From 54957a144bce03d14b337b3eb3007ea220266880 Mon Sep 17 00:00:00 2001
From: David Sargeant <chorpler@gmail.com>
Date: Sat, 25 Nov 2023 11:34:07 -0700
Subject: [PATCH] Change bx_fprintf to a function pointer to enable unit
 testing on MacOS

---
 src/tools.c | 15 ++++++++++++++-
 src/tools.h | 21 +++++++++++++++++++--
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/tools.c b/src/tools.c
index 4d9aca8..58a8de7 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -42,6 +42,15 @@
 static pcre2_code *pattern_ascii_id = NULL;
 static pcre2_code *pattern_ascii_id_strict = NULL;
 
+/**
+ * Initialize the `bx_fprintf` function pointer to point to the original
+ * `bx_fprintf` function, now renamed `bx_fprintf_original`. During unit
+ * tests, this will be replaced with `__wrap_bx_fprintf`, which stores
+ * the result that would have been printed so the output can be validated.
+ * This is necessary for unit testing and CI to work with MacOS.
+ */
+bx_fprintf_t bx_fprintf = bx_fprintf_original;
+
 
 static pcre2_code *get_pattern_ascii_id(int strict)
 {
@@ -849,7 +858,7 @@ char *bx_strndup(const char *s, size_t n)
 
 
 
-void bx_fprintf(FILE *stream, const char *format, ...)
+void bx_fprintf_original(FILE *stream, const char *format, ...)
 {
     va_list va;
     va_start(va, format);
@@ -858,6 +867,10 @@ void bx_fprintf(FILE *stream, const char *format, ...)
 }
 
 
+void set_bx_fprintf(bx_fprintf_t bx_fprintf_function) {
+    bx_fprintf = bx_fprintf_function;
+}
+
 
 FILE *bx_fopens(bxstr_t *pathname, char *mode)
 {
diff --git a/src/tools.h b/src/tools.h
index 65b3ba0..b483240 100644
--- a/src/tools.h
+++ b/src/tools.h
@@ -40,6 +40,18 @@
 }
 
 
+/**
+ * Define type for a function pointer to specify which `bx_fprintf` function
+ * will be called. This enables unit testing on MacOS, since Apple's `ld`
+ * linker does not support the `--wrap` flag that GNU `ld` does.
+ */
+typedef void (*bx_fprintf_t)(FILE *stream, const char *format, ...);
+
+/**
+ * Declare function pointer to be changed when running unit tests
+ */
+extern bx_fprintf_t bx_fprintf;
+
 int empty_line(const line_t *line);
 
 
@@ -173,7 +185,7 @@ int tag_is_valid(char *tag);
 
 /**
  * Duplicate at most `n` bytes from the given string `s`.  Memory for the new string is obtained with `malloc()`, and
- * can be freed with `free()`. A terminating null byte is added. We include this implementation because the libc's 
+ * can be freed with `free()`. A terminating null byte is added. We include this implementation because the libc's
  * `strndup()` is not consistently available across all platforms.
  * @param s a string
  * @param n maximum number of characters to copy (excluding the null byte)
@@ -187,9 +199,14 @@ char *bx_strndup(const char *s, size_t n);
  * @param stream Where to print, for example `stderr`
  * @param format the format string, followed by the arguments of the format string
  */
-void bx_fprintf(FILE *stream, const char *format, ...);
+void bx_fprintf_original(FILE *stream, const char *format, ...);
 
 
+/**
+ * Set the bx_fprintf_ptr function pointer to point to a specific function
+ */
+void set_bx_fprintf(bx_fprintf_t func_to_use);
+
 /**
  * Determine if the given string is an "ASCII ID", which means:
  * - It consists only of the letters `abcdefghijklmnopqrstuvwxyz-0123456789`. If not in strict mode, upper case A-Z