Use custom type bufsize_t for string buffer sizes

This makes it easier to change the type later.

No functional change. The rest of the code base still has to be
adjusted to use the new type.

Also add some TODO comments in buffer.c.

2 files changed, 51 insertions, 31 deletions

diff --git a/src/buffer.c b/src/buffer.c
index e2ebc02..78d0a00 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -22,20 +22,21 @@ unsigned char cmark_strbuf__initbuf[1];
 #define MIN(x,y)  ((x<y) ? x : y)
 #endif
 
-void cmark_strbuf_init(cmark_strbuf *buf, int initial_size)
+void cmark_strbuf_init(cmark_strbuf *buf, bufsize_t initial_size)
 {
 	buf->asize = 0;
 	buf->size = 0;
 	buf->ptr = cmark_strbuf__initbuf;
 
+	// TODO: Check for negative initial_size.
 	if (initial_size)
 		cmark_strbuf_grow(buf, initial_size);
 }
 
-void cmark_strbuf_grow(cmark_strbuf *buf, int target_size)
+void cmark_strbuf_grow(cmark_strbuf *buf, bufsize_t target_size)
 {
 	unsigned char *new_ptr;
-	int new_size;
+	bufsize_t new_size;
 
 	if (target_size <= buf->asize)
 		return;
@@ -51,9 +52,11 @@ void cmark_strbuf_grow(cmark_strbuf *buf, int target_size)
 	/* grow the buffer size by 1.5, until it's big enough
 	 * to fit our target size */
 	while (new_size < target_size)
+		// TODO: Check for overflow.
 		new_size = (new_size << 1) - (new_size >> 1);
 
 	/* round allocation up to multiple of 8 */
+	// TODO: Check for overflow.
 	new_size = (new_size + 7) & ~7;
 
 	new_ptr = (unsigned char *)realloc(new_ptr, new_size);
@@ -95,12 +98,13 @@ void cmark_strbuf_clear(cmark_strbuf *buf)
 		buf->ptr[0] = '\0';
 }
 
-void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, int len)
+void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, bufsize_t len)
 {
 	if (len <= 0 || data == NULL) {
 		cmark_strbuf_clear(buf);
 	} else {
 		if (data != buf->ptr) {
+			// TODO: Check for overflow.
 			ENSURE_SIZE(buf, len + 1);
 			memmove(buf->ptr, data, len);
 		}
@@ -117,16 +121,18 @@ void cmark_strbuf_sets(cmark_strbuf *buf, const char *string)
 
 void cmark_strbuf_putc(cmark_strbuf *buf, int c)
 {
+	// TODO: Check for overflow.
 	ENSURE_SIZE(buf, buf->size + 2);
 	buf->ptr[buf->size++] = c;
 	buf->ptr[buf->size] = '\0';
 }
 
-void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, int len)
+void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, bufsize_t len)
 {
 	if (len <= 0)
 		return;
 
+	// TODO: Check for overflow.
 	ENSURE_SIZE(buf, buf->size + len + 1);
 	memmove(buf->ptr + buf->size, data, len);
 	buf->size += len;
@@ -140,8 +146,8 @@ void cmark_strbuf_puts(cmark_strbuf *buf, const char *string)
 
 void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap)
 {
-	const int expected_size = buf->size + (strlen(format) * 2);
-	int len;
+	// TODO: Check for overflow.
+	const bufsize_t expected_size = buf->size + (strlen(format) * 2);
 
 	ENSURE_SIZE(buf, expected_size);
 
@@ -149,7 +155,7 @@ void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap)
 		va_list args;
 		va_copy(args, ap);
 
-		len = vsnprintf(
+		int len = vsnprintf(
 		          (char *)buf->ptr + buf->size,
 		          buf->asize - buf->size,
 		          format, args
@@ -168,11 +174,13 @@ void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap)
 			abort();
 		}
 
+		// TODO: Check for overflow.
 		if (len + 1 <= buf->asize - buf->size) {
 			buf->size += len;
 			break;
 		}
 
+		// TODO: Check for overflow.
 		ENSURE_SIZE(buf, buf->size + len + 1);
 	}
 }
@@ -186,10 +194,11 @@ void cmark_strbuf_printf(cmark_strbuf *buf, const char *format, ...)
 	va_end(ap);
 }
 
