Implement semantics analyzer

6 files changed, 126 insertions, 6 deletions

diff --git a/src/main/java/no/eliashaugsbakk/kompilator/Main.java b/src/main/java/no/eliashaugsbakk/kompilator/Main.java
index fa7f79c..b1ad70a 100644
--- a/src/main/java/no/eliashaugsbakk/kompilator/Main.java
+++ b/src/main/java/no/eliashaugsbakk/kompilator/Main.java
@@ -9,6 +9,8 @@ import no.eliashaugsbakk.kompilator.assembleAndLink.AssemblerAndLinker;
 import no.eliashaugsbakk.kompilator.parsing.AST;
 import no.eliashaugsbakk.kompilator.parsing.Parser;
 import no.eliashaugsbakk.kompilator.parsing.ParserException;
+import no.eliashaugsbakk.kompilator.semanticAnalysis.Analyzer;
+import no.eliashaugsbakk.kompilator.semanticAnalysis.SemanticException;
 import no.eliashaugsbakk.kompilator.tokenization.Lexer;
 import no.eliashaugsbakk.kompilator.tokenization.Token;
 
@@ -44,10 +46,17 @@ public class Main {
       ast = new Parser(tokens).parse();
     } catch (ParserException e) {
       IO.println("Error while parsing: " + e.getMessage());
+      System.exit(1);
+    }
+
+    try {
+      new Analyzer(ast).analyze();
+    } catch (SemanticException e) {
+      IO.println("Semantic error: " + e.getMessage());
+      System.exit(1);
     }
 
     // TODO:
-    // new Analyzer(ast).analyze();
     // List<String> IR = new IRGenerator(ast).generate();
 
     List<String> IR = List.of();
diff --git a/src/main/java/no/eliashaugsbakk/kompilator/parsing/AST.java b/src/main/java/no/eliashaugsbakk/kompilator/parsing/AST.java
index 95ec77c..ad8a3a2 100644
--- a/src/main/java/no/eliashaugsbakk/kompilator/parsing/AST.java
+++ b/src/main/java/no/eliashaugsbakk/kompilator/parsing/AST.java
@@ -3,9 +3,13 @@ package no.eliashaugsbakk.kompilator.parsing;
 import no.eliashaugsbakk.kompilator.parsing.node.ASTNode;
 
 public class AST {
-  ASTNode root;
+  private final ASTNode root;
 
-  AST(ASTNode root) {
+  public AST(ASTNode root) {
     this.root = root;
   }
+
+  public ASTNode getRoot() {
+    return root;
+  }
 }
diff --git a/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/Analyzer.java b/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/Analyzer.java
index 891018c..0b01b14 100644
--- a/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/Analyzer.java
+++ b/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/Analyzer.java
@@ -1,4 +1,56 @@
 package no.eliashaugsbakk.kompilator.semanticAnalysis;
 
