

src/codegen/Assembly.java

@@ -127,6 +127,18 @@ public void unspill(int free) {
         }
     }
 
+    public int spillTo(int free, String target_reg) {
+        int orig_free = free;
+        while (!target_reg.equals(reg(free))) {
+            spill(++free);
+        }
+        return free;
+    }
+    public void unspillTo(int free, int orig_free) {
+        while (free > orig_free) {
+            unspill(free--);
+        }
+    }
     public void spillAll(int free) {
         int toSpill = Math.min(free, numRegs - 1);
         for (int i = 1; i <= toSpill; i++) {
@@ -176,6 +188,34 @@ public void loadThis(int size, int free) {
         emit("movl", indirect(thisOffset(size), "%ebp"), reg(free));
     }
 
+    private String whereIsTmp(int x86_tmp, int free) {
+        int diff = free - x86_tmp;
+        if (diff < 0) {
+            throw new RuntimeException("Saved Tmp is higher than stack free");
+        } else if (diff < numRegs) {
+            return reg(x86_tmp);
+        } else {
+            return indirect((diff - numRegs) * WORDSIZE, "%esp");
+        }
+    }
+    /*loads the value from tmp into free */
+    public void loadTmp(int x86_tmp, int free) {
+        String where = whereIsTmp(x86_tmp, free);
+        if (!where.equals(reg(free))) {
+            emit("movl", where, reg(free));
+        } else {
+            /* oddly, it's already in the correct reg */
+        }
+    }
+
+    public void setTmp(int x86_tmp, int free) {
+        String where = whereIsTmp(x86_tmp, free);
+        if (!where.equals(reg(free))) {
+            emit("movl", reg(free), where);
+        } else {
+            /* oddly, it's already in the correct reg */
+        }
+    }
     //- emit individual instructions, with varying numbers of arguments ------
 
     public void emit(String op) {

src/interp/Interp.java

@@ -60,8 +60,9 @@ public static void interp(Reader reader, String description,
         Source fake = new JavaSource(null, "<MJCInternal>", null);
         Position fake_pos = new SourcePosition(fake, 0, 0);
         Parser      parser  = new Parser(handler, lexer);
-        ClassType[] classes = parser.getClasses();
-        Context     context = new Context(fake_pos, handler, classes);
+        Context     context = new Context(fake_pos, handler);
+        parser.setContext(context);
+        parser.parseNow();
         MethEnv     main    = context.check();
         MethEnv init = context.findClass("MJCStatic").findMethod("init");
         if (main != null) {

src/lexer/MjcLexer.java

@@ -333,15 +333,15 @@ private int identifier() {          // Assumes isJavaIdentifierStart(c)
 
     //- Numeric integer literals ----------------------------------------------
 
-    private int number() {              // Assumes c is a digit
-        int n = 0;
-        int d = Character.digit((char)c, 10);
+    private int number() {
+        // We defer computing the value of the intliteral until later
+        // to allow min and max int values (minus sign may be added later).
+        StringBuilder b = new StringBuilder();
         do {
-            n = 10 * n + d;
+            b.append((char)c);
             nextChar();
-            d = Character.digit((char)c, 10);
-        } while (d >= 0);
-        semantic = new IntLiteral(getPos(), n);
+        } while ((char)c >= '0' && (char)c <= '9');
+        semantic = new IntLiteral(getPos(), b.toString());
         return token = INTLIT;
     }
 

src/syntax/ArrayAccess.java

@@ -71,10 +71,10 @@ public Type typeOf(Context ctxt, VarEnv env) throws Diagnostic {
      *  leave the result in the specified free variable.
      */
     public void compileExpr(Assembly a, int free) {
+        a.spill(free + 1);
         array_check.compileExpr(a, free + 1);
         index.compileExpr(a, free);
         a.emit("imull",  a.immed(array_class.getElementType().getWidth()), a.reg(free));
-        a.spill(free + 1);
         object.compileExpr(a, free + 1);
         FieldEnv f = array_class.findField("array");
         a.emit("movl", a.indirect(f.getOffset(), a.reg(free + 1)), a.reg(free + 1));
@@ -87,8 +87,8 @@ public void compileExpr(Assembly a, int free) {
      *  this expression.
      */
     void saveVar(Assembly a, int free) {
-        array_check.compileExpr(a, free + 1);
         a.spill(free + 1);
+        array_check.compileExpr(a, free + 1);
         index.compileExpr(a, free + 1);
         a.emit("imull", a.immed(array_class.getElementType().getWidth()),
                a.reg(free + 1));
@@ -98,6 +98,7 @@ void saveVar(Assembly a, int free) {
         a.emit("movl", a.indirect(f.getOffset(), a.reg(free + 2)), a.reg(free + 2));
         a.emit("addl", a.reg(free + 1), a.reg(free + 2));
         a.emit("movl", a.reg(free), a.indirect(0, a.reg(free + 2)));
+        a.unspill(free + 2);
         a.unspill(free + 1);
     }