-void cmark_strbuf_copy_cstr(char *data, int datasize, const cmark_strbuf *buf)
+void cmark_strbuf_copy_cstr(char *data, bufsize_t datasize, const cmark_strbuf *buf)
 {
-	int copylen;
+	bufsize_t copylen;
 
+	// TODO: Check negative datasize.
 	assert(data && datasize && buf);
 
 	data[0] = '\0';
@@ -224,16 +233,19 @@ unsigned char *cmark_strbuf_detach(cmark_strbuf *buf)
 	return data;
 }
 
-void cmark_strbuf_attach(cmark_strbuf *buf, unsigned char *ptr, int asize)
+void cmark_strbuf_attach(cmark_strbuf *buf, unsigned char *ptr, bufsize_t asize)
 {
 	cmark_strbuf_free(buf);
 
 	if (ptr) {
 		buf->ptr = ptr;
 		buf->size = strlen((char *)ptr);
+		// TODO: Check for negative asize.
 		if (asize)
+			// TODO: Check for overflow.
 			buf->asize = (asize < buf->size) ? buf->size + 1 : asize;
 		else /* pass 0 to fall back on strlen + 1 */
+			// TODO: Check for overflow.
 			buf->asize = buf->size + 1;
 	} else {
 		cmark_strbuf_grow(buf, asize);
@@ -247,19 +259,21 @@ int cmark_strbuf_cmp(const cmark_strbuf *a, const cmark_strbuf *b)
 	       (a->size < b->size) ? -1 : (a->size > b->size) ? 1 : 0;
 }
 
-int cmark_strbuf_strchr(const cmark_strbuf *buf, int c, int pos)
+bufsize_t cmark_strbuf_strchr(const cmark_strbuf *buf, int c, bufsize_t pos)
 {
+	// TODO: Bounds check.
 	const unsigned char *p = (unsigned char *)memchr(buf->ptr + pos, c, buf->size - pos);
 	if (!p)
 		return -1;
 
-	return (int)(p - (const unsigned char *)buf->ptr);
+	return (bufsize_t)(p - (const unsigned char *)buf->ptr);
 }
 
-int cmark_strbuf_strrchr(const cmark_strbuf *buf, int c, int pos)
+bufsize_t cmark_strbuf_strrchr(const cmark_strbuf *buf, int c, bufsize_t pos)
 {
-	int i;
+	bufsize_t i;
 
+	// TODO: Bounds check.
 	for (i = pos; i >= 0; i--) {
 		if (buf->ptr[i] == (unsigned char) c)
 			return i;
@@ -268,17 +282,19 @@ int cmark_strbuf_strrchr(const cmark_strbuf *buf, int c, int pos)
 	return -1;
 }
 
-void cmark_strbuf_truncate(cmark_strbuf *buf, int len)
+void cmark_strbuf_truncate(cmark_strbuf *buf, bufsize_t len)
 {
+	// TODO: Check for negative len.
 	if (len < buf->size) {
 		buf->size = len;
 		buf->ptr[buf->size] = '\0';
 	}
 }
 
-void cmark_strbuf_drop(cmark_strbuf *buf, int n)
+void cmark_strbuf_drop(cmark_strbuf *buf, bufsize_t n)
 {
 	if (n > 0) {
+		// TODO: Bounds check.
 		buf->size = buf->size - n;
 		if (buf->size)
 			memmove(buf->ptr, buf->ptr + n, buf->size);
@@ -304,7 +320,7 @@ void cmark_strbuf_rtrim(cmark_strbuf *buf)
 
 void cmark_strbuf_trim(cmark_strbuf *buf)
 {
-	int i = 0;
+	bufsize_t i = 0;
 
 	if (!buf->size)
 		return;
@@ -322,7 +338,7 @@ void cmark_strbuf_trim(cmark_strbuf *buf)
 void cmark_strbuf_normalize_whitespace(cmark_strbuf *s)
 {
 	bool last_char_was_space = false;
-	int r, w;
+	bufsize_t r, w;
 
 	for (r = 0, w = 0; r < s->size; ++r) {
 		switch (s->ptr[r]) {
@@ -347,7 +363,7 @@ void cmark_strbuf_normalize_whitespace(cmark_strbuf *s)
 // Destructively unescape a string: remove backslashes before punctuation chars.
 extern void cmark_strbuf_unescape(cmark_strbuf *buf)
 {
-	int r, w;
+	bufsize_t r, w;
 
 	for (r = 0, w = 0; r < buf->size; ++r) {
 		if (buf->ptr[r] == '\\' && cmark_ispunct(buf->ptr[r + 1]))
diff --git a/src/buffer.h b/src/buffer.h
index 417df26..99e6feb 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -3,20 +3,24 @@
 
