From 8e3a8018f52834414cbd1184664554e4ddad04cb Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Sun, 31 May 2020 21:01:00 +0200
Subject: some work on type compatibility for strings

---
 ecomp-c/ec.c    | 34 +++++++++++++++++++++++++++++-----
 ecomp-c/test1.e |  3 ++-
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/ecomp-c/ec.c b/ecomp-c/ec.c
index 275cec9..4da751d 100644
--- a/ecomp-c/ec.c
+++ b/ecomp-c/ec.c
@@ -742,6 +742,7 @@ static Symbol *insert_symbol( Scope *scope, char *name, SymbolClass class )
 	strlcpy( sym->name, name, strlen( name ) + 1 );	
 	sym->initialized = 0;
 	sym->size = 0;
+	sym->dim = 0;
 	sym->next = scope->symbol;
 	sym->string_value = NULL;
 	scope->symbol = sym;
@@ -878,6 +879,25 @@ static void EmitConditionTest( Scope *scope, S_Symbol relation )
 	free( jump_label1 );
 }
 
+static int is_compatible_type( Symbol *to, Symbol *from )
+{
+	if( to == from ) {
+		return 1;
+	}
+	
+	if( to->class == SYMBOL_CLASS_ARRAY_TYPE &&
+		from->class == SYMBOL_CLASS_ARRAY_TYPE ) {
+		if( to->type == character_type && 
+			from->type == character_type ) {
+			if( to->dim >= from->dim ) {
+				return 1;
+			}
+		}
+	}
+	
+	return 0;
+}
+
 static int get_size( Symbol *symbol )
 {
 	switch( symbol->class ) {
@@ -1213,7 +1233,7 @@ static void parseAssignment( Scope *scope )
 	
 	node = parseExpression( );
 	
-	if( symbol->type != node->actual_type ) {
+	if( !is_compatible_type( 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 );
 	}
@@ -1424,8 +1444,7 @@ static void generate_variable_comment( Symbol *variable )
 
 static void symbol_copy_value( Symbol *from, Symbol *to )
 {
-
-	if( from->type != to->type ) {
+	if( !is_compatible_type( from->type, to->type ) ) {
 		Abort( "type mismatch when copying symbol value (from: '%s', to: '%s')",
 			from->type->name, to->type->name );
 	}
@@ -1558,18 +1577,20 @@ static void parseConstDeclaration( Scope *current_scope )
 	Expect( S_equals );
 	
 	node = parseConstExpression( );
-	if( type != node->actual_type ) {
+	if( !is_compatible_type( type, node->actual_type ) ) {
 		Abort( "Assigning a constant of type '%s' from an expression of type '%s'",
 			type->name, node->actual_type->name );
 	}
 	
 	if( node->type == EXPRESSION_NODE_TYPE_CONST ) {
 		for( i = 0; i < nof_constants; i++ ) {
+			/* TODO: type copying and type conversion */
 			constant[i]->type = node->actual_type;
 			symbol_copy_node_value( node, constant[i] );
 		}
 	} else if( node->type == EXPRESSION_NODE_TYPE_VAR ) {	
 		for( i = 0; i < nof_constants; i++ ) {
+			/* TODO: type copying and type conversion */
 			constant[i]->type = node->symbol->type;
 			symbol_copy_value( node->symbol, constant[i] );
 		}
@@ -1626,18 +1647,20 @@ static void parseVariableDeclaration( Scope *current_scope )
 	if( sym == S_assign ) {
 		sym = getSym( );
 		node = parseConstExpression( );
-		if( type != node->actual_type ) {
+		if( !is_compatible_type( type, node->actual_type ) ) {
 			Abort( "Assigning a variable of type '%s' from an expression of type '%s'",
 				type->name, node->actual_type->name );
 		}
 
 		if( node->type == EXPRESSION_NODE_TYPE_CONST ) {
 			for( i = 0; i < nof_variables; i++ ) {
+				/* TODO: type copying and type conversion */
 				variable[i]->type = node->actual_type;
 				symbol_copy_node_value( node, variable[i] );
 			}
 		} else if( node->type == EXPRESSION_NODE_TYPE_VAR ) {	
 			for( i = 0; i < nof_variables; i++ ) {
+				/* TODO: type copying and type conversion */
 				variable[i]->type = node->symbol->type;
 				symbol_copy_value( node->symbol, variable[i] );
 			}
@@ -1648,6 +1671,7 @@ static void parseVariableDeclaration( Scope *current_scope )
 			variable[i]->integer_value = 0;
 			variable[i]->boolean_value = 0; /* false */
 			variable[i]->character_value = 0; /* NUL */
+			/* TODO: type copying and type conversion */
 			variable[i]->type = type;
 		}
 	}
diff --git a/ecomp-c/test1.e b/ecomp-c/test1.e
index 40e32ce..fa66f92 100644
--- a/ecomp-c/test1.e
+++ b/ecomp-c/test1.e
@@ -14,7 +14,7 @@ const
 	INIT_STATE : boolean = true;
 	
 	// string constant
-	S : array 6 of character = "hello";
+	S : array 10 of character = "hello";
 
 var
 	// this is an integer
@@ -28,6 +28,7 @@ var
 	i : integer;
 	j : character := C;
 	s : array 6 of character := S;
+	s2 : array 10 of character := "hello";
 
 begin
 	a := 1;
-- 
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