llvmir some opt

frontend/ast/exp/LVal.java

@@ -0,0 +1,59 @@
+package frontend.ast.exp;
+
+import frontend.ast.Node;
+import frontend.ast.SyntaxType;
+import frontend.ast.token.TokenNode;
+import frontend.lexer.TokenStream;
+import frontend.lexer.TokenType;
+import midend.symbol.SymbolManager;
+import midend.symbol.Symbol;
+import midend.symbol.ArraySymbol;
+import error.Errors;
+import error.Error;
+import error.ErrorType;
+
+public class LVal extends Node {
+    public LVal(TokenStream ts) {
+        super(SyntaxType.LVAL_EXP, ts);
+    }
+
+    public void parse(Errors errors) {
+        addChild(new TokenNode(this.ts)); // idenfr
+        if (getCurrToken().getType() == TokenType.LBRACK) {
+            addChild(new TokenNode(this.ts)); // lbrack
+            Exp exp = new Exp(this.ts);
+            exp.parse(errors);
+            addChild(exp);
+            if (getCurrToken().getType() == TokenType.RBRACK) {
+                addChild(new TokenNode(this.ts)); // rbrack
+            } else {
+                errors.addError(new Error(this.ts.peek(-1).getLine(), ErrorType.k));
+            }
+        }
+    }
+
+    public int getType() {
+        if (getChildren().size() == 1) {
+            TokenNode idenfr = (TokenNode) getChild(0);
+            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
+            if (symbol instanceof ArraySymbol) {
+                return 1;
+            }
+            return 0;
+        } else {
+            return 0;
+        }
+    }
+
+    public int getValue() {
+        TokenNode idenfr = (TokenNode) getChild(0); //idenfr一定是个常量，可在符号表找到且有值
+        if (getChildren().size() == 1) {
+            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
+            return symbol.getValue(0);
+        } else {
+            int index = ((Exp) getChild(2)).getValue();
+            Symbol symbol = SymbolManager.getSymbol(idenfr.getName());
+            return symbol.getValue(index);
+        }
+    }
+}