 #include <stddef.h>
 #include <stdarg.h>
+#include <limits.h>
 #include "config.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+typedef int bufsize_t;
+
 typedef struct {
 	unsigned char *ptr;
-	int asize, size;
+	bufsize_t asize, size;
 } cmark_strbuf;
 
 extern unsigned char cmark_strbuf__initbuf[];
 
 #define GH_BUF_INIT { cmark_strbuf__initbuf, 0, 0 }
+#define BUFSIZE_MAX INT_MAX
 
 /**
  * Initialize a cmark_strbuf structure.
@@ -24,12 +28,12 @@ extern unsigned char cmark_strbuf__initbuf[];
  * For the cases where GH_BUF_INIT cannot be used to do static
  * initialization.
  */
-void cmark_strbuf_init(cmark_strbuf *buf, int initial_size);
+void cmark_strbuf_init(cmark_strbuf *buf, bufsize_t initial_size);
 
 /**
  * Grow the buffer to hold at least `target_size` bytes.
  */
-void cmark_strbuf_grow(cmark_strbuf *buf, int target_size);
+void cmark_strbuf_grow(cmark_strbuf *buf, bufsize_t target_size);
 
 void cmark_strbuf_free(cmark_strbuf *buf);
 void cmark_strbuf_swap(cmark_strbuf *buf_a, cmark_strbuf *buf_b);
@@ -38,9 +42,9 @@ size_t cmark_strbuf_len(const cmark_strbuf *buf);
 
 int cmark_strbuf_cmp(const cmark_strbuf *a, const cmark_strbuf *b);
 
-void cmark_strbuf_attach(cmark_strbuf *buf, unsigned char *ptr, int asize);
+void cmark_strbuf_attach(cmark_strbuf *buf, unsigned char *ptr, bufsize_t asize);
 unsigned char *cmark_strbuf_detach(cmark_strbuf *buf);
-void cmark_strbuf_copy_cstr(char *data, int datasize, const cmark_strbuf *buf);
+void cmark_strbuf_copy_cstr(char *data, bufsize_t datasize, const cmark_strbuf *buf);
 
 static inline const char *cmark_strbuf_cstr(const cmark_strbuf *buf)
 {
@@ -49,20 +53,20 @@ static inline const char *cmark_strbuf_cstr(const cmark_strbuf *buf)
 
 #define cmark_strbuf_at(buf, n) ((buf)->ptr[n])
 
-void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, int len);
+void cmark_strbuf_set(cmark_strbuf *buf, const unsigned char *data, bufsize_t len);
 void cmark_strbuf_sets(cmark_strbuf *buf, const char *string);
 void cmark_strbuf_putc(cmark_strbuf *buf, int c);
-void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, int len);
+void cmark_strbuf_put(cmark_strbuf *buf, const unsigned char *data, bufsize_t len);
 void cmark_strbuf_puts(cmark_strbuf *buf, const char *string);
 void cmark_strbuf_printf(cmark_strbuf *buf, const char *format, ...)
 	CMARK_ATTRIBUTE((format (printf, 2, 3)));
 void cmark_strbuf_vprintf(cmark_strbuf *buf, const char *format, va_list ap);
 void cmark_strbuf_clear(cmark_strbuf *buf);
 
-int cmark_strbuf_strchr(const cmark_strbuf *buf, int c, int pos);
-int cmark_strbuf_strrchr(const cmark_strbuf *buf, int c, int pos);
-void cmark_strbuf_drop(cmark_strbuf *buf, int n);
-void cmark_strbuf_truncate(cmark_strbuf *buf, int len);
+bufsize_t cmark_strbuf_strchr(const cmark_strbuf *buf, int c, bufsize_t pos);
+bufsize_t cmark_strbuf_strrchr(const cmark_strbuf *buf, int c, bufsize_t pos);
+void cmark_strbuf_drop(cmark_strbuf *buf, bufsize_t n);
+void cmark_strbuf_truncate(cmark_strbuf *buf, bufsize_t len);
 void cmark_strbuf_rtrim(cmark_strbuf *buf);
 void cmark_strbuf_trim(cmark_strbuf *buf);
 void cmark_strbuf_normalize_whitespace(cmark_strbuf *s);