debug option (off by default), for BLI_string to help find incorrect sizes being passed in (enable in source files only)

3 files changed, 39 insertions, 9 deletions

diff --git a/source/blender/blenlib/BLI_string.h b/source/blender/blenlib/BLI_string.h
index c6f0bc49c9b..02eb0734f8c 100644
--- a/source/blender/blenlib/BLI_string.h
+++ b/source/blender/blenlib/BLI_string.h
@@ -93,14 +93,14 @@ __attribute__((nonnull))
 #endif
 ;
 
-size_t BLI_snprintf(char *__restrict buffer, size_t len, const char *__restrict format, ...)
+size_t BLI_snprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...)
 #ifdef __GNUC__
 __attribute__ ((format(printf, 3, 4)))
 __attribute__((nonnull))
 #endif
 ;
 
-size_t BLI_vsnprintf(char *__restrict buffer, size_t count, const char *__restrict format, va_list arg)
+size_t BLI_vsnprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, va_list arg)
 #ifdef __GNUC__
 __attribute__ ((format(printf, 3, 0)))
 #endif
diff --git a/source/blender/blenlib/intern/string.c b/source/blender/blenlib/intern/string.c
index 03bed428c07..24e14d04c68 100644
--- a/source/blender/blenlib/intern/string.c
+++ b/source/blender/blenlib/intern/string.c
@@ -47,6 +47,8 @@
 #  pragma GCC diagnostic error "-Wsign-conversion"
 #endif
 
+// #define DEBUG_STRSIZE
+
 /**
  * Duplicates the first \a len bytes of cstring \a str
  * into a newly mallocN'd string and returns it. \a str
@@ -111,6 +113,10 @@ char *BLI_strncpy(char *__restrict dst, const char *__restrict src, const size_t
 	size_t srclen = BLI_strnlen(src, maxncpy - 1);
 	BLI_assert(maxncpy != 0);
 
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
 	memcpy(dst, src, srclen);
 	dst[srclen] = '\0';
 	return dst;
@@ -134,6 +140,10 @@ size_t BLI_strncpy_rlen(char *__restrict dst, const char *__restrict src, const
 	size_t srclen = BLI_strnlen(src, maxncpy - 1);
 	BLI_assert(maxncpy != 0);
 
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
 	memcpy(dst, src, srclen);
 	dst[srclen] = '\0';
 	return srclen;
@@ -149,21 +159,21 @@ size_t BLI_strcpy_rlen(char *__restrict dst, const char *__restrict src)
 /**
  * Portable replacement for #vsnprintf
  */
-size_t BLI_vsnprintf(char *__restrict buffer, size_t count, const char *__restrict format, va_list arg)
+size_t BLI_vsnprintf(char *__restrict buffer, size_t maxncpy, const char *__restrict format, va_list arg)
 {
 	size_t n;
 
 	BLI_assert(buffer != NULL);
-	BLI_assert(count > 0);
+	BLI_assert(maxncpy > 0);
 	BLI_assert(format != NULL);
 
-	n = (size_t)vsnprintf(buffer, count, format, arg);
+	n = (size_t)vsnprintf(buffer, maxncpy, format, arg);
 
-	if (n != -1 && n < count) {
+	if (n != -1 && n < maxncpy) {
 		buffer[n] = '\0';
 	}
 	else {
-		buffer[count - 1] = '\0';
+		buffer[maxncpy - 1] = '\0';
 	}
 
 	return n;
@@ -172,13 +182,17 @@ size_t BLI_vsnprintf(char *__restrict buffer, size_t count, const char *__restri
 /**
  * Portable replacement for #snprintf
  */
-size_t BLI_snprintf(char *__restrict buffer, size_t count, const char *__restrict format, ...)
+size_t BLI_snprintf(char *__restrict dst, size_t maxncpy, const char *__restrict format, ...)
 {
 	size_t n;
 	va_list arg;
 
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
 	va_start(arg, format);
-	n = BLI_vsnprintf(buffer, count, format, arg);
+	n = BLI_vsnprintf(dst, maxncpy, format, arg);
 	va_end(arg);
 
 	return n;
diff --git a/source/blender/blenlib/intern/string_utf8.c b/source/blender/blenlib/intern/string_utf8.c
index ab0073a7585..edfcdf145eb 100644
--- a/source/blender/blenlib/intern/string_utf8.c
+++ b/source/blender/blenlib/intern/string_utf8.c
@@ -45,6 +45,8 @@
 #  pragma GCC diagnostic error "-Wsign-conversion"
 #endif
 
+// #define DEBUG_STRSIZE
+
 /* from libswish3, originally called u8_isvalid(),
  * modified to return the index of the bad character (byte index not utf).
  * http://svn.swish-e.org/libswish3/trunk/src/libswish3/utf8.c r3044 - campbell */
@@ -203,6 +205,10 @@ char *BLI_strncpy_utf8(char *__restrict dst, const char *__restrict src, size_t
 
 char *BLI_strncat_utf8(char *__restrict dst, const char *__restrict src, size_t maxncpy)
 {
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
 	while (*dst && maxncpy > 0) {
 		dst++;
 		maxncpy--;
@@ -224,6 +230,10 @@ size_t BLI_strncpy_wchar_as_utf8(char *__restrict dst, const wchar_t *__restrict
 
 	BLI_assert(maxncpy != 0);
 
+#ifdef DEBUG_STRSIZE
+	memset(dst, 0xff, sizeof(*dst) * maxncpy);
+#endif
+
 	while (*src && len < maxncpy) { /* XXX can still run over the buffer because utf8 size isn't known :| */
 		len += BLI_str_utf8_from_unicode((unsigned int)*src++, dst + len);
 	}
@@ -302,6 +312,12 @@ size_t BLI_strncpy_wchar_from_utf8(wchar_t *__restrict dst_w, const char *__rest
 {
 	size_t len = 0;
 
+	BLI_assert(maxncpy != 0);
+
+#ifdef DEBUG_STRSIZE
+	memset(dst_w, 0xff, sizeof(*dst_w) * maxncpy);
+#endif
+
 	if (dst_w == NULL || src_c == NULL) {
 		return 0;
 	}