implemented some type checks in assignments and expressions

10 files changed, 97 insertions, 4 deletions

diff --git a/ecomp-c/README b/ecomp-c/README
index e13b90e..58bf2db 100644
--- a/ecomp-c/README
+++ b/ecomp-c/README
@@ -79,7 +79,7 @@ inner-nested functions/procedures
 don't do automatic type promotion, maybe something like uint8, int8, etc.
 no recursion, well, we might need that
 
-3:21:00 video Hjalfi writes an assembler
+4:09:00 video Hjalfi writes an assembler
 
 no frees as things are freed in the end, well, we don't obey that rule,
 compiler/assember should be embedable and they have local scopes which
diff --git a/ecomp-c/ec.c b/ecomp-c/ec.c
index e095dc0..f560d6b 100644
--- a/ecomp-c/ec.c
+++ b/ecomp-c/ec.c
@@ -658,6 +658,7 @@ typedef struct ExpressionNode {
 	struct ExpressionNode *left, *right;
 	int number;
 	Symbol *symbol;
+	Symbol *actual_type;
 } ExpressionNode;
 
 static ExpressionNode *create_expression_node( void )
@@ -878,6 +879,7 @@ static ExpressionNode *parseFactor( void )
 		node = create_expression_node( );
 		node->type = EXPRESSION_NODE_TYPE_CONST;
 		node->number = num;
+		node->actual_type = get_symbol( current_scope, "integer" );
 		sym = getSym( );
 	} else if( sym == S_ident ) {
 		symbol = get_symbol( current_scope, ident );
@@ -891,6 +893,7 @@ static ExpressionNode *parseFactor( void )
 			node = create_expression_node( );
 			node->type = EXPRESSION_NODE_TYPE_CONST;
 			node->number = symbol->value;
+			node->actual_type = symbol->type;
 		}
 		if( symbol->class == SYMBOL_CLASS_VARIABLE ) {
 			if( !symbol->initialized ) {
@@ -899,6 +902,7 @@ static ExpressionNode *parseFactor( void )
 			node = create_expression_node( );
 			node->type = EXPRESSION_NODE_TYPE_VAR;
 			node->symbol = symbol;
+			node->actual_type = symbol->type;
 		}
 		sym = getSym( );
 	} else if( sym == S_lparen ) {
@@ -911,6 +915,7 @@ static ExpressionNode *parseFactor( void )
 		node->op = sym;
 		sym = getSym( );
 		node->left = parseFactor( );
+		node->actual_type = node->left->actual_type;
 	} else {
 		Abort( "Expected a literal, a variable or a constant." );
 	}
@@ -931,6 +936,13 @@ static ExpressionNode *parseTerm( void )
 		sym = getSym( );
 		node->left = tmp;
 		node->right = parseFactor( );
+		
+		if( node->left->actual_type == node->right->actual_type ) {
+			node->actual_type = node->left->actual_type;
+		} else {
+			Abort( "Incompatible types in expression: '%s' on the left, '%s' on the right",
+				node->left->actual_type->name, node->right->actual_type->name );
+		}
 	}
 	
 	return node;
@@ -949,6 +961,13 @@ static ExpressionNode *parseSimpleExpression( void )
 		sym = getSym( );
 		node->left = tmp;
 		node->right = parseTerm( );
+
+		if( node->left->actual_type == node->right->actual_type ) {
+			node->actual_type = node->left->actual_type;
+		} else {
+			Abort( "Incompatible types in expression: '%s' on the left, '%s' on the right",
+				node->left->actual_type->name, node->right->actual_type->name );
+		}
 	}
 	
 	return node;
@@ -981,6 +1000,13 @@ static ExpressionNode *parseExpression( void )
 		sym = getSym( );
 		node->left = tmp;
 		node->right = parseSimpleExpression( );
+		
+		if( node->left->actual_type == node->right->actual_type ) {
+			node->actual_type = get_symbol( current_scope, "boolean" );
+		} else {
+			Abort( "Incompatible types in expression: '%s' on the left, '%s' on the right",
+				node->left->actual_type->name, node->right->actual_type->name );
+		}
 	}
 	
 	return node;
@@ -1005,9 +1031,13 @@ static void parseAssignment( Scope *scope )
 
 	Expect( S_assign );
 	
