check for undefined labels

1 files changed, 16 insertions, 3 deletions

diff --git a/ecomp-c/asm-i386.c b/ecomp-c/asm-i386.c
index 268ca2b..4bc13ea 100644
--- a/ecomp-c/asm-i386.c
+++ b/ecomp-c/asm-i386.c
@@ -480,12 +480,17 @@ static int LC = 0;
 
 typedef struct Symbol {
 	char *name;
+	int defined;
 	int addr;
 	struct Symbol *next;
 } Symbol;
 
 struct Symbol *symbol = NULL;
 
+enum {
+	ADDRESS_UNDEFINED = 0x7FFFFFFF
+};
+
 static Symbol *get_symbol( char *name )
 {
 	Symbol *sym = symbol;
@@ -512,7 +517,7 @@ static Symbol *insert_symbol( char *name )
 	sym = Allocate( sizeof( Symbol ) );
 	sym->name = Allocate( strlen( name ) + 1 );
 	strlcpy( sym->name, name, strlen( name ) + 1 );	
-	sym->addr = 0;
+	sym->addr = ADDRESS_UNDEFINED;
 	sym->next = symbol;
 	symbol = sym;
 	
@@ -559,7 +564,7 @@ static void parseLabel( void )
 	
 	symbol = get_symbol( ident );
 	if( symbol != NULL ) {
-		if( symbol->addr == 0 ) {
+		if( symbol->addr == ADDRESS_UNDEFINED ) {
 			symbol->addr = LC;
 		} else {
 			Abort( "label '%s' has already been defined", ident );
@@ -736,7 +741,7 @@ static OperandInfo *parseOperand( void )
 	
 	operand_info = Allocate( sizeof( OperandInfo ) );
 	operand_info->next = NULL;
-	operand_info->addr = 0;
+	operand_info->addr = ADDRESS_UNDEFINED;
 
 	if( sym == S_ident ) {
 		/* op like eax or an address jmp x */
@@ -877,6 +882,14 @@ static void epilogue( void )
 	
 	sym = symbol;
 	while( sym != NULL ) {
+		if( sym->addr == ADDRESS_UNDEFINED ) {
+			Abort( "Undefined address for label '%s'", sym->name );
+		}
+		sym = sym->next;
+	}
+	
+	sym = symbol;
+	while( sym != NULL ) {
 		ptr = sym->next;
 		free_symbol( sym );
 		sym = ptr;