lex: add filename to error

Brings lexing error message format more into line with parser

1 files changed, 4 insertions, 2 deletions

diff --git a/lex.c b/lex.c
index 6dc38d2..6777e42 100644
--- a/lex.c
+++ b/lex.c
@@ -6,7 +6,7 @@
 #include "common.h"
 #include "token.h"
 
-#define emit_error(...) fprintf(stderr, "Error (%zd,%zd): ", line_number, 1 + column_number);\
+#define emit_error(...) fprintf(stderr, "%s at (%zd,%zd): ", filename, line_number, 1 + column_number);\
                         fprintf(stderr, __VA_ARGS__)
 
 #define BUFFER_SIZE 1024
@@ -50,6 +50,7 @@ static struct keyword token_descriptors[] = {
 
 static char buf[BUFFER_SIZE];
 static FILE* fd;
+static const char *filename = NULL;
 static size_t line_number = 0;
 static size_t column_number = 0;
 static ssize_t leading_whitespace_len = 0;
@@ -230,7 +231,8 @@ lex_line(void) {
 }
 
 struct token *
-lex_file(FILE *fd_local) {
+lex_file(const char *filename_local, FILE *fd_local) {
+	filename = filename_local;
 	fd = fd_local;
 
 	line_number = 1;