-	/* TODO: RHS is an expression tree, must be a) interpreted,
-	 * b) simplified c) generate code */
 	node = parseExpression( );
+	
+	if( symbol->type != node->actual_type ) {
+		Abort( "Incompatible assignment of expression of type '%s' to variable '%s' of type '%s'",
+			node->actual_type->name, symbol->name, symbol->type->name );
+	}
+	
 	Emit( "; LET %s <- ", symbol->name );
 	generate_expression_comment( node );
 	Emit( "\n" );
diff --git a/ecomp-c/test1.e b/ecomp-c/test1.e
index 88a6d26..2836091 100644
--- a/ecomp-c/test1.e
+++ b/ecomp-c/test1.e
@@ -47,7 +47,7 @@ begin
 	end;
 
 	i := 0;
-	while ( i < 10 ) and not flag do
+	while ( i < 10 ) and ( not flag ) do
 		i := i + 1;
 	end;
 end
diff --git a/ecomp-c/tests/run_tests.sh b/ecomp-c/tests/run_tests.sh
index 884821c..e40b4d9 100755
--- a/ecomp-c/tests/run_tests.sh
+++ b/ecomp-c/tests/run_tests.sh
@@ -17,6 +17,8 @@ variable_assign_from_expression
 boolean_variable
 if_statement
 bool_conditions
+type_check_assignment
+type_check_comparision
 while_statement
 example_divisors
 "
@@ -25,6 +27,10 @@ run_test( )
 {
 	TEST=$1
 	echo -n "$TEST"
+	if test ! -f "$TEST.e"; then
+		echo " SKIP (not found)"
+		return
+	fi
 	../ec < $TEST.e > $TEST.asm 2> _tmp
 	COMPILATION_RES=$?
 	grep -v '^Total ' _tmp | grep -v '^Arena' | grep -v 'bytes.*=' | grep -v 'max mmap' > $TEST.comp_err
diff --git a/ecomp-c/tests/type_check_assignment.e b/ecomp-c/tests/type_check_assignment.e
new file mode 100644
index 0000000..d030525
--- /dev/null
+++ b/ecomp-c/tests/type_check_assignment.e
@@ -0,0 +1,14 @@
+/*
+ * make sure assignment from illegal types throws an error
+ */
+
+module bool_conditions;
+
+var
+	i : integer;
+	b : boolean;
+
+begin
+	i := 1;
+	b := i;
+end
diff --git a/ecomp-c/tests/type_check_assignment.easm b/ecomp-c/tests/type_check_assignment.easm
new file mode 100644
index 0000000..5c13f33
--- /dev/null
+++ b/ecomp-c/tests/type_check_assignment.easm
@@ -0,0 +1,10 @@
+format binary
+use32
+org $1000000
+; DECL i -> integer
+; DECL b -> boolean
+; LET i <- 1 
+mov eax, 1
+push eax
+pop eax
+mov [i], eax
diff --git a/ecomp-c/tests/type_check_assignment.ecomp_err b/ecomp-c/tests/type_check_assignment.ecomp_err
new file mode 100644
index 0000000..9daaf6d
--- /dev/null
+++ b/ecomp-c/tests/type_check_assignment.ecomp_err
@@ -0,0 +1 @@
+Error line 14, pos 1: Incompatible assignment of expression of type 'integer' to variable 'b' of type 'boolean'
diff --git a/ecomp-c/tests/type_check_comparision.e b/ecomp-c/tests/type_check_comparision.e
new file mode 100644
index 0000000..ceaa9ef
--- /dev/null
+++ b/ecomp-c/tests/type_check_comparision.e
@@ -0,0 +1,16 @@
+/*
+ * make sure assignment from illegal types throws an error
+ */
+
+module bool_conditions;
+
+var
+	i : integer;
+	b : boolean;
+
+begin
+	i := 1;
+	b := false;
+	if i = 2 and false do
+	end;
+end
diff --git a/ecomp-c/tests/type_check_comparision.easm b/ecomp-c/tests/type_check_comparision.easm
new file mode 100644
index 0000000..2441f17
--- /dev/null
+++ b/ecomp-c/tests/type_check_comparision.easm
@@ -0,0 +1,15 @@
+format binary
+use32
+org $1000000
+; DECL i -> integer
+; DECL b -> boolean
+; LET i <- 1 
+mov eax, 1
+push eax
+pop eax
+mov [i], eax
+; LET b <- 0 
+mov eax, 0
+push eax
+pop eax
+mov [b], eax
diff --git a/ecomp-c/tests/type_check_comparision.ecomp_err b/ecomp-c/tests/type_check_comparision.ecomp_err
new file mode 100644
index 0000000..a772c01
--- /dev/null
+++ b/ecomp-c/tests/type_check_comparision.ecomp_err
@@ -0,0 +1 @@
+Error line 15, pos 1: Incompatible types in expression: 'integer' on the left, 'boolean' on the right