diff --git a/asm/main.c b/asm/main.c
index 3413d44..72d6597 100644
--- a/asm/main.c
+++ b/asm/main.c
@@ -30,6 +30,43 @@ typedef struct {
     int col;
 } Loc;
 
+#define REPORTF_INNER(FMT, ...)                                                \
+    (fprintf(stderr, "error: " FMT "\n", __VA_ARGS__))
+#define REPORTF(...) REPORTF_INNER(__VA_ARGS__)
+
+static inline void report_with_loc(const char* filename,
+    const char* text,
+    size_t text_len,
+    const char* msg,
+    Loc loc)
+{
+    size_t line_start = loc.idx;
+    while (line_start > 0 && text[line_start] != '\n') {
+        line_start -= 1;
+    }
+    if (text[line_start] == '\n') {
+        line_start += 1;
+    }
+    size_t line_end = loc.idx + 1;
+    while (line_end < text_len && text[line_end] != '\n') {
+        line_end += 1;
+    }
+    const char* line = &text[line_start];
+    int line_len = (int)line_end - (int)line_start;
+
+    REPORTF("%s", msg);
+    fprintf(stderr,
+        "    --> %s:%d:%d\n     |\n%5d|%.*s\n     |%*c^\n",
+        filename,
+        loc.line,
+        loc.col,
+        loc.line,
+        line_len,
+        line,
+        loc.col - 1,
+        ' ');
+}
+
 typedef enum {
     TT_Err,
     TT_Eof,
@@ -136,32 +173,7 @@ static inline int lexer_skip_literal_char(Lexer* lexer)
 static inline void lexer_report(Lexer* lexer, const char* msg, Loc loc)
 {
     lexer->error_occured = true;
-
-    size_t line_start = loc.idx;
-    while (line_start > 0 && lexer->text[line_start] != '\n') {
-        line_start -= 1;
-    }
-    if (lexer->text[line_start] == '\n') {
-        line_start += 1;
-    }
-    size_t line_end = loc.idx + 1;
-    while (line_end < lexer->text_len && lexer->text[line_end] != '\n') {
-        line_end += 1;
-    }
-    const char* line = &lexer->text[line_start];
-    int line_len = (int)line_end - (int)line_start;
-
-    fprintf(stderr,
-        "error: %s\n    --> %s:%d:%d\n     |\n%5d|%.*s\n     |%*c^\n",
-        msg,
-        lexer->filename,
-        loc.line,
-        loc.col,
-        loc.line,
-        line_len,
-        line,
-        loc.col - 1,
-        ' ');
+    report_with_loc(lexer->filename, lexer->text, lexer->text_len, msg, loc);
 }
 
 Tok lexer_next(Lexer* lexer)
@@ -513,33 +525,11 @@ static inline char* parser_ident_val(const Parser* parser, Tok tok)
 static inline void parser_report(Parser* parser, const char* msg, Loc loc)
 {
     parser->error_occured = true;
-
-    size_t line_start = loc.idx;
-    while (line_start > 0 && parser->lexer.text[line_start] != '\n') {
-        line_start -= 1;
-    }
-    if (parser->lexer.text[line_start] == '\n') {
-        line_start += 1;
-    }
-    size_t line_end = loc.idx + 1;
-    while (line_end < parser->lexer.text_len
-        && parser->lexer.text[line_end] != '\n') {
-        line_end += 1;
-    }
-    const char* line = &parser->lexer.text[line_start];
-    int line_len = (int)line_end - (int)line_start;
-
-    fprintf(stderr,
-        "error: %s\n    --> %s:%d:%d\n     |\n%5d|%.*s\n     |%*c^\n",
+    report_with_loc(parser->lexer.filename,
+        parser->lexer.text,
+        parser->lexer.text_len,
         msg,
-        parser->lexer.filename,
-        loc.line,
-        loc.col,
-        loc.line,
-        line_len,
-        line,
-        loc.col - 1,
-        ' ');
+        loc);
 }
 
 static inline void parser_skip_newlines(Parser* parser)
@@ -857,8 +847,7 @@ int main(int argc, char** argv)
 
     FILE* input_fp = fopen(args.input_file, "r");
     if (!input_fp) {
-        fprintf(stderr,
-            "error: could not open input file '%s': %s\n",
+        REPORTF("could not open input file '%s': %s",
             args.input_file,
             strerror(errno));
         return -1;
@@ -871,8 +860,7 @@ int main(int argc, char** argv)
     size_t bytes_read = fread(input_text, sizeof(char), file_size, input_fp);
     fclose(input_fp);
     if (bytes_read != file_size) {
-        fprintf(stderr,
-            "error: could not read input file '%s': %s\n",
+        REPORTF("could not read input file'%s': %s",
             args.input_file,
             strerror(errno));
         return -1;
@@ -903,20 +891,20 @@ static inline Args parse_args(int argc, char** argv)
         if (strcmp(argv[i], "-o") == 0) {
             i += 1;
             if (i >= argc) {
-                fprintf(stderr, "error: no filename given to -o\n");
+                REPORTF("%s", "no filename given to -o");
                 exit(1);
             }
             output_file = argv[i];
         } else {
             if (input_file != NULL) {
-                fprintf(stderr, "error: multiple input files specified\n");
+                REPORTF("%s", "multiple input files specified");
                 exit(1);
             }
             input_file = argv[i];
         }
     }
     if (input_file == NULL) {
-        fprintf(stderr, "error: no input file\n");
+        REPORTF("%s", "no input file");
         exit(1);
     }
     if (output_file == NULL) {