+import no.eliashaugsbakk.kompilator.parsing.AST;
+import no.eliashaugsbakk.kompilator.parsing.node.Program;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.Expression;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.FunctionCall;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.StringLiteral;
+import no.eliashaugsbakk.kompilator.parsing.node.statement.ExpressionStatement;
+import no.eliashaugsbakk.kompilator.parsing.node.statement.Statement;
+
 public class Analyzer {
+  private final AST ast;
+
+  public Analyzer(AST ast) {
+    this.ast = ast;
+  }
+
+  public void analyze() throws SemanticException {
+    Program program = (Program) ast.getRoot();
+
+    for (Statement stmt : program.statements) {
+      analyzeStatement(stmt);
+    }
+  }
+
+  private void analyzeStatement(Statement stmt) throws SemanticException {
+    if (stmt instanceof ExpressionStatement exprStmt) {
+      analyzeExpression(exprStmt.expression);
+    } else {
+      // Analyze the statement
+      // NO other statements implemented
+    }
+  }
+
+  private void analyzeExpression(Expression expr) throws SemanticException {
+    if (expr instanceof FunctionCall call) {
+      checkFunctionCall(call);
+    } else {
+      // analyze the expression
+    }
+  }
+
+  private void checkFunctionCall(FunctionCall call) throws SemanticException {
+    if (!call.functionName.equals("print")) {
+      throw new SemanticException("unknown function: " + call.functionName);
+    }
+
+    if (call.arguments.size() != 1) {
+      throw new SemanticException("print expects 1 argument, got " + call.arguments.size());
+    }
+
+    if (!(call.arguments.getFirst() instanceof StringLiteral)) {
+      throw new SemanticException("print expects String argument only");
+    }
+  }
 }
diff --git a/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/SemanticException.java b/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/SemanticException.java
new file mode 100644
index 0000000..402cfe7
--- /dev/null
+++ b/src/main/java/no/eliashaugsbakk/kompilator/semanticAnalysis/SemanticException.java
@@ -0,0 +1,7 @@
+package no.eliashaugsbakk.kompilator.semanticAnalysis;
+
+public class SemanticException extends Exception {
+  public SemanticException(String message) {
+    super(message);
+  }
+}
diff --git a/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java b/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java
index 133e9a6..ac31dfc 100644
--- a/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java
+++ b/src/test/java/no/eliashaugsbakk/kompilator/parsing/ParserTest.java
@@ -30,9 +30,9 @@ class ParserTest {
     AST ast = new Parser(tokens).parse();
 
     // Verify tree structure
-    assertNotNull(ast.root);
-    assertInstanceOf(Program.class, ast.root);
-    Program program = (Program) ast.root;
+    assertNotNull(ast.getRoot());
+    assertInstanceOf(Program.class, ast.getRoot());
+    Program program = (Program) ast.getRoot();
     assertEquals(1, program.statements.size());
 
     ExpressionStatement stmt = (ExpressionStatement) program.statements.getFirst();
diff --git a/src/test/java/no/eliashaugsbakk/kompilator/semanticAnalysis/AnalyzerTest.java b/src/test/java/no/eliashaugsbakk/kompilator/semanticAnalysis/AnalyzerTest.java
new file mode 100644
index 0000000..531673d
--- /dev/null
+++ b/src/test/java/no/eliashaugsbakk/kompilator/semanticAnalysis/AnalyzerTest.java
@@ -0,0 +1,48 @@
+package no.eliashaugsbakk.kompilator.semanticAnalysis;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.List;
+import no.eliashaugsbakk.kompilator.parsing.AST;
+import no.eliashaugsbakk.kompilator.parsing.node.Program;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.FunctionCall;
+import no.eliashaugsbakk.kompilator.parsing.node.expression.StringLiteral;
+import no.eliashaugsbakk.kompilator.parsing.node.statement.ExpressionStatement;
+import org.junit.jupiter.api.Test;
+
+class AnalyzerTest {
+
+  @Test
+  void validPrintStatementDoesNotThrow() {
+    AST ast = buildAST("print", "hello");
+    assertDoesNotThrow(() -> new Analyzer(ast).analyze());
+  }
+
+  @Test
+  void unknownFunctionThrows() {
+    AST ast = buildAST("unknown", "hello");
+    assertThrows(SemanticException.class, () -> new Analyzer(ast).analyze());
+  }
+
+  @Test
+  void missingArgumentThrows() {
+    AST ast = buildASTNoArgs("print");
+    assertThrows(SemanticException.class, () -> new Analyzer(ast).analyze());
+  }
+
+  private AST buildAST(String functionName, String argument) {
+    FunctionCall call = new FunctionCall(functionName, List.of(new StringLiteral(argument)));
+    ExpressionStatement stmt = new ExpressionStatement(call);
+    Program program = new Program();
+    program.addStatement(stmt);
+    return new AST(program);
+  }
+
+  private AST buildASTNoArgs(String functionName) {
+    FunctionCall call = new FunctionCall(functionName, List.of());
+    ExpressionStatement stmt = new ExpressionStatement(call);
+    Program program = new Program();
+    program.addStatement(stmt);
+    return new AST(program);
+  